LOW DENSITY HIGH TEMPERATURE GAS DYNAMICS.
Abstract
Preliminary experiments to test the feasibility of measuring directly the difference between a free molecule and a near free molecule effect were successfully carried out. The magnitude of the correction was found to be inversely proportional to the free stream Knudsen number and asymptotically approached zero as the Knudsen number became large compared to one. The drag coefficients of a sphere and a cylinder in the hypersonic, near free molecule regime were accurately measured with a modulated force probe. The results exhibit considerably less scatter than previously obtained by other experimenters. Qualitatively correct measurements of the local mass flux and speed ratio in a hypersonic rarefied free jet were carried out with a modulated cold wire probe presently under development. Heat transfer rates to small flat surfaces at varying angles of incidence in an arc heated, hypersonic, rarefied flow indicate that the thermal accommodation coefficient decreased with decreasing angle of incidence. An analytical study of the gas-surface interaction problem was carried out using a modified Baule model. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1967
- Accession Number
- AD0666474
Entities
People
- Jean J. Smolderen
Organizations
- von Kármán Institute for Fluid Dynamics