WER-24rev.: Horizontal axis wind turbine wake and blade surface flow measurements from model tests
Wentz, W.H., Octowari, C., Manor, D. and M.H. Snyder. Horizontal axis wind turbine wake and blade surface flow measurements from model tests. Wichita State University. Center for Energy Studies, 1985.- 60 p.
Wind tunnel tests have been conducted to measure the wake and surface flow associated with a 50.8 cm diameter twisted, tapered rotor and a 50.8 cm diameter untapered, untwisted rotor. A disk model of 50.8 cm diameter was also tested. Torque and thrust were measured with a unique generator-mounted balance. Wake surveys were conducted using a scanning total pressure probe and special hot film anemometer. Blade surface patterns were observed using small tufts and a strobe light. The untwisted rotor produced thrust coefficients higher than 1, and wake regions of velocity reversal at high tip speed ratios. For high tip speed ratios the wake flow is quite similar to the solid disk. Blade surface flow patterns reveal the blade stall progression associated with angle of attack changes as the tip speed ratio varies.