naca-”:”””,. - apps.dtic.mil · performa—=-e with e~b conditionsand, fmthemore ~the...

ARR No. E6E1

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

M?Alrlwm luuBolr”

A CORRELA!ITON

ORIGINALLY ISSUED

June 1946 asAdvance Restricted Report E6E13

OF THE EFFECTS OF COMPRESSION RATIO AND

INLET-AIR TEMPERATURE ON THE KNOCK LiIMITS

OF AVIATION FUEIX IN A CFR ENGINE - II

By Henry E. Alquist, Leon O’Delland John C. Eward

Aircraft “Engine Research LaboratoryCleveland, Ohio

‘,. ..,.

NACA-”:”””“’”,.!,.

— ,*X

-’

WASHINGTON

NACA WARTIME REPORTS are reprints of papers originaUy issued to provide rapid distribution ofadvance research results to an authorized group requiring them for the war effort. They were pre-viously held under a security status but are now unclassified. Some of these reports were not tech-nically edited. All have been reproduced without change in order to expedite general distribution.

E -240

1’,, m .- ., , , ,.--., ,,,. ,-,. —

/-’.31176013541918

—.. —...— —--—- _.—

lWCA ARR Nd , E6K13

,.

K~TmHAL ADY~RY COMKDTEE FOR AEHXJAUTIOS------ -. ——

A CORRELATION OF THE E?FZETS OF COMl?RISSIO~RATIO MD ... .

* I?mT-AJR- TEWWUHlm OHWIVOCKLfi “. .

OF”AVIATmlV FUELS IN A CIfR ENG~ - II. .. .. .

By He& E Alquist, Leon O‘DelJand John Q. Evvazd

., Suhwx

EJ%ekncck-llmlted performance of nbe fuels, comprising Isolatedmember? of four clamw”s of I@=%xr%ons [armat ics, p=affins ~ oyclo-parafflna, anA olefina), is ~resented f~ +* fom of three-Mmeqsfonslplots of fuel-air ratio, mmpre ssion temperature, ~a cmpresslon-airdensity. The plots are based oa a correlation that is shown to applyfor these fuels over a wide r-s of cmpreseion ratios and Inlet-air .temperatures. The si@ ficance of the term “temperatm’e seneitivlty”is sketch@, and.It is emphaslmd that no generalized number such asoctane number can be applied even to mbers “ofa given clam of hy&o-carbons when broad ranges of e~ine severity are encountered.

INTmmxmm

One of the aims of fundamental studies of fuel lmock Is todefine the lmocklng characteristics of the fuel In suoh a manner asto be Independent of the test engine and the test conditions. Com-parison rating ecalea (mzotia~ octane number) partly &compllah thisaim hut they & not Indicate the magnltuie nor the trends in engineperforma—=-e with e~b conditions and, fmthemore ~ the refermmefuel iteelf Is not rated in terms of absolute units. The use of.e@-gas densi%ies and tmpmatures to define the knock-lWted pek’fomanceof a fuel was suggested In I’efereme 1 as a means of mitigating thesedisadvantages. Aq .cd.culatlonof the end-ga8 density and t%mperatln?e@ tezms of nozyal.lymaeured engine variables, however, 1s “ccmgiliCatedand.tiertaln equgh to s~egt that a more easily-.calculated tinsitymid t-rature might be umd. b refemmce 2 the.compression-alr

. .. .

. .

..”. . . .i ..

. . .-.. . . ... . .,

1 .—

.-—.—.-— --— ... . . . . .... . .

G

density When .tiepistonpression temperature as

n4cA ARRx’Jo.mEz3. .

.. .

1s at top center 10 plotted against the ccan-oslcvl.atedby adlabatlc:cmmession fozmulas.

~S plot wailfound to be effective ‘incorrelating ‘* effects ofoaupression ratio and met-ah tempera- upon the knock-limitedperfomeme of a Cm engine. Tests conducted by Pratt & Whltmy Alr-oraft showed the plot to be equally effective for data taken on anR-.183OC-9 shgle-oyllnder engine.

h the present report the correlation presented In reference 2 isappllOd in evaluating most of the t~s of fuel currently us9d orbeing considered for use in reciprocating aircraft engines.

The data for this report wem obtained at the MACA Clevelandlaboratory between December 194A and June 19+%5.

- m APZMWUS

The fuels tested were choesniqpomtant olasses of fuel * oraircraft engines. The fuels ere:

S-4 reference fuel28-R mlAviation slkylateCyclohexeneCyclopentaneTripteneDilso~pylTrIptaneToluene

All of the fuels except 28-R wre

because they remsent mmt of themnsldered for use h reclprocatIng

leaded to 4 ml TEL per gallon.

Three CM? engines were used to obtain the kta for this report.Ror the tests on ell of the fuels except cyclopentane, toluene, andtriptane, a CFR engine was equipped with a four-hole cyllnder (pertNo. 106074), dual Ignition, end fuel- and air-metering system similarto those described In refmence 3. The coolant for this .englnewas a=~ of ethylene glycol snd water that gave a bcillng temperature of

.

Because of anticipated high power levels In the tests of triptane,cyolopentane, and toluene, sane engine alterations were c0~itir9aadvisable. A Cm engine was eqtippod with a strengthened cylinder

—. —

(part No. 109098) aud tke test set~~ descr~bed In reference 4, ex-cept for the followfmg featwes:

.------ ... . . . . .. ., ..-.. ----

1. An auxilim Lntake-valve qprkng was InstsUGd inside thestmdard spring whea it was founiiW.at a maalfald pm es-me cvel’65 BOW o‘psr sqaare:imh gage WOUL2 opm the.i~take valve;

“2.An aluminum piston was used for the triptane tests, whichcomaponded to ps?t No. 106s6OD except that the eecond ring landwm double width nnd the dlmeter of this land was &ellevsdO.CM inch. With PIston part No. 10636CD, omsiderable trouble”hadbeen experienced with either burning or breaking of the second ringlati.at hi@z-pmxw operi.ticm.

5. A greamre water-c.}oling aya+~ was Installed and a $acket-oul&t water %mpsratuw malatamed at 2SW F. Because of thebetter coolii~ ciaracteri~tics of water, 1L was hoped that the “lowor cyl~ndar-m“~ temperature at a ccmd%uti ccolant t~peratureWOtid redrujetie p~eigl~ti~n tiilCOUUtG.%dat hi@ YOWSr_ .

Duriw the tolumm tests +Ae cmmec ti~ rod “Eroke~ust b’elowthe plfkm-@n “boss and ?tiul.lskedthe mcoad engine. (TlilifailurecccumGd *8L ‘We angim.ewas operating at a compression ratio cfe.0, an inlet-air ttiperatu.reof ~oo-i?, end an indicated meanefhctive gremum cf 6’36lb/s~ In.)

The third engine was set Up exactly like the second exceptthe following two features:

1. TIM connecti~ rod was shot-poenedbefore iastallatlon

2. Piston part No. 10636(IIJwas used with the secoti ring-land’diameter relleved O.00S inch.

Check teste ueing 28-R fuel Indicated that the kcock-llmltedpower outputs were cnly sll@L’1 affected by the vsriow des~alteration.sof the three engjnes. Simild teat data obtained onW thx’seenglme are therefore considered cmperable. In testsof sJJ.the engines, knock and preignition wbre ds+~cted hy acathode-ray oscilloscope in ccn$unction with a magaetostrlctionpica Unit.

Each fuel was testeda wide -9 of severity.

TEST PROCl!UEHE‘“’ .

at Xl.sets cf engine conditions coveringFor a given fuel and an inlet-air

4 WA ~ ~0 . E6E13

t~eratmre of 250° F, the cwtpreeslon ratio was set at 5.0, 6.0, 7.3,8.7, and 10.0 and a Jmock curve was run at each of these compreestonl%tios; llkewlse, fcr a given fuel and a compression ratio of 8.0, theInlet-air temperature was set at 100°, 150°, 20C0, 250°, 300°, W350° Fend a knock curve was run at each of these Inlet-alr tompma-tures. The other engine conditions mm:

S~-kadvance, deg B.T.C . . . . . . . . . . . . . . . . . ...30Spee&, ~ . . . . . . . . . . . . . . . . . . . . . . ...1800Coolant temperature,%.. . . . . . . . . . . . . . . . ..250Oiltemlperatlme, %...... . . . . . . . . . . . . ...145

Although only knock-llmlted performance data are presented, thecurves are often Incmaplete (partfculsrly at the M@ power levels) .because of the occurrence of preQnAticm. The data were taken atthe hock Umits until the engine continued to Fire IS to 30 secodsafter the Ignltfon was turned off. Because no fuel- or air-flowmeasurements were made under conditions of occasional afterflring,the beglnnlng of afterflr~ Is not noted on the curves but concur-rent afterflrlng is noted by tails on the knock-lhnited points. Mobtaining the data for triptane at a compression ratio of 5.0, thepower level was so high and afterflring and prelgnltlon were soprevalent that the data had to be taken wlthln M seconds after theIgnition was turned on. For this reason, the data for the triptanecurve at a ccmmresslon ratio of 5.0 mey be In error. (The me@mwnerror Is estlm&ed to be about 50 lb/s~ in.pressure.)

Presentation of Data

The knock-llmited-perfomance data for

indicated mean effective

the nine fuels Is pre-sented In figures 1 to 9. (Because of the tide raqe of power itwas necessaq to use several ordinate sceles for these plots.) Thecorrelation of the effects of ccqpression ratio and inlet-alr tml-perature on the lmock-limlted perfommnce of the nine fuels was madeby plotting,thelmock-llmtted compression-alr density agdnst thecompression-air temperature (ftgs. 10 to 18). These compressiondensities and teqperaturss were calculated frcnnthe formulas set wIn reference 2. The deneit~ factor Is calculated by dlvidlng thealr flow to the cyllnder per Intake cycle by the clearance volume.- terns of the cylincer-displacementvolume end the compressionratio, the knook-llmited compression-air density is

5

.. -....3 . . . . . . . . . .-..

~= A(r -l)... , . -ma-... - . . .. ------- ----- -.

Wel%i

P mqpresaion-alr (iensi@, pounds per o@lc Inoh

.-A intake-air flow, pounds per minute

n Intake cycles per minute

Ccmpresaion ratio

&bplaosment volune, cubic inohes

The temperature faotor is celodated by t& adlabatlo ompressicmfomula

where

T ccqp”ession-ati temperature, %

To Intake-air tauperature, OR

7 mtio of specific heats of charge air at constant volumeand constant pressure (As in referenoe 1, a value of 1“.41was wed for 7.)

In figures 10 to 18 lmock-llmited data obtained in tests of-able Met -air teqperatum are shown by the plaln data polmts;the tailed data points denote variable compression-ratio data. Thecheck of the o~mlaticm methcd was detenulned by how weU the plainand ~Oa points feU elong a single curve at any given *l-airratio. (~ test at a ccmmresslon mtio of 8.0 and an inlet-alrtemperature of 25W I’is ccnmnonto both sets of data.) Curves arePZWsented for ~1-alr ratios of 0.06, 0.07, 0.08, 0.09, 0.10, andO.U.. ~ the oaee of mums, & pmlgnitlon mdtia the extentof the knook-llmlted data, other fuel-dr mtlos were chosen toohmk the mrrelation. On certain other correlation plots sane ofthe points ere laoklng because of immqplete data due to preignition.

- RESULTS MID DIBCCISSIDI?

Althou@ W6 pro~eot was set up prhmirllythe oomwlation presented in refemnoe 2 (figs.

to cheak further .10 to 18), other

6 MAoA Ammo. lm13

fiteresting features appear In the lmook-limited—perfmmanoe datapmeentd in figures 1 to 9. ti SCUM cases (of which the triptanedata is a notable example), as the engine condltione becaue Wbr ~the fuel-air ratio of peek Imock-limlted power shifted toward thestolchlcmetrio. This trend Occ~a whenthe severity of’engineconMtions was altered by variations in either the cqmlon ratioor the Mlet-air tampemture. Ho Correspandlng shift In the fuel-air ratio of minimum powr was observed. .

.,

As an Indication of the possible trends In futurs reclprooatlng-e@ne designs, broad ranges of Imock-llmited-power outputs arepemlssible simply by choosing the various ranges of engine severity.h the case of trfptane In these tests, an eightfold range of knock-Muitad power outputs was.obtalnsd. All the fuels tested elso showedrelatively low knock-llmited power outputs at lean fuel-air ratiosend extreme engine conditions.

Greater ohanges In Imock-llmited Wcated mean effective pres-sures were aocaupllshed by vbrlations of the caupmssion mtiothrough the praotical llmits than by changes in the inlet-air &m-perature (figs. 1 to 9). Whereas a decrease h canpression ratio”18~ Uc_ti by en inomase in the fuel cone~pti~, thequestion of whloh method would be the better for inoreaalng the knocklimits of an almraft engine depends upon the practicability.of uelngInterooolel?send afterooolers.

ti mmnection with fuel-rat+ng ~rlments, the data show thatno.generalized soale such as ootane numbdr can be applied even tomenibers of a given class of hydrocaz%ons when broad ranges bf engineseverity are encountered. For exemple, under ndld conditions theperfomanoe of triptane was approxlm te4 twice as.good as that ofS “refemnoe fuel; whemm at lean fuel-alr z%tid6 and SeVere CoIldl-tllme, S ref6rence fuel gave better perfomanqe Wan en. the otherfuels tested, Inoludlng triptane . “.

Ae Indicated by the Inlet-air-temperaturecurve:df ~0° F atfhel-alra’atiosabove about 0.084 (flg. 6), Inoreases of knock-llmlted power.~ not elweys aoccqpmy decremes ‘ofinlet-air tm-peredmre. This effect is alao reflected In the positive elopes ofthe curves of ccmpremion density “hgalnstcompression temperaturelnflgure 17. Knook-lhlted data are laoklng; b.ec”aueeof preigni-tion, fm trlptane at a ccqression ratio or S.0 and an inlet-air~tm of Iw” W Mo” F, exoept for three points at aninlet-air temperature of 150° F. The dotted e.~e was calculatedfrcm the curves of compression &msi& plOttia agalnet ccaupressiontauperature ~sented In f@m 17 by the use.of t&, Identity

..-.

HAOAARR NO. E6EM” 7

A=. . ...... -—- ,.,... --myT- F1772%* ..- , ~ ., ,-

whem l?/A is the fuel-air ratio. T!IIscalculation I.llustz=tesone ap@icatlon of the correlation.

&, the 8ev9rlty of engine ccnditicne was leeaened for thetoluene tests, tha knock-llnd.’~dparformsnce ourves became steeperuntil, at a compression ratio of 6.0 and an inlet-air temperateof =0° F ~ the operator could not detemins knock mre belaw anindicated ineemeffective“pressureof 460 pounds per square inch)when preig@ti~ halted further testing. A check at even mildercondltiona also gave preignition before hook. Similsr results wereexperienced.at a cmpreasion ratio of 8.0 and an inlet-air tempera-ture of 150° F . Th<s reeult waa expected on the basis of the curveof canpresslon.deneltyplotted against cmnpression temperature comonto both sets of data (fig. 18). (Beoausa of the absence of knockwithin the pemlsslble tsst range at ‘&e miMer engine conditions,the compression-densitysurface of fig. 22 wus ~xtrapolated.)

b the ~arSon of fuel test engineer9, the term “temperaturesensitivity” is applied to explain a multitude of effecto. Nouniversal and clear-cut definition of tm~eratw*e seaeitivityj how-eVer, exists. The curves of knock-limited compression densityplotted egainst compression temperature presented herein euggestthat the slope of the curve of capression density plotted againstcompression temperature would give a precise measurement of temp?ra-ature sensitivity. Whereas this defInitfon is less general than theall-inclusive statement of the ~~gon, it Is more general than tem-perature sensitivities that are often calculated frcm knock-limitedindicated mean effective pressure data in that it includes theeffects of compression ratio as well as Met-air tfmuperature. Ona CI’Rengine operat~ at constant speed, fuel-air ratio, aud com-pression ratio, where the correlation has been shown to be valld,this definition would be proportional to the &ate of change ofkck-ljm.ited tiicated mean effective’pressure with inlet-air temp-erature. As the,effects OF other engine variables such as sparkadvance and coolant temperature are included in the aorz%latlcm,”thedefinition would become increasingly general.

As judged by the slopes of the curves of knock-limited compressslon deheity plotted against compression temperature presented infigures 10 to”M, the temperature sensitiiitlesof S reference fuelJ .28-R fuel, en aviation all@ate, and diiao~Jl were almoat inde-xnt of e~l.m c-itions; the takperature sensitivity of trij?xanedecreased as the se~erity of the engine conditions decreased, whereas

— —

8 lWAARRlfo. E~3

the temperature sensitivities of cyclopentane, cyclohexsne, triptene,and toluene Increased as the severity of the en@e conditionsdecreased.

If the hypothesis is corrsct that the knock Mmlt of a fuelcan be represented In tezms of compreselon density~ ccmrpressiont~eraturs, and fuel-air ratio, then three-dimensional plots con-taMng these variables should give comprehensive indications ofthe absolute knock-limited performance of fuels. Such plots havebeen pre~ed frcm figures 10 to 18 for the nine fuel componentsstudied end are presentet in f@urss 19 to 22. For ccnnparisonpur-poses, S reference fuel is repeated on each of the plots with twoother fuels. On these chsz’tsvisible boundm~ lines and visibletitersectione of the three l.mock-llmitedperformance surfaces aredrawn as solid llnes, All tivisible lines and Intersections are shownas dotted Mnes. The same color has been used throughout the fourfigures for S reference fuel but tbe other tm colors have been usedto signify vexiorm fuels on these fQuree. The three-Mmmsionel plotsgive a ~pia and adeqm.te ~J of the knock-limlted performance ofthe nhe fuels tested h this programi

SiMhnEY 0)?RI!EULTS

The meults of Imock tests of nine fuels in a CIR engine atU sets of engine conditions involvlng variations of Inlet-air tem-perature and ccqpression ratio are summarized as folJ_ows:

1. A good com”elation of the effects of ccmipressionratio andInlet-air temperature upon the knock-limlted performance exists forthe nine fuels, cc%nprlshg Isolated maibers of four classes ofI@roc-bone: ~tics} p~d?ftij cychptii~) - defh6.

2. For scaueof the fuels tested (of which triptene was anotable example) the fuel-alr ntio of peak lmock-limited power

“ decreased as the severity of engine condlthns decreased; for agiven fuel, ths fusl-air ratio of ~ lumck-ltiited power-ma near~ constant regardless of enghe severity.

3. As judged by the slopes of the curves of lmock-lhitedcompression density plotted egalmt campreesion temperature, thetemperature sensitivities of S reference fuel, 28-R fuel, anaviation elkylate, end dlisopropyl were elmost Independent of engineconditlonso The temperature sensitivity of triptane decreased asthe severity of ths engine conditions decreased; whereas the tem-perature sensitivities of cyclohexsme, cyclopentane, triptene, andtoluene Increased as the severity of engine conditions decreased.

-—

——- .—.

4..The dab show that no genmmlized number such as octanenumber can be a~ll ad evan to the members of a @ven clans of’hydro-carbons when broad ranges of engine severlty are encountered. Asan example, at mlld conditions ~lp tans gave a higher hock llmitedperformance than the o+br pera?fins tested; whereas at severe con-ditions and lean fuel.air ratios, S reference tuel gave a betteryerfozmmce than aid.of the fuels ~es&d.

Alrwaft Engine Research Laboratory,National Advisrmy Ccmmlttee for AeronautiCS,

Cleveland, Ohio

REFlmENm

1. Rothrock, A.M., end Bierme.nn,Arnold E.: The Rhocklng Char-acter et:cs of Fuels In RelatZon to &ximun PermissiblePerformance of Aircraft Ii@ nes. NACA Rep. Nh. 655, 1939.

2. Evvard, John C., and Rranstetter, J. Robert: A Correlat?.onofthe Effects of Ccunpresslon Ratio and Inlet..AirTemperature cmthe Rhock Lisdts of Aviatlon Fuels in a CFR Engine - I.~~ Am NO. F5D20, 1945.

3. Bellman, Donald R., and Evvard, John C.: lCnock-LlmltedPer-formance of Several Internal Coolants. liACAACR No. 433}8,1944.

4. Bellmn, Donald R., Moeckel, W. E., and Eward, John C.: Khock-Limlted ?ower Outputs form a CFR Engine Usjng Internal Coolants.II - SiX ~i~hatic Alll’neS. NACA ACR No. E5H31., 1.945.

—

NACA ARR NO. E6E13 Fig. I

400NATIONAL AOVISORY

CWMITTEE FOR AERONAUTICS

~a

3

3

3

1 1 P I 1I I I

I I I 1 1 II 1 I I

1 I I I II I I I 3

, , , , , . , ,I I Y 1/ I I 4

r’ ! 1v l.>❑ 8.7

F I 1 1- 0 10.0

2

1

140

11 .131~ Inlet-air temperature

1=.05 .07 .09 .11 .13 .05 .07 .09 .:

Fuel-air ratio

Figure 1. - Effect of compression ratio and inlet-air temperature on knock-limited performance ofs reference fuel PIUS 4 ml T= per gallon in @R ●ngine.

Fig . I concl. NACA ARR No. E6E

NATIONAL ADVISORY: COMMITTEE FOR AERONAUTICS

90.

:2;D

2

.5.

2..EQ

J.al2.-l

i

iz+0

/

/

\ /

/ Y3

f

.g-i ,

PL ‘

~ i.1

1 a

t

$+.v.~.4 D 100

v 150200

t 250. ❑ ;g

o

Inlet-air temperature, 2500 F Compression ratio, ~.~

+67-, II.

.05 .07 .09 .11 .13 .05 .07 .09 .11 .13Fuel-air ratio

Figure 1. - Concluded.

NACA ARR No. E6EIS Fig. 2

orlz1#,,:l,,1nmn,al,1,,t,8 111111 , r , , ,

NATIONAL ADVISORY, r , I m, , , , r, # r , , ,

J

: CCMMITTEE FOR AERONAUTICS

,.

yo . — ~j

r

300 1

/

280 A.

260

240 .

I‘-

-

&/ K “ -

w

<

.2CQ . 4// $

L \ ir c

6“MO i i

,/

{160 1

/

i

{o

140 1VJ p /

0

/ temperatureC0mprest3i0n (OF)

ratio iD 100

v 5.0 v 1506.0 200

$ 7.3 $ 250❑ 8.7 ❑ 3000 10.0 0 350

Inlet-air temperature. 250° F COmrn-eaOlOnratio, g.O

l&#l,!iJit% m,, ,A ,[slll60’’” .05 .0 . .0 .

Fuel-a;r ratio. .

Figure 2. - Effect of compression ratio and inlet-air temperature on knock-limited PerfOr~nceof 2g-R fuel in Cf’Rengine.

I

Fig. 2 concl. NACA ARR NO. E6E13

NATIONAL ADVISORY: CCMMITTEE FOR AERONAUTICS

w>z2m

x

.5.

al

w:k

5

:5dal

;

~c

10&

.8—Compression ratio, 6.0

Inlet-air temperature, 250° F

.7 :

Aq

~.-l

.!!

●

Fuel-air ratio


NACA

320

300

260

260

Mo

160

140

120

100

ARR NO. E6E13 Fig. 3

b,,, —,, .,, ,, .,...... . . . . . . . . . . . . . . . . . . . . . .. . . . .. . . . ..— . . . . . . . .COMMITTEE FOR AERONAUTICS

Inlet-air temperature, 2500 F

)

.Inlet-air

.U5 .07 .09 .11 .1? .u5 .--Fuel.dr- rat10

Figure 3. - Effect Or ccmpremion ratio 8M inlet-air tmperaturo on knook-lhit.d Vrtomanooor ●viation alkylate plus 4 ml m par gallon in ~ ●nsine.

Fi 9“ 3 concl. NACA ARR No. E6E13

90

23

.9

.8

.7

.6

NATIONAL AIWISORY: COMMITTEE FOR AERONAUTICS

\ P ~& ‘

/J

u I 1- 1 1 1 1 ,

I

r

Inlet-sir

COmPI-esS1ontemperawre

(OF)rat10

~.;b 100

I 1500 7:3

z 200n o 2500 1::: ❑ 300

0 350Inlet-air temperature, 250° F Compression ratio, S.0

4

/

Ev -

* /

7 #t

FlgI

cm , n

ltt,ll,.j.l,il.lil,&,,l,li,lll,ll~ !,il,,lll,ll,l,,,tl,ililll,#1 n 1 1 1 n 1 n m 1 1 1

s-6

.05 .07 .09 . .13 .05 .0 .09 . 11 .1}Fuel-air ratio

lre ~. - Concludecl.

NACA

440

400

II

760

>20

2~o

2LL0

200

160

120

80

40


NATIONAL ADVISORYCOMMITTEE FOR AERONAUTICS

Inlet-air temperature, 2500 F Inlet-air

#

A —D 100

/v 150

?00

f

$ 250❑ Jooo 350

Compression ratio, g.O

/T

A

#

I

/9- 1

j

[

h k (

1

f f /

/

d / /

[\ , i

/

d

\{/

ui A /

r

L. L, $ ‘ / \ , ) A / f“ .f

\

9

{ f k1 r

\ /

S-6X

.05 .07 .09 .11 .13 .05 .07 .09 .11 .13?uel-alr ratio

Figure 4. - Eff’eotof OOM ression ratio and inlet-air tem~rature on knook-limited perfomanoed oyobhexnne plus 4 J TEL per gallon in CF’Iiengine.

Fig.

.

4 concl. NACA ARR NO. E6E

110

COMMITTEE FOR AERONAUTICS -

F“ ‘

100 /

I

:90

IT 1

-80 i M - ~)

I

:70 /

\ .

1

/ ‘

60w

)~ /

-50P

J{ f

4$A F!/ v /

/:40 \ , ) /

:30

.54

.3 .Ov .07 .09 .11 .1? .Oy .07 .09 .11 .13?uel-alr ratio

13

a

Figure b. - Concluded.

NACA ARR NO. E6E13 Fig. 5

. .,.—

720

,680

640

600

560

Inlet-air temperature, 2500 F

520 Tailed pointe indicate after-

480.

:

S’440>r-l

Go 400IiJ

m:E!~ 360

~0~ ~20

21%

*

200

160

120

80

.* .07 .0’9 .11 .13 .* .07 .09 .11 .13Fuel-tiprstlo

Figure 5. - ~feetof~uressian?atloti ltiat-eirtemperature on knock-limited perfor-unoe ofoyelopentaneplus 4 ml TU per gallea in VR sngine.

Fig.

,4

‘1

5. concl. NACA ARR No. E6E13


16

rv

16

?:2 14 b0:

312 w

2d

d-2 100,:wLG~ go*I>3S

60;.-1. . I I P F

I I I I Inlet-air

)0-n

,,nE l\l I WI kfl,li-e,> I I

4 -“D 10

;% mo;

.8 , —COmpreOslon ratio, 8.

/4 # I /1 I

tl“ .,-❑ Jooo 350

TI,0

Inlet-air temperature, 250° F -■

I I I

.3.05 .07 ●WJ .11 .lJ .05 .07 .09 ●11 .1>

Fuel-airret10


NACA ARR No. E6E13 Fig. 6

NAT IWAL ADVISORYCWMITTEE FOR AERONAUTICS

I I

Compreaslon

$ ; Inlet-airi:{

o

Inlet-air temperature, 2500 F b 100

0 250

f o 350

440

Pw

h

/360 *

320

..5w 2go;1+!ig 240

z:;~ 2m00

~

16o {

120

60

Figure 6. - Effect of compreagion ratio and inlet-air temperature on knook-limlted performanceof triptene plus U ml TEL per gallon in CFR engine.

.?4

.7

.4

.3

6 concl. NACA ARR No. E6E13

NATIONAL AOVISORYCWITTEE FOR AERONAUTICS

-1oo

- !50

- 40 i

10r

Cmpresslon ratio, 8.0

1,,,,,. Inlet-air rempwature, 250° F.ua.tstl.l-mts.* ‘-~. ittl..-1,,, 1 tt- ,,,

9-6,,,!

.05 .07 .09 .11 .13 .05 .07 .09 .11 .13Fuel-air-ratio


NACA

56U

520

MO

400

.

Xlo

y?o

2s0

240

m

160

120

80

ARR NO. E6E13,.. .

Fig. 7

COmpre SS1on NATIONAL ADVISORY

rat 10 CDMMITTEE FOR AERONAUTICS

Inlet-air temperature, 2500 FI

I

1

/,

A/

/

i

) f

5 ‘

r

\ d ‘ # o

9-6z

.

Fig-we 7. - Effect of compression ratio and inlet-air temperature on knock-limited performanceof dilsopropyl plug k ❑l TEL per gallon.



\ ,

h d

k!

Compression 2Q0ratio : 250

5.0: G.o

o 350

g Compression ratio, g.O2:{

o 10.0/ /

let-air temperature, 250° F

— . . . — — .

d

.

.Fuel-air ratio


‘5’-


NATIONAL ADVISORYCOWITTEE FOR AERONAUTICS

6s0Inlet-air temperature, 250° F

11oo

720

Compreeslon ratio, 6.0— — — —

------Calculated from fig. 17

6 Tailed polnta indicate after-firing

.

:5

:.-l.g;ti

:

j

~0E

3

z

1

6

Fuel-air ratio

Figure 6. - Effect of comprenslon ratio and inlet-air temperature on knock-limited performanceof trlptane plus 4 ml TZL per gallon in G’R ●ngine.

‘ w--

Fi 9* 8 concl. NACA ARR No. E6E13

Pigure .%.- Concluded.

-—I

NACA ARR NO. E6E13 Fig. 9

NATIONAL ADVISORYCMITTEE FOR AERONAUTICS

Inlet-airtemy;ture

Compre9sionratio

A 2000 250

0 350

Compreaaion ratio, 8.C

Inlet-air temperature, 250° F Tailed points indicate afterfiring

480

m

c

T60 - II’

(

. (%

:320 IJ

:d 4. I.& o

{, a

: 2801

L~ c

z\

R.d~ 240u2m

200

160

120

S-6

80.

Fuel-airratio

Figure g. - Effect of compression ratio and inlet-air temperature on knock-limited performanceof toluene PIUS k ml TEL per gallon in CFR engine.


T“ViFi ONAL mvlsowCOMMITTEE FOR AERONAUTICS

~

110

100

90 - — —

$sz:

~lxllx

2.alk 70:

i t oh

;&l:d.5~

z 50E;g

:=40

>To

o

A 200

Compress1ono 250

ratioc1 yoo

200 350

Compression ratio, 8.0-

.6

Inlet-air temperature, 250° F

~ .5

~A

- .4:z


..—..,... ..,.—....—-.-.-—...- .. . .. .,,.,.. . . . . . ........ ... ----.-..--..-..—

NACA

g>l-l


MAT IOHAA AOVISORYCOMMITTEE FOR AERONAUTICS

.

0 Variable inlet-sir temperature+ Vzrlable compre.slon ratio

.

.

.

.

.

.

.

.4

.i?lxnl 1

--, , , I I , i s i ,lm 150 200250W33W 100 150 200 250 3c0 350

Inlet-air temperature, W (oompresnionratio, 8.0), , 1 , , 1 ,

5.o 6.0 7.3(hmp%i~~”~~tio (inlet-alr tempera%%, ~o ~

f.3’6.’7 MLO

?’1 ure 10. - If’featof coapreeaion temperature on knook-limlted Compreaaion-alr deneltyi:&l) for S ref~rence fuel plus !4 ml TEL pergallmm.

Fig. II NACA ARR NO. E6E13

NATIONAL ADVISORYCOMMITTEE FOR AERONAAITICS

O Variable inlet-air temperature~ Variable compreeel.nratio

Fuel-alr Fuel-air

.

.

..5

~

:0:

~.

4u .2a

.4

.212W 14ca

CcmDressiontemperature,T.r, 8 , 1 1 t I I , 1

1(XI 150 2WJ 250 yx 350 lW 150 200 250 3co 350Inlet-air temperature,‘W (compressionratio, 8.0)

, I I , 1 1 , ,5.o 6.0 7.3 8.7 10.0

Cunpressionratio (inlet-airtemuerat%:, 2#0 F6 J:3 ‘t%:? 1:.0

“TIKe 11. - Effect of compresslvn temperatureon knock-llmlted compression=alr density

nVd for 28-R fuel.

NACA A

II

a

RR NO. E6E13 Fig.

NATIONAL AOVISORY:COMMITTEE FOR AERONAUTICS ‘

Variable inlet-air temperature

Fuel-nlr Fuel-airFatlo rat 10

.

.

.Og.

t 1 , 1 , , 1100 150 200 250 300 350 100 l~o 200 250 300 350

Inlet-air temperature,OF (compressionratio, 6.0), , , , 1 I 1

5.0 6.0 7.3 ~.7 10.0 6Compressionratio (Inlet-airtempera?ti”e.$0° JJ3

6.7 10.0

Figure 12. - Effect of compression temperatureon knock-limited ccmp~ession-alrdensityA_ for ~vlatlon alk~l~te PIUS 4 ml TFL Per gallOn.nvd

12

Fig. 13 NACA ARR NO. E6E13

NATIONAL AOVI SORYCOMMITTEE FOR AERWAUTICS

o Variable inlet-air temperature~ Variable compreaclonratio

.4 10“3

Fuel-alr Fuel-alr\

.$?0.06

0

.6

v

~~\~.

4;:.24ua

o

.6

.2

co%ssion Vqratur&Yoro.41~4%1600 1800 2030

1 I , 1 , 1 1 I I 1lMI 150 20U 250 J&J 350 100 150 ~ 250 300

Inlet-air temperature, W (compression ratio, 8.0)350

1 , 1 , , 1 1 1 1 , ,5.0 6.0 7.3 6.7 10.0 5.0 6.0 7.3 g.? 10.0

:6 Campresslnn ratio (Inlet-air tenperatus.e, 2500 F)

Figure lJ, - Effect of com~reesicm temperature on knock-limited compresalon-alr density~ for cyclohexane plus b ml TEL per gallon.nvd

--

NACA ARR No. E6E13 Fig. )4

11

a

F1

.2

0

1.0

sO Variable inlet-air temperature+ Varl.ble comprceslonratio

.6 -

\ ,

x

.4 “+

\ ~

>.0s .09

1.2 :

0 -

1.2 $ 10“‘3

,

1.0 \

.g 7

.21200 1400 1600 18w . 2000 12m 0.417% 16cm MOO 21XI0

Ccapression teqmrature, Tor1 t 1

lCO 150 205 250 yxl 39 100 150 mInlet-air temperature,W (compressionratio, g.0)

250 loo 350

, I , ,5.0 6.0 7.7 LIST10.0 5.o 6.o .3 8.7 10.0

Ccmpresshn ratio (inlet-ah temperature,2500 F

.fpme14. - Effect of compressiontemperature on the knock-limited compression-air density

A* ror cyolopentanepIus Q ml~ per gallon.

.

I


NATIONAL ADVISORYCOMMITTCE FOR AERONAUTICS

O Variable Inlet-air temperature+-Variable compression ratio

.6z la

.

.

0

.6

.

.

j; [iii iii Tiiiiiii iii-l.

4II

a

.

.

.

.2

01200 1400 1600 1800 2oca 1200

0.41y%1600 1800 2000

Compression temperature,TOr, , 1 1 ,

100 150 2C0 100 150 2001~%-a~~tem~~~ature, W (compression ratio ,S.0)

250 >00 350

t , 1 , I

.0 b.o 7.3 g.7 10.0 5.o 6.o 7.3 g.7 10.0Compresfilonratio (inlet-airtemperature,2S00 F1

Figure 15. - Effect of compression temperature on knock-llmlted comcresslofi-alr density

w for trlPtene plus U ml TEL per sailOn.nv~

NACA

,,

F

ARR NO. E6E13 Fig.

NATIONAL ADVISORYCalTTEE FOR AERONAUTICS

O Variable inlet-air temperature~ Variable compression ratio

.

.

\

.

0.06

●

x.

\ ~ \

.

.

.e

.8

.6

1 , , I I 1 #mm 150 200 250 2c0250300y50

Inlet-al%emp%sture, %’ (compres%n ri?!o, 6.0), , , 1 , I , ,

5.0 6.0 7.3 5.0 6.0 7.3 0.7 10.0C0mpr2L0~0;St 10 (inlet-air temperature, 2j0° ~)

lgurc 16. - Effect of compression temperature on knock-limited compression-air density~ ~Or di~~OprOpyl ~IUS 4 ml T2L per gallOn.

n~a

16


1.210-3

NATIONAL ADVISORY l“’’I’’’’ l’’’’ l’’’’ l’’~’’l’’’’l””jCOUM”ITTEE FOR AERONAUTICS

1.0

0 Variable inlet-air temVepatu~e

.4

H II II NIIIIII III Pill.2

0.06

rj

so 1.2 x ~o- 3 I I>F1. 0

1 :‘“%(~:z 1n /‘ ‘1 $a .8 7 I \,.6

.091

.4.Oa

1.2 10”3 ,2 Y

s

1.0

\ \ ,:

.a “.10 \ ‘ .11

.61200 1400 1600 1600 2om 1% 3.4119R 1603 1600 2000

C0mpre6s10n teayrature, LOr ,1 I , 1 1 1 1

2001

250 300IXt-a%’tem~Z~atw. e,%(ocmpression rat10,2S%0 ) .

350

, 1 1 , ,5.0 6.o 7*Y g.? 10.0 5.o 6.0 7.J 0.7 10.0

Compression ratio (Inlet-air temperature, 250° F)

Fi re 17. - Effect of compre86~on temperature nn knoub-linlted compression-air densityr-nvfl for trlptane P1U6 4 ml TEL per gallon.

.. . .. —.—.


NATIONAL ADVISORYCWMITTEE FOR AERONAUTICS

Fuel-airratio

.

.

.

..!Io Variable Inler-alr temperature+ Varlablc compre.rjlonratio

.6

.2

.0

.6 -

F \ \ %

.4

.214JXI 1600 Moo EUoo

1 1 #I I

1 1 1- n m nI 1 1 1 I 1

C0imre6s10n tempera

AIJ.ture.

. Ogk

1 ltw f!ooo~“ro. 41:%

1 I I 1 , 1

200 250 200 250 300 350Inlet-a?~tem~ature, ~ (compressionratio, g.0)t 1 I I , I

7.3 7.3 8.7 10.0comp%~si%”~atlo, (lnlet-afitemperature, 250°’F)

FIAq~l;g. - Effect or compression temperature on knock-limited cowresslo~alr denalty

~ rOr toluene plus 4 ml TEL per gallon.—

...—.---. ..—

NACA ARR No. E6E13

“A

Fig. 19

Figure 19. - Correlation of knock-limited compression-air

density, compression temperature, and fuel-air ratio using

s reference fuel, 28-R fuel? and triptane”

NACA ARR No. E6E13 Fia. 20

/

73 ~~~ ‘Axl o

. I N /2?

TEL/gal

Di isopropyl + 4ml TEL/gal

Figure 20. - Correlation of knock-limited compression-airdensity, compression temperature, and fuel-air ratio usingS reference fuel, diisopropyi, and cyclopentane.

~-- . . . .

N

.

Fig. 21

./gal

Fi igure 21. - Correlation of knock- Iim ited compression-airdensity, compression temperature, and fuel-air ratio usin

S reference fuel, aviation alkylate, and triptene.9


EL/gal

Fi’gure 22. - Correlation of knock-limited compression-air

density, compression temperature, and fuel-air ratio using

S reference fuel, cyclohexane and toluene.

I DISTRIBUTIONo

FOREIGN TITLE :

TITLE : A Correlation of the i'ects of Compressi cn Ratio andIn -Air Temperature on the Knock Limits of AviationFuels in eRE En g; ne - IT

AUTHOR Is):

Committee for AeronauWashington, D. C.

DATE:

~ Jun'SUBJECT

DIY. SECT.

12 g

CO UNTRY: REMARKS :

O r ( •I

ATI No: US Classification: OA No:

15609 ltestr„ None T,TLE Cancelled «=» Dupe of 12443 S

A Correlation of the "Effects of Compression Ratio" g And IggLet^Air Teraperature on The Knock Lis&ts of Aviation Fuels in A CFR Engine <= 12 = o

AUTHOR(S):

Alqtdsfcp Henry Eoj Q'!?ell0 Laong ErraFdg John OA: '

Rational Advisosy Consnittee fop Aeronautics Foreign Title:

55 S3

Previously cataloged under No: Translation No:

Subject Division: Section: -1 KSULC-

naca-”:”””,. - apps.dtic.mil · performa—=-e with e~b conditionsand, fmthemore ~the...

Documents