PRESSURES IN THE STAGNATION REGIONS OF BLUNT BODIES IN THE VISCOUS-LAYER TO MERGED-LAYER REGIMES OF RAREFIED FLOW
Abstract
Experimental data on pressures in the stagnation regions of hemispherical and flat noses on axisymmetric bodies in rarefied, hypersonic flow are presented. Diatomic and monatomic gases were used in the study, thereby illustrating the effect of molecular structure on the impact pressure. The experiments were conducted with the models in both cold-wall and insulated-wall conditions. It is concluded that impact pressures may be smaller than the corresponding inviscid values, although this reduction may amount to only a few percent. Small influences of wall heat transfer and molecular structure on impact pressure at a given Reynolds number are demonstrated. Pressure distribution on highly cooled, flat and hemispherical noses are predicted with generally acceptable accuracy by theories for inviscid flows. Flow conditions for these experiments were such that the Knudsen number of a full-scale nose having a radius of one foot and moving with hypersonic speed at altitudes of roughly 300,000 ft was duplicated. Thus, this report concerns the viscous-layer to merged-layer regimes of flow at altitudes above Earth where thermochemical reactions in the shock layers of blunt bodies are believed to be essentially frozen.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1963
- Accession Number
- AD0416004
Entities
People
- Allan B. Bailey
- J. L. Potter
Organizations
- Arnold Engineering Development Complex