Effect of Alternative Kinetic Mechanisms on Turbulent Combustion in a Shear Coaxial Injector

The use of full detailed kinetics in turbulent combustion simulations is impractical given the associated large computational cost. Studies have shown that turbulent flames may involve key reaction pathways that are significantly different from those in laminar flames, thus affecting the ability of reduced kinetic models to reasonably capture turbulence-chemistry interactions and related flow field behavior. The present study examines the effects of alternative kinetic models on turbulent combustion processes as a means of determining the conditions (if any) under which certain reaction pathways are altered and to aid in the development of more accurate reduced kinetic models. Utilizing the General Equation and Mesh Solver (GEMS) code, 2D axisymmetric parametric studies and simulations for a single element shear coaxial rocket injector are performed. GRI-Mech 3.0 and several reduced kinetic models are used to study the combustion of gaseous methane and oxygen, with a focus on global effects of the kinetics on flow and reaction dynamics. Results show differences in peak temperatures and flame anchoring among the models, in addition to differing grid and time resolution requirements.