Reacting flow simulation for a large-scale ram accelerator

Computational fluid dynamics solutions of the full Navier-Stokes equations have been used to numerically simulate the reacting in-bore flowfield for the ram accelerator projectile propulsion system. In this system a projectile and obturator are injected at supersonic velocity into a stationary tube filled with a pressurized mixture of hydrocarbon, oxidizer, and inert gases. Flow stagnation on the obturator initiates combustion of the mixture, before it is discarded. A system of shock waves on the projectile, in conjunction with viscous heating, sustains combustion. The resulting energy release, which travels with the projectile, also generates high pressures that impart thrust to the projectile. Numerical simulation utilizing finite rate chemical kinetics have been used to investigate this flowfield. Numerical results are used to visualize the flowfield, predict the effects of variation in system parameters, and predict projectile in-bore velocity.