The influence of equivalence ratio and wall temperature on the ignition of hydrogen(2)/air mixtures in hypersonic flow boundary layers

The ignition of H{dollar}sb2{dollar} in air in the boundary layers of high-enthalpy hypersonic flows was numerically solved for a flat plate geometry using the Thin-Layer Navier-Stokes equations coupled with a complex thirteen species chemical solver. The Mach number range of study was between 2 and 17. Four different constant wall temperatures and three equivalence ratios were implemented. The heat transfer rate along the wall was studied and the solutions compared to each other. For higher Mach number flows (approximately greater than Mach 9), the heat transfer rate to the wall becomes largely independent of the inflow Mach number. The heat generation within the flow was analyzed at various transversal sections along the flat plate. As the inflow Mach number is increased, the presence of H{dollar}sb2{dollar} originally in the flow eventually result in endothermic reactions which cause the heat produced in the boundary layer to be less than that of a chemically frozen flow.