VIBRATION EXCITATION IN LAMINAR HYPERSONIC BOUNDARY-LAYERS

The boundary layer equations of steady, 2-dimensional, laminar flow of a chemically reacting gas mixture according to the first order boundary layer theory, are extended to a flow model, the includes thermal non-equilibrium. The thermal state of the gas is characterized by a vibrational temperature for each molecular species and one translational temperature. The additional vibrational energy conservation equation for each molecular species is deduced. Electronic excitation so far, ist not taken into account. A similarity and compressibility transformation yields quasi similar boundary layer profiles in the computational plane, which allow larger spacings in the streamwise direction. The governing equations are simplified to compute a binary gas mixture composed of the atomic and the molecular species. The computation of oxygen and nitrogen flows about a cone at hypersonic freestream velocities demonstrates the influence of the thermal non-equilibrium region on the flowfield.