these simulation numerique et modelisation de l'ecoulement autour ...

LES of a bi-periodic turbulent flow with effusion 13
12
10
a
12
10
b
8
8
y/d
6
4
y/d
6
4
2
2
0
0
0.0
0.2
0.4
0.6
0.8
1.0
0.00
0.05
0.10
0.15
0.20
12
10
< U > /V j
c
12
10
< V > /V j
d
8
8
y/d
6
4
y/d
6
4
2
2
0
0.00
0.04 0.08 0.12
u rms/V j
0.16
0
0.00
0.04 0.08
v rms/V j
Figure 6. Velocity profiles from the 1-hole ( , Run B) and the 4-hole ( , Run D)
computations at position (d) in figure 9 (viz. in between two consecutive holes in the spanwise
or streamwise direction): (a): time averaged streamwise velocity, (b): time averaged normal
velocity, (c): RMS of streamwise velocity, (d): RMS of normal velocity.
0.12
0.16
12
10
a
12
10
b
8
8
y/d
6
4
y/d
6
4
2
2
0
0
0.0
0.2
0.4
0.6
0.8
-40x10 -3 -20 0 20
12
10
< U > /V j
c
12
10
< V > /V j
d
8
8
y/d
6
4
y/d
6
4
2
2
0
0.00
0.04 0.08
u rms/V j
0.12
0
0
10
20 30
v rms/V j
Figure 7. Velocity profiles from the 1-hole ( , Run B) and the 4-hole ( , Run D)
computations at position (e) in figure 9 (x = 0, z = −1.5 d): (a): time averaged streamwise
velocity, (b): time averaged normal velocity, (c): RMS of streamwise velocity, (d): RMS of
normal velocity.
40x10 -3
hole results where the points located one streamwise hole-to-hole distance apart are not
correlated. Figures 8(a,c) suggest that in Run D, with 4 holes computed, no jet-to-jet
interaction occurs, supporting the idea that the use of a periodic domain containing one
aperture does not break any natural interaction. In general, with the exception of the
periodicity effect, no major difference appears between the 1-hole and the 4-hole runs.
Note however that non-negligible differences between the 1-hole and the 4-hole runs are
sometimes visible (for example in figure 8(a) at a reduced separation of 0.1). Given the
very good agreement observed previously for the time-averaged and RMS of streamwise
and normal velocity components (figures 6 and 7), these differences are most likely due