Pressures in the Stagnation Regions of Blunt Bodies in the Viscous-Layer to Merged-Layer Regimes of Rarefied Flow
Report Number: AEDC TDR 63-168
Author(s): Potter, J. Leith, Bailey, Allan B.
Corporate Author(s): ARO, Inc.
Date of Publication: 1963-09
Pages: 56
Contract: AF 40(600)-1000
DoD Project: 8953
DoD Task: 895306
Identifier: AD0416004
Abstract:
Experimental data on pressures in the stagnation regions of hemispherical and flat noses on axi symmetric 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 pres sure. The experiments were conducted with the models in both cold-wall and insulated-wall con ditions. 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 demon strated. Pressure distribution on highly cooled, flat and hemispherical noses are predicted with generally acceptable accuracy by theories for inviscid flows. Flow conditions for these ex periments 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 e 0ially frozen.
Provenance: IIT
Author(s): Potter, J. Leith, Bailey, Allan B.
Corporate Author(s): ARO, Inc.
Date of Publication: 1963-09
Pages: 56
Contract: AF 40(600)-1000
DoD Project: 8953
DoD Task: 895306
Identifier: AD0416004
Abstract:
Experimental data on pressures in the stagnation regions of hemispherical and flat noses on axi symmetric 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 pres sure. The experiments were conducted with the models in both cold-wall and insulated-wall con ditions. 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 demon strated. Pressure distribution on highly cooled, flat and hemispherical noses are predicted with generally acceptable accuracy by theories for inviscid flows. Flow conditions for these ex periments 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 e 0ially frozen.
Provenance: IIT