investigation of the characteristics of the direct current glow … · 2016-07-05 ·...
TRANSCRIPT
![Page 1: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/1.jpg)
Calhoun: The NPS Institutional Archive
Theses and Dissertations Thesis Collection
1949-07-24
Investigation of the characteristics of the direct
current glow discharge under the influence of
pressure and velocity up to the speed of sound
Timmes, Francis Xavier
St. Paul, Minnesota; University of Minnesota
http://hdl.handle.net/10945/6441
![Page 2: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/2.jpg)
![Page 3: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/3.jpg)
js^apoks
valPostgraduate
Ma.
School
![Page 4: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/4.jpg)
![Page 5: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/5.jpg)
\
![Page 6: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/6.jpg)
of fir. .1 ciiiinjgaw
0*
^ieuteaaat Coiaaenaer, U. 6. Levy
Jul, %4, I94d
.hells outfitted to the Acuity of the uste School,University of Minoeaots, In pert Is i fu aent of the
Beqtilreaients for the t/egret ei iter of science
•
![Page 7: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/7.jpg)
![Page 8: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/8.jpg)
imary
Introduction* ••••«•••• • •
theory a Previous .Experiments. .. « ••••
Ivark Current n«t icn.uiow discharge Keg ion •• • •
Equipment ana Procedure* •• • 12
Testing end lest ijsts 19
neeuite end juiscuseion** ....... •
Conclusions* * zt
iiogrephy.* «•••• £5
Figure I. laboratory Equipment* ................... •« 36
are k, »ina tonne i Zl
ure 3, #os£le Block Design * • 38
Figure %, Pressure purvey Jar, So*£le and Probes.... 59
jre 4a, i>hadoagraph o£ the Probes* *. ...........
•
40
at9 4 0, arrange (sent of the Proves. *.. •• 41
Figure 5, 4ie
Figure u, Circuit % U*
figure 7, Jit t 8 * • -J4
Figure is, t los L -rj-e acterleties at VariousTreasures for .003 inch Platinum .ire*. 45
Figure 9, tio* files racteristioa show!Constant Microsape r< ines . in*
•••••«•••••«••••«••.•*••*••••••**•• 4 €
lUuie 10, Ulow discharge Cnaraci eristic a -
Mach wuiiioe; KllsS" *003 in* "iatlnum wire** 47
'.actis:
t«ach ^um: In. re*# 48
![Page 9: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/9.jpg)
-
![Page 10: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/10.jpg)
labia el Con teats (con't.
Figure IS, Oiios Discharge Characteristics ShoalsMfich number £ffeet for .003 la* Platinum wire,** 4 9
ure io» Discharge Character let lea Shoal,iach dumber inflect fox .003 In. ?la tin ire.-.Hi
Figure H. Clow Discharge Characteristics She » Inifeach number Efiect fur .003 In. Plati. ire...
Figure 15, Cloa i>ischaree Characteristics She slogthe Variation la Voltage at Constant jw^persgeDue to ttseh i^Uiftber.. 5£-
Pi&ure 16, Cio» Discharge Characteristics showinge Variation In Current at Constant Volta,
juue to feacn jtuaber for .003 lu. Pletlness ., ire.
r if ure 17, Clow discharge Characteristics atVarious Pressures lor #005 In. iatlnua a ire..
are lei, Clow -uiSGh&rge Characteristics iiho*
o Variation ol r reesure alth Voltage forConstant Current for .005 In. .'latinuat *ire...
Figure 19, C10P discharge Characteristics bhoel.llect of *ach lojaber for .005 in. Piatlnuare ...........*.*........*...................
ure 20, (lift! Discharge Characteristics sfoovl-eet Due to fcach number for .003 In. ^latlr
re ....••.••••....••
ure Si, Csiow Discharge Characteristics whowi(feet of i&ach er for .003 in. "iftir.ua
a Ire
J if ure **, Clow discharge Characteristic- singfleet of Mach er for .005 1 ^iatir
I ire
Figure low Discharge Charaeterietlea ohowithe Variation In Voltage at Constant
• to i&aeh Ire.
Figure 8€, ulo» Discharge racteristlctthe Variation in Current at Cons tan' .tagei>ue to i»eeh fcuatber for .005 In. Platlni ire.
![Page 11: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/11.jpg)
![Page 12: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/12.jpg)
this study sea conducted to determine the teas-
ilty of uaing a direct current glow discharge as a
velocity aieter up to tne speed of eounct. the primary
problem vas to aho« the dependence of the glow diacharpe
characteristics on velocity as separable from the msny
variables that effect the characteristics. It sas conf
ed that oy using sn asymmetries! arrangement of materiel
fliiC form, the previously experienced burning of
electrodes could he auccessfuily avoided. % ue discharge
proved to be both pressure end velocity sensitive sad a a
auch adapts ltaelf to use as a pressure probe or velocity
meter. swever, since the glow is Insensitive to tern*
persture, it cannot be utilised aa a Meehmeter. \ki-
fortunately the results aoove 740 ft./aec aeh number •
U.7QJ in this report csnnot be relied upon but It is
expected that sith adequate equipment, reliable data up
to and beyond the speed of aound can be obtained. The
characteristics proved also to be a function of the
electrode materia La, site, spacing, polarity, and possibly
sire length. 4 .001 inch diameter platinum sire proved to
be too smell sad flexiole for velocity measurements shere-
ss the .003 inch aire provec sst isfactor
![Page 13: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/13.jpg)
![Page 14: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/14.jpg)
IttV LOS
Although in all probability itore papers nave
been published on various aspects of the glow discharge
than on all the other electrical discharge phenomasa , it
is only in the last fee years that attention has teen
Drought to its poasibliltlea as a pressure , velocity, or
fcach aeter. There is a great need at present for a good
instrument that can record accurately the pressure, velc
or iiach ouAw-er not oni.y in the laboratory but also in the
field, such as in am aircraft* In the latter cete
an accurate instrument does not exist today ss all present
instruments are subject to position errors (errors . to
the position of the probe «ith respect to the line of
flight and the attltuoe of the aircraft), Instrument
errors, losses in the tubes and lines, temperature, sad
compressibility errors. Then too, air speec indicator
reacings of the present day auat be corrected for altitude
(pressure, density change) and temperature if the true
air speed is desired* thus, today a pilot raay be flying
at 15000 ft. incieatiog £15 *ts. while in reeiity his
true air speed aaay be in the vicinity oi 400 kts., a
markeo difference very essential to navigation, flight
plana in^ iao gasoline consumption. It is tonarda a
solution of this problem that this Investigation was .aede
to find out if a teat cased on the glow discharge
characteristics would be feasible. To the author's
icnosied^e, there is no such instrument sva liable or in
![Page 15: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/15.jpg)
![Page 16: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/16.jpg)
existence ttiat measures flo» op to the velocity of sou
bated on this principle* e priiae purpose of fc study
shall deal aith the £lo« discharge characteristics for a
point in dry air as dependant on pressure and iuuch nuvaoer
#heu using difierent sUe platinum sires, changing
electrode spacing, and changing the polarity of the aire
from negative to positive, this study w» not intended
to be a final quantitative solution of the probiea but
only an exploratory stuoj? of the ssajor paraoetera affect-
toe application of the glow discharge for a preesure,
velocity or «&ach aster*
Le atuai? t»as carried out at tbe Onivereit}, of
Minnesota's feeaearch Center, iteaesaount, Minnesota uucer
the supervision of advisor, Frofeasor J. sad
of the Department of Aeronautical oeering of the
iversity of Minnesota* * debt of appreciation is a
osec to I utenant Commander Robert i*« boilenber^er, a
fellow stuoeat, Mr* Fran* bermr , scientist at the center,
and Professor »• Brsithesite, for their help in construe
ion and alleviation of R«ny of the troubles encountered
daring the experiments.
As is Known there are in general three types of
electrical discharges in air that have asro.ee -a nee
and diflere aracter istics, na,sely, the lownaend
scharge or dar* current oischarje, I lee discharge
![Page 17: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/17.jpg)
![Page 18: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/18.jpg)
and the fire or apei Leeherre. 01 thee<
only one tnat gives oil no light,
indicates rou&hly the c teri sties of
st is the
ten
.echarges.
Volts
fmi rrent(lowneeno j
net ion• Ignition Ischsrge
\
> / txefion
lark current Keg ion
.or to U nit ion, a current can be snde to
flow between two electrodes (the eo-eelled daris current
discharge or 'lownaend discharge) in air out it is
essential that tnere be an external current in consider-:
the tna^nituue of this dtris: current, isrge earriere
(positive Ions) can be generated externally in the cie-
chsr§e region Iron sucn sources as X-rays, ultra violet
light or elevated temperature* as Iron fla^ee, and these
ions will drift to the cathode. If a voltage differential
exist* acroae the electrodes, electrons will be attracted
towards the anode. ece electrons in air at ataos-heric
pressure naw# a raean free path of a xlnatei .6 x 10-5
due to t eaeed voltage, they will fall freely
through this distance, striding the gea aoleculee with
![Page 19: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/19.jpg)
V.
![Page 20: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/20.jpg)
the energy gained In the fai This klo« orgy Is
then available for excitation, ionization relation*
If the energy Is insufficient to produce an inelastic
collision* the electrons rebound in en almost perfectly
elastic recoil end carry the energy gained int. <ext
free path. Thue the electrons can accumulate energy
(thereby raising their temperature). Is
accumulation of energy, therefore, no nes electrons are
formed ana the current cannot rise despite the 1 see
In voltage, the Initial electrons are eventually trans-
ported to the anode with the ions going to the cathode*
when enough energy is accumulated, an electron
in traveling to the anode ionises a neutral molecule by
colliding with it and one shell electron is se^arati
Both electrona no» available after %\ '.rst toolset
travel towaroe the anode and ionise anew. After the next
ionization there are then four electrons and tbree to
e continuation of this process being known as <send'e
sctroo and Ion Avalanche. Although depending on t
or if inal current for excitation and magnitude, the process
it now self -sustain ut the current ie ver email be
of the order of lQ~6 to 10* l0 amperes.
ie feaeiDiiity of this t^pe c t aa a
velocity vseter was successfully invest tgete< ailhelm
;*s in 194 , he f that the effect of the air flow
consisted la weakening the current by that amount blown
away from the electrode while the iona move from the
![Page 21: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/21.jpg)
![Page 22: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/22.jpg)
snoce to the eathode* ;e aeealn^ -earn* of i«vlar teo
curi exits ci &ifierent &agn itudea flowing
(seise voltage aita and aithout velocity) la soivec e
by using- a circuit aa follows:
ifI
Hot s 4 *o
Itot s total current
X̂I G « current bioaa a»a.y ahii
aooehoa £-oea roundJ
Ip * current in atiil air
lie diacovereo that oy changing the ahape of the
electrodes toe ion velocities are chatted a
the characteristics of the apparatus Bill change shea
subjected to impressed air f ioa due to the tirae the ions
are exposed to it* en the ahape of tne electrode sea
changed from a point to a sphere* even do an to a diameter
of l ma. (•039& in.y, no decrease In current was eatat
ed at velocities up to *•/••*• tnereby indicatiaf
that a point or a sphere of extreneiy asaali c La meter la
necessary, at least at subsonic apeeda. -.eke also shose
that the ignition current (beginning of the floe
increaaed with increasing ilea v-.iocities. this is very
si£ nil leant for the present study aa I lea tec the
discharge to oe velocity aenaltlve> a working ranfe o
the instrument proved to oe a function of the diatanee
cetseen electrodes. aaglaj i apacing between elect
r
changes the characteristic (1) due to a large anode-
![Page 23: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/23.jpg)
:
T
![Page 24: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/24.jpg)
pa lb and (*> a reeuced loo velocity due to a reduced field
intensity in the vicinity at the anode* the erne lie r the
distance the higher the velocity needed to distinguish It
from etlli air characteristics* Ita upper limit was de-
fiaec by ignition ana a vertical tangent to tr sracter-
let Ice curve* Again if the anode and cathode are of
sajae size no velocity respooae »aa noticed* tivi
however* proved to he very good for constant voltage (isrej
changes In amperage at various velocities; hut poor for
constant es&perage* As expected there was no burning assy
of the electrodes*
sshen there are two electrodes of different sis.es
snd sell separated, the field la concentrated at
electrodes and the sechaaiems which are active center, in
the region of the intense fiei k* the voltage Is raleed
a hove the dark current region, the fields fcceo^ sufflclen
ly high for ores fide si* In these regions long before s
spar it oan propagate across the $*t space. I ill reaicdovn
occurs in two steps , one, at the electrode or electrodes,
and sec ?* a Ores idown of the cap itself; i.e. a spai
The asanif estation of oreasiuosn at rode is \
.sslon of iigiit, generally celled corona or flow
discharge*
is© ha rge ite&ion
Ihus as tto« Held strength is raised above t
i/iscna, sufficient energy is eccumuiste<
![Page 25: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/25.jpg)
![Page 26: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/26.jpg)
7*
by ttie Ions to dislodge sn electron froT. the cathode on
iapset. ese new electrons have collisions on t
to the anode and cause another avalanche of lona and
electrons* At first there are not enough of tneae second*
ary lone to laa^e the process self-austainiap arid wh
there ere pulses of corona , they are quickly est lsbed
(in the order of iO*7 to 10*^ sec.j* Vhis is due to
rapid decline of the field as one *oves away fre&
cutboce and eleo beeauae the electrons in &ovlhg away
leave behind relatively Utatobile positive iona whose
positive space charge reduces the field (electron's
velocity is 500 times that of en ion in atmospheric air J*
.s apace charge then la cleared by being swept into I
cathode and the current declines* en the field heev
been lucres aed sufficiently by the removal of positive
ions, the lest ions start new electron avalanches and the
precast repeats, the current increasing as the fie if.
crease: . :1s region of non self-sustaial:. zona la
known as the &ei£er counter reg i&e end hes been utilised
In atomic wor* to oetect electrons, ees&le ra , :amm or
beta ray ionization ( . . 48£«£Q5). In thia
region the current la increasing and when sufficient
secondary ions t^e for saed, (in the vicinity of 1.0 to 1.5
mlcreaapaj a steady vlslole glow is observed snei the
process becomes self-sustaining as electrons I on-
tinuously being displaced from the ea e. The eurrc
now increases re /, being of the order of 100 to 1000
![Page 27: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/27.jpg)
![Page 28: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/28.jpg)
times dark current magnitude* 1'he color of the glow la
dependent of composition of the gas and In the ease of air
la either Miami pink or lavender. It is this discharge
that Is to be atucien In thla report* At atmospheric
pressures with the wire point of negative polarity, the
, a li iocs Used over a email area bat as the pressure
la reduced and there la a high diffusion of electrons
,
the glee becomes very luminous and diffuse over
surface of the electrodes. th the aire of positive
polarity at atmospheric pressure the nosity sometimes
spreads as a thin film over the high field portlona of
the conductor, while st reduced pressure it may extend
Into the M*P somewhat in the form of streamers or
etriations*
In the previous description of tb ow dlscnsi-
phenomena * the needle has been assumed of negative polarity
D the needle la positive, the discharge, while at 111 a
ow, is of a different nature* Ion last Ion takes place
at the needle point as before but the positive ions in
traveling to the cathode find the field too lot tt e
secondary emission of more electrons* ever, Ionization
from photoelectric emission ai travlolet radiation
from the cathode ta faces place , necessary ll^ht coming
the flow st the anode ana the discharge is sfsin
self -sustainii;
tile &uch has been done to establish
characteristics of tne .<&* discharge as a function of
![Page 29: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/29.jpg)
•
![Page 30: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/30.jpg)
9.
pressure, alaioet a 11 of it has dealt Kith pressures of
m. Hf . or leas as need la peseous tubes. -ssur©
ifi these regions has e marvel effect as would be expected
froa the 1©» density of the gas, diffusion of electrons,
fine the increased utean free path. Very Little has been
cone in the region betaeen atmospheric (760 aau Hg*) and
urn* tig*, a region highly important if the gloa dis-
charge la to be used in wind tunnels and the earth's
atmosphere* ierner has ahosn (±tef . 2) that pressure hss
s profound effect on the position of the characteristic
curves sue inciuoes several characteristics In the desired
range. as clearly shoes furthermore, that these chars
lstics shift appreciable due to humidity and sire size,
and change aoaeshat due to plate radius, polarity and
electrode spacing* Thus it can be seen that the preaent
study shall have to incluoe a pressure survey for the
particular apparatus and the changes In Kire size, polarity
and spacing. *>ince dry air is to be used at all tisaes,
the variable, humidity, need not be considered*
A* stated In the discourse dealing with dark
current, velocity is ex pec tec to have an effect on the
characteristics cue to the blowing asay of some of the
charge carriers, resulting in a loss of current for a
given voltage*
fhe suitability of the gloa discharge for
velocity dependence saa investigated firstly by F.
icvall. According to ..Inovau the gloa discharge in air
![Page 31: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/31.jpg)
.
'
![Page 32: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/32.jpg)
10.
at atmospheric preasure *as e ed to be suitable alao
far investigation of the area liar turbulence of flow
with the burning away of the electrodes the only Dis-
turbing factor* 0* feeler* of the German Aeronautical
research Institute, attempting to check ^lndvell's a.
could obtain no good results for oscillation aeasuresients,
primarily due to the burning a stay of the electrodes,
heating up of the electrodes and sudden changes Into other
discharge foraa. iiowevsr, as pointed out by Werner,
Andvall's needles sere relatively large (.16 cm. in
diameter), tne axis of his points sere perpendicular to
the alrstream and it is possible that ho wb working *
an arc instead of a glow. Werner's preliminary invest*
igation indicated the floe to be sensitive to air stress
up to 411 ft./sec. i. Pucks, in investigating the burning
s say of the electrodes in a glow discharge eneraooeter,
shoved that the burning away is essentially due to s con*
traction of the discharge at the anode (hot spot) and that
avoiding the burning away amounts to avoiding the hot
spot. is could be done by introducing esvaraetry of form
or material tor both; into the electrodes, or acre I
by using alternating current of high frequency. ;cfca
and cchumeoher invest igg ted the latter pose ity, using
platinum electrodes of .5 (•0198*) and .5 am. (.0118'
because of their pre-eminence in resistance to oxidation,
and found the alternating current glow discbarge aneiaoaetei
to have a venting range of only 50 au/aec* (164 ft. /sec.)
![Page 33: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/33.jpg)
![Page 34: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/34.jpg)
II.
but yet had store reproducibility then any previous glos
instrument.
Consequently the m. in eaphaale of this Invest-
igstion is to continue Werner's experiment end it ia
hoped that by uain* a platinum aire ma another sseterial
as elect rode a, both of different shape, and of the
Bias lines £ used by *>erner, the burning away my m avoide<
and velocity sensitivity up to the speed of sound may be
recorded.
![Page 35: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/35.jpg)
![Page 36: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/36.jpg)
neiore descrii in>; the equipment and netbode In
conducting the experimented It nust be Sortie in Bind that
tiiis study vee carried on jointly with soother individual
eeefcin§ similar informs tlon for operations at supersonic
instead of subsonic speeds. Consequently the ^nt
ass designed to accomodate and test the effect of both
types of floe on the glee discharge*
the slnd tunnel used to obtain the required sir
flow ess designed specificsliy for supersonic speeds in
the order of *\ * 5*0 sith the intention of wakinf all
subsoaie runs either in front of the throat, in the tbroSt
itself or, to a limited degree, aft of the throat. In
this gjanoer it «as believed that results close to % * i.O
could be sttained, and slao, the ssme Msch number could
be had at various pressures, showing thereby, a ange
in the effect of Msch number at different pressures, the
sir supply vss obtained b. tapping into the Kosemount
iiesearch »mboratorlea , hypersonic Tunnel's hifh pressure
tank with s one inch pipe line, fhls huge tenic (1750
cubic feet; holds air st >sl gs|e, and 11 desired,
the lar§e compressor used to pump up this reservoir, could
be used simultaneously shen test th the vine tunnel
used in this experiment, it sas possible to operste con-
tinuously up to the saxlmum &sch number sttslned utilising
e compressor, en. definitely long period si.
aonlcaily without using the compreaaor. The a lr e Led
![Page 37: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/37.jpg)
![Page 38: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/38.jpg)
is.
waa dry* having « des point in trie order of -40° ?. sod
tee dried before storage by en electredryer*
Xne arrangement of the wind tunas 1 is a 8 seen la
. 1. * air coming from the storage tank enters by
one inch pipe as shown supported on the extreme lef-
then proceeds into an expanaien valve to a pipe two inches
in diameter and thence into the control valve* This ex-
pons ion was neeeasary auperaeniesl ly to avoid having the
actual throat appear in the valve as sea the ease with s
one inch high pressure glebe type valve* Ilth the valve
open* toe air then trevela past a union joint into the
stagnation chaaoer, a section of three six inch steel
pipes, s total of forty-one {41) inches lor twenty
inches down this chamber in the center of the channel was
installed a total head tube of 1/16 inch brass tubing*
lief . fig* £, section 4-A>. this pressure tap was then led
through 3/8 inch steel pipe to a pressure gage, or for
finer measurements » and ss used in connection with this
report, by rubber tuoing to a ^ manes**ter where
this stagnation pressure was read in Inches of mercury*
Thirty-five inches down this stagnation chamber the flow
was converted from that in a circular cross-section of six
inch diameter to a rectangular cross-sect ion , two by one
inches, by means of a hydrostone meld, six Inches Long*
Uiis .sold was east in the pipe with hydros tone by means of
a wooaen plug cut to the required dimensions on a lathe*
sealiog in all the above named sect lone was accomplish*
![Page 39: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/39.jpg)
;
![Page 40: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/40.jpg)
14.
the use of hard composition gaaksts a no Per;aatex #8 gasket
pa ate
•
Following the flow converter was the nozzle
block, cut fross plexiglass, the design of which appears
In Fig. 5. Shis nozzle f8i aeeured to the stags*
t
chamber toy aeaaa of elgbt ball inch bolts with the heads
counteraunk is the end adapter plate, dealing eaa ssade by
the use ol 1/8 inch robber padding between the end piste
and the pXexli iaea pulled tightly by mesas of the Lag
bolts, the throat dimension* of the nozzle were
2.00 inches and the nozzle vaa of the sedge type a lth a
slight rounding fit the throat and had a downstream diverge-
nce ha If -angle of four degrees (4°). It was des
i
according to the Method of Characteristics by Buseamnp
and the reader is referred to the report by &•
bollenberger, rief. 10, ss to the supers on ic flow character-
istics of the nozzle. absonicsily, in the vicinity of
the throat, the flew appeared satisfactory as evidenced by
a very steady aanometer up to e fetch number of approximately
•35 or .90. Above this, alight fluctuations of the mercury
was noticed Indies tint unsteady conditions and possibly
erroneous pressure readings.
le probes, Fi§. 4, used to aessure the static
pressure in the nozzle to Insert the platinum wire
electrode into the flow parallel. to the stetle tube (used
siso ss the positive electrode or piste J, offered difficulty
in construction. the original static e was a slender
![Page 41: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/41.jpg)
![Page 42: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/42.jpg)
hypodermic stsei neeo.* silver soldered to e l/lt inch
bress tube lA iaeh long, which la turn was silver solder*
to a 1/4 inch brass tube about 12 inchee Ions:• *fets
proved unsatisfactory aa the needle tie not steady when
subjected to air flow, and finally snapped off at super*
sonic speeds, fhe eventual solution was to use a l/lfc
Inch brass tuoe one inch long as the static probe' aith
the static orlflee elfht ciaraetera back from the point.
This see then silver soldered to a 5/8 inch steel tube
about fifteen inches long, similar steel construction vsi
necessary for the platinum sire holder to avoid unstead-
iness • Eventually it consisted of the platinua sire l/5£
Inch long aoluereo to a steel needle point ground from
solid stock steel Z/Z& inch In diameter and about 1 1/2
inches long, followed by a half inch piece of 1/4 inen
brass tube and approximately fifteen inches of S/8 inch
steel tab*. Ihis slos increase in thickness sss sasde in
order to avoid any possible disturbance of the floe near
the point. &s there was to be as <auoh as 10,000 volts of
electricity across these probes, all surfaces except the
platinum sire and the l/lt>" tube of the static probe sere
an coated sith a plastic insulator, itcyrolold, to a
thickness of l/lfe to 1/8 inch* These probes sere fastened
at inches bee* from the pro.'.-e tips in plexiglass holdei
which, In turn, sere secured to a sooden support.
ie support 4 j wee c seven inch piece of
£ x 4 Inch sood cut to a sed$e ahaped leading edge and
![Page 43: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/43.jpg)
![Page 44: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/44.jpg)
ated by across to a 4 x 4 x XjA inch ateel plat*. Thia
Plata alth two i/4 inch colts as guides, fitted on a steel
track t*enty-four inches long and it could be securec in
any desired position by tightening the bolts, this arrange-
..eat, then, alloaed the movement of the pro bea foraard a ad
oft to any desired distance do an the middle of the tu
aclng oi the electrodes apart was accomplished by merely
relocating the platinum aire probe holder into the desired
set of specially located holes in the wooden support.
order to obtain the glow disc iris rge at the tip
of the platinum aire it vae neeeeaary that a voltage
supply and a means of seasurini the current floa be avail-
sole, aa the aork of previous experimentore, a voltage
supply of 10, 0U0 volts was deemed ample as was the ability
to meaaure amperage fr©« aero (0) ap to 500 microamperea.
Since the effect of changing needle polarity eaa to be
investigated, two similar electrical arrangements aere
made, differing only in the polarity, the circuit diagrams
appear in Figs. S, 6, and 7 and a picture of the cont;
panel appears In *ig. 1.
Essentially, \ oaer ly circuit .sted
of a Variac to control the line voltage to the power supply
Lob, in turn, was able to deliver op to 2 olts
direct current. In this circuit two aa itches sere install-
ed, one to the filament and anot for the high voltage
side of the power sup ly to be usee, only after the filament
had been alloaed sufficient time to heat u iere were
![Page 45: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/45.jpg)
![Page 46: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/46.jpg)
17.
t*o such power sup lice.
From the output terrains la of the power supplies
two similar circuits were origins tec, differing only In
polarity (Fig. 6 and 7j, circuit one being used to test a
positive platinum sire and circuit two to teat a negative
aire, a voltmeter with a three-say switch incorporatl
varloua reelstancea aaa Installed across the line to vary
the voltage ss desired and also a mlcroammeter with a three-
waif switch with various resistance to allow measuring cur-res
en t^ree different range acalea - 50, - 150, and -;
microamperes. f« protect the mlcroammeter a neon tube was
put Into the circuit and to limit the current through the
voltmeter t tio megohms resistor and a 1/200 ampere fuse
was placed In the line. However, this lstter was found In-
adequate as no fuse could be obtained with high enough
voltage rattiif , Consequently it became necessary to increai
the resistance to four Tie?; ohms and use no fuse, thus limit-
ing the current to the maximum allowable* 411 resistors
were meaaured to two decimal places by means of a wheat-
stone bridge resistor box anu the voltmeter calibrated
accordingly*
£s ro<& the large reaistors across the line* it
became necesssry to use extra heav? co-axial cable (line
round terminals in single ecsingj to han igh
voltage. Ibis cable was then U:
voltage line going to 1 late or atatic tube and t
shield or grouna e otion t e sire probe.
![Page 47: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/47.jpg)
-
.
![Page 48: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/48.jpg)
18.
the circuits were reversed lo polarity, attae one cable
sb above gave a negative aire anile the other , a positive
aire* to iaaure against leakage , all high voltage iiaei
xere aeli aepa rated, all connections faade very secure, any
sharp corners sere siaoothad round and the probes sere in*
suiated heavily with Acyreloid*
In order to obtain pressure aaa aureeients,
number of zero) lor dry air, the glass jar containing a
.-ooiature absorbing che.nl eal In the left of Fl£. 4 aaa used*
the plastic cover incorporated a fitting for the suet
puap lead, and t«o terminals for the electri)
a aging straight do an frea one terminal aaa a point*
strip to ahleh aaa soldered the platinum wire. n£ing
vertically froa the other terminal sas a two inch piece of
approxlfsately 1/2 laeh thicic solid brass* inning through
the lower end of this brats, aac radicular to it in I
rection of the other terminal aas a steel machine screw,
rough the end of which, in a vertical direction, aaa
secured a one inch piece of 1/16* brass tubirr he
electrodes aere similar to those used la the wind tunnel
and the spacing aaa obtained by adjusting a holding
the brass tubi-i,, » JsaosBeter aas attached to the auction
p lead to measure the suction in inches of aereury and
again to insure iaauiatir .old aas use avily*
order to avoid any po La ionization of the air in
the air aas changed after eac* set of measurements at a
particu. .-seure*
^u
![Page 49: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/49.jpg)
its «
![Page 50: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/50.jpg)
19.
. Aft
The test data a 8 recorded la fig. 8 to Pig. £4,
vera obtained b fsliding the prooee, iceeping the tip of
the platinum aire juet op;osea the atatie orifice, into
the tunnel to the desired location and securing the sup~or 4
to the steel tree* b.; me*m of the 1/4 inch bolts,
fortunately due to vibration troubles the length of the
eantilevered probes had to he shortened until the static
orifice and aire could just be located in the throat.
This unpredieted difficulty eliminated any testing unatreas
of the throat and all data had to be secured either in the
throat or, aa ouch a a possible, do ana tream of the at.
The latter sea of course limited, the flow in the throat
could just be allowed to reach sonic velocity and then
dlfluae again eubsonicaiiy aft of the throat. This la
eo&etlmes known aa the first critical pressure ratio.
If the flea reached auperaonic proportions at any time,
the atatie pressure readings aft of the throat sere erron-
eous for aubaonle apeeda. (the only exception to this
may be at the first critical pressure ratio when with
certain type throats a saail supersonic region may appear
near the walla in the throat. aef . Ho. 8). i>otaeshere
betaeen the atatie probe and the throat the supersonic
flow would have to have broicen down through a aftock save,
with a corresponding entropy leas. eae losses would
have to have been conputeo and the atatie pre a sure res
![Page 51: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/51.jpg)
![Page 52: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/52.jpg)
related to • sen stagnation pressure (Pg>« Any downstreaa
tatting aaa than limited to tho first critical pressure
ratio acid subsonic diffusion aa dictated by affective area
ratio. *s a result, all testing wsa m&% in the vicinity
of the throat to a point 1 l/t inches downstream, fhta
also greatly handicapped the obtaining of data, showing
the effect of &aeh number at constant pressure. &s a re-
sult all data ban to be referred to the character is t lea
curve for the particular static pressure under no flow
conditions, and the effect due to siach number noted. Uy
at a fee isolated spots waa it poaaible to observe the Each
number effect at conatant preasure and this almost ex*
cluaiveiy la the lot speed range. c*uper8onicaily , of
course, this problem aas eliminated. Furthermore a8 expect-
ad since the platinuia sire aas directly oppose j static
orifice, no effect on the preasure readings aaa had on the
air ilea measurements. ith or without the sire probe in
place, the static readings obtained were the ease.
spaci tne electrodes, which proved to
be very important also left something to be desired,
though the spacing was meaaured prior to each ran an »e*>
ed after the ran, there was believes to be soae play in
toe arrangement of approximately l/t>4 Inch. This could
alter the reauits significantly. . too, since the
platinum wire Is small (.003 In. diameter J, it too may
have bean attracted electrically toaarda the plate or even
bent si Ly oue to the sir velocity. This eiec
![Page 53: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/53.jpg)
![Page 54: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/54.jpg)
attraction aaa aoticea one© during static pleasure testa
in the jar* Visual 17 this did not appear to happen In the
tunnel but the buiaan eye ia a poor evaluator of very saail
wittancee. egaif y ins. g lessee sere available but cue to
an error In constructing the nozzle (solvent «aa alloaed
to pour uoan toe sails) the original planned excellent
optical propertiea aere ceatroyeb. 'lime aaa insufi iclent
to have another nozzle constructed*
Before taking data, it became evident that
aire had to be "burned in", t.e* it hod to be burned aith
a hi* ji for several sinutes. This In effect, as
obeerved under the microscope, had the result of aiiphtiy
rounding the blunt ed&e ox the cut aire* the character 1st
change a during this burning in aith the current deereaaing
and it «aa only aneu the edgee aere rounded and character*
is tics became steady and reliable that testing coula be
aecosr lished. This verify a some of Fue*8* nor a as the ion
velocity is chanson by the point else snd sharpness,
Burning in at £ .ieroa&peres for tso to three ainutes
jved to be as tit ,*ry«
'ihe data stag o uineo then simply by securing
the probes in place, as near the throat eata Lishinf
air floa. the stagnation pressure and static preasuree
aere recorded from tha euometer and the characteristics
ta ined b> increasl e voltage s current.
this aaa generally continue* the aire sparked ae
evidenced by a sna. in eat, sound sue the
![Page 55: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/55.jpg)
.
![Page 56: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/56.jpg)
observer's eye. fa* ^Io» ess clearly visible la subdued
ht at aeax atmospheric prtaQare *uu very noticeable lo
dayiifbt at reduced pleasures.
ieatint with another siae platinum aire ;
was also attempted and with opposed polarity* s latter
aaa accomplished merely by changing the leads to the
obes aria ueinjj? the other circuit* fhe pressure aeasure-
taents in the jar aere conducted, after securing an; lei
ag«# ny setting a desired pressure by the use of a auction
pump as read froa the sanoaeter and reading t o*
characteristics. *fter each pressure, the air aas alio**
to return to atmospheric conditions to dispel any
possible ionization of the gas. This last procedure
aas not necessary curing teats in the alnd tunnel, einee
according to tuichter, an electrical field about a body
has a strong influence on the air stream only if s
intenalty field is act up. (100,000 to 500,000 volts) snd
then only up to velocities in the order of 65 ft*/sec.
(M »
![Page 57: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/57.jpg)
![Page 58: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/58.jpg)
* »r •rih« data a a ottainec appears In PI
In order to obtain a aero &sch number curve at anj
the data as ( iven in Fig. 3 aas cross plotted at
amperage in Fig. 9. fie curves at the desired pressures
vera then compared to the cists taken at the eaae pressure
out with impressed flow. As toe air vaa at all tinea
extremely dry, no correction need be made for humidity
and, according to the wora: of ierner, the glow is in-
aenaltive to temperature. For a particular arranre-aent
of electrode listeria I, size and spacing, the only
vsriabiea expected to be encountered were pressure end
velocity. It may be that this assumption aas in error.
The platinum *ire used was always approximately l/2&* long
and for a seemingly good reason. On never*, occasions
sires 1/ long sere used sue the ohsracterietics were
noted to be Sv iy different, with zero velocity, the
amperage a lth the longer sire appeared one to two mtei
aaperes higher. Thus it nay be in the arrange aent used
. is relotea not only to the size wire,
the point size s scinf between the electrodes but
also to toe length of the aire. La understanuoole
as nos more area is subjected to i ardraent snd a
fcr-vster avalanche MM eldi current.
avoid this pos* Ity, the aires were cut to
approximately l/Zk inch length for ail teats.
impressed velocity, an effect of this length could also
![Page 59: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/59.jpg)
![Page 60: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/60.jpg)
expected as a longer region of Ion flow and a p. roster
nuaoer ol charge carriers asy be aubjee o*n
s*s>« I aire Voo ior:; and 6len< ai tooid, el so m . eot
be feasible aa it would be subject to bee and vlbrati<
when in a flea atreaa. thia possibility should be
investigated further.
I&:;teulBteLy evident frosi Pig. 8 and d is that
the glow discharge ifi very aena it ive to treasure c:
with the Intenaity increasing aa the asuro is red
due to the reduced density, larger saeaa free path oi X
.ao tec ui.ee aad diffusion of the electrons* This is as
expected and thus It lends itself to the possibility of
iaeaau pressure a in wind tunnels.
be tapped into a tightly sealed container to eliminate tin
efiect of &ach numier and characteristic readings
giving the pressure and the corresponding gach number*
i a preesure survey at hi ressures aas not
included, it is expected that such flos disc
characteristics ceo be obtainec and thaa extending the
g*e uae to reading stagnation and total head preaeures
A survey should be made . e characteristics at hi
pressures and it is expected that voltage in the order of
, . be require aal
survey was conducted with a s.iaa) >ire, sly,
inehea in diameter in an endeevc eLat;
*or&* several tests sort e at Ue. ere belou
![Page 61: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/61.jpg)
![Page 62: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/62.jpg)
£5.
with very erratic results and no reproducibility of
result*. Kt tests above this Maeh nuaber, no ent
could be ootained and invest igatlon shoved that the aire
hen bent itself baca around the Insulation a&terisi of
the probe* At supersonic speeds , the needle sea bio an
aaay on four successive attempts ana it seas conduced
the aire was too saell and flexible for velocity measure-
ita. 6,11 tests were then conoucted aith .005 aire
ahich proved to be satisfactory.
^similarly the first tests eere to be >aade eitfe
the platinum wire as the positive electrode and It wai
expected that the current aouid be very eaall. In every
attempt, art was experienced before any aape rag* read-
i could be aaoe. oroa-ameter needle aaa observed
to iaake several a;aall unsteady laovements just prior to the
srei .jved insensitive to any eurre. at say have
been f Ionia; . It ass c lately apparent that s atlve
aire aas more sensitive and useful end no further testa
eere aade with a positive aire.
In previous Boric aith direct current glow dis-
charge an , the greatest disadvantt ad been
oui aiay t electrodes **ever, in all those
experiments it aas not* at similar materia is aero uaed
for anode aad cathode a no the errs ent of euctrodea
*as very symmetrical, -urn log away is teiievec due
to i temperature due to burn lag, oxiastion in active
![Page 63: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/63.jpg)
![Page 64: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/64.jpg)
oxygen of discbarge G* at loiter temperature and csthoce
a putter lr. this burning a say was aoti .\ voiced
by using an asymetrieal arrangement of electrodes as
gesteo b: •** using a noble natal, platJ
its Saifh resistance to oxidation and -stricting
trie amperage to a hundred aileroa&reres or reducing t
voltage istsediately upon any evidence of sputtering or
sparisin It is to be noted that transition to spc
sea very abarp and care had to be taken to ae th#
voltage quickly, less possible denude to installation
result*
The data obtsinea was recorded as a lion of
meh i 9t as a ptraaetajj jce the - sag cerrie
in a slnd tunnel* sever > as the local velocity of
sound decreases lees than 100 ft*/sec. »ver t n of
Maeh numbers due to the temperature drop. It is tc
understood that the velocity change is *t line
var froiii ft. /sec. at a ;*aeh nesaber of to
.3 ft./sec* at * • 0.99. js for each one-tenth eta*
'.•eh nua&er, a cone in£ change of 103 ft./sec. -nay
be •asu&ed as approximately correct, the error not exceed-
ing 7 ft. /see. a stagnst'. er tea;p«rsture »aa
assumed constant for ail runs*
In rigs. suite of ue
:
the electi odee 0.1. @s spart. it is
.ious that the glow is Itive t. .
![Page 65: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/65.jpg)
![Page 66: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/66.jpg)
I r m *s
until ft &ach nuaber of about 0.30 le reached (351 ft.,
feany tests sere coBduct.ec «t lover ilach nuranera, and <
©ocsaion slight, sensitivi tlced especially at
s&perage. However, the taajority of results showed no
displacement of the curve and as the curves turned toi
a vertical tangent, results aere erratic. They -nay hi
seen cue to slight fluctuations in the voltage at
critical points or possible sputter!: is Isck oi
rise is understandable as the ion velocity is ve
compared to the velocity of fioa of the air molecules, ^s
the air floa is Increased response eould be expected end
8 8 .a ted, this ass true at all M&eh numbers above
Fife. 1£ shows results at the sasie pressure for
different velocities Indicating a marked displacement of
ve for the increased velocity, the reveres I of t
curve at the lo^er current is expected to be in error as
In Bi>at tests, the lower limits were not well define It
is also well to note that the point of ignition appeared
to Increase in current as the velocity increased.
•ves a good comparison of the s& ach
nuaoer at two different pressures and while it indicates
8 ar eft act 1 low asperate range, t
essure *ore sensitive as the current is
increases* «* aevice sbould that wo
allow the testing of the sense velocity up to the ft of
sounc and slifhtly above, at the se ie a.
device could be a vino tumiei with the throat downstr-
![Page 67: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/67.jpg)
![Page 68: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/68.jpg)
of the probes snd « vary 6.mlL an^le convergence to the
throat, fhis a-aali angle convergence eouid be necessary
,'t the a.rea ratio controlling the Haeh number fro a G.40
to unity only chaoses fro . >9 to i , . are aleo she
be e .aeani of changing the stagnation temperature* thus
,ne velocity at a constant Meeb number.
tunnel uaen ooulb not be so designed since, as it sag to
be useu super eon lea lly and had a snail throat , the
c-ouadary layer could not be alloseb to build up excessive
keproQuclbllity of results at this l/S inch
spacing sas fair with very similar curves resulting, aerely
being displaced slightly, and this generally tosards
higher aaperage for the seme voltage, these fluctuations
it is feared stay have been due to slight rending of /the
sire or v lore t ions due to tne force of the floe, the sire
prebe eas alaays at an angle to the fios, due to the thick-
nese of the probes and to insure good insulation, and any
oenbin£ sou la Ym^te been tosards a closer epac s
correspondingly higher current.
She variation in voltage at constant current
appears in rig. 15. ere is sjooq aeneltivit to
* .: j for amperage celoa croaaps and a~. to M «
for hi t tier a&pera£e but above these limits the curves sre
shoe a drop in at . ^ is no appan
theoretical reason i e vicinity of
u s i.O •ac' it aey be due to either poor er ital
results, 8 oanoin^ sire, oi a Decrease 1 sitivlty st
![Page 69: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/69.jpg)
![Page 70: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/70.jpg)
-
lover pressures as all testa in this reiiae eere conducted
necessarily at reauced pressure. be scatter of points
la also believed cue to the fact that the Mech numbers ten
obtained at various atatlo pressures with the assumption
that the response eas similar at ali pressures. la
assumption should be closely invest i^s tea. These curves
siso indicate that sensitivity to velocity can be had at
loser uach numbers in the order oi 0*20 instead of 9t»
evidenced at 0*31
•
At constant voltage the sensitivity to ampermpe
drop as velocity is increaaed la good hut the renje ia
definitely lLsitea at each voltage, sensitivity is food
at a particular voltage until a near vertical tangent is
experienced with respect to current, the preasurB is a
very Important factor here »ith a higher voltage required
for a higher pressure. Thus the curves shown sre rue rely
representative of anat occurs since each is plotted over
a rsafQ of pressures (benee the scatter of points;
those of loser voltage being ta. an over a reduced pressure
range, everthelees, food sensitivity can be expeetea
and a*. a in constant pressure lines of constant voltage aust
be obtained.
In Fig. 17 to *4 the data obtained for a l/e
Inch electrode spacing is plotteo sac as is e;
higher voltages are I ,he larger spe.
This lsrger epaeiu , o sever, faea: at the anode to
csrtnode travel is greater fit ions sre subji to
![Page 71: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/71.jpg)
I
•
![Page 72: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/72.jpg)
m
the flow for a longer time* je th© sensitivity,
especially at lower velocities, should be increase
la the case experienced (Fif* 19) tilth results obtained
at U. » 0.1b {ii05 ft. /sec.) and fro* the plots of constant
current and constant voltage, results my be obtainable
witn finer equipment down to H • 0.13 (145 It. /sec
should a probe be desired for very aloe floe, it la
anticipated that .001 inch aire with a Urge enough
spacing would be more sensitive. :»ever, since flow of
such eiaall awgnitude is generally of little interest in
aerodynat&los, the possibility was not invest lgeted*
lest at slightly different pressures (not
exceeding 8" Hg • differential) up to a Each number of 0*55
showed excellent correlation of data with the Ma oh nuia er
effect being very close to constant and the reproducibility
excellent, adqvo this velocity teats could only be
ted at one pres; for each Mach number but the re-
producibility rema ine jq. e kL a was not as
inclined to the flow as aith the smaller -he
vir rat ions *$; fcly mei duce
s variation in voltage at constant ampers
.•as alalia r to that at the ei£ht inch i was a
little acre aenaltlve and restricted to a ?4ach sr of
G.S The curvea of constant v- also .lar
displayed a greater aensttivit» sin constant pressure
curvea are eeeentlal.
•je it can be aec *•* 6 ouad
![Page 73: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/73.jpg)
.
![Page 74: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/74.jpg)
« )
effeet ooth a a to the voltage required, the ranee of the
velocities (a larger space le sensitive to lo«er velocity)
and the aeneitlvity to velocity change.
Consequently the glow discharge lends Itself to
use aa a treasure probe, which haa many uses such as in
wind tunuele sod preasure surveys in poser pleats or over
surfaces. It also can be used aa a velocity aeter either
In a «ind tunnel or aa an aircraft air speed indicator,
wince it Is insensitive to temperature, it cannot be uaed
as a Mach&eter for, as in an aircraft, one oay be traveling
at kta. true air speed ehlch at sea level wou a a
keen nuater of approximately 0.81 but at Zl tOQQ feet it
aould be in the orcer of K » 1.05, r ue to the cnange
in temperature. Arove this altitude to about 100,000
feet, the Each nuiaber vould be constant due to a constant
temperature but the asure would continue to drr • If
the velocity response of the glow discharge is irrespective
of pressure the indications would be tne aa^ie at all
altitudes which wouic. rrect .sen r. If it
la r< sive according to preasure, above St ft. it
would show a changing response rut the Mack r would
not na^a changed.
en ofoaerved wind tunnel, the £ low at
first appeared to dim as the velocity was at as
a velocity increased furthe. . w Lnereee in-
tone ity. Is latter increase was -js r to the
reduction in pressure. a location of Vie flow dli
![Page 75: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/75.jpg)
I
![Page 76: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/76.jpg)
i. *<
ear t sq^q at *ny ti^a*.
![Page 77: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/77.jpg)
![Page 78: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/78.jpg)
32,
a» the forego lag study the following con-
clusions may be made:
1. The glow discharge characteristics at a wire point
are a function of tfc» erlala, size, spacing and polarity
of the electroaes. They i»ay also be a function of the
length of the aire elect rot©.
£loa aisciarge ie pressure senaltlve and a a
such lenda itself to use aa a possible pressure probe In a
ainci tunnel to measure such items aa atatic preasure and
quite possible, high stagnation and total head pressures.
i«88 -voltage ie required to aetata in a constant current
aa the pressure decresaes.
$• the glen discharge is also velocity sensitive,
the sensitivity and ranee being a function of the electrode
epaciag:, and aire si&e. er voltage Is required to
maintain a constat rent as the velocity increasea.
4» u platinum aire, .001 Inches In diameter proved
to be too •:aall an ..© for velocity measurements, k
aire . '.er was used for all testa*
It la necessary that the aire e rode be made
the negative electrode as no r e suite c ed
when uaing positive polar it
The burning aeay a e electrodes pre v iou a ly
experlencec, can be avoldet ii'te: slse
electrodea of differ nt oateriala wit e aire electr
bel )Q6 of platinum, a istterial resistant to
![Page 79: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/79.jpg)
• ollol e
;0JDarn ecf jlo
V^iifilo 8 gnloe
![Page 80: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/80.jpg)
54.
©x lea t ion
•
7. fhe glo* discharge, while velocity and preasure
reaponeive, caaaot be used a« a Macb&eter due to Its
inaeneitlvltv to teapereture*
e glo* discharge, *hen aobjectad to air floa, la
iaore sensitive to voltage changes «t constant current than
to current ehangee at constant voltage and thia seas ity
incroaaed with iacreaalng electrode apse lag*
It la re aried that further studies be carried
out to deter aloe the following;
lm a effect of sire siae a i on the characte)
latlcs aac velocity seaeitlvlt?. res up to .01 iachee
ia dlaiseter should be tested la length* var froa 1,
to 1/4 inch. y
The velocity effect at coaataat pressure over a
aide range of pressures*
S. ie pressure sensitivity of I io* at preaeu
up to is5o psla.
4. a effect of electrode spacing to velocity
aeaaitlvity over a wider range* preferably frora 1/16 to 1
inch*
c and aonlc studies be carried oo
jol to afiord t* a range o c&ti
![Page 81: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/81.jpg)
'
![Page 82: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/82.jpg)
bib I
g btaoiiity of a Lark Current tfiacbarge for thaeteaaurement of i' Low Velocities of i.esee% elmi-ucice, uenaaa Aeronautical Aeaearoh Institute,
rli» # 194i&.
"investigation of the Possible Utilization of anElectrical Glow discharge as a Means for MeasuringAir Flow Gharacteriatica", Prank I>. Werner, Thesis*or the itogree of master of Science, univeraiof Minnesota, November, 1948*
Z, "Fundamental Proceasea of Electrical Dlacharge inGases", L* &• ^oeb, John *iley and Sena, I;;c,Sew York, 1959*
4. "iiinetic theory of Gates", B. I nnard, McGraw-Hilljotj Co., iiiew York, 1938<
5. "teste with an Alternating Current Glow Anemometerunder steady Concitione", Bilhela tucks and G«rdJ&chaaacher, German Aeronautical itesesrch Institute,beriin, 1944*
®Aerodynamic a of a Ooaipreaaible Fluid", j.
and a. I,. , uckett, John Wiley and sons, Inc.vilea £ork, 1947.
7. "Gae 'iablea*, J. . aenan and J. Kaye, Jol .leyauct dons, Inc., &ew York, 194
8. "Flow Pattern in a Converging diverging &oaale H, &.
Oswatitech and fif» riothateln, j . 1215,&areh, 134 9.
"Influence of an Electric Field on the Air Flow Arounda Body", 0. ater, Translation froea Germanwartime reports.
vestife-ation of tl Possibility of Utilizing an»etrloal Glow discharge as a Velocity Meter at.peraonie speeds", n. u. bo J- .?rge* I as is
for the iiegree of Master of Science, Universlof kinnesota, July, 1949.
![Page 83: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/83.jpg)
![Page 84: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/84.jpg)
A- .Stagnation CHf\riB£R,
B NOZZLE
E Qa iPm£N T~
D- £L£CTR t CAL ^~P*AJ£L,
Fig 1
![Page 85: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/85.jpg)
![Page 86: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/86.jpg)
v.
o
1
-I
z:
> i_ ^
5
![Page 87: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/87.jpg)
![Page 88: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/88.jpg)
*:<oo-J
CQ ^<^)
uj i/>
>*J Uj
N QNO*
«9
k
Ctf
T,
ooo
O
O
<—
8X)
4
N>l
OCO —->
8-oo-
o:>—CO
2
>
UlQ
oO
<ol- -
- - 1-
![Page 89: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/89.jpg)
![Page 90: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/90.jpg)
Pressure ^Sur^e/ Jrr/a/oizle * wd Probes
fiG ^
![Page 91: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/91.jpg)
![Page 92: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/92.jpg)
Shadowgraph °S th? "Probes
ffc y *
![Page 93: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/93.jpg)
![Page 94: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/94.jpg)
y^ BRASS TvJB£ -^
AIR FLOW
^ f!
piftTiMun Wi ae/$2 LONG
' P*- 7&* STEEL NE60t£
M
Yf 5T££l XjqE.
,/W^
PLEXIGLASS
SCRfWS
WqooPPqRT
1
6-Oo"
J
f/oo"
17
S
ARRANGEMENT °j
*he PROB&S
fjG y-B
![Page 95: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/95.jpg)
![Page 96: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/96.jpg)
Q
i
o
I*. v
i
t
\
X
^£^
V
-5
i
O
\y-
![Page 97: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/97.jpg)
![Page 98: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/98.jpg)
![Page 99: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/99.jpg)
![Page 100: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/100.jpg)
i
JC"VVKW-
-o•^
* !:!
1̂
i
I
M
A
10
![Page 101: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/101.jpg)
![Page 102: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/102.jpg)
1= 10 1
ISTiCS51-rjvr- DISCHARGE iCHAR/iCT fi R
AT VARIOUS PRE53 UPs
IR
FC R
61?r003 NCH 3 lAT!rs un
V/IRP *
iES&TJ VL
S4 ,
SPACi SG Q.IZ5 /A'.
£.0
1
kf6
2F« 1
i
4fl 8 0«VSi algijj? 1
'.''.
.
* ^Z<i
>W £6 M 27. (>4"
£rt 40 £3,12' tte
ui
&U
^6
'
•
u
Ef
<^?2
:
i 1
/
J J f
1
/
/ J
30
/6.
J-
j
T
I 1/
1
/
/
/
i
*
J / /
-i—
—
/ ' > •
f~-\i ; .
/£ -/ /
z' y / :jS ,^^
8 / j^> -^
r^"" J
.... ,.
S^^
_^A*-"•
H
""^""^
<26 00 3<^ 00 3>j 00 38VOLTS 00
_
^4 00 U00 So00
i i
'
j i—
i
i :,. .:
![Page 103: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/103.jpg)
![Page 104: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/104.jpg)
![Page 105: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/105.jpg)
![Page 106: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/106.jpg)
FIG /
HA ncl2£A *!$£»? wf*fci 5 .
:
SHOW!
.H G
4G F\f CM NUMBER EFFE
E6H
93 P .ATlKlUM WIF• 1
WIRE-
hitC-f:"1
isV SPB Q7J&$ «£ .
i
6tf
jr#
imo"/:
. .
k5/i...
..... .
.
47?
.... ....
1
-
/
^4 .
^0 -
1 /
I|!
i/\ [ '"
_cx.36 R8; s".36
/ 1
. _
uJ.
M:
/
: /
<oa:
5S-
/
//
/
/
/ f /
"
34
f
i/
•
/ i
&£.
i f
/
Ji j
ft/7 j
" X^/ /
/£ ^r^• />^ •
0?R
^^ _>
~'Z8 «r*7
H —.._
^ ^"
3£&>!
30 50 OO \W 00 :^6 0G " :5tf 30
i
![Page 107: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/107.jpg)
![Page 108: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/108.jpg)
1— 1
4 -dlSdHA RGE-lWfifeflC if R^iTHL^t
Stfd NG MAC i Mj£IBEjR-fi
rtff
t
US!' J 3 jW. I v •—
^E Biiiki
£V 5P<= iCf-F'Q ; - m fcS /,v.;
f>Q
5f>.
li/U-...
Is n " J lr.''.'.
....
«5 I . 7
1 M *
: .'.':.
^R1
~*t
... ' '
'
:
....
$4 r?, 7JJ2it LLS
90
r 1.&5 M=01
, e>
rr
in 1 -
UJ/•/
,va
t£?? i i
. m'
!'
/
t*W i i X .
' I 1 / J#4> /- -
*
A E
/A/
j jy &\ •'MM109
m //-//O v/ r
R/> '
*
^Si wi"s
j-"-, z<305hi*-T r)
M
V
- i
i" /v r
$4k- '
' 77 J.
taal
3^( )U 3f Ob ^200iini T cJ
KJ 10 s<y ij(3 ssvo
,.," ... —!—
i
-
Ul, : t o
![Page 109: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/109.jpg)
![Page 110: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/110.jpg)
![Page 111: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/111.jpg)
![Page 112: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/112.jpg)
![Page 113: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/113.jpg)
![Page 114: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/114.jpg)
i :i !'•
,
1 ]
—- -
r iB
1
,
1
———,
glow bisbtfAR HMACTPfclSTtCS
M>Vi ^G bC;^ [gf
3 <'-b
"wire si:
i"6 ftihv&
-
&vi( //v:
feO
Sitsi
i
K}Xf i^.fi? "M i
NUC!7.?6'
/
^8 h'-'O /S,^' ur
/
'w
/
7.8i" Hii>,97
*
5
. 4V
j
HOi
gV //
i
.TO j
-
:0i
%%i
j
zv
1 a '
'.
1
—
1\/
\SLCt.
t
1
\~ri
J
.
>
/
y'
th s y ^
s-
1
? r " *
%
pal
^00^^
<
—^^"^' :-
. i?*
s-
-1
2&<M> \30CS<r 2>H »;\fO
38T c.
)0 H% >0 ^ 30 $i»
i_ : .
i L. 1
-r J—
-
1. ;,. . 1 "v
![Page 115: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/115.jpg)
![Page 116: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/116.jpg)
_SijftW_jilSiLHi
FIG JS
nc$SHOWING t«z vflfiMATlOi* In VOLT/^ £
-VCO^STAmT A.lVe£MC(i flu^
![Page 117: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/117.jpg)
![Page 118: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/118.jpg)
![Page 119: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/119.jpg)
![Page 120: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/120.jpg)
![Page 121: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/121.jpg)
![Page 122: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/122.jpg)
![Page 123: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/123.jpg)
![Page 124: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/124.jpg)
![Page 125: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/125.jpg)
![Page 126: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/126.jpg)
T n1
...
Fi G. £<?
i
{ si.
1
liiitaflRuE.. O AC
*c#
r
-f./.S.77<3 s
....3 H o w i
^0R '
MG £F -EE Mid s E&
j£&-
. m Kg
£PflC
SEUAT v£
64 dUJfti ///.
. . ,
L'a •
. :
;
, . ._
-iftf?. . ./
ftfii
•
: : :
i
....
:::;] ....
....:.'..
.... 1
'f4K. . ,
,
.
*' • '
f5j£
i
/
w ...—
,
' " 7 *
1
J
w ...
a *$w •j ' rfi -0
/i y /
UJ<5ifi
/
^9£#r,
# r
HK1 H/'
/ ft. D
1 ^1 '
< v~-l
!
£ hi:f-5™
/J m7
J m
§?/
f? .189>r y
/-'-/
/
/
f r -.553///
1
£ // ///'
(V j
7> /rrT^-'
?0HfLi
/to// /
1$
, /
r y
y8
. r: 7< >/
A'r
i»
r^///'
'
//....
*
5& a 5tC 3
i
j
66 jo
vet
: 7400re:
40 : 90i p*
1 i 1
![Page 127: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/127.jpg)
![Page 128: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/128.jpg)
![Page 129: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/129.jpg)
![Page 130: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/130.jpg)
![Page 131: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/131.jpg)
![Page 132: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/132.jpg)
1111—-
—
- ' '
H^PtTE RUSTICS
T*i COM
o MA
M £3
1MFJERAG0ER
DOE
CH NUMB
![Page 133: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/133.jpg)
![Page 134: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/134.jpg)
![Page 135: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/135.jpg)
![Page 136: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/136.jpg)
![Page 137: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/137.jpg)
BUS DOB
1
![Page 138: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/138.jpg)
Thesis11474
15 TimmesDirect current glow
discharge under the in-
fluence of pressure...
_
![Page 139: Investigation of the characteristics of the direct current glow … · 2016-07-05 · IG«currentbioaaa»a.yahii aooehoa£-oea round J Ip*currentinatiilair liediacovereothatoychangingtheahapeofthe](https://reader035.vdocument.in/reader035/viewer/2022070615/5c03729e09d3f290408c1532/html5/thumbnails/139.jpg)
'?™n^la*!°" °f
_the characteristic s of
3 2768 002 03540 4DUDLEY KNOX LIBRARY