Fluid Dynamics

Dynamics and destabilization of helical vortices

In the field of wind turbine aerodynamics, exciting the wake for inducing earlier wake breakdown has been proposed as an attractive possibility to increase the energy yield. At the heart of this concept is the stability of a helical wake. Although analytical treatments of the problem exist for idealized conditions, experimental and numerical investigations identifying the most effective modes of excitation are required if effective measures are to be well understood and exploited. The research plan of the ongoing DFG funded project “Dynamics and Destabilisation of Helical Vortices” aims directly at addressing this knowledge gap by undertaking a synergetic collaboration between experimental testing in a towing tank (Fig. b) and advanced numerical simulation. It is planned to generate for the first-time high resolution experimental and numerical data illustrating the practically excitable modes of instability of a wind turbine wake. A down scaled wind turbine tank (Fig. b) called UBeRT (Under water Berlin Research Turbine) will be towed in the towing tank and its wake will be analysed using Particle Image velocimetry.