A study of analysis method for hydrodynamic stabilities of solid rocket motors with side-induced flow

A local non-parallel (LNP) hydrodynamic stability approach was applied to investigate the partial vortex shedding phenomenon observed in solid rocket motors with side-induced flow with large length to radius ratio. Two disturbance equations based on stream function formulation and primitive variable formulation were solved and results were compared. The effects of flow parameters on stability results are obtained. It is showed that the predicted values of the most unstable frequencies by two disturbance equations differ less than 2% and the frequencies increase along streamwise. Large Eddy Simulations were performed on two different configurations and compared with the results obtained by the LNP method based on spatial evolution of the flow instabilities. The comparison shows good agreement in a certain degree in terms of amplified frequency range when no resonance happens.