Comparison of Hybrid RANS/LES Models for Rocket Combustion Chamber Simulations

Abstract

In the development process of rocket combustion chambers, the demand of high-fidelity numerical models is rising in order to capture all the occurring phenomena. As wall-resolved large eddy simulations (LES) are extremely expensive for the conditions prevailing in these combustors, hybrid Reynolds-Averaged Navier Stokes (RANS)/LES calculations are a good compromise. In this work, two hybrid RANS/LES methods, namely the so-called iDDES and l 2 -ω-DDES, are compared to each other with the aim of testing their applicability for rocket combustion chambers. These are first validated on non-reacting test cases. Although the mean quantities do not differ significantly, the instantaneous flow fields exhibit a different behavior. In addition, simulations of a laboratory-scale rocket combustion chamber are performed. The results show clear differences in the prediction of some of the mean quantities such as the wall heat flux, highlighting the strong dependence of the combustion process from the turbulence modeling.