Design and Preliminary Numerical Analysis of a Flexible Structure for a Cold Gas Nozzle Experiment

Abstract

An experimental setup for the investigation of fluid-structure interaction in rocket engine nozzles is proposed. The configuration consists of a flexible nozzle and a strap mechanism to apply a defined initial deformation. After release of the strap the damping characteristics of the system will be measured and compared to numerical simulations for validation. Finite element simulations of the structure are used for its preliminary design with focus on the strain safety margins and the shape of the deformation caused by the strap. Unsteady coupled simulations of the strap actuation and release sequence are presented from which the damping characteristics of the aeroelastic system are derived. The local contribution to the systems global dynamic stability is qualitatively analyzed. The described nozzle model was manufactured, the strap mechanism built and the setup will be used to validate the numerical simulations in a planned experimental campaign.