Investigation of chemical kinetics integration algorithms for reacting flows

Abstract

A numerical investigation was conducted for integrating the chemical kinetics in computation of chemical reacting flows when an operator-splitting (point implicit) procedure was used to couple the chemical kinetics source term and fluid dynamics. The stiff initial value problems of ordinary differential equations were solved by an implicit formulation over a characteristic time scale of fluid. Analytical Jacobian has been derived to improve the numerical efficiency. Numerical test was first conducted for simplified one-dimensional ignition delay problem. It was then applied to a two-dimensional shockinduced combustion using both uniform and adapted grids. Some important issues have been addressed when the operator-splitting procedure is employed. It was found that evaluation of the kinetics source terms had a significant effect to combustion phenomena such ignition delay time. The current prediction was compared well with the experimental shadowgraph.