Compressible Turbulent Reading Flows
Abstract
Research was conducted under this grant to advance fundamental understanding and predictive models of turbulent reacting flows relevant to Air Force needs in high-speed propulsion Advanced computational schemes including direct numerical simulation (DNS) and large eddy simulation (LES) were used in addition to turbulent combustion theory. Reduced chemical mechanisms for hydrogen-air combustion were developed and tested. Specific flows investigated include the reacting shear layer and the jet. A new mechanism that relates the reduction in fuel/oxidant mixing in high-speed flows to the inhibited communication of pressure signals was proposed. A resulting compressibility model was found to give good predictions. Both mean density changes and Mach number were found to affect the flow development in high-speed combustion. It was found that the transport and molecular mixing of reactive scalars are substantially affected by heat release and must be accounted for in closures of turbulence/chemistry interaction. LES of a spatially-evolving jet were performed and successfully compared with our DNS and previous experiments. New subgrid scale models were developed for LES of nonequilibrium flows. The results obtained here should help improve current abilities to analyze and design propulsion systems that employ high-speed turbulent combustion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1999
- Accession Number
- ADA378325
Entities
People
- F. A. Williams
- P. A. Libby
- Suman Sarkar
Organizations
- University of California, San Diego