Thrust Oscillations in Reduced Scale Solid Rocket Motors, Part II : A New Theoretical Approach

Abstract

Large solid rocket motors exhibit undesirable thrust oscillations during their firing. These oscillations are connected to inflow pressure fluctuations induced by flow instabilities. Recent classical hydrodynamic stability calculations have pointed out the role of the parietal vortex shedding in this phenomenon. However, this first attempt to explain the thrust oscillations, is based on a wave-like form decomposition for the perturbation field leading to a non-consistent approach. To avoid this problem, a new theoretical approach has been developed, which aims to calculate the perturbation field with a more general form. The results lead to significant changes in the understanding of the thrust oscillations arising.