Supersonic Combustion Heat Flux in an RDE Model

Analyses of heat flux distributions in the commonly used two-dimensional unwrapped CFD model of the rotating detonation engine combustor are reported in this paper. The axial and azimuthal components of the heat flux vector are calculated as functions of the equivalence ratio, with a delineation of the effects of using Navier-Stokes versus Euler, and large-eddy simulation versus laminar models. A 10-step, 8-species hydrogen-air chemistry is used. Predicted azimuthally averaged heat flux is compared to measured data, with promising agreement. The distributions of heat flux in the entire domain and along the combustor inlet and outlet boundaries are reported, as are those on the periodic boundaries. The effects of thermal conductivity modeling are also studied. With respect to the periodic boundaries, temperature and other primary dependent variables are roughly equal along these boundaries, but the heat flux is not. An attempt was made to address this problem, with the implication of the strong temperature gradients and the temporal dynamics of the waves. The present studies appear to be useful as a baseline for evaluating more advanced heat flux prediction models.