Modeling and analysis of transition to turbulence in wind turbines

Background

Prediction of transition to turbulence in wind turbine blades plays a major role in the accurate determination of aerodynamic loads and performance of wind turbines. The turbulent flow regime is generally associated with higher loads on the blades, but it can prevent flow separation, which is linked to a sharp deterioration of the blade performance.

Aims

The current project aims at providing reliable estimates for the transition location with a faster and computationally less demanding method. It also aims to analyze the effects of rotation and three-dimensionality on transition.

Approaches

A model based on the boundary layer equations in a rotating frame of reference has been developed to generate velocity profiles along the blade. This model allows obtaining an approximation for the base-flow over a portion of the blade in a much faster way compared to RANS simulations. The stability analysis, which provides an estimate for the transition location, is subsequently carried out by providing the Parabolized Stability Equations (PSE) with the velocity profiles previously obtained.

Keywords

Hydrodynamic stability; transition to turbulence; wind-turbine aerodynamics

Links

See the preprint of the article “Low-order modeling for transition prediction applicable to wind-turbine rotors” submitted to the Wind Energy Science journal here.

Project leaders

Dan Henningson, KTH

Other project members

Ardeshir Hanifi, KTH; Thales Fava, KTH.

Other funding agencies

In 2021, the project has received funds from the European Project TRANSEP.