Accession Number:

AD0854247

Title:

Measured and Predicted Air Ionization in Blunt Body Shock Layers.

Descriptive Note:

Final rept. 1 Jan 67-31 Dec 68,

Corporate Author:

GENERAL ELECTRIC CO PHILADELPHIA PA MISSILE AND SPACE DIV

Personal Author(s):

Report Date:

1969-04-01

Pagination or Media Count:

60.0

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

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE