Analysis of Pressure Oscillations within Vega Launchers First Stage SRMs

We investigate and discuss the unsteady behavior of two solid rocket motors of primary importance for the European space transportation systems, i.e. the P80 and the P120C, both affected by the presence of pressure oscillations during the quasi-steady state. In the present work, a Q1D two-phase model specifically developed to analyze the pressure oscillations within solid motors is applied in order to provide precious insights into the physical origin of the flow instability. The outcomes of the work reveal the paramount importance of both vortex-shedding and aluminum combustion as root cause for the pressure oscillations onset, offering, at the same time, an assessment of the contribution given by each source to the overall scenario.