DNS and LES of Stabilization and Instabilities in Rocket Engines

Speaker: Thierry Poinsot, The French National Center for Scientific Research (CNRS)
July 16, 2015

Presentation

Abstract

Liquid fuel rocket engines using H2/O2 combustion are a major research theme in Europe, especially for the future Ariane 6 rocket. This talk will present recent progress in two critical mechanisms controlling combustion in cryogenic H2/O2 rocket engines: (1) flame stabilization (the fact that the flame can be ignited and anchored in the engine) and (2) flame stability (the fact that the whole engine will not enter a regime of self-sustained oscillations leading to strong vibrations and sometimes to engine destruction).

Flame stabilization: the stabilization zone of the H2/O2 flame on the lips of a coaxial injector will be studied using DNS with full chemistry and a dual resolution of heat transfer within the splitter plate of the injector.
Flame stability: the first full LES of instabilities in a complete H2/O2 rocket engine installed at DLR Lampoldshausen will be described. Using LES and a simplified chemical model, this simulation allows to capture and identify the two strongest modes (10 and 20 kHz) appearing in this 100 MW engine. Comparisons with experiments show that LES is able to discriminate between stable and unstable regimes and to identify the nature of the unstable modes when they are triggered.

Biography

Thierry Poinsot is a research director at CNRS Toulouse (IMFT lab), head of the CFD group at CERFACS, Toulouse, and a senior research fellow at Stanford University. He has authored more than 180 papers in refereed journals and 200 communications in the field of combustion. He is the author of the textbook "Theoretical and Numerical Combustion" with Dr. D. Veynante (École Centrale Paris) and an associate editor of Combustion and Flame. He was a post doc at CTR (1988-1990) and worked at Stanford and Moffett Field for two years.

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