Flow analysis of a solid propellant rocket motor with Aft fins

Solid rocket motors often have a complex grain geometry, such as fins slots to optimize the ballistic performance, These shapes result in a complex three-dimensional flowfield that locally augments the propellant burning, nozzle ablation, and insulator erosion. This work solved a steady-state, three-dimensional inviscid flowfield for a complex internal geometry with 16 fins, For the computation, 1/16 of the motor geometry is simulated, The results predicted the presence of circumferential and swirl now in the nozzle region, The distribution of the flowfield indicated the likelihood of nonsymmetric heat flux at the wall in this area. The specific mass flow rate in the fins are below the predicted levels that would induce erosive burnings.