Project Details
Projekt
Wake-Aware Wind Turbine Rotors
Subject Area
Fluid Mechanics
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 531570398
Wakes produced by upstream wind turbines have a profound influence on the performance of downstream machines. In fact, compared to clean isolated conditions, waked turbines experience a lower power output and increased loading. The wake of a turbine consists of a sheet of vorticity caused by the spanwise change in bound circulation along the blade, which rolls up forming concentrated root and tip vortices. These near-rotor coherent vortical structures distort and eventually break down, leading to an increased turbulent mixing and entrainment of kinetic energy across the wake shear layer. In turn, this leads to the recovery of the wake further downstream. The WakeAware project shall help to further understand the wake recovery mechanisms and finding techniques to enhance it, thus the central scientific question is: How can one accelerate wake recovery by a suitable combination of choices in the design of the rotor and adhoc control inputs, without significantly affecting power capture at the rotor disk? An answer to this central question will be achieved by a combined experimental and numerical study pursuing the following related objectives: Advance the fundamental understanding of wake physics, clarifying what inputs, at which frequencies, and through which mechanisms accelerate the recovery of wind turbine wakes. Understand the main parameters in the aerodynamic design of a rotor that drive near-wake instability, breakdown, recovery and deflection. Optimize the choice of these parameters marrying the classical requirement of an efficient isolated-rotor power capture with the one of an enhanced wake recovery (which leads to an improved power capture at the plant level). Maximize the synergy among all aspects of the problem by co-designing the aerodynamics with the control inputs. Assess the benefits gained by the new knowledge generated within the project, by exercising the new analysis and design methods on relevant applications, capable of showing the potential impact of these results on the field. These objectives build on an improved understanding of wake physics, and marry rotor design with wake deflection, induction and mixing control inputs through the emerging concept of co-design. By reaching these objectives, a step towards the goal of “mitigating the crucially important problem of wake effects in wind farms”, recognized as one of the main priorities in the field of wind energy science can be accomplished.
DFG Programme
Research Grants
Co-Investigators
Filippo Campagnolo, Ph.D.; Franz Muehle, Ph.D.
