Effects of vortex shedding position and temperature on vortex-acoustic pressure oscillation characteristics

To explore the vortex-acoustic effect on pressure oscillation characteristics in solid rocket motors, different cases with variation of inhibitor position and gas temperature were numerically studied via the Large Eddy Simulation (LES) method based on the VKI motor. The aim of this work is to study the mechanism of pressure oscillations induced by vortex shedding. The coupling analysis indicates that pressure amplitude reaches to a high level when the inhibitor is located at the acoustic velocity antinodes. Vortex energy can be easily dissipated by turbulence during the transport process. The vortex shedding pressure amplitude at the second acoustic velocity close to nozzle head is larger than that of others. The decoupling analysis shows that temperature has little effect on vortex shedding frequency. Pressure amplitude rapidly decreases when the vortex shedding frequency departs from natural acoustic frequency.