abstract for invited lecture to be presented at th · abstract for invited lecture to be presented...
TRANSCRIPT
Abstract for Invited Lecture to be presented at 10th CEAS-ASC Workshop on Jet Noise Prediction Methodologies, Sept 28-29 2006, Dublin, Ireland “Jet Measurements for Development of Jet Noise Prediction Tools” James Bridges, NASA Glenn Research Center The primary focus of my presentation is the development of the jet noise prediction code JeNo with most examples coming from the experimental work that drove the theoretical development and validation. JeNo is a statistical jet noise prediction code, based upon the Lilley acoustic analogy. Our approach uses time-average 2-D or 3-D mean and turbulent statistics of the flow as input. The output is source distributions and spectral directivity. NASA has been investing in development of statistical jet noise prediction tools because these seem to fit the middle ground that allows enough flexibility and fidelity for jet noise source diagnostics while having reasonable computational requirements. These tools rely on Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) solutions as input for computing far-field spectral directivity using an acoustic analogy. There are many ways acoustic analogies can be created, each with a series of assumptions and models, many often taken unknowingly. And the resulting prediction can be easily reverse-engineered by altering the models contained within. However, only an approach which is mathematically sound, with assumptions validated and modeled quantities checked against direct measurement will give consistently correct answers. Many quantities are modeled in acoustic analogies precisely because they have been impossible to measure or calculate, making this requirement a difficult task. The NASA team has spent considerable effort identifying all the assumptions and models used to take the Navier-Stokes equations to the point of a statistical calculation via an acoustic analogy very similar to that proposed by Lilley. Assumptions have been identified and experiments have been developed to test these assumptions. In some cases this has resulted in assumptions being changed. Beginning with the CFD used as input to the acoustic analogy, models for turbulence closure used in RANS CFD codes have been explored and compared against measurements of mean and rms velocity statistics over a range of jet speeds and temperatures. Models for flow parameters used in the acoustic analogy, most notably the space-time correlations of velocity, have been compared against direct measurements, and modified to better fit the observed data. These measurements have been extremely challenging for hot, high speed jets, and represent a sizeable investment in instrumentation development. As an intermediate check that the analysis is predicting the physics intended, phased arrays have been employed to measure source distributions for a wide range of jet cases. And finally, careful far-field spectral directivity measurements have been taken for final validation of the prediction code. Examples of each of these experimental efforts will be presented. The main result of these efforts is a noise prediction code, named JeNo, which is in mid-development. JeNo is able to consistently predict spectral directivity, including aft angle directivity, for subsonic cold jets of most geometries. Current development on JeNo is focused on extending its capability to hot jets, requiring inclusion of a previously neglected second source associated with thermal fluctuations. A secondary result of the intensive experimentation is the archiving of various flow statistics applicable to other acoustic analogies and to development of time-resolved prediction methods. These will be of lasting value as we look ahead at future challenges to the aeroacoustic experimentalist.
https://ntrs.nasa.gov/search.jsp?R=20070010450 2020-07-20T04:48:29+00:00Z
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
w.n
asa.
gov
Jet N
oise
Dia
gnos
tics
Sup
porti
ng S
tatis
tical
N
oise
Pre
dict
ion
Met
hods
Jam
es B
ridge
sA
cous
tics
Bra
nch
NA
SA
Gle
nn R
esea
rch
Cen
ter
Cle
vela
nd, O
H 4
4135
Pre
sent
ed a
t
10th
CEA
S-A
SC W
orks
hop
28/2
9 Se
ptem
ber,
2006
Scho
ol o
f Eng
inee
ring
Trin
ity C
olle
ge, D
ublin
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
62
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iona
l Aer
onau
tics
and
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e Ad
min
istra
tion
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asa.
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Ack
now
ledg
emen
ts
•W
ork
cont
aine
d he
rein
was
don
e in
col
labo
ratio
n w
ith–
Mar
k W
erne
t (P
IV)
–C
liff B
row
n (J
et n
oise
aco
ustic
s)–
San
g S
oo L
ee (P
hase
dar
rays
)–
Abb
as K
hava
ran
(Jet
noi
se p
redi
ctio
n)–
Nic
k G
eorg
iadi
s (C
FD)
–M
arv
Gol
dste
in(A
eroa
cous
tic th
eory
)–
The
staf
f of t
he A
eroA
cous
tic P
ropu
lsio
n La
b at
NA
SA
Gle
nn•
With
sup
port
of m
any
othe
r col
leag
ues!
10th
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-AS
C W
orks
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Oct
200
63
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iona
l Aer
onau
tics
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e Ad
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istra
tion
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Out
line
•A
cous
tic a
nalo
gies
and
sta
tistic
al p
redi
ctio
n m
etho
ds•
Ass
umpt
ions
and
mod
els
in s
tatis
tical
jet n
oise
cod
es•
Sta
tistic
al q
uant
ities
requ
ired
•A
dvan
ced
inst
rum
enta
tion
used
•Te
sts
and
resu
lts–
Flow
dia
gnos
tics
–A
cous
tic d
iagn
ostic
s–
Ove
rall
valid
atio
n–
Flig
ht te
sts
•P
redi
ctio
n co
de s
tatu
s
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orks
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200
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iona
l Aer
onau
tics
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e Ad
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istra
tion
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Aco
ustic
Ana
logi
es
•C
lass
ic e
xerc
ise
of a
pplie
d m
athe
mat
ics
•R
earr
ange
Nav
ier-
Sto
kes
equa
tions
of m
otio
n as
in
hom
ogen
eous
wav
e eq
uatio
n to
app
ly fa
mili
ar m
etho
ds o
f lin
ear a
cous
tics.
–N
eed
not b
e si
mpl
e w
ave
equa
tion
to b
e us
eful
.–
Man
y de
rivat
ions
/cho
ices
of v
aria
bles
(‘an
alog
ies’
) pos
sibl
e.•
Ugl
y R
HS
to b
etre
ated
as
‘equ
ival
ent s
ourc
e’–
Up
to h
ere
equa
tions
are
exa
ct--
no n
eed
for ‘
insi
ght’
•M
assi
ve s
impl
ifica
tion/
mod
elin
g do
ne to
RH
S to
mak
e pr
oble
m
tract
able
.–
Her
e’s
whe
re th
e an
alys
t nee
ds e
xper
imen
tal i
nsig
ht a
nd d
ata!
–S
tatis
tical
qua
ntiti
es w
hich
fall
out a
re v
ery
diffi
cult
to m
easu
re!
–Th
is is
whe
re c
hoic
e of
anal
ogy
impo
rtant
.
10th
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-AS
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orks
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Oct
200
65
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iona
l Aer
onau
tics
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e Ad
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istra
tion
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Rep
rese
ntat
ive
Der
ivat
ion
Lπ'≡
D Dt
D2
Dt2
−∂ ∂x
ic2
∂ ∂xi
⎡ ⎣ ⎢ ⎤ ⎦ ⎥ π
'+2c
2∂U ∂x
i
∂2 π'
∂x1∂
x i
Γ≡
D Dt∂ζ
i∂x
i−
2∂U ∂xi
∂ζi
∂x1
ζ i≡
∂(u i
uj)
∂xj
+γℜ
T'(
)∂π'
∂xi
Lπ'=
Γ,π
'≡(p
/p0)
(1/γ
)−
1
p=
p 0+
p',
v i=
δ i1U
(x2,
x 3)+
u i,
T=
T 0(x
2,x 3
)+T'
LΠ≅
D Dt∂2 (u
iuj)
∂xi∂
x j−
2∂U ∂xi
∂2 (uiu
j)∂x
i∂x j
,Π
≅p' γp
0
Flow
fiel
d:
Wav
e op
erat
or fo
rm:
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orks
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200
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iona
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Rep
rese
ntat
ive
Der
ivat
ion,
con
t’d
p2 ( x ,
y ,ω
)=G
* ( x ,
y −ξ
/2,ω
)G(
x , y +
ξ /2
,ω)
∫∫S(
y ,ξ ,
τ)eiω
τdτ
dξ
S ijk
l( y ,
ξ ,τ)
=u i
uj(
y − ξ /2
,t)u k
u l(
y + ξ /2
,t+
τ)(
y )
G(
x , y +
ξ /2
,ω) i
s the
Gre
en's
func
tion
for L
.
Far-
field
spe
ctra
l dire
ctiv
ity:
For c
old
jets
, the
key
qua
ntity
for m
odel
ing
the
sour
ce is
the
four
th
orde
r cor
rela
tion
mat
rix S
ijkl.
Ass
umin
g a
com
pact
sou
rce,
Mod
el S
,sol
ve fo
r the
Gre
en’s
func
tion,
and
inte
grat
e. S
impl
e!
p2 (
x , y ,ω
)=|G
|2(
x , y ,ω
)∫∫
S( y ,ξ ,
ω)d
ξ
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200
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iona
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e Ad
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Key
Ass
umpt
ions
/Mod
els
to b
e C
heck
ed
•C
ompa
ct s
ourc
e as
sum
ptio
n•
Mod
el o
f fou
rth-o
rder
two-
poin
t spa
ce-ti
me
corr
elat
ion
of v
eloc
ity•
Qua
si-n
orm
al a
ppro
xim
atio
n•
Turb
ulen
ce a
niso
tropy
mod
el•
Tim
e-an
d le
ngth
scal
es m
odel
s•
Acc
urac
y of
RA
NS
CFD
turb
ulen
ce m
odel
s•
Ass
umpt
ion
of n
eglig
ible
ent
halp
ic s
ourc
e•
Effe
ct o
f hea
t on
all a
bove
•E
ffect
of c
ompr
essi
bilit
y on
all
abov
e
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-AS
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orks
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200
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iona
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e Ad
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istra
tion
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Exp
erim
enta
l Tec
hnol
ogy
•Fa
cilit
ies
•Fl
ow D
iagn
ostic
s•
Aco
ustic
Dia
gnos
tics
•H
igh-
Fide
lity
Sim
ulat
ed F
light
•Fl
ight
Tes
ts
CFD PIV
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orks
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200
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iona
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e Ad
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tion
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Gle
nn A
eroA
cous
tics
Pro
puls
ion
Lab
(AA
PL)
Sm
all H
ot J
et A
cous
tic R
ig (S
HJA
R)
Low
-cos
t ope
ratio
n fo
r bas
ic
jet n
oise
exp
erim
ents
–3m
arc
mic
roph
one
arra
y, 4
5°-
165°
cove
rage
•20
0Hz
cuto
ff•
50dB
bac
kgro
und
–Si
ngle
stre
am je
t•
2.5
kg/s
up
to 8
60K
•1–
7 N
PR•
Mj,
T j/T
amb
±0.2
%–
Acou
stic
ally
cle
an fo
r 0.2
5 <
M
< 2
with
50m
m n
ozzl
e–
Full
seed
ing
capa
bilit
y fo
r flo
w
diag
nost
ics.
–A
mbi
ent c
ondi
tions
mon
itore
d to
with
in 0
.2K
, 1%
RH
–Ty
pica
l noz
zle
25m
m–7
5mm
10th
CE
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-AS
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orks
hop—
Oct
200
610
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iona
l Aer
onau
tics
and
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e Ad
min
istra
tion
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Flow
+Sou
nd D
atab
ase
Con
ditio
ns(A
ugm
ente
dTa
nna
Mat
rix)
AFAP
L-tr-
76-6
5 (L
ockh
eed-
Geo
rgia
)“T
he in
fluen
ce o
f tem
pera
ture
on
shoc
k-fre
e su
pers
onic
jet n
oise
”, JS
V 3
9 19
75
Vj/c
amb
Ts,j/Tamb
00.
51
1.5
22.
53
0.5 1
1.5 2
2.5 3
M=1
M=2
Col
d
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orks
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200
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iona
l Aer
onau
tics
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e Ad
min
istra
tion
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Gle
nn A
eroA
cous
tics
Pro
puls
ion
Lab
(A
AP
L) N
ozzl
e A
cous
tic T
est R
ig (N
ATR
)H
igh-
fidel
ity a
sses
smen
t of e
xhau
st
syst
ems
in fl
ight
with
dia
gnos
tics
–20
m ra
dius
ane
choi
c do
me
–14
m a
rc m
icro
phon
e ar
ray,
45°
-165
°co
vera
ge.
–D
ual f
low
eng
ine
sim
ulat
or•
Cor
e st
ream
9 k
g/s
up to
850
K•
Fan
stre
am 1
2kg
/s u
p to
390
K
–Fl
ight
sim
ulat
ion
0 <
M <
0.4
–20
0mm
typi
cal n
ozzl
e di
amet
er–
Full
seed
ing
capa
bilit
y fo
r flo
w
diag
nost
ics.
10th
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-AS
C W
orks
hop—
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200
612
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iona
l Aer
onau
tics
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e Ad
min
istra
tion
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Flow
Dia
gnos
tics
•P
artic
le Im
age
Vel
ocim
etry
–Fi
eld
of v
iew
–S
eedi
ng–
Res
olut
ion
–S
tere
o–
Stre
amw
ise,
Cro
ss-s
tream
U u’
CFD PIV
SFN
T200
0
Brid
ges
& W
erne
t, “T
urbu
lenc
e m
easu
rem
ents
of s
epar
ate
flow
no
zzle
s w
ith m
ixin
g en
hanc
emen
t fea
ture
s,”A
IAA
200
2-24
84
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-AS
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orks
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200
613
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iona
l Aer
onau
tics
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e Ad
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istra
tion
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Dua
l PIV
Sys
tem
Sch
emat
ic L
ayou
t
CP
U
PS
2P
S1
PS
1P
S2
21
Com
bust
or
Muf
fler
See
d in
ject
ion
Scr
eens
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iona
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e Ad
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Dua
l PIV
for S
pace
-Tim
e C
orre
latio
ns
Brid
ges
and
Wer
net“
Mea
sure
men
ts o
f the
A
eroa
cous
tic S
ound
Sou
rce
in H
ot J
ets”
AIA
A 2
003-
3130
:
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-AS
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orks
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iona
l Aer
onau
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e Ad
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tion
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Cro
ss-s
tream
Ste
reo
PIV
Brid
ges
& W
erne
t, “C
ross
-Stre
am P
IV M
easu
rem
ents
of J
ets
with
Inte
rnal
Lob
ed M
ixer
s,”A
IAA
200
4-28
96(2
004)
.
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orks
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iona
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e Ad
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Aco
ustic
Dia
gnos
tics
Nea
r-Fi
eld
Em
issi
on A
rray
*
RR
C P
olar
Cor
rela
tion
Arr
ay
Inte
rnal
Mod
e Pr
opag
atio
n A
rray
*3D
Pha
sed
Arr
ay*
1D P
hase
d A
rray
2D A
rray
at G
E E
ngin
e St
and
10th
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iona
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Val
idat
ing
Sou
rce
Mod
els
•M
odel
off
ourth
-ord
er tw
o-po
int s
pace
-tim
e co
rrel
atio
n of
vel
ocity
–Q
uasi
-nor
mal
app
roxi
mat
ion
–Tu
rbul
ence
ani
sotro
py m
odel
–M
odel
of s
econ
d-or
der t
wo-
poin
t spa
ce-ti
me
corr
elat
ion
of v
eloc
ity•
Tim
e-an
d le
ngth
scal
es m
odel
s•
Com
pact
sou
rce
assu
mpt
ion
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iona
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Mod
el o
ffou
rth-o
rder
two-
poin
t spa
ce-ti
me
corr
elat
ion
of v
eloc
ity•
Qua
ntity
of i
nter
est i
s
•Th
efo
urth
ord
er s
pace
-tim
e te
nsor
is o
ften
appr
oxim
ated
by
to u
se s
econ
d-or
der c
orre
latio
ns w
hich
can
be
deriv
ed fr
om s
impl
e tu
rbul
ence
mod
els,
suc
h as
thos
e of
Bat
chel
or:
•Q
uest
ions
:–
Is th
e qu
asi-n
orm
al a
ppro
xim
atio
n va
lid?
–A
re th
e se
cond
-ord
er c
orre
latio
n m
odel
s fo
r Rij
valid
?–
Wha
t are
the
mod
el c
oeffi
cien
ts (l
engt
hsca
le L
and
tim
esca
le T
)?
S ijk
l(y ,
ξ ,τ)
=u i
uj(
y −ξ
/2,t)
u ku l
(y +
ξ /2
,t+
τ)
S ijk
l=
u iu
juk'
u l'≈
u iu
ju k
'ul'
+u i
u k'u
jul'
+u i
u l'u
juk'
u iu
j'=
R ij(
ξ )g(
τ)=
u 12
f+ξ
′ f 2⎛ ⎝ ⎜
⎞ ⎠ ⎟ δij
−ξ i
ξj
′ f 2 ξ
⎡ ⎣ ⎢ ⎤ ⎦ ⎥ g
( τ),
f( ξ )
=e−π
ξ2 L2
g(τ)
=e−π
τ2
T2
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Qua
si-n
orm
al a
ppro
xim
atio
n
•C
ompa
re <
uuu’
u’>
to <
uu>
<u’u
’>
•App
roxi
mat
ion
not
valid
exc
ept n
ear ξ
=0.
•Mus
trem
ove
<uu>
fr
om e
ach
first
!
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Axi
sym
met
ric T
urbu
lenc
e M
odel
for S
econ
d O
rder
Cor
rela
tions
•A
n ax
isym
met
ric tu
rbul
ence
mod
el c
an b
e co
nstru
cted
whi
ch h
as a
n ex
pone
ntia
l co
re w
ith tw
o le
ngth
scal
e pa
ram
eter
s K
1, K
2
•W
e ch
oose
sin
gle-
pow
er e
xpon
ent f
orm
bec
ause
of s
uper
ior f
it to
dat
a:
˜ R 11
˜ R 22
ξ 1ξ 1
e−πξ2
K 12
e−πξ
K 1
e−πξ2
K 12
e−πξ
K 1
Q 1=
−u 1
2 2e−π
ξ 12
K 12
+ξ 2
2+ξ
32
K22
⎛ ⎝ ⎜ ⎜ ⎞ ⎠ ⎟ ⎟
;Δ
=K
2 K 1
10th
CE
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-AS
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orks
hop—
Oct
200
621
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iona
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onau
tics
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e Ad
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istra
tion
ww
w.n
asa.
gov
Spa
ce-T
ime
Cor
rela
tions
of V
eloc
ity D
atas
et
•D
ata
acqu
ired
at 5
axi
al
loca
tions
–x/
Dj =
2, 6
, 10,
16,
22
•D
ata
proc
esse
dfo
r 9 ra
dial
lo
catio
ns–
y/D
j =0,
±0.
25, ±
0.5,
±0.
75,
±1•
Dat
a ac
quire
d at
6 s
pace
-tim
e se
para
tions
, ant
icip
atin
g co
nvec
tion
velo
citie
s.•
Dat
aset
yie
lds
Ruu
, Rvv
, Ruv
fo
rξ 1
/Dj,
ξ 2/D
j, τU
/Dj
•C
an b
e m
ined
fort
urbu
lenc
e m
odel
s, c
onve
ctio
n ve
loci
ty,
leng
thsc
ales
, and
tim
esca
les.
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
622
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iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
w.n
asa.
gov
Inte
rpol
ated
2nd
ord
er, s
pace
-tim
e co
rrel
atio
n
Sig
nific
ance
of r
ippl
es in
tails
?
10th
CE
AS
-AS
C W
orks
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Oct
200
623
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iona
l Aer
onau
tics
and
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e Ad
min
istra
tion
ww
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gov
Ext
ract
ing
Tem
pora
l Cor
rela
tions
•M
inin
g th
e R
uu(ξ
,τ) f
orξ 2
= 0,
at d
iffer
ent ξ
1 pr
oduc
es ‘s
tand
ard’
(hot
-wire
)tem
pora
l cor
rela
tions
.•
Ma
= 0.
9 sh
own
at x
/Dj=
6, y
/Dj=
0.5
for
T j/T
∞=
0.84
.
•Ti
mes
cale
τ0
deriv
ed fr
om fi
tting
pea
ks o
f Ruu
to e
xp(-τ
/τ0)
τU/D
Ruu
02
4
0
0.51
ξ/D
=0ξ/
D=0
.2ξ/
D=0
.4ξ/
D=0
.6ξ/
D=0
.8ξ/
D=1
.0ξ/
D=1
.5ξ/
D=2
.0ξ/
D=3
.0
Ma=
0.9,
Ts/T
∞=.
084
x/D
=6,y
/D=0
.5
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
624
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iona
l Aer
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tics
and
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e Ad
min
istra
tion
ww
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Ext
ract
ing
Spa
tial C
orre
latio
ns—
Axi
al
•M
inin
g R
uu(ξ
,τ) f
orξ 2
= 0,
at d
iffer
ent τ
prod
uces
spa
tial
corr
elat
ions
.•
Ma
= 0.
9 sh
own
at x
/Dj=
6, y
/Dj=
0.5
for
T j/T
∞=
0.84
.
•Le
ngth
scal
e L u
u,x
obta
ined
by
inte
grat
ing
Ruu
(ξ1;
ξ 2=0
, τ=0
) ov
er ξ
1
ξ 1/D
Ruun
-20
24
6
0
0.51
τU
/D=0
.0τ
U/D
=0.2
7τ
U/D
=0.6
8τ
U/D
=1.3
6τ
U/D
=2.7
3τ
U/D
=6.8
1
Ma=
0.9,
TTr=
1.0
x/D
=6,y
/D=0
.5
10th
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-AS
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orks
hop—
Oct
200
625
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iona
l Aer
onau
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and
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e Ad
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istra
tion
ww
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Par
amet
ers
of T
wo-
Poi
nt C
orre
latio
n M
odel
s
•Le
ngth
scal
es, t
imes
cale
s
10th
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orks
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Oct
200
626
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
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Com
pact
Sou
rce
Ass
umpt
ion
•In
tegr
al L
engt
hsca
le L
uux,
prop
ortio
nal t
o le
ngth
of s
igni
fican
t co
rrel
atio
n: ro
ughl
y fa
ctor
of 5
.•
Wav
elen
gth
to c
orre
latio
n le
ngth
λ/L
~ τ
/(5L u
uxM
)
Ruu
Rvv
ξ 1L uux
=R u
udξ
∫=
0.2
L vvx
=R v
vdξ
∫=
0.1
10th
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-AS
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orks
hop—
Oct
200
627
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iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
w.n
asa.
gov
Sou
rce
Com
pact
ness
Est
imat
ion
•W
avel
engt
h to
cor
rela
tion
leng
th λ
/L ~
τ/(5
L uux
M)
•M
=0.9
, col
dλ/
L in
the
rang
e of
2 is
not
a c
ompa
ct s
ourc
e!
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
628
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
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asa.
gov
Val
idat
ing
Pro
paga
tion
•U
nder
stan
ding
impa
ct o
f jet
asy
mm
etry
•W
hen
can
inte
gran
ds b
e si
mpl
ified
to p
rodu
ce 2
.5-D
app
roac
h?•
Mea
sure
azi
mut
hal v
aria
tion
of s
ound
fiel
d fo
r jet
plu
mes
with
va
rious
low
-ord
er a
zim
utha
l fea
ture
s.•
Use
d S
MC
-ser
ies
chev
ron
nozz
les
–S
MC
002
(4 c
hevr
ons)
–S
MC
004
(5 c
hevr
ons)
–S
MC
001
(6 c
hevr
ons)
•Te
sted
ove
r ran
ge o
f sub
soni
c co
ld c
ondi
tions
, 0.5
< M
a <
0.9
•A
zim
utha
l var
iatio
ns a
ccom
plis
hed
by ro
tatio
n of
noz
zle
on ri
g.
f=0°
is a
long
che
vron
tip.
•P
lots
of D
SP
L =
SP
L(f)-
SP
L(0°
).
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
629
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iona
l Aer
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and
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e Ad
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istra
tion
ww
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Set
poin
t 7 (M
a=0.
9), S
MC
002
(4 c
hevr
ons)
St D
DSPL
10-1
100
101
-4-3-2-101
1100
-00�
1129
-07.
5�11
15-1
5�11
38-2
2.5�
1122
-30�
1146
-37.
5�11
07-4
5�
SM
C00
2(4
chev
rons
)S
P7
φ=
90�
rdg-
azim
uth
St D
DSPL
10-1
100
101
-4-3-2-101
1100
-00�
1129
-07.
5�11
15-1
5�11
38-2
2.5�
1122
-30�
1146
-37.
5�11
07-4
5�
SM
C00
2(4
chev
rons
)S
P7
φ=
150�
rdg-
azim
uth
0°
45°
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
630
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
w.n
asa.
gov
Set
poin
t 7 (M
a=0.
9), S
MC
004
(5 c
hevr
ons)
St D
DSPL
10-1
100
101
-4-3-2-101
1312
-00�
1201
-18�
1223
-36�
SM
C00
4(5
chev
rons
)S
P7
φ=
90�
rdg-
azim
uth
St D
DSPL
10-1
100
101
-4-3-2-101
1312
-00�
1201
-18�
1223
-36�
SM
C00
4(5
chev
rons
)S
P7
φ=
150�
rdg-
azim
uth
0° 36°
10th
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orks
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Oct
200
631
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iona
l Aer
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tics
and
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e Ad
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istra
tion
ww
w.n
asa.
gov
Set
poin
t 7 (M
a=0.
9), S
MC
001
(6 c
hevr
ons)
St D
DSPL
10-1
100
101
-4-3-2-101
1168
-00�
1176
-15�
1184
-30�
1192
-60�
SM
C00
1(6
chev
rons
)S
P7
φ=
90�
rdg-
azim
uth
St D
DSPL
10-1
100
101
-4-3-2-101
1168
-00�
1176
-15�
1184
-30�
1192
-60�
SM
C00
1(6
chev
rons
)S
P7
φ=
150�
rdg-
azim
uth
0° 60°
10th
CE
AS
-AS
C W
orks
hop—
Oct
200
632
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
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asa.
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1D P
hase
d A
rray
•O
ne-d
imen
sion
al, n
onlin
early
spa
ced
phas
ed a
rray
•8–
24 fl
ush
mou
nt m
icro
phon
es
St
X/D
Ma=
0.7
Ma=
0.7
•Lee
& B
ridge
s, “P
hase
d-ar
ray
Mea
sure
men
ts o
f Sin
gle
Flow
Hot
Jet
s,”A
IAA
2005
-284
2
10th
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orks
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Oct
200
633
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iona
l Aer
onau
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and
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e Ad
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istra
tion
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Jet N
oise
Und
erst
andi
ngM
appi
ng 3
D A
cous
tic S
ourc
e D
ensi
ty•
GR
C/S
HJA
R F
ebru
ary
2004
•80
mic
roph
one
arra
y•
Bet
ter p
oint
repo
nse
func
tion
than
D
ough
erty
/Hon
eyw
ell
arra
y.•
Res
ults
from
co
nven
tiona
l be
amfo
rmin
g co
nfus
ing-
-app
aren
t so
urce
s lo
cate
d ou
tsid
e th
e je
t at l
ow
frequ
enci
es!
10th
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orks
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200
634
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iona
l Aer
onau
tics
and
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e Ad
min
istra
tion
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Jet N
oise
Sou
rce
Den
sity
—P
hase
d A
rray
Pre
dict
ion
Pha
sed
Arr
ay
M=0
.9, c
old,
90°
obse
rver
•C
onvo
lve
pred
icte
d so
urce
dis
tribu
tion
thro
ugh
phas
ed a
rray
‘fi
lter’
for a
pple
s-ap
ples
com
paris
on o
f aco
ustic
sou
rce
stre
ngth
.
10th
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orks
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Oct
200
635
Nat
iona
l Aer
onau
tics
and
Spac
e Ad
min
istra
tion
ww
w.n
asa.
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Val
idat
ing
RA
NS
CFD
•M
ean
velo
citie
s, te
mpe
ratu
res
•TK
E, d
issi
patio
n•
Ran
ge o
f M, T
, geo
met
ries
10th
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-AS
C W
orks
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200
636
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iona
l Aer
onau
tics
and
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e Ad
min
istra
tion
ww
w.n
asa.
gov
Bas
elin
e D
ata
for C
FD/C
AA
val
idat
ion—
Flow
Sta
ts•
Obj
ectiv
e: T
urbu
lent
flow
sta
tistic
s fo
r RA
NS
val
idat
ion 0 3
01
2Vj
et/C
amb
Hav
e al
l sta
tistic
s ne
eded
for j
et n
oise
U/U
j
V/U
j
TKE/
Uj2
v2 /u2
L 11/D
j
L 11/
L 12
τ 1U
j/D
j
τ 2/τ
1
10th
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orks
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200
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iona
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onau
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e Ad
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istra
tion
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Bas
elin
e D
ata
for C
FD/C
AA
val
idat
ion—
Turb
ulen
t Kin
etic
Ene
rgy
0 3
02
Vje
t/Cam
b
Dat
aset
sho
ws
impa
ct o
f tem
pera
ture
, co
mpr
essi
bilit
y on
turb
ulen
ce s
tatis
tics.
10th
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-AS
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orks
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200
638
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iona
l Aer
onau
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and
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e Ad
min
istra
tion
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WIN
D; V
aria
ble
Diff
usio
n k−
ε
DA
TA
WIN
D; S
ST
DA
TA
Turb
ulen
t Kin
etic
Ene
rgy
Ma=
0.9,
col
d
Eva
luat
ing
RA
NS
Tur
bule
nce
Mod
els
for J
ets
•B
ig p
robl
em fo
r tur
bule
nce
mod
els
in je
ts is
that
inst
abili
ties
whi
ch d
rive
turb
ulen
ce c
hang
e fro
m 2
D s
hear
laye
r mod
es to
3D
co
lum
nar m
odes
. •
Mod
els
mus
t be
awar
e of
geo
met
ry.
•V
aria
ble
Diff
usio
n k-
eps
mod
el is
one
atte
mpt
.
Pote
ntia
l cor
e le
ngth
crit
ical
!
10th
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orks
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200
639
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iona
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e Ad
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istra
tion
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Fina
l Val
idat
ion
ofS
pect
ral D
irect
ivity
•R
ig D
epen
denc
e•
Err
or a
naly
sis
–U
ncer
tain
ty in
mea
surin
g at
mos
pher
ic c
ondi
tions
whi
ch fe
ed th
e ca
lcul
atio
n of
atm
osph
eric
atte
nuat
ion
•~0
.1dB
, giv
en th
e m
easu
rem
ent u
ncer
tain
ty o
f 0.5
K, 2
% re
lativ
e hu
mid
ity–
Unc
erta
inty
in s
etpo
int
•0.
17dB
by
hold
ing
0.5%
tole
ranc
e on
the
jet v
eloc
ity
–U
ncer
tain
ty in
spe
ctra
l est
imat
ion
•0.
33dB
at l
ow th
ird-o
ctav
e ba
nds
(St <
0.0
5).
–U
ncer
tain
ty in
pis
tonp
hone
cal
ibra
torB
&K
422
0•
0.15
dB–
Mic
roph
one
hold
er re
flect
ion
•0.
2dB
from
aut
ocor
rela
tion
mea
sure
men
ts•
But
repe
atab
le to
with
in 0
.2dB
!
10th
CE
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orks
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Oct
200
640
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iona
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onau
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and
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e Ad
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istra
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Jet N
oise
Spe
ctra
l Dire
ctiv
ity
Pol
ar a
ngle
s fro
m p
ilot P
OV
!90
°, 1
50°
repr
esen
tativ
e
10th
CE
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C W
orks
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200
641
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iona
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onau
tics
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e Ad
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istra
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Bas
elin
e D
ata
for C
FD/C
AA
val
idat
ion
—Fa
r-fie
ld A
cous
tics
•O
bjec
tive:
Ver
ified
far-
field
jet n
oise
dat
abas
e, in
depe
nden
t of
faci
lity
•N
ote
depe
nden
ce o
n fa
r-fie
ld c
ondi
tion!
φ=90
°φ=
150°
Freq
uenc
y (S
trouh
al)
Freq
uenc
y (S
trouh
al)
X/D
X/D
X/D
Mj=
0.9,
col
d, n
orm
aliz
ed, l
ossl
ess
Far-
field
inva
riant
r/D
>50
8
100
8
100
10th
CE
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C W
orks
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200
642
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iona
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e Ad
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istra
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Effe
cts
of S
cale
, Ups
tream
Noz
zle
Geo
met
ry•
SH
JAR
rig
nois
e do
cum
ente
d,–
Wel
l bel
ow th
is d
ata.
•V
aria
tions
foun
d du
e to
no
zzle
det
ails
.–
Rey
nold
s nu
mbe
r de
pend
ence
–S
tate
of t
urbu
lenc
e in
exi
t bo
unda
ry la
yer!
–C
ontra
ctio
n ra
tio–
Con
tract
ion
rate
–Le
ngth
of c
ontra
ctio
nS
t DSPL(dB)
10-1
100
101
6570758085
Tann
aA
FAP
LV
ishy
JFM
St D
SPL(dB)10
-110
010
1
6570758085
Tann
aA
FAP
LV
ishy
JFM
SH
JAR
SM
C00
0
St D
SPL(dB)10
-110
010
1
6570758085
Tann
aA
FAP
LV
ishy
JFM
SH
JAR
SM
C00
0S
HJA
RA
RN
2S
HJA
RA
RN
3
10th
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200
643
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Com
paris
on w
/ Tan
na D
ata
for H
ot J
ets
150°
90°
150°
90°
150°
90°
Vj/c
amb=
0.5
150°
90°
150°
90°
150°
90°
Vj/c
amb=
0.9
All d
ata:
third
-oct
ave,
loss
less
, r/D
j=40
Trat
io=0
.86
Trat
io=1
.76
Trat
io=2
.27
Tann
a
SH
JAR
10th
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iona
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Flig
ht T
ests
10th
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iona
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Che
vron
ben
efit
com
paris
on—
PN
L
NA
TRLe
arje
t
Nic
e ag
reem
ent m
odel
to fu
ll sc
ale!
10th
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-AS
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orks
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200
646
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iona
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e Ad
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istra
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Che
vron
ben
efit
com
paris
on—
SP
L at
pea
k P
NL
NA
TRLe
arje
t
Pas
sabl
e re
cogn
ition
of s
pect
ral b
enef
it.
10th
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-AS
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orks
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200
647
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iona
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Pro
blem
with
Fre
ejet
Cor
rect
ion
in S
mal
l Sca
leS
ourc
e D
istri
butio
n A
ssum
ptio
n
Issu
es w
ith p
roje
ctin
g to
flig
ht a
t ang
les
near
jet a
xis.
10th
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orks
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200
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iona
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MG
BK
: A L
illey
-Bas
ed A
nalo
gy•
Ligh
thill
’s o
rigin
al a
nalo
gyca
st e
quat
ions
as
sim
ple
wav
e eq
uatio
n•
Lille
y pr
opos
ed a
ccou
ntin
g fo
r con
vect
ive
char
acte
r of s
ourc
e in
to w
ave
oper
ator
.•
In 1
976,
Man
i-Glie
be-B
alsa
cre
ated
aje
t noi
se p
redi
ctio
n co
de
whi
ch u
sed
this
app
roac
h (M
GB
)–
Man
y as
sum
ptio
ns re
gard
ing
para
llel f
low
, sou
rce
com
pact
ness
.–
Man
y m
odel
s of
turb
ulen
t qua
ntiti
es, s
uch
as s
pace
-tim
e co
rrel
atio
nm
atrix
–A
naly
tic a
sym
ptot
ic s
olut
ion
to G
reen
’s fu
nctio
n fo
r sol
utio
n.–
Crit
ical
mea
n an
d tu
rbul
ence
info
from
sem
i-ana
lytic
al m
odel
for
roun
d je
t.•
In 1
989,
Kha
vara
n an
d K
rejs
a (N
AS
A G
lenn
) pic
ked
up th
e M
GB
cod
e an
d be
gan
by s
ubst
itutin
g C
FD s
olut
ions
for m
ean
and
turb
ulen
ce fi
elds
for t
he s
emi-a
naly
tical
sol
utio
n us
ed
befo
re.
10th
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-AS
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orks
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200
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iona
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MG
BK
to J
eNo:
Wha
t Cha
nged
?•
Rea
listic
two-
poin
t spa
ce-ti
me
corr
elat
ion
mod
el.
•A
ccou
ntin
g fo
r non
-com
pact
sou
rces
.
•A
ccur
ate
refra
ctio
n by
adj
oint
Gre
en’s
func
tion.
---f
=G
auss
ian
f: E
xpon
entia
lM
easu
rem
ents
, Bri
dges
et a
l.
λ
10-1
100
10-3
10-2
10-1
100
/λ
N
dx1
(m)
00.
050.
1
01(a
)
Ruu
’
ξ
10th
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iona
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Goo
d pr
edic
tion
of c
old
jet n
oise
sp
ectra
at 9
0°
…an
d at
aft
angl
es!
JeN
oM
GB
K
Ma=
0.9
cold
(Tan
na S
P7)
JeN
o v1
.0
•V
alid
ate
all a
ssum
ptio
ns a
nd m
odel
s in
aco
ustic
ana
logy
cod
e.•
Res
ult:
Impr
ovem
ents
in p
redi
ctio
n co
de s
o su
bsta
ntia
l it
war
rant
s a
new
nam
e—Je
No
10th
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iona
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JeN
o v1
.0 S
tatu
s—N
ov 2
005
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10th
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orks
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200
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iona
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Sum
mar
y
•E
xper
imen
tal D
iagn
ostic
s ha
vepl
ayed
crit
ical
role
–un
ders
tand
ing
jet n
oise
phy
sics
,–
guid
ing
pred
ictio
n co
de d
evel
opm
ent,
–ch
ecki
ng a
ssum
ptio
ns–
feed
ing
mod
el d
evel
opm
ent
–gi
ving
insi
ght i
nto
nois
e re
duct
ion
conc
epts
•Fu
ture
Cha
lleng
es–
Tem
pera
ture
spe
ctra
for s
tatis
tical
mod
els
–In
itial
con
ditio
n sp
ecifi
catio
n fo
r LE
S–
Ref
ract
ion,
Diff
ract
ion,
Impi
ngem
ent