Segmented solid rocket motor internal flow simulations

Navier-Stakes and inviscid simulations of the internal flow in a 5-112 segment solid rocket motor were performed and validated against detailed subscale cold flow measurements obtained by Dunlap for various propellant burnback configurations. Detailed comparisons of the radial Mach number profiles at each segment midsection and through each joint slot validate the accuracy of the current Navier-Stokes model. The centerline Mach number and pressure coefficient distributions are greatly influenced, not only by the segment shape, but by the small insulation (restrictor) nubs protruding into the flow at each segment forward face. This influence is accurately replicated by the Navier-Stakes simulations. The modeling of the restrictor nubs influences the relative agreement between the data and simulations for the initial propellant configuration more than neglecting viscous effects. Inviscid simulations adequately simulate the flowfield distributions at later times due to the enlarging slot and bore dimensions as the propellant burns.