Accession Number:

ADA612441

Title:

Large-Eddy/Reynolds-Averaged Navier-Stokes Simulation of Shock-Train Development in a Coil-Laser Diffuser

Descriptive Note:

Final rept. 1 January 2013-6 September 2014

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s):

Report Date:

2014-09-06

Pagination or Media Count:

22.0

Abstract:

This report describes the application of a hybrid large-eddy simulation Reynolds-averaged Navier-Stokes method to predict shock train formation and reactant mixing in a model Chemical Oxygen Iodine Laser COIL unit. The configuration consists of a converging-diverging nozzle, a lasing cavity, and a diffuser. Results have been obtained for several grids and for several back pressures, the variation of which fixes the average shock-train position within the nozzle. Predictions of wall pressure are in reasonable accord with experimental observations for both LESRANS and RANS model but tend to under-predict the initial rate of pressure increase as the flow encounters the leading edge of the shock train. Though the shock train induces a transition to turbulence as well as local flow separation, the effects of resolved turbulence and unsteady separation do not appear to influence the mixing process in the lasing cavity significantly.

Subject Categories:

  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE