near-field pressure signature prediction by jaxa...near-field pressure signature prediction by jaxa...
TRANSCRIPT
-
Near-field Pressure Signature Prediction
by JAXA
Hiroaki ISHIKAWA (ASIRI)
Yoshikazu MAKINO (JAXA)
Atsushi UENO (JAXA)
Yohei KASUGA (University of Tokyo)
-
Outline
I. Summary of cases analyzed
II. Flow solver / Computing platform Flow solver (TAS)
Computing platform : JSS2
III. JWB Design method and Wind tunnel test schedule
Flow solver convergence
Limiter function
Results
IV. AXIE
V. C25D
VI. Comparison AXIE, JWB, C25D
VII. Conclusion
-
Summary of cases analyzed
Model Providor viscousity meshmixed 2.56 2 1.6 1.28 1
tetrahedra 2.56 2 1.6 1.28 1jwb SBPW inviscid tetrahedra 1 0.83 0.7
mixed 2 1.6 1.28 1 0.8 0.64tetrahedra 2 1.6 1.28 1 0.8
Grid Spacing(Resolution)
axie
c25d-flowthru
SBPW
SBPW
inviscid
inviscid
axie
C25D
JWB
Propagation (optional) analysis are carried out for above cases.
-
Flow solver/Computing Platform
Solver TAS
Tohoku university Aerodynamic Simulation
developer Tohoku university & JAXA
Mesh Unstructured mesh
cell-vertex finite volume
discretization scheme HLLEW
spatial accuracy 2nd order
limiter function Venkatakrishnan
time integration LU-SGS implicit method
Equation Euler
CFD solver
Computing PlatformJSS2 SORA-MA- JAXA Supercomputer System generation 2
- Fujitsu Supercomputer PRIMEHPC FX100
- Architecture: Scalar machine
- Processor Type = SPARC64 Xlfx (32 cores/node)
- Nodes/System = 3,240 nodes
- Memory/Node = 32GiB
- Memory/System = 101.25TiB
- Peak Performance = 3.495 PFLOPS
3-400 processors x 2-3.5h for SBPW2
Propagation(Optional) Xnoise : Burgers equation MPnoise : Multi-pole method
Boom metre : Loudness estimation
Details will be presented by Knamori
(tommrrow).
-
JWB
viscousity meshinviscid tetrahedra 1 0.83 0.7
Grid Spacing(Resolution)
-
JAXA Wing Body (JWB) designed
• Step 1; Equivalent area (AE) based optimization– Euler analysis to evaluate lift component of equivalent area.
– Free-form deformation (FFD) to optimize body shape.
• Step 2; Reversed equivalent area (AE,r) based optimization– Euler analysis to evaluate near-field pressure distribution.
– Multi-pole analysis to consider pressure propagation in circumferential direction.
AE_lift
AE_volume
pole08
pole12pole16
pole20pole24Input
-20 0 20 40 60 80 100-0.04
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
Multi-pole analysisEuler analysis
Euler analysis
AE
AE,r
-
JAXA Wing Body (JWB) designed
0 4 8 12 16 20 24 28 32 36 40
1
2
3
4
• Optimization of body shape to meet NASA 25D
– Wing was fixed. AE optimized shape
FFD
Euler analysis
End
No
Yes
Yes
NoMeet target
AE,r?
Multipole analysis
AE,r
Meet target
AE_body?
Target AE_body
Target AE,r
Xs [m]
Re
ve
rse
d e
qu
iva
len
t a
rea
[m
2]
NASA 25DTarget AE_body
Initial AE_body
Initial shape
Designed shape
-
JAXA Wing Body (JWB) designed
0 4 8 12 16 20 24 28 32 36 40
1
2
3
4
5
Boom signature at ground
Time [ms]
Ove
rpre
ssu
re (
RF
=1.9
) [p
sf]
h=15,760m
Equivalent area
Xs [m]
Re
ve
rse
d e
qu
iva
len
t a
rea
[m
2]
75.1 PLdB; NASA 25D
84.7 PLdB; AE optimized
78.9 PLdB; AE,r optimized
-20 0 20 40 60 80 100 120 140-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
-
Wind tunnel test
Wind Tunnel Testing will be held in 2 weeks.
-
-0.006
-0.003
0
0.003
0.006
-10 0 10 20 30 40 50 60 70 80
DP
/Pin
f
X(m)
10003000500070009000
H/L=2.55, f=0deg
-0.012
-0.008
-0.004
0
0.004
0.008
0.012
-10 0 10 20 30 40 50 60 70 80
DP
/Pin
f
X(m)
10003000500070009000
H/L=0.85, f=0deg
0.90
0.92
0.94
0.96
0.98
1.00
1.02
1.04
1.E-13
1.E-11
1.E-09
1.E-07
1.E-05
1.E-03
1.E-01
1.E+01
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
D/D
fin
al
Re
sid
ua
l
Iteration
Residual
D/Dfinal
Flow solver convergence
9000
converged
7000-9000
converged
-
Limiter Function
Venkatakrishnan limiter (AIAA 93-080)
DDDD
DDDD
D
222
222
2/12
21
i
32 D K
where is an average grid size and K is a constant (limiter factor).D
Low
High
High
Low
K Stability Accuracy Provided data
1 JWB
0.1
0.01 C25D
0.001 AXIE
Limiter factor, K
-
Limiter Function
K=1.0 0.1 0.01 0.001
Different
-
Limiter Function :K=1.0
-
Limiter Function :K=0.1
-
Limiter Function :K=0.01
-
Limiter Function :K=0.001
-
Limiter Function
K=0.001K=0.01K=0.1K=1
-0.006
-0.004
-0.002
0
0.002
0.004
0.006
-20 0 20 40 60 80 100
DP
/Pin
f
X(m)
K=0.001
K=0.01
K=0.1
K=1
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
Time, msec
K=0.001
K=0.01
K=0.1
K=175
76
77
78
79
80
81
0.001 0.01 0.1 1
SP
L, P
Ld
B
Limiter factor: K
Near Field (H/L=2.55)
Ground Signature Loudness
Front shocks same
Aft shocks different
K=0.001 blunt
K=1 is sharp and same as K=0.1
K=1 is used for JWB simulation.
-
Near field
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=0.85, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=0.85, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=0.85, f=50deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=2.55, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=2.55, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50 60
DP
/Pin
f
X(m)
100
083
070
H/L=2.55, f=50deg
Grid dependency is not observed among 100 – 070.
f=0 1020
30
H/L
=2
.55
H/L
=0
.85
-
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=0.85
H/L=2.55
070, f=10deg
Ground & Loundness
100083070
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
a
X(m)
100
083
070
H/L=0.85, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
100
083
070
H/L=0.85, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
100
083
070
H/L=0.85, f=50deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
100
083
070
H/L=2.55, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
100
083
070
H/L=2.55, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
100
083
070
H/L=2.55, f=50deg
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
100, H/L=0.85 083, H/L=0.85 070, H/L=0.85
100, H/L=2.55 083, H/L=2.55 070, H/L=2.55
Ground Signature
Loudness
f=0 1020
30
H/L
=2
.55
H/L
=0
.85
-
AXIE
Model Providor viscousity mesh
mixed 2.56 2 1.6 1.28 1
tetrahedra 2.56 2 1.6 1.28 1
Grid Spacing(Resolution)
axie SBPW inviscid
-
Limiter Factor, K=0.1
Oscillations
-
Limiter Factor, K=0.05
Oscillations
-
Limiter Factor, K=0.01
-
Limiter Factor, K=0.001
Oscillations disappear.
K=0.001 is used for AXIE.
-
axie-inv-mixed-256, K=0.1
Provided mesh
Better for TAS code
TAS code is sensitive for mesh quality.
C25D viscous and powered could not be solved using provided grid from SBPW2.
-
Near Field Propagation
Grid spacing is changed.
Cut the Near-field signature.
Propagate
Ground level
sonic boom
1.7L(0.12sec)
-
256200160128100
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=1, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=3, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=5, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=1, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=3, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=5, f=0deg
256200160128100
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=1, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=3, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
256 200
160 128
100
H/L=5, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=1, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=3, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=5, f=0deg
Near-field & Ground (f=0deg)
Mixed
Near-field Ground
TetraNear-field Ground
H/L
=1
H/L
=3
H/L
=5
Mixed series have similar characteristics as Tetra series.
-
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=1, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=3, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
X(m)
256 200160 128100
H/L=5, f=0deg
10
15
20
0 10 20 30
DP, P
a
X(m)
256 200160 128100
H/L=1, f=0deg
10
15
20
0 10 20 30
DP, P
a
X(m)
256 200160 128100
H/L=3, f=0deg
10
15
20
0 10 20 30
DP, P
a
X(m)
256 200160 128100
H/L=5, f=0deg
AXIE-mixed
100-160 are almost same. converged128-160 are almost same.
But 100 is different.
H/L=1 H/L=3 H/L=5
-
AXIE-mixed : 100 vs 128
mixed-100 mixed-128
Oscillations appear again even at K=0.001.
-
Loudness of AXIE
70
75
80
85
90
0.5 1 1.5 2 2.5 3
SP
L, P
Ld
B
Grid spacing
mixed, H/L=1 mixed, H/L=3 mixed, H/L=5
tetra, H/L=1 tetra, H/L=3 tetra, H/L=5
100 128 160200
256
100-160 are almost same. converged
almost same
-
C25D (Flow through)
Model Providor viscousity meshmixed 2 1.6 1.28 1 0.8 0.64
tetrahedra 2 1.6 1.28 1 0.8
Grid Spacing(Resolution)
c25d-flowthru SBPW inviscid
-
Near field: mixedH
/L=
1H
/L=
3H
/L=
5
f=010
20
30
40
50
200160128100080064
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=1, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=1, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=1, f=50deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 080
H/L=3, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=3, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=3, f=50deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=5, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=5, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080 064
H/L=5, f=50deg
H/L
=1
H/L
=3
H/L
=5
f=0(deg) f=30(deg) f=50(deg)
-
Near field: tetraH
/L=
1H
/L=
3H
/L=
5
f=010
20
30
40
50
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=1, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=1, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=1, f=50deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=3, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=3, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=3, f=50deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=5, f=0deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=5, f=30deg
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
-10 0 10 20 30 40 50
DP
/Pin
f
X(m)
200 160
128 100
080
H/L=5, f=50deg
H/L
=1
H/L
=3
H/L
=5
f=0(deg) f=30(deg) f=50(deg)
-
Ground: mixedH
/L=
1H
/L=
3H
/L=
5
f=010
20
30
40
50
200160128100080064
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
a
X(m)
200 160
128 100
080 064
H/L=1, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=1, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=1, f=50deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 080
H/L=3, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=3, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=3, f=50deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=5, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=5, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080 064
H/L=5, f=50deg
H/L
=1
H/L
=3
H/L
=5
f=0(deg) f=30(deg) f=50(deg)
-
Ground: tetraH
/L=
1H
/L=
3H
/L=
5
f=010
20
30
40
50
200160128100080
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
a
X(m)
200 160
128 100
080
H/L=1, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=1, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=1, f=50deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=3, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=3, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=3, f=50deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=5, f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=5, f=30deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP
, P
a
X(m)
200 160
128 100
080
H/L=5, f=50deg
H/L
=1
H/L
=3
H/L
=5
f=0(deg) f=30(deg) f=50(deg)
-
Loudness : Grid dependencyH
/L=
1H
/L=
3H
/L=
5
f=010
20
30
40
50
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
064
from H/L=3
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
064
from H/L=5
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
064
from H/L=1
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
from H/L=1
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
from H/L=3
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
200
160
128
100
080
from H/L=5
Mixed Tetra
-
Loudness : Extracted position
70
75
80
85
90
0 10 20 30 40 50 60
SP
L,
PL
dB
f, deg
from H/L=1
from H/L=3
from H/L=5
70
75
80
85
90
0 10 20 30 40 50 60
SP
L,
PL
dB
f, deg
from H/L=1
from H/L=3
from H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=1
H/L=3
H/L=5
f=0deg
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=1
H/L=3
H/L=5
f=0deg
Coarse mesh (200) Fine mesh (100)Loudness Loudness
Ground signature Ground signature
-
Model Providor viscousity meshmixed 2.56 2 1.6 1.28 1
tetrahedra 2.56 2 1.6 1.28 1jwb SBPW inviscid tetrahedra 1 0.83 0.7
mixed 2 1.6 1.28 1 0.8 0.64tetrahedra 2 1.6 1.28 1 0.8
Grid Spacing(Resolution)
axie SBPW inviscid
c25d-flowthru SBPW inviscid
Multi-pole + Burgers
-
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=1
H/L=3
H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
aX(m)
H/L=0.85
H/L=2.55
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
a
X(m)
H/L=1
H/L=3
H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=1
H/L=3
H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
H/L=0.85
H/L=2.55
Ground signature
AXIE
Multi pole & Burgers
Burgers only
C25D JWBBurgers only Burgers only
Multi pole & Burgers
-
BergersMultiPole+Bergers
70
75
80
85
90
0 1 2 3 4 5 6
SP
L, P
Ld
B
H/L
Bergers
70
75
80
85
90
0 1 2 3 4 5 6
SP
L, P
Ld
B
H/L
Bergers
MultiPole+Bergers
70
75
80
85
90
0 1 2 3 4 5 6
SP
L, P
Ld
B
H/L
Bergers
MultiPole+Bergers
MP+B, H/L=5
B, H/L=0.85B,H/L=2.55MP+B, H/L=0.85MP+B,H/L=2.55
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150D
P, P
a
X(m)
B, H/L=1
B, H/L=3
B, H/L=5
MP+B, H/L=1
MP+B, H/L=3
MP+B, H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
B, H/L=1
B, H/L=3
B, H/L=5
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150
DP, P
a
X(m)
B, H/L=0.85
B,H/L=2.55
MP+B, H/L=0.85
MP+B,H/L=2.55
Multi-Pole & Burgers
AXIE
Loudness Loudness
Ground signature
C25D JWBGround signature Ground signature
Loudness
-
AXIE vs C25D vs JWB
-
70
75
80
85
90
0 10 20 30 40 50 60
SP
L, P
Ld
B
f, deg
AXIEC25D-flo.JWB
-20
-15
-10
-5
0
5
10
15
20
-50 0 50 100 150 200
DP, P
a
Time, msec
AXIE
C25D-flo.
JWB
All Models
-0.006
-0.004
-0.002
0
0.002
0.004
0.006
120 130 140 150 160 170
DP
/Pin
f
X(m)
AXIE
C25D-flo.
JWB
Near Field (H/L=3 of C25D)
Ground Signature (f=0deg)
Loudness
Viscosity : inviscid
Mesh : Tetra
Resolution
AXIE : 100
C25D : 080
JWB : 070
Near field, Z= -99m
AXIE : H/L=3
C25D : H/L=3
JWB : H/L=2.55
f=0 10 2030
4050deg
-
Conclusion
• Analyzed cases
- AXIE, JWB, C25D(flow-thorough)
• Limiter function
Limiter function is related to sharpness of near field pressure signature.
Venkatakrishunan limiter : limiter factor;K=1.0, 0.1, 0.01, 0.001
K=0.01 – 1 are almost same results.
Limiter factor(K) is changed if unexpected oscillation is observed.
• Mesh type
Mixed and Tetra has similar characteristics.
•Mesh resolution
AXIE: 100-160 are almost same.
JWB : 070-100 are almost sane.
C25D : 064-100 are almost same.
• 3 models
It is found that JWB has similar to the low-boom effect of the C25D.