Numerical Computations of Nozzle Performance Losses in Solid Rocket Motors

This paper investigates nozzle performance losses in solid rocket motors using comprehensive computational fluid dynamics simulations and compares these results with the traditional Solid Performance Program methodology. By analyzing the Space Shuttle Booster and Inertial Upper Stage second stage, the study highlights the advantages of the CFD approach, which allows to capture the direct interaction between multi-phase and reactive flow phenomena to provide a direct and accurate estimation of motor performance. The present outcomes indicate that the presence of a radially stratified flow and the free-particle zone enhance the exothermic reactions, promoting the performance gain from the chemical reactions. This assures that the fully-coupled CFD method offers significant improvements over the separated effects approach, particularly for motors characterized by a flow strongly affected by the particle dynamics as those with large expansion ratios. The findings underscore the importance of advanced numerical simulations in optimizing SRM design and performance.