EFFECT OF DRAG-REDUCING POLYMER INJECTION ON THE LIFT AND DRAG OF A TWO-DIMENSIONAL HYDROFOIL

摘要

The present paper describes an experimental investigation on the effects of injecting drag-reducing polymer solutions into the turbulent boundary layer of two NACA 63, two-dimensional, symmetrical, hydrofoils. The experiments were performed in a high-speed circulating channel with free stream velocities of up to 13 m/sec. The two foils used were 10 and 20 cm in chord, though both had a maximum thickness of 2 cm. The incidence of the foils varied between plus or minus 5 degrees with the ratios of the injection to free stream velocity of up to 0.2, and a concentration of poly(ethylene oxide), POLYOX WSR 301, of 200 ppm. The injection slits on both foils are situated one-tenth of a chord downstream of the leading edge. The gap of the injection slit was 0.0127 cm for the small foil and twice this value for the larger foil. (Modified author abstract)