DLR Research about Wind Turbine Wake Impact on Helicopters

Abstract

Through the massive expansion of wind energy in Germany, helicopter operations, onshore and offshore, are more frequently conducted in the vicinity of wind turbines. Especially during typical maintenance, search and rescue or police operations, the pilot has to fly close to the ground and may cross the wake of these turbines. Evaluations about the impact of wind turbine wakes on helicopters are very scarce and thus operational limits for aircraft flying close to them are not based on physical reasons. Therefore DLR has decided to investigate this issue in detail. Starting from trim calculations about an isolated rotor hovering in a straight line vortex, the work was extended to forward flight. This paper will give an overview about this topic by describing the approach, first results and next steps in detail.