Comparison of experimental and analytical predictions of rotor blade-vortex interactions using model scale acoustic dataHelicopter blade-vortex interaction (BVI) noise is studied using a model scale rotor acoustic data base and an analytical rotor wake prediction method. The variation of BVI acoustic levels with vehicle flight conditions (forward speed and disk attitude) is presented. Calculations of probable BVI locations on the rotor disk are made for a range of operating conditions using the measured acoustic signals and an acoustic ray tracing technique. Analytical predictions of possible BVI locations on the rotor disk are made using a generalized distorted wake analysis program. Comparisons of the interaction locations are made with the results of both the analytic approach and the acoustic ray tracing technique.
Document ID
19850028682
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Martin, R. M. (NASA Langley Research Center Hampton, VA, United States)
Elliott, J. W. (NASA Langley Research Center Hampton, VA, United States)
Hoad, D. R. (U.S. Army, Structures Laboratory, Hampton VA, United States)