Numerical Simulations of Flowfields in a Central-Dump Ramjet Combustor. 3. Effects of Chemistry
Abstract
This report is the third in a series which presents the results of numerical simulations performed to isolate and study acoustic-vortex-chemical interactions in an idealized ramjet consisting of an axisymmetric inlet and combustor and a choked nozzle. Both reactive and nonreactive flows have been simulated. The nonreactive flow calculations show complex interactions among the natural instability frequency of the shear layer at the inlet-combustor junction and the acoustics of both the inlet and the combustor. The entire flow oscillates at a low frequency which corresponds to that of a quarter-mode in the inlet. For the reactive flow cases studied, energy release alters the flow field substantially. Energy release in a large vortex is in phase with the pressure oscillation over a substantial region of the combustor and results in the observed amplification of the low-frequency oscillations and leads to combustion instability. The large pressure oscillation also modifies the vortex shedding process. Keywords: Ramjet, Turbulence, Combustion instability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1990
- Accession Number
- ADA224145
Entities
People
- Elaine Oran
- Jay Paul Boris
- John H. Gardner
- Kazhikathra Kailasanath
Organizations
- United States Naval Research Laboratory