Whole-Field Velocity Measurement for Rotorcraft Aerodynamic Interactions

Measurements of instantaneous velocity fields in rotorcraft flows are reported. The Spatial Correlation Velocimetry (SCV) technique is used to study two configurations - the first is an isolated rotor, and the other is a wing-rotor combination. Previous results are shown to indicate the expected accuracy and application to various problems. Both configurations are tested in low speed forward flight in a wind tunnel. In the wing-rotor flowfield, data acquired with a pulsed laser sheet are used, along with a continuity equation solver, to extract all three components of the periodic velocity field within a large volume. The isolated rotor experiments are made with pulsed white light sources, identical to those used in testing at large rotorcraft facilities. Preliminary comparisons are made with point-wise velocity data acquired using laser velocimetry.