Qualitative and quantitative comparison of rans simulation results for a 7 element gox/gch₄ rocket combustor

The present study aims at comparing the different methodologies used in the modeling and simulation of combustion and heat transfer in rocket thrust chambers. Different approaches were implemented by five different groups within the framework of the SFB-TRR 40 Summer Program 2017, in order to simulate the flow and combustion inside a multi-element rocket combustor, operated with gaseous oxygen (GOX) and gaseous methane (GCH₄ ). The test results provided for the validation of the different techniques, were obtained by experiments run at the Chair of Turbomachinery and Flight Propulsion of the Technical University of Munich (TUM). All five different approaches were based on RANS models for turbulence and turbulence-chemistry interaction (TCI) and the corresponding results were evaluated based on their agreement with the experimental data. The main focus was placed on the pressure and heat flux profiles along the thrust chamber wall and all methods were able to qualitatively capture the experimental trends. Significant differences were observed regarding the azimuthal variation of heat flux at the chamber wall. The secondary flows and the injector-injector interaction were identified as the primary culprits for the measured deviations. However, due to the absence of experimental data, the validity of this azimuthal variation could not be evaluated.