Wall Heat Fluxes in Rocket Combustion Chamber with Porous Injector Head

Kurzfassung

Wall heat fluxes in a rocket combustion chamber with a porous injector head have been measured by the calorimetric method at the ratio of oxidizer to fuel (ROF) of 6 and pressure of 80 bars. The hot tests were run on the P8 test bench at DLR-Lampoldshausen. The wall heat fluxes, temperature of wall, pressure were measured along the axis of the chamber every 50 mm. The experimental results are characterised by the pressure drop within the first 50 mm from the injector face and by the increase of the wall heat flux after the first 50 mm. The flow inside the combustion chamber has been simulated using ANSYS CFX (commercial computational fluid dynamics (CFD) code). Turbulence was modelled using the Reynolds Averaged Navier-Stokes (RANS) equations and the Shear-Stress-Transport (SST) model. The combustion has been modelled with the help of different models: the Eddy Dissipation Model (EDM) and the Extended Coherent Flame Model (ECFM). The results of the simulations agree with the experimental data well. The EDM model yields the results which agree with the experimental data within experimental error. The quantitative disagreement of the numerical models with the experimental data is observed only in a region near the injector head. The employed combustion models were compared with each other and with the experimental data. The EDM model gives better results. This is explained by the more correct estimation of the model coefficients in the absence of empirical data on hydrogen combustion at high pressure.