Modeling of a 7-elements GOX/GCH4 combustion chamber using RANS with Eddy-Dissipation Concept model

A 7-element rocket combustion chamber using GOX/GCH₄ as propellant has been modeled and simulated to get a more comprehensive knowledge for combustion and heat transfer process inside a combustion chamber. All the computational cases in our investigation use the Eddy-Dissipation Concept (EDC) combustion model for detailed chemistry and two equations RANS model for turbulence closure. The preliminary results of the base case without considerations on the reactions within the boundary layer show a good agreement with the experimental data in terms of pressure distribution, but the wall heat load is overestimated about 30%. Further investigation found that changing the turbulence model will alter the heat transfer characteristics significantly by delayed combustion process; changing the Prandtl number will tune the wall heat load slightly without changing the combustion field too much when using RANS model. It has been also found that the different reduced kinetic mechanism will slightly change the heat transfer characteristics through reducing the overall pressure level in the chamber by altering the thermodynamic properties of the combustion products. After carefully estimation, the boundary layer reactions for methane rocket chamber with multi-elements account for the most overestimation of the wall heat load.