Accession Number : ADA297061

Title :   Multiplexed Laser Induced Fluorescence and Non-Equilibrium Processes in Arcjets.

Descriptive Note : Final Technical rept. 15 Mar 91-14 Sep 94,

Corporate Author : TENNESSEE UNIV SPACE INST TULLAHOMA CENTER FOR LASER APPLICATIONS

Personal Author(s) : Keefer, Dennis ; Rhodes, Robert ; Moeller, Trevor ; Burtner, David

PDF Url : ADA297061

Report Date : 14 NOV 1994

Pagination or Media Count : 21

Abstract : For the past five years there has been an ongoing experimental and analytical program at the University of Tennessee Space Institute (UTSI) to improve our understanding of arcjet physics. A computational model that assumed local thermodynamic equilibrium was first used to simulate arcjet thrusters operating on ammonia, hydrogen, and argon. The UTSI arcjet code was later extended to include a two temperature, finite rate kinetic model for hydrogen plasma. Recently, this code has been used to simulate a radiation-cooled arcjet (MARC thruster) experiment and a water-cooled arcjet (TT1 thruster) experiment performed at The Universitat Stuttgart Institut fur Raumfahrtsysteme. The results of these simulations are presented along with a review of UTSI arcjet computation code development. A two-beam multiplexed laser induced fluorescence (LIF) technique was developed at UTSI to provide detailed measurements of arcjet flows near the nozzle exit plane. Comparison of detailed flowfield measurements with predictions of the computation model were used to provide insight into the physical models used in the arcjet code. The method was first demonstrated using a small, 300 W, water-cooled arcjet operated with argon propellant. The method was then applied to a 1 kW arcjet operated with hydrogen and nitrogen propellant mixtures using the Balmer alpha line of hydrogen. Recently, the method has been extended to use an excited state line in nitrogen. The results of this most recent research are presented. (MM)

Descriptors :   *LASER INDUCED FLUORESCENCE, *ARC JET ENGINES, COMPUTERIZED SIMULATION, THERMODYNAMICS, PLASMAS(PHYSICS), COOLING, AMMONIA, HYDROGEN, OXYGEN, NOZZLES, MULTIPLEXING, THRUSTERS.

Subject Categories : Electric and Ion Propulsion
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE