ICNPAA 2010: Mathematical Problems in
Engineering, Aerospace and Sciences

Most aerodynamic design tools for wind energy converters are based on the blade element-momentum theory. Due to the nature of this theory, the design tools need “2D steady” sectional lift and drag curves as an input. In practice, flow over a wind turbine rotor blade is neither two-dimensional nor steady, and is affected by rotation. Pioneering experiments have identified a consequence: at inboard rotor blade sections stall is delayed. This so-called Himmelskamp effect gives a longer lift than predicted, and, as a result, a higher power and loading than expected. Consequently, an aerodynamic analysis tool is needed to predict sectional lift and drag under rotating conditions. In this paper, development and validation of such a tool is described, with the wind turbine application in mind.