Résumé:
A rocket engine nozzle is a propelling nozzle through which combustion gases are expanded and
accelerated to supersonic velocities. For high thrust performance, the energy released by the propellants in
the combustion chamber is converted into kinetic energy which leads to extremely high heat flux levels
and temperature. These heat loads and temperatures may damage the nozzle wall and lead to loss in
performance of the engine. Additionally, when the gases are expanded through the nozzle from subsonic
to supersonic conditions, the flow under goes many forms of unique phenomena including flow
separation and its associated shock system, unsteadiness, flow mixing etc. Some of these phenomena may
lead to pressure loss, thereby reduce the overall thrust generated by the nozzle. The present work aims to
provide a numerical analysis of flow separation in an overexpanded nozzle and the influence of wall
temperature on a free shock-induced separation and thrust performance. The numerical method used is
based on a finite volume scheme where the equations of Navier-Stokes, energy and turbulence were
averaged in a Favre form using Ansys-Fluent®.