Study of instantaneous regression rate in hybrid rocket motor

In order to study the characteristics of the changes in regression rate of solid grain in hybrid rocket motor, a numerical model to indicate the instantaneous regression rate in hybrid rocket motor was developed based on the operational traits. The model was based on coupled simulation of gas-phase combustion and heat transfer in solid fuel, as well as dynamic mesh. An experimental motor with pre-combustion chamber, after-combustion chamber and diaphragm was then studied using the model. The temperature of the pyrolysis surface of solid grain decreases as the motor works, and so does the regression rate; at the same moment, the regression rates of the pyrolysis surface of solid grain differ along the axial direction, so does the temperature; diaphragm is capable of raising the local regression rate and surface temperature of the solid grain just after the diaphragm.