COMBUSTION OSCILLATIONS IN A TWIN-STREAM AFTERBURNER

✍ Scribed by M.A. Macquisten

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 514 KB
• Volume: 188
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1995.0610

✦ Synopsis

In a modern turbo-fan engine, the afterburner flame-holders are positioned in the mixing flow between the core and bypass streams. These two streams have different velocities and temperatures. They also have different duct lengths and, therefore, different acoustic properties. The influence of such a twin-stream supply on acoustically coupled combustion oscillations is investigated in this paper. Measurements on an experimental rig show how differences in the acoustic impedances, the mean velocities and the mean temperatures in the two supply streams lead to appreciably different unsteady heat release rates in the two streams. These affect the frequency of the combustion oscillation. A theory explains these results and correctly describes the variation in frequency as the properties of the two supply streams are varied.