Measured and Predicted Air Ionization in Blunt Body Shock Layers.
Abstract
Electron density shock layer profiles measured in a hypersonic shock tunnel on a sphere-cone model are presented for air flows of 15,000 and 20,000 fps and gas densities corresponding to altitudes of 210 and 195 kft. The data were obtained with Langmuir probes in the stagnation region and near the spherecone junction of the 3 inch nose radius and 10 degree half-angle model. The test facility and experimental procedures, including the methods for interpreting the probe data in collisionless and transitional operating regimes, are described. The data are compared with thermochemical equilibrium and chemical nonequilibrium theoretical predictions for the inviscid layer, matched inviscid-boundary layer and fully viscous layer. Chemical nonequilibrium predictions employing both the dissociated tunnel free stream and a corresponding undissociated free stream having the same gas density and stagnation enthalpy are included. The theoretical methods and their assumptions are discussed. The results show that to predict electron densities correctly within an order of magnitude, chemical nonequilibrium effects must be included. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1969
- Accession Number
- AD0854247
Entities
People
- D. L. Mcmenamin Jr
- E. M. Kaegi
Organizations
- General Electric