Airfoils in Turbulent Inflow

The objective of the study is to investigate the influence of inflow turbulence on the performance of wind turbine airfoils. The turbulent flow past an airfoil is simulated by Computational Fluid Dynamics using techniques to resolve the turbulent structures.

The turbulent velocity field used for inflow is generated by the method of Mann (1998) or a method developed during the project. To avoid that the turbulence prescribed on the inlet boundary decays before it reaches the airfoil, a method to sustain the turbu-lence will be developed.

The results of the simulations will be validated against results from wind tunnel and full-scale tests. The pressure distribution along the chord is measured for an airfoil in a wind tunnel with grid generated turbulence. The full-scale experiments will provide validation for simulations of a blade rotating in an atmospheric turbulence field.

The outcome of the analyses is basic knowledge of the influence of inflow turbulence. This knowledge may contribute to making new guidelines for design of more efficient airfoils for wind turbines.