Analysis of the impact of heat losses on an unstable model rocket-engine combustor using Large-Eddy Simulation

摘要

This paper presents the numerical simulation of a model rocket combustor with continuously variable acoustic properties thanks to a variable-length injector tube. An unstable operating point is chosen and simulated with fully compressible three-dimensional unsteady simulations. Two wall conditions are used for the simulations, one is an adiabatic condition and the second one models heat losses through the chamber's wall. The mechanism of the instability is studied for the adiabatic case, the structure of the acoustic mode is determined, and a balance on acoustic energy are performed. Then, the damping of the instability due to heat losses is observed.