Cerfacs Enter the world of high performance ...

PhD Defense: Raphaël MARI – Influence of heat transfer on high pressure flame structure and stabilization in liquid rocket engines

  Thursday 25 June 2015

  Phd Thesis       Cerfacs - Salle de Conference Jean-Claude André    

Abstract :
This research work deals with the problem of the flame stabilization in the context of high pressure liquid rocket engines. Flame stabilization in a rocket engine is a critical feature. An instability can lead to important damages of the engine or the destruction of the launcher and the satellite. The engines (Vulcain 2 and Vinci) of the Ariane 5, and the future Ariane 6, use the hydrogen/oxygen propellants. One characteristic of this couple is its high specific impulse. The launcher performance is linked to the ratio of the payload to the total mass of propellants. For volume reasons the propellants are stored at low temperature of the order of a few tens of Kelvin. When injected in the combustion chamber, their combustion releases a huge amount of heat leading to temperature of 3500K. In order to predict the heat transfer between the flame, the solid injector and the cold propellants the Large Eddy Simulation, which allows to capture the unsteady features of the flow, is used in association with a thermal solver for the injector. This approach is validated with a low pressure experiment conducted at Centrale Paris, then a basic 1D configuration allows to understand the phenomena of high pressure flame-wall interaction. Finally a configuration representative of a coaxial rocket engine injector allows to evaluate the structure and the stabilization mechanisms of a cryogenic flame, the heat flux and the temperature of the injector.

Jury

Pascale DOMINGO         CORIA, Rouen               Referee
Thierry SCHULLER         Ecole Centrale, Paris     Referee
Richard SAUREL            Polytech Marseille,         Member
Dany ESCUDIE              INSA, Lyon                      Member
Laurent SELLE               IMFT, Toulouse                Co-advisor
Didier SAUCEREAU       Snecma                          Invited member
Marie THERON              CNES, Paris                    Invited member
Bénédicte CUENOT       CERFACS, Toulouse       Advisor