Assessment of Presumed/Transported Probability Density Function Methods for Rocket Combustion Simulations

Combustion models of different fidelity are applied to a seven-element gaseous methane/oxygen subscale rocket combustion chamber. The covered region of thermo-chemical states is analyzed for two non-adiabatic flamelet-based methods, from which one is well established and the other one has just recently been proposed for hydrogen/oxygen combustion. Of particular interest is their applicability in situations with strong heat losses. Consequently, the tabulated combustion models are linked with a presumed probability density function approach, and the results are assessed using a transported probability density function method. An analytically reduced chemical reaction mechanism with 13 species and 73 reactions is used for all models in order to allow for direct comparison of turbulence–chemistry interaction. The results are evaluated with respect to temperature, gas composition, and wall heat transfer and they are brought in context with their respective computational costs. Finally, the results are compared to available experimental data in terms of wall heat flux and pressure measurements. Locally and temporally resolved results provide additional insights to the experiment.