Efficient numerical investigation of flow control on wind turbine rotors under realistic conditions

• Applicant: Professor Dr.-Ing. Christian Oliver Paschereit
• Subject Area: Fluid Mechanics
• Term: from 2012 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 218654480

The common goal of the research focus is the improvement of design and calculation methods for wind turbine load control solutions through experimental and numerical means. In addition to detailed high fidelity CFD simulations, engineering level design tools, which allow for parametric investigations or certification like simulations of different flow control concepts were developed during the first project phase. Additionally these tools are also used to project experimentally obtained results from wind tunnel tests to real size wind turbines. In PP1, a toolchain for the aero-elastic and unsteady simulation of flow control equipped wind turbine rotors has been established and validated. Successively the performance and feasibility of different flow control technologies considering realistic inflow conditions and aero elastic effects was investigated. However, many additional aspects of load control applications need further investigation before this technology can be integrated in the complex wind turbine system. To realistically asses the performance and potential of active and passive flow control, advanced simulations that not only include realistic unsteady aerodynamics, inflow and structural, but also realistic wind turbine controllers, shall be carried out. As wind turbines are often clustered in large windfarms, the effects of wake-rotor interactions on flow control performance, and the effect of flow control solutions on the loads and yield of successive turbines are questions that will also be addressed within the proposed prolongation. To achieve such feasibility for the simulation tools the functionality will be extended around the following aspects: In a first step the aerodynamic model will be extended with an advanced dynamic stall model, which also captures the dynamic lift response of flap movement. To enable the investigation of the interaction between flow control elements, their control and the resulting load changes with the main wind turbine controller, wind turbine controllers will be integrated in the simulation environment. Furthermore the code will be extended such that the mutual interaction between wind turbines in a wind park and the effects of this wake-turbine interaction on the feasibility and performance of different load control systems can be simulated. A focus during the continuation of development will be set on computational efficiency, as it is necessary to simulate a large amount of load cases to fully address the feasibility and performance of load control on wind turbine rotors.

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Christian Nayeri