A MODEL FOR THE TRANSITION REGIME IN HYPERSONIC RAREFIED GAS DYNAMICS,
GENERAL ELECTRIC CO PHILADELPHIA PA MISSILE AND SPACE DIV
Pagination or Media Count:
A new, two-fluid model is presented for the hypervelocity rarefied regime. A set of partial differential moment equations is presented they are of the same order of difficulty as the conventional gas dynamic equations. Those particles reflected from the surface of the body are considered as the wall fluid, while all scattered and free-stream particles comprise the cold fluid the assumption being that collisions between wall and cold particles convert wall particles to cold particles. Kinetic models are then constructed for both fluids. To obtain expressions for the absorption and emission terms in the model, the distribution function of each fluid is represented by an expansion in the derivatives of the delta function and the relevant integrations are performed. Although the model does not provide a description of the entire transition between free molecule flow and a fully developed shock wave, the results obtained for the piston problem do give insight into the shock formation.