Kinetic Mechanism Validation and Numerical Simulation of Supersonic Combustion of Methane-Hydrogen Fuel

Ignition characteristics of methane can be significantly improved by adding some hydrogen. The aim of the present work is to obtain a suitable kinetic mechanism for the methane -hydrogen fuel and to integrate it into the MSD code. Several comprehensive, skeletal, and reduced kinetic mechanisms have been tested using simple reactor models (shock-tube and perfectly stirred reactor) to identify an appropriate mechanism able to describe combustion parameters of the methane -hydrogen-air reacting system such as temperature profile, ignition delay, and extinction limits. Two new reduced kinetic mechanisms have been derived from the LCSR mechanism for the natural gas. They include respectively 79 and 69 reactions between 21 and 19 species, 5 and 4 of which are supposed in the quasi-stationary state. The new reduced mechanisms provide a good agreement of the combustion parameters with experimental correlations and data from the original comprehensive kinetic mechanism. A series of 2D numerical simulations of a reacting methane -hydrogen supersonic jet in a duct have been performed to assess the MSD performance with a new kinetic mechanism. The duct configuration corresponds to that of the LAERTE facility at ONERA. These results are considered as a first approach to plan future experimental studies of methane supe rsonic combustion and as a contribution to the current activity in the field of hype rsonic propulsion.