Computational Issues in Analysis and Design of Chemical-Laser FLow-Fields

Abstract

The Phase-I COIL effort has focused on extending AeroSoft's GASP and SENSE software for COIL-laser analysis and design. Important improvements include: modifications to the species diffusion model to account for effective diffusion coefficients and pressure-driven diffusion effects, modifications to account for laser power extraction, the addition of a COIL chemistry model, and the development of a strategy for implementing a coupled flow-solver/power-extraction sensitivity analysis method. Results for test problems involving helium and iodine injection showed significant effects from the pressure-diffusion terms. Fully-coupled, power-on laser simulations exhibited an instability resulting from an uncoupling of grid points caused by the bi-linear interpolation method used to transfer data back and forth between the optics mesh and the flow-solver mesh. This problem occurred when there was a large disparity in the number of grid points for the flow-solver and optics mesh in the lasing cavity. Stable power-on results, however, could be obtained for well-matched flow-solver/optics grid systems. Future plans to implement a conservative interpolation scheme should eliminate this problem.

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Document Details

Document Type
Technical Report
Publication Date
Dec 31, 1999
Accession Number
ADA380326

Entities

People

  • Eugene Cliff
  • W. M. Eppard

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Chemical Lasers
  • Chemical Oxygen Iodine Lasers
  • Chemistry
  • Computational Fluid Dynamics
  • Diffusion Coefficient
  • Flow
  • Flow Fields
  • Fluid Dynamics
  • Fluid Mechanics
  • Geometry
  • Interpolation
  • Laser Applications
  • Lasers
  • Numerical Analysis
  • Payload
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Optical Fiber Sensing and Electromagnetic Propagation.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers