Model and full scale study of twin supersonic plume resonanceThis paper examines the effect of both nozzle geometry and scale on the twin supersonic plume resonance phenomenon associated with aircraft having engine nozzle center-to-center spacings less than two diameters. Exit plane near field dynamic pressures were measured for both single and dual nozzle operation in 4.7 percent model and full scale under static conditions. The frequencies associated with this phenomenon were predicted to within 5 percent for a full scale F-15 aircraft. Amplitude levels associated with this phenomenon were found to dominate the dynamic pressure fluctuations in the inter-nozzle region, and reach a level near the structural design limit for this aircraft. The model scale studies, which involved both axisymmetric and rectangular geometry, indicated that amplitude levels could be expected to be much higher in flight. High amplitude levels would likely occur in the overexpanded region for axisymmetric geometry, and in the underexpanded region for rectangular geometry.
Document ID
19870035233
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Seiner, John M. (NASA Langley Research Center Hampton, VA, United States)
Manning, James C. (NASA Langley Research Center Hampton, VA, United States)
Ponton, Michael K. (PRC Kentron International Hampton, VA, United States)