Modeling of Fuel Film Cooling on Chamber Hot Wall

Abstract : A numerical model is constructed to simulate hydrocarbon fuel film cooling of the hot-gas side of liquid rocket engine chamber walls. The model consists of the steady Reynolds-averaged Navier-Stokes equations for multi-species flow with heat transfer and equilibrium chemistry. Preliminary results are presented in this extended abstract. The predictive performance of the model is studied by comparison to experimental heat flux data. Several flow conditions and film cooling mass flow rates were used in the simulation case matrix. Comparisons between numerical predictions of the wall surface heat flux and experimental data are used to guide further development of the model which is expected to provide improved predictions in the final version of the paper. Good agreement was obtained in one case with no film cooling, if radiative heat transfer was included in the model. A key finding is that radiative heat flux is comparable to convective heat flux upstream of the injection slot, as shown by the current numerical simulations. Several physics and chemistry aspects are identified that are not properly accounted for in the current model. The chief of these is soot formation and the deposit of a thermal barrier coating of carbon on the wall. Most of these aspects are currently being addressed to improve the model, and results using a model with improved accuracy will be reported in the final paper.