Laminar boundary layers behind blast and detonation waves

Boundary layer flows in air behind nonuniform strong blast waves and in the burned gas of a stoichiometric mixture of hydrogen and oxygen behind uniform Chapman-Jouguet detonation waves were investigated. The results show that the Prandtl number profoundly influences boundary layer flow. For a blast wave and Pr less than unity it controls a boundary layer velocity overshoot which decreases with increasing Prandtl number. For a Chapman-Jouguet detonation wave similar results are obtained for a Pr = 0.72; however, for an actual Pr = 2.26, a flow reversal occurs away from the wave where the inviscid flow velocity approaches a small value. The viscous exponent was found to have a significant effect on the wall shear stresses and heat transfer. The effect of the wall temperature is small. Velocity profiles were computed for spherical and planar detonation waves. Because of the rapid decrease in density behind a blast wave, the boundary layer thickness becomes very much larger than their detonation wave counterparts at the same wave velocity (but different physical conditions). The velocity boundary layer thickness in air behind a quasistationary planar shock wave is somewhat more than for a planar detonation wave at the same wave velocity (but in different gases). The heat transfer to the wall behind a planar detonation wave was calculated.