Airfoil design and wind tunnel verification
The aerodynamic properties of a rotor blade and therefore the efficiency of the wind turbines are significantly influenced by the design of the airfoils. The IAG has a long-year experience in aerodynamic and acoustic design of airfoils for the use in wind energy applications and in the assesment of airfoils. The airfoils are specifically designed for the requirements of the considered wind turbine. A verification of the theoretical results can be made at the Laminar Wind Tunnel of the Institute, which has a very low turbulence level. Additionally to polar, pressure distribution and boundary layer measurements, aeroacoustic measurements can be performed using the CPV method. Measurements performed at the Wind Tunnel are also used for the improvement of the airfoil design and analyse methods.
- Boundary Layer Methods, Transition detection, Modelling of laminar separation bubbles
- Noise prediction tools
- Optimization methods
- Fabrication of wind tunnel models
- Aerodynamic measurements (polar, pressure distribution and boundary layer measurements)
- Aeroacustic measurements
Steady and unsteady CFD simulation of wind turbines
To analyze the aerodynamics of a wind turbine is not just important for the energy production but also important for loads and fatigue. As the wind turbines are rising in size and power output, measurements of the aerodynamics are often not possible or too expensive. Therefore numerical methods are used to identify the wind turbine aerodynamics. For this purpose a CFD based process chain was developed and applied at the Institute of Aerodynamics and Gas Dynamics (IAG), University of Stuttgart. The process chain consists of a grid generator with scripting capability for automated meshing, the block structured flow solver FLOWER, which is provided by the German Aerospace Center (DLR) and optional of a multibody simulation for aeroelastic simulations.
Interaction with turbulent inflow and turbine wake
The atmospheric boundary layer has a significant impact on the blade aerodynamics. Therefore the used CFD-code has been extended by an unsteady inlet boundary condition. This condition allows to set time depended boundary layer conditions. Because of this it is possible to simulate wind turbines under more realistic atmospheric conditions (wind speed distribution, density and turbulence) and to determine the interaction between the atmospheric boundary layer including resolved turbulence and the wind turbine as well as the wake of the turbine.
Highly resolved CFD wake simulations
There is an increasing interest in the numerical simulation of the unsteady aerodynamics and the determination of the interaction between wake and turbulent atmospheric boundary layer to investigate the effect on the inflow conditions of following wind turbines, the loads and their fluctuations. To do so, the wake is highly resolved and simulated with methods of higher order.