Numerical Investigation of Roll Torque Induced by Solid Rocket Motor Internal Flow

摘要

To understand the mechanism of the generation of large roll torque in an operating solid rocket motor with axially slotted propellant grain and a narrow nozzle-submergence region, fully three-dimensional Navier-Stokes numerical simulations are conducted. Several grain configurations are computed, and it is found that there are at least two groups of quasi-steady-state solutions: one shows large roll torque, and the other shows small roll torque. From the current simulation results, it is observed that large roll torque is generated as a result of the interaction of the circling flow around the nozzle inlet with the slot jet exhausting from the slot end into the aft-end cavity. Although the roll torque evaluated from the computation is one order higher than that observed in real fight, the simulations provide an insight into the qualitative mechanism of real roll-torque generation.