Accession Number:

ADA209657

Title:

Coupling between Radiation and Gas Dynamics

Descriptive Note:

Final rept. 1 Feb 1988-1 Feb 1989

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING

Report Date:

1989-05-24

Pagination or Media Count:

40.0

Abstract:

Heat addition in flowing gases by electromagnetic wave absorption is being considered for propulsive purposes. The research includes both microwave and solar radiation. In the microwave studies, an experimental investigation of helium and nitrogen discharges has shown that free-floating plasmas can be established in either medium for a range of input powers and gas flow rates, although helium gives the broader range of stable limits. The discharges are being set up in a 10.2 cm quartz sphere. For pressure ranges from 0.5 to 5.0 atm and input powers to 3 kW, maximum coupling efficiencies are measured to be between 40 and 65 with higher efficiencies for cases with larger flow rates. Spectroscopic techniques are being introduced to provide detailed local measurements of conditions inside the discharge. In companion analytical efforts, computational techniques are being used to model the experimental flowfields to provide improved understanding of the absorption process and to enable us to extend the experimental findings to broader conditions. In the solar radiation studies, the feasibility of direct absorption of solar energy in flowing conditions is studied. Similar computational studies are also being used to study the absorption of solar radiation in hydrogen with alkali seedants. Results show peak gas temperatures of about 3500-4000 K can be reached with reasonable solar concentration ratios.

Subject Categories:

  • Lasers and Masers
  • Fluid Mechanics
  • Atomic and Molecular Physics and Spectroscopy
  • Optics
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE