The application of planar Doppler velocimetry (PDV) measurements to three-dimensional velocity vector fields in the tip-vortex flows between the blades of a full-scale UH-60 rotor operating in the 80- by 120-Foot Wind Tunnel at NASA Ames Research Center is described. The unique capabilities of PDV for remotely measuring complex velocity fields in large-scale flows are demonstrated and the factors affecting the quality of PDV data from a large-scale facility are defined. Because the wind tunnel is a noncirculating, in-draft configuration, and very large, the principal factor that prevented the acquisition of time-resolved, instantaneous measurements was the spatially and temporally sporadic behavior of the aerosol seeding in the sample area. Nevertheless, time-averaged velocity fields were obtained that characterize the locations and velocity distributions of the blade tip vortices and that provide magnitudes and directions of the velocity vectors in the surrounding flow with better than 1-cm spatial resolution within a square, 1.2 m x 1.2 m, sample area from distances up to 20 m.
Three-dimensional planar Doppler velocity measurements in a full-scale rotor wake
Ebene Doppler-Geschwindigkeitsmessung der dreidimensionalen Strömung im Nachlaufgebiet eines Hubschrauberrotors
AIAA Journal ; 43 , 3 ; 489-499
2005
11 Seiten, 14 Bilder, 25 Quellen
Article (Journal)
English
dreidimensionale Strömung , Geschwindigkeitsfeld , Hubschrauber , Laser-Doppler-Geschwindigkeitsmessung , Modellversuch , räumliche Auflösung , Rotor (Drehflügel) , Schaufelspitze , Strömungsgeschwindigkeitsmessung , Versuchsaufbau , Windkanalprüfung , Wirbelströmung , zeitlicher Mittelwert , Nachlaufströmung , Wirbelkern , bildgebendes Verfahren