Assessment of low-speed mixing and diffusion models for detonating compressible turbulence

The motivation for the present study is the relevance to supersonic spray combustion, such as in scramjet engines where the fuels are used in the liquid state. The evaluation of various drag, heat, and mass transfer models for two-phase high-speed flows is undertaken in this study. Several models for hydrodynamic drag coefficient in high-speed flows are introduced and four nonlinear first order differential equations appropriate for supersonic flows that carry particles are numerically solved to examine the comparative effects of the drag models. A preliminary study on a constant-area nozzle shows the differences in the performance of the drag models as a function of the Reynolds number and the Mach number. The particle velocity, time-of-flight of the particle, and the variation of the flow variables along the nozzle will be reported. The drag models give comparable results for some quantities, except one model which shows a significantly different result for intermediate Mach numbers (1.0 ≤ Ma ≤ 1.7).