Patent ID: 9664173
Date: 2017-05-30
CPC Classifications: F03D,F05B,Y02E

Claim:
1. A tip airfoil of a blade of a small-scale wind turbine, the tip airfoil having a suction surface and a pressure surface formed at an upper side and a lower side of a chord line which connects a leading edge and a trailing edge, wherein the chord line has a length C extending in a straight line between the leading edge and the trailing edge, wherein the pressure surface has contours expressed by coordinates (X/C, Y/C) substantially as follows: (0.2, −0.028), (0.4, −0.015), (0.6, −0.008), (0.8, 0.003), and (1.0, 0.0), wherein the X/C values are dimensionless coordinates that represent locations on the chord line and the Y/C values are dimensionless coordinates that represent heights from the chord line to points on the pressure surface or the suction surface, wherein an operating Reynolds number is 30,000 to 1,000,000, an angle of attack of the airfoil is 0 to 21 degrees, a maximum lift coefficient is 1.2 to 1.5, and a minimum drag coefficient is 0.01 to 0.06.