Instability of channel flow with fluid injection and parietal vortex shedding

摘要

This paper is devoted to the computation of the stability properties and the aeroacoustic interaction in a planar channel flow driven by air injection through porous wall. The purpose is to establish a simulation method which estimates the vortex-shedding and acoustic-wave interaction. To perform these unsteady computations, turbulent motion is taken into account by a first-order model based on a nonlinear relationship between time-dependent Reynolds stresses and velocity gradients. Model coefficients are explicit functions of both strain and rotation. This model is applied to the computation of parietal vortex shedding in a simplified configuration. It is a channel flow with fluid injection. Two cases are computed here. The first one is stable and the second one is unstable. To improve the evaluation of the turbulent effects, computations of the second case are presented with and without a turbulence model. In first configuration, a good agreement with experimental data is found. In the second case both with and without turbulence model the natural unsteadiness of the flow is captured. The parietal vortex shedding is described and the turbulence effects are characterized.