The Effects of Electrical Enhancement on Pulsating Instabilities in Detonating Gas.

An investigation of instability of pulsating detonation waves with electrical enhancement is presented. One dimensional inviscid flow with a single irreversible chemical reaction is considered. The numerical algorithm developed is a Godunov - Glimm type scheme. Chemical reaction equation is integrated while the reactive Riemann problem is solved such that the chemical reaction is coupled with the fluid dynamic equation. Both reactive shock and rarefaction waves are treated when a reactive Riemann problem is solved. The Glimm random choice method is used to evaluate the Riemann solution for the desired grid points. The algorithm is also extended to the detonation problem with viscosity. The testing problems show this algorithm has advantages other algorithms do not have. Several new parameter studies (such as CJ detonation and underdriven detonations) to investigate the pulsating instability boundaries of detonation are performed. The calculated results show that the chemical reaction rate of the system plays an important role in the instability of detonation. Both activation energy, E^+ , and degree of overdrive, f, affect the chemical reaction rate of a system. The effects of electricity on the instability of pulsating detonation is examined. The addition of a small amount of electrical energy relative to chemical reaction energy released in the reaction process suppresses the normal pulsating pattern and stabilizes the system.