Fluid-structure interaction in rocket engines

Numerical approaches to predict side-loads on over-expanded launcher engines, resulting from the aeroelasticity, are proposed in this study: a stability model and a fluidstructure model. The main idea is to offer a better understanding of the repercussions likely to appear from the aeroelastic coupling in terms of side loads resulting from the motion of the compression shock and that may be responsible of damage effects on the current engines. It is notably shown the existence of a given natural torsional frequency of the nozzle for which the measured side loads are maximum, phenomenon associated with a transversal wave in the flow between both walls. These studies aim to improve the only current aeroelastic stability model in over expanded nozzle.