Numerical Model Of Gas Flow In Solid-Propellant Rocket Motors

Abstract

Optimal design of a rocket motor requires accurate prediction of the propellant and nozzle characteristics under a range of important parameters. This predictive ability enables motor designers to specify a combination of propellant formulations, grain type and exhaust nozzle geometry to achieve the desired rocket motor characteristics. The paper presents a numerical model to predict the solid rocket motor characteristics and performance. The equation for the solid propellant reaction rate is coupled to the continuity, momentum, and energy equations of the gas flow. The solution of these governing equations through the combustion chamber-nozzle combination is obtained using finite difference approach. The procedure is validated against simple cases and some well-known theoretical solutions, and the comparison shows the validity of the procedure. It is then applied to a solid-propellant rocket motor (SRM) study case. The main results of the procedimi are the shape of combustion chamber, pressure and the thrust-time histories. It also predicts the burning time, thrust level, and final propellant residual. It can be used for the design of solid rocket motors. The results show the universality and accuracy of the procedure where strong interactions between combustion of the solid propellant and the gas flow are completely permitted.