Large eddy simulation of vortex shedding for model SRM

In order to investigate the influence of vortex shedding initiated by backward stepping on the flow stability in the rocket motor, large-eddy simulation of the flow in a scale model solid rocket motor was carried out. Pressure evolution and its FFT results were gained. Also comparison was made between the numerical results and the experimental results as well as an existing numerical results. It is shown that the results calculated by LES model are more accurate than those computed by k-ε turbulence mode; the magnitude of the pressure oscillation in the scale rocket motor is small, but its frequency is high and also increases along with increasing incoming flow velocities; in backward stepping, vortex usually generates at the edge of the step and sheds periodically downstream; the size of the computational mesh has little influence on the computed oscillation frequency if γ⁺ is small enough.