Improvement of BEM and Vortex-wake models, TKI WoZ VortexLoads WP4
report
Within the framework of the TKI WoZ VortexLoads, improvements to both BEM and free vortex wake codes have successfully been implemented with the end goal to make wind turbine design load calculations more accurate. Here we can distinguish improvements to BEM type codes, which focus on engineering models and their implementation to make these more accurate. A model to account for the influence of the blade shed vorticity has been successfully implemented based on the time history of the vortices in the wake of each blade element. Application of this model was shown to bring BEM simulation results closer to the free vortex wake simulations at a relatively small extra computational expense. Another approach that has been researched is the definition of a representative streamtube wind speed in non-uniform inflow conditions for improved induction tracking. Although the first result of this approach both in sheared and turbulent inflow are very promising (in combination with shed vorticity modeling, the fatigue load difference with vortex wake codes almost disappears), more research is necessary on this topic to come to a more conclusive implementation, assuring not to unintendedly cover up other effects such as shed and trailed vorticity variation.
Topics
TNO Identifier
868955
Publisher
TNO
Collation
55 p.
Place of publication
Petten