Wind turbines contain generators, power electronics and other components that release heat during operation. These components are installed in the nacelle, where excessive temperatures can reduce efficiency and component life. Cooling is therefore essential, but active cooling systems also consume energy and require maintenance.
FlowMotion investigated whether the external airflow around the nacelle could be used for passive cooling. CFD was used to calculate the pressure and velocity distribution around the nacelle for relevant operating conditions.
The local pressure differences around the nacelle can drive ventilation flow through appropriately positioned openings. The amount of cooling air is therefore determined not only by the free-stream wind speed, but also by the aerodynamic pressure distribution over the nacelle surface and the resistance of the internal flow path.
The simulations made it possible to determine suitable positions for air inlets and outlets and to assess the resulting internal volumetric flow. The concept could therefore be evaluated before physical modifications were made.
Using the naturally available external airflow can reduce the need for active cooling while maintaining acceptable component temperatures.
