Accession Number:

ADA361428

Title:

Double Layer Effects on Shock Wave Propagation.

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING

Personal Author(s):

• Walker, Shannon L.

Report Date:

1999-03-01

Pagination or Media Count:

102.0

Abstract:

An analysis and assessment of two mechanisms in plasma shock interactions was conducted under conditions typically encountered in a weakly ionized glow discharge. The mechanisms of a spatially-dependent electron temperature and additional electron impact ionization at the shock front were examined for effects on shock structure and propagation. These mechanisms were incorporated into an existing one-dimensional, time-dependent, fluid dynamics code that uses the Riemami problem as a basis and numerically solves the Euler equations for two fluids the neutral gas and the charged component. The spatial variation in electron temperature was modeled as a shock-centered rise in temperature. Additional ionization was modeled by incorporating a variable electron temperature and a quasi-kinetic collision function, for both unrestricted ionization and ionization mitigated by ion-electron recombination. Introduction of a spatial variation in electron temperature resulted in a broadening and strengthening of the electric field associated with the electronic double layer EDL at the shock front. Results of unrestricted ionization were a broadening and strengthening of the electric field associated with the EDL, acceleration of the neutral shock front, and the development of a neutral precursor ahead of the shock. Ion-electron recombination was seen to reduce these effects.

Descriptors:

• *PLASMAS(PHYSICS)
• *SHOCK WAVES
• *GLOW DISCHARGES
• THESES
• ELECTRIC FIELDS
• WAVE PROPAGATION
• NONEQUILIBRIUM FLOW
• EULER EQUATIONS
• FLUID DYNAMICS
• DRAG REDUCTION

Subject Categories:

• Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE