Extensions to the Wilson-Lissaman prop code for steady and dynamic rotor performance prediction.

Wind turbine rotor performance prediction using the Wilson-Liss man 'prop-code' has several limitations that restrict its usefulness. This paper presents a brief theoretical discussion and computation algorithms developed to overcome the limitations of the prop code and these extensions are used to predict performance of a prototype wind turbine for use at Corps facilities. Both algorithms use the individually computed blade element approach, as in the prop code, but compute the locally induced velocity based on either generalized, classical rotor performance equations and a prescribed induced velocity pattern, for steady state application, or a time dependent, state variable approach with dynamic inflow variation for transient analysis. Correlations of experimental and analytical performance results for a prototype 7.6 meter (25 foot) diameter wind turbine are presented both illustrating the method, and showing that dynamic effects are important in predicting performance of constant tip speed ratio wind turbines, and that the dynamic effects degrade their performance. (from author's abstract)