INFLOW MEASUREMENT MADE WITH A LASER VELOCIMETER ON A HELICOPTER MODEL IN FORWARD FLIGHT Volume II RECTANGULAR PLANFORM BLADES AT AN ADVANCE RATIO OF 0.23

摘要

An experimental investigation was conducted in the 14- by 22-Foot Subsonic Tunnel at NASA Langley Research Center to measure the inflow into a scale model helicopter rotor in forward flight (μ∞ = 0.23). The measurements were made with a two component Laser Velocimeter (LV) one chord above the plane formed by the oath of the rotor tips (tip path plane). A conditional sampling technique was employed to determine the azimuthally position of the rotor at the time that each velocity measurement was made so that the azimuthally fluctuations in velocity could be determined. Measurements were made at a total of 180 separate locations in order to clearly define the inflow character. This data is presented herein without analysis.