HEAT LOSS THROUGH SOLID ROCKET MOTOR CASE AND NOZZLE WALLS

摘要

There are several assumptions made when the ballistics of a solid rocket motor (SRM) is being modeled. Among them is the assumption that the case wall of the motor is adiabatic, i.e., no heat from combustion is lost through the case and nozzle walls as a solid rocket motor burns. However, this adiabatic assumption has not been numerically validated. This work intended to prove or disprove such an assumption through computational studies. First, CAD models is built using ProE, that represent successive layers of a solid fuel as it burns back. Each individual model is then meshed in the computational fluid dynamics (CFD) preprocessor, GAMBIT. The individual mesh files are then imported into the CFD program FLUENT and the simulations are finally run in FLUENT. Heat loss models are compared to adiabatic models. The results show radiative heat loss is most significant inside the motor case whereas convective heat loss is greater in the nozzle. Convective losses in the nozzle dominate the overall SRM heat loss. The heat loss in general does not significantly affect ballistic performance, however the CAD-CFD method is useful for other ballistics analysis.