On the solution of the unsteady Navier- Stokes equations including multicomponent finite rate chemistry

Abstract

An explicit-implicit time-dependent finite difference technique is presented which has been successfully implemented for the solution of the unsteady Navier-Stokes equations including multicomponent finite rate chemistry. Stability restrictions encountered in explicit schemes due to the variable relaxation times associated with the finite rate chemical reactions are eliminated. As a result, the stability of the coupled Navier-Stokes and species conservatiion finite difference equations is shown to be governed only by the hydrodynamic stability cri- terion. The viscous nonequilibrium flow about a blunt axisymmetric nosetip at high Mach number and low Reynolds number, where the viscous shock layer and shock transition zone are merged, was computed using this time-dependent numerical scheme. Solutions along the stagnation streamline are compared with corresponding solutions obtained by Dellinger using the thin layer approximation of the Navier-Stokes equations.