HYPERSONIC SURFACE PRESSURE AND HEAT TRANSFER ON SLENDER BODIES IN VARIABLE COMPOSITION AND NONEQUILIBRIUM ATMOSPHERES.
Abstract
The aerodynamic testing of slender bodies in high energy wind tunnels is complicated by the effects of the nonequilibrium expansion process in the wind tunnel nozzle. The atmosphere that a model sees varies in composition dependent upon the degree of nonequilibrium. This variation affects the inviscid flow field through changes in the ratio of specific heats and the viscous equations by changes in the transport as well as the thermodynamic properties of the gas. Within the limitations of hypersonic small disturbance theory the inviscid and viscous equations are formulated with a minimal dependence on Mach number and in a way that brings out their explicit dependence on the thermodynamic and transport properties of the gas. The resulting gas property parameters then are calculated for air-argon mixtures, air-helium mixtures, and frozen dissociate air. These parameters appear to provide a realistic estimate of the effect of a variable atmosphere on surface pressure and heat transfer based on the current series of tests on sharp cones and flat plates in air-argon mixtures and in a low pressure arc tunnel. In addition, the present experiments and comparative experiments in other facilities demonstrate a result of more general interest; namely, that the Mach number is not a dominant parameter in slender body viscous hypersonic aerodynamics. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1970
- Accession Number
- AD0707883
Entities
People
- D. J. Harney
- S. L. Petrie
Organizations
- Ohio State University