A study of the effects of nitrogen injection into the reacting boundary layer on a graphite surface at hypersonic speeds
Weston, Kenneth Clayton
Wierum, Frederick A.
Master of Science
This study considers the effects of injection of a non-reacting gas (taken to be nitrogen) on the heat and mass transfer of a porous chemically reacting surface (graphite) at hypersonic speeds. All chemical reactions are considered to occur in a reacting sheet adjacent to the wall. Equations for the determination of species mass fractions at the wall are derived under the assumptions of a frozen boundary layer and chemical equilibrium in the flame sheet. Schmidt and Prandtl numbers are taken as unity. Heat and mass transfer relations are obtained for the carbon surface. Numerical results are presented for the case of the stagnation point at hypersonic speeds. Reductions in carbon surface mass loss and aerodynamic heating as a result of nitrogen injection are demonstrated. Comparisons with more rigorous computer solutions for zero nitrogen injection show the some qualitative trends and numerical differences of about 10%.