Numerical Simulations of Wall and Shear Layer Instabilities in Cold Flow Setup

Abstract

Experimental and numerical investigations were performed to characterize the potential sources of unstable behavior in a confined chamber that was both bounded by injecting walls and contained an emerging obstacle. The effect of the vortex shedding occurring in the wake of the obstacle and the wall vortex shedding phenomenon are described. The latter was found to be the most important source of acoustic energy in the chamber, and both experimental and numerical results demonstrated the interaction of pressure waves with vortex development. In addition, turbulent computations were performed to improve numerical results with regard to the experimental ones. Different levels of the pseudoinjected turbulence at the porous walls were also investigated, and such boundary conditions were found to affect strongly the unstable nature of the internal flowfield.