Numerical Simulation of the Decay of Grid-generated Turbulence in a Shock Tube

Abstract

The decay of the grid-generated turbulence has been investigated numerically by solving the time-dependent threedimensional Navier-Stokes equations with k-e turbulence model for a compressible fluid. Turbulence grids are placed in the shock tube to generate shock induced turbulence in the wake of the grid plate. All turbulent fluctuations are computed along the longitudinal distance in the wake of the grid plate in the shock tube and it is observed that the decay of the turbulence and the decay of Turbulence Kinetic Energy (TKE) level are accelerated along the downstream direction and the percentage of decay depends on the strength of incident shock wave. Due to stronger compressibility effects on decaying turbulent field, all length scales are decreased along the downstream direction. The decay of dissipation rate of TKE is observed along the downstream direction for gradually decreasing the turbulence intensity in the wake of the grid plate.