An investigation of the flowfield characteristcs around a rotor blade during a blade-vortex interaction (BVI) was conducted at the NASA Langley Research Center by the Army's Aeroperformance Division and the Boeing Defense and Space Group, Helicopter Division, during a wind-tunnel test in the 14 by 22-foot Subsonic Tunnel. A two-component laser velocimeter was used to measure the flowfield near the rotor blade, and the blade-mounted surface pressure transducers were used to measure the blade pressure during a BVI. This paper presents velocity measurements that indicate the presence of a vortex in the flowfield and blade surface pressures during a BVI. The following conclusions can be made from this investigation: 1) The streamlines and vectors of the induced velocity, when studied in conjunction with the blade surface pressures, inicate how the flowfield is behaving during a BVI. The blade approaches and intersects a vortex, and the vortex slides beneath the blade. 2) The data provide detailed flowfield information for validating computational predictions of BVI and also for evaluating and improving current wake models. Among the options investigated, only the free-wake calculation by TECH-01 indicated any BVI activity in the first quadrant.
Laser velocimetry and blade pressure measurements of a blade-vortex interaction
Laser-Geschwindigkeits- und Rotorblattdruckmessungen während einer Rotorblatt-Wirbel-Interaktion
Journal of the American Helicopter Society ; 40 , 2 ; 15-23
1995
9 Seiten, 11 Bilder, 3 Tabellen, 34 Quellen
Article (Journal)
English
Laser Velocimetry and Blade Pressure Measurements of a Blade-Vortex Interaction
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