An Efficient Flamelet-based Combustion Model for Supersonic Flows

A combustion model based on a Flamelet/Progress Variable approach for high-speed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and tabulated species mass fractions. The combustion is thus modeled by 3 additional scalar equations and a chemistry table that is computed in a pre-processing step. This approach is very efficient and allows the use of complex chemical mechanisms. An approximation is also introduced to eliminate costly iteration steps during the temperature calculation. To better account for compressibility e ects, the source term for the progress variable is rescaled with the pressure. The model is tested in both RANS and LES computations of a hydrogen jet in a supersonic transverse flow. Comparison with experimental measurements shows good agreement, particularly in the LES case. It is also found that the disagreement between RANS results and experimental data is mostly due to the mixing model de ciencies used in RANS.