Rotorcraft Aerodynamics
Group

Measurements of Rotor Tip Vortices Using Three-Component Laser Doppler Velocimetry

Dr. J. Gordon Leishman, Andrew Baker, and Alan Coyne

Abstract

Phase-resolved measurements were made of the three-dimensional velocity field and tip vortex structure in the wake of a hovering rotor using laser Doppler velocimetry (LDV). A one-bladed rotor was used to generate a single helical vortex in the rotor flowfield. The measurements were analyzed to establish the detailed structure of the rotor tip vortex, such as tangential velocity profile, axial velocity deficit, circulation distribution, core size, and core growth with vortex age. Also discussed are possible sources of error and uncertainties in extracting these results using LDV.

Picture of
LDV and Rotor Set-up

Presented at the American Helicopter Society Aeromechanics Specialist's Conference, Fairfield County, CT, October 11-13, 1995.

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Alan Coyne

Last modified: Sat Feb 10 14:39:36 EST 1996 by fencer