Research on Noise Generated by Ducted Air-Fuel Combustion Systems.
Abstract
Throughout the research program, emphasis has been placed on obtaining a better understanding of the importance of combustion as a source of noise in jet engines. This has been pursued in terms of theoretical modeling and experimental investigations. A theoretical model was developed to allow computation of the role internal sources as well as external sources. Calculations based on reasonable approximations indicated that for subsonic jet velocities, internal sources could be much more important than the jet noise sources. Experiments in a cold flow with cylindrical struts immersed in the flow to generate unsteadiness demonstrated this effect. More to the point, experiments with a ducted combustor also verified that the combustion, though occurring inside the duct, causes unsteadiness in the exhaust flow which is directly responsible for noise generation. The noise thus attributable to the combustion was found to be dominant over jet noise for subsonic jets to mach numbers of approximately 0.6. A unified theory of combustion noise generation was developed. Direct verification of the importance of the various source terms was begun. Initial results suggest that at least several of the terms are important.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1977
- Accession Number
- ADA039957
Entities
People
- E. G. Plett
- M. Summerfield
Organizations
- Princeton University