Numerical Simulation of Fuel Regression Rate Behavior of Hybrid Rocket Motors

The present study attempts to predict the performance of hybrid rocket motors using a physics-based comprehensive model in which all the submodels that govern the various processes that occur during heating and combustion of solid fuel are based on physical-based mathematical models. Based on the fluid-solid coupling technique and some comprehensive physical processes during operation of hybrid rocket motors, a numerical model is developed to predict the regression rate for the solid fuel surface of the hybrid rocket motor under different operation conditions. The muti-dimensional Favre-averaged compressible turbulent Navier-Stokes equations are used as the governing equations of the reacting flow, the two-equation turbulence model is used to simulate the turbulent flow, and the eddy breakup model is used to simulate the gas combustion. The results presented are for hydroxyl-terminated-polybutadiene fuel and gaseous oxygen. The Navier-Stokes model results allow more detailed and realistic observation of the chamber flow field than is permitted by simpler boundary layer analyses. The model predications indicate that fuel surface regression rates are considerably impacted by both the size and geometry of the configuration. This study provides considerable information to the understanding of flow and combustion process in hybrid rocket motors. Methods for optimizing the hybrid combustion characteristic are put forward.