Pressure oscillations in solid rocket motors: Numerical study

A numerical study of pressure oscillation generated in Solid Rocket Motors (SRM) is presented. Attention is focused on the effect of the cavity located in the vicinity of the nozzle on the flow–acoustic coupling and therefore on the consequent pressure oscillations. A parametric study with different cavity volumes has been conducted assuming the flow to be axi-symmetric. Results show that the cavity volume plays an important role in the flow–acoustic coupling mechanism. Indeed, the maximum pressure oscillation magnitude is observed to be highly dependent on the cavity volume and a close to linear dependence of the maximum excited mode against the volume of the cavity is documented. Satisfactory comparisons with experimental data available on the same geometrical configuration are also presented and discussed.