CFD simulation of the ignition of coaxial injected methane and oxygen

The ignition of methane by laser spark in a small combustion chamber has been modelled using CFD-code ANSYS CFX. The numerical simulations were performed in a 2D axisymmetric geometry. Turbulence has been modelled using SST turbulence model while the combustion of methane has been modelled with the help of the combined Eddy Dissipation/Finite Rate Chemistry model and a one-step kinetic mechanism. The numerical results have been compared with the experiments by the pressure inside the combustion chamber. The filling of the combustion chamber with the propellants before the ignition and the stationary combustion in the chamber have been modelled accurately. However the numerical model predicts notably higher pressure peak immediately after the ignition. The reasons of the disagreement with experimental data have been discussed