NONEQUILIBRIUM HYPERSONIC SIMILITUDE IN A DISSOCIATED DIATOMIC GAS

Similitude requirements are presented for nonequilibrium dissociated diatomic gas flow around affinely-related, slender, blunted bodies at zero angle of attack, assuming small hypersonic disturbances. A dissociated nonequilibrium free stream is also considered for applications to highly nonequilibrium flows in a hypersonic wind tunnel and flight through a dissociated atmosphere produced by nuclear explosions. A discussion is given of sharp-nosed cones and wedges or slender, blunted rods and slabs, for which practical nonequilibrium similitude correlations of surface pressure and shock shape are possible. In addition, the limiting cases of equilibrium and completely frozen shock layer flow are examined. In the latter case, with a nonequilibrium dissociated free stream, a simplified limiting frozen similitude is obtained for the small disturbance flow. (Author)