COLD GAS SIMULATION OF A SOLID-PROPELLANT ROCKET MOTOR

The objective of this study is to characterize experimentally the mean and fluctuating flowfield and the dynamic instabilities that develop along a two-dimensional channel with porous walls, The channel is a 1/ 40 scale model of the ARIANE 5 segmented solid rocket motor. This cold gas simulation is based on an aeroacoustic similitude that reproduces the Strouhal and Mach numbers and the complex internal geometry (obst acles, flowing cavity, submerged nozzle) of the full-scale motor. Meas urement data, mean and fluctuating velocities, and shear stresses were obtained using a two-component laser Doppler anemometer, The injectio n wall, composed of a sintered Poral and of a metallic weaved sieve, g ave a uniform injection velocity, with a controlled injected turbulenc e intensity. The second obstacle divided the flowfield into two region s. Upstream, the how was laminar. A shear layer developed at the top a nd in the wake of the obstacle because of the interaction of the upstr eam main flow with the downstream injected flaw. Downstream of the obs tacle, velocity fluctuations increased and the shear layer became turb ulent.