Accession Number : AD0658859

Title :   MERGED LAYER IONIZATION IN THE STAGNATION REGION OF A BLUNT BODY.

Descriptive Note : Technical rept. Aug 65-Apr 67,

Corporate Author : AEROSPACE CORP SAN BERNARDINO CALIF SAN BERNARDINO OPERATIONS

Personal Author(s) : Lee,Richard H. C. ; Zierten,Thomas A.

Report Date : JUN 1967

Pagination or Media Count : 35

Abstract : Nonequilibrium air dissociation and ionization in the stagnation region of a blunt body are investigated in the merged layer regime. A chemical system of seven species undergoing six simultaneous reactions is considered. The species conservation equations are decoupled from the simplified Navier-Stokes equations for a thin layer model. However, the complex chemical system is allowed to experience the entire merged layer flow environment in a continuous manner from the shock transition region to the viscous shock layer. Solutions are presented for a catalytic blunt body flying at 23,000 fps and at Re = 814 and 1230. The results show that viscous effects dominate the entire merged layer and that the air dissociation and ionization are mainly confined to the viscous shock layer with negligible reaction rates in the shock transition region. Comparisons with nonequilibrium inviscid solutions indicate that the inviscid theory overestimates the peak electron density by as much as two orders of magnitude at the lowest Reynolds number considered. This difference between the merged layer solution and the inviscid solution is attributed to a combination of wall cooling and diffusion of atoms and electrons away from the shock layer. (Author)

Descriptors :   (*BLUNT BODIES, STAGNATION POINT), (*GAS IONIZATION, *STAGNATION POINT), BOUNDARY LAYER, NONEQUILIBRIUM FLOW, DISSOCIATION, CHEMICAL REACTIONS, SHOCK WAVES, ELECTRON DENSITY, ATMOSPHERE ENTRY, AERODYNAMIC HEATING, PLASMA SHEATHS

Subject Categories : Aerodynamics
      Physical Chemistry
      Fluid Mechanics
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE