Numerical simulation of influences of solid rocket motor post-thrust on missile base drag

Coupled with two-dimensional axisymmetric N-S equation and turbulence model, integral flow field simulation models were established for solid rocket motor nozzle tail flow and missile outer flow. For a given missile model, numerical simulations were carried out under different combustion gas mass flow rates. Velocity and pressure contours were obtained and influences of solid rocket motor post-thrust on missile base drag were analyzed under different combustion gas mass flow rates. According to the results, compared with the case when the motor was in idle condition, the missile base pressure increased and base drag decreased under low combustion gas mass flow rate. As the combustion gas mass flow rate increased, the missile base pressure decreased first and then increased; on the contrary, the missile base drag increased first and then decreased. As the combustion gas mass flow rate increased, resultant force of post-thrust and base drag increased, and the proportion of momentum thrust increased gradually.