Joint investigation of dynamic inflow effects and implementation of an engineering method

Abstract

The aim of the projects was to develop one or more engineering models, for the wake induced unsteadiness and non-uniformity in the rotor inflow, which occur at pitching variations (full span as well as partial span), coherent wind gusts and yawed conditions. An engineering method means a computationally effective model which can be implemented in state of the art aeroelastic computer programs for wind turbine design. Validation of the engineering methods was based on full scale measurements, wind tunnel measurements and comparison of results with advanced free wake methods. It is shown that the models which have been developed lead to a definite improvement to standard blade element momentum theory. This is of particular importance for the correct prediction of yaw loads and loads on turbines which are exposed to pitching variations