Simulations of Flowing Supercritical N-Decane

The Air Force is interested in the research of supercritical jet and rocket fuels, as well as the effects of thermally induced fuel degradation. As future flight vehicles travel at ever increasing Mach numbers, greater heat loads will be imposed upon the fuel. The primary purpose of this study is to develop a computational model for predicting fuel decomposition and bulk fuel temperatures in a simulated heated flow reactor. The System for Thermal Diagnostic Studies (STDS), located in the Air Force Research Laboratory's Fuels Branch, is used to analyze fuels under supercritical temperatures and pressures. Computational simulations of the STDS reactor are performed to better understand the heat transfer, fluid dynamics, and chemistry associated with fuel flow through the STDS reactor. A simplified global chemistry model is incorporated into the computational simulation. Predictions of the current model are compared to the results of the STDS experiments, which employ flowing N-Decane. The proposed computational model is validated using experimental data obtained at different flow rates after thermally stressing the N-Decane fuel. The model predictions agree well with the experimentally measured results. The computational model serves as a tool to study how various physical and experimental parameters affect fuel degradation.