High-order spatial discretizations significantly improve the accuracy of flow simulations. In this work, a multi-dimensional limiting process with low diffusion (MLP$$^\text {ld}$$) and up to fifth order accuracy is employed. The advantage of MLP is that all surrounding volumes of a specific volume may be used to obtain cell interface values. This prevents oscillations at oblique discontinuities and improves convergence. This numerical scheme is utilized to investigate three different rocket combustors, namely a seven injector methane/oxygen combustion chamber, the widely simulated PennState preburner combustor and a single injector chamber called BKC, where pressure oscillations are important.

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.