Large Eddy Simulation of High-Speed Combustion in Dual Mode Ramjet Combustors
Abstract
Hypersonic air-breathing flight vehicles capable of reaching flight speeds of Ma 7 to 8 are believed to be part of the future in fast long-range civil transportation, long-distance fast strike capabilities, and space transportation to low-earth orbit. Among the challenges for developing such capability, the propulsion plant is probably the single most challenging element. At flight speeds in excess of ~Ma 3, dual-mode ramjet engines have been identified as the most promising candidate, which seamlessly can operate both in ramjet mode at 3<Ma<5 and in scramjet mode above Ma 6. The aerothermodynamics involved is extremely challenging and exhibits different flow conditions for ramjet and scramjet operation, and particularly for the mode-switching conditions around 5<Ma<6. Many successful experimental high-speed combustor studies have been reported during the last decades using direct-connect vitiated-air facilities, arc-heated facilities, or piston driven shock-tunnels, providing data for analysis and validation. The alternative to experiments is numerical simulations based on the reactive flow equations and a chemical reaction mechanism representing the combustion process. The Large Eddy Simulation (LES) turbulence modeling method has proven most useful for reactive flows, and particularly for ram- and scramjet flows in which the flow and chemical time scales are similar. The key attributes for successful LES of high-speed combustion is that the LES model is well-balanced i.e. that all sub-models are of the same generation, that the chemical reaction mechanisms are of sufficient complexity, and that all relevant physics is properly included using models of the same generation. This is not always the case. In the proposed study we will develop improved, well-balanced, LES models for high-speed combustion applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2023
- Source ID
- FA86552217169
Entities
People
- Christer Fureby
Organizations
- Air Force Office of Scientific Research
- Lund University
- United States Air Force