D. Couton et al., NUMERICAL-SIMULATION OF VORTEX-SHEDDING PHENOMENON IN A CHANNEL WITH FLOW-INDUCED THROUGH POROUS WALL, International journal of heat and fluid flow, 18(3), 1997, pp. 283-296
Segmented solid propellant rocket motors tend to develop unpredicted p
ressure and thrust oscillations that could be attributed to a periodic
phenomenon. An experimental and numerical assessment of the stability
of a solid propellant motor was conducted. This numerical computation
was based on an experimental study carried out on a cold-flow, reduce
d-scale, bidimensional duct with a complex internal geometry (obstacle
s, outflowing cavities, submerged nozzle). The objectives of our study
are to characterize the internal flow (mean, fluctuating induced by i
njection through a porous wall and the shear layer created at the top
of the second obstacle. The code employed solves the unsteady, compres
sible two-dimensional (2-D) Navier-Stokes equations in a laminar regim
e by a predictor-corrector MacCormack scheme. Three grids are develope
d for the evaluation while respecting the complexity of the internal g
eometry. The results obtained allow us to separate the flow into two z
ones: one, laminar, upstream of the obstacle; the other, disturbed, do
wnstream, in which vortex structures develop. The phenomena of instabi
lities (vortex-shedding, pairing) are in accordance with the first two
acoustic longitudinal modes of the chamber. Last, the numerical compu
tations are discussed and systematically compared with the experimenta
l results. (C) 1997 by Elsevier Science Inc.