Patent ID: 6729846
Filing Date: 2004-05-04
Classification: B08B,F03D,F05B,F05D,Y02E,Y02P

Abstract:
A wind power installation rotor blade comprising:means for reducing the sound generated by a rotor blade, wherein the means are formed by a fluid-repellent surface which is provided at least on a surface portion of the rotor blade, said means including a plurality of ribs over which a turbulent flow, having a main flow direction, passes, wherein said ribs are orientated in the main flow direction, wherein said ribs are spaced laterally in relation to the main flow direction, and wherein said ribs have a height, which is between 30% and 70% of a lateral rib spacing of the ribs, the ribs being spaced from each other a distance within a range of the values 12 to 22 for a standardized lateral rib spacing s+ described by the equation: s+=(s/ny)*(tau0/rho) wherein s is the lateral rib spacing, tau0 is the wall thrust stress of a smooth reference surface which is exposed to the same flow, rho is the density of the fluid and ny is the kinematic viscosity of the fluid.