Modeling Coriolis and stability effects on wake dynamics for wind farm flow control

在风电场内运行的风力涡轮机在空气动力学上相互作用。通过从风中提取电力，风力涡轮机在顺风向产生以低风速和高湍流为特征的尾流区。尾流相互作用会显着降低风电场的效率，但可以通过控制风场中的风流来缓解。鉴于风能发电量的不断扩大，人们越来越需要提高有关风力涡轮机和大气流动之间相互作用的流体力学知识，并利用这些知识来提高农场的效率。该研究项目将对大气流动对风力涡轮机尾迹的影响进行表征和建模。这项研究的工作假设是，考虑地球自转、浮力和温度变化的大气影响将提高风电场流动模型的预测精度，并在使用基于模型的流动控制时提高农场的效率。这项研究将在广泛的大气条件下通过计算机模拟来表征这些大气效应对尾迹的影响。将开发和验证一个新的流动模型来捕捉这些影响，并将该模型用于流动控制的案例研究。该项目的气候变化缓解影响将被整合到与K-12学校的合作中，为麻省理工学院的学生提供关于能源系统物理职业生涯的课程和指导，以及与能源行业关于尾流损失、建模和流动控制的研讨会。这项研究将描述和模拟地球自转的科里奥利力的影响，以及浮力和温度梯度对尾流动力学的大气稳定影响，这将导致改进流动控制策略，以最大限度地提高农场效率。首先，将通过受控大涡模拟(LES)数值试验来表征科里奥利效应和稳定性效应对尾迹的影响。科里奥利效应通过直接强迫和改变进入涡轮机的大气边界层(ABL)风廓线中的风速和方向切变来影响尾迹偏转、变形和恢复。将开发新的受控数值实验，将这些影响分离为独立的流动参数，并表征它们对尾流的影响。稳定性对尾迹的影响将利用分层ABL中涡轮的大涡模拟来表征和量化，在一系列无量纲流动参数范围内进行模拟。其次，将开发一种新的、计算效率高的流动模型，该模型可以从第一原理中捕捉到这些影响。第三，将对模型进行验证和不确定性量化，该模型将用于使用LES的风电场流量控制案例研究。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Wind turbines operating within wind farms interact aerodynamically. By extracting power from the wind, wind turbines produce wake regions downwind that are characterized by low wind speed and high turbulence. Wake interactions can significantly reduce the efficiency of wind farms but they can be alleviated by controlling the wind flow in the farm. Given the continuing expansion of wind energy generation, there is a growing need to improve the fluid dynamics knowledge of the interactions between wind turbines and the atmospheric flow and to leverage this knowledge to improve farm efficiency. This research project will characterize and model the impacts of atmospheric flow on wind turbine wakes. The working hypothesis of this research is that the incorporation of the atmospheric effects from Earth’s rotation, buoyancy, and temperature variations will improve the predictive accuracy of wind farm flow models and will increase farm efficiency when using model-based flow control. This research will characterize the impacts of these atmospheric effects on wakes using computer simulations under a wide range of atmospheric conditions. A new flow model which captures these effects will be developed and validated, and the model will be used for case studies of flow control. The climate change mitigation impacts of this project will be integrated into engagements with K-12 schools, courses and mentoring for Massachusetts Institute of Technology students about careers in the physics of energy systems, and workshops with energy industry about wake losses, modeling, and flow control.This research will characterize and model the impacts of Coriolis forces from Earth's rotation and atmospheric stability effects from buoyancy and temperature gradients on wake dynamics, which will lead to improved flow control strategies to maximize farm efficiency. First, the impacts of Coriolis and stability effects on wakes will be characterized using controlled, large eddy simulation (LES) numerical experiments. Coriolis effects influence wake deflection, deformation, and recovery both through direct forcing and through modification of the wind speed and direction shear in the atmospheric boundary layer (ABL) wind profiles incident to turbines. Novel controlled numerical experiments will be developed to isolate each of these effects as independent flow parameters and to characterize their impacts on wakes. The influence of stability on wakes will be characterized and quantified using LES of turbines in stratified ABLs, simulated over a range of non-dimensional flow parameters. Second, a new, computationally-efficient flow model which captures these effects from first-principles will be developed. Third, validation and uncertainty quantification of the model will be performed, and the model will be used for wind farm flow control case studies using LES.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.