A Fluid Structure Coupling of the Ariane-5 During Start Phase by DES

Abstract

Concerning the requirements of future rocket technologies, which are the cost-efficient access to orbit as well as an increase in system reliability, a deeper insight into the unsteady phenomena during ascent of modern launchers is essential. Especially unsteady interactions and resonances of flow separation inside the nozzle, the turbulent launcher wake and the nozzle structure play an important role for the design of future main stage propulsion systems. The so called buffeting coupling phenomenon is one of the main challenges during ascent. In the present study of the Ariane-5 launcher a coupled simulation of the afterbody with a realistic structural and aerodynamic representation of different nozzle configurations is carried out using unsteady Detached Eddy Simulations on the CFD side, coupled with second order structural computations for different nozzle configurations. The essential features of the interaction process are well captured.