NUMERICAL SIMULATIONS OF HIGH-SPEED CHEMICALLY REACTING FLOW

The essentially nonoscillatory (ENO) shock-capturing scheme for the so lution of hyperbolic equations is extended to solve a system of couple d conservation equations governing two-dimensional, time-dependent, co mpressible chemically reacing flow with full chemistry. The thermodyna mic properties of the mixture are modeled accurately, and stiff kineti c terms are separated from the fluid motion by a fractional step algor ithm. The methodology is used to study the concept of shock-induced mi xing and combustion, a process by which the interaction of a shock wav e with a jet of low-density hydrogen fuel enhances mixing through stre amwise vorticity generation. Test cases with and without chemical reac tion are explored here. Our results indicate that, in the temperature range examined, vorticity generation as well as the distribution of at omic species do not change significantly with the introduction of a ch emical reaction and subsequent heat release. The actual diffusion of h ydrogen is also relatively unaffected by the reaction process. This su ggests that the fluid mechanics of this problem may be successfully de coupled from the combustion processes, and that computation of the mix ing problem (without combustion chemistry) can elucidate much of the i mportant physical features of the flow.