Computation of high-speed reacting flow for gun propulsion applications

The launch cycle of a conventional gun system is simulated using a computational fluid dynamics code that has been developed as a design code for gun muzzle devices. A primary phenomenon of interest is the blast overpressures generated by the gun. The governing equations, which include both fluid dynamics and chemical processes, are solved to predict the peak pressures in the field exterior to the gun. A finite rate chemistry model to simulate reactions is implemented to assess the effects of reactions on the blast overpressures. The physical models and the solution algorithm are discussed with emphasis on accuracy and efficiency. simulations for both large- and small-caliber guns are carried out and compared with experimental data to ascertain the utility of the design code. Computations prove the reaction processes are key in determining the overpressure levels throughout the field.