Advanced Numerical Framework for Wind Turbines in Atmospheric Boundary Layer Flow

现代风力涡轮机运行在非常复杂的湍流大气边界层（ABL）中，具有广泛的含能长度尺度和不同的大气稳定机制。当风力涡轮机与ABL相互作用时，叶片在旋转周期中经历了载荷和扭矩的显著变化。这直接影响到风力机的气动性能、发电量和叶片结构响应。当风力涡轮机排成阵列时，这个问题就会放大。在这种配置下，任何顺风涡轮机都在顺风涡轮机的尾流中运行，这增加了电力生产的损失，并且由于尾流相互作用而降低了疲劳寿命。

Modern wind turbines operate in the very complex turbulent Atmospheric Boundary Layer (ABL) with a wide range of energy-containing length scales and with different atmospheric stability regimes. When wind turbines interact with the ABL the blades experience significant variations of the loading and torque during the rotation cycle. This directly affects the wind turbine aerodynamic performance, power production and blade structural response. The problem amplifies when wind turbines are arranged in arrays. In this configuration any downwind turbines operate in a wake of upwind turbines, which increase losses of power production and reduce the fatigue life due to wake interaction. To accurately predict the unsteady aerodynamic and structural behavior of wind turbines operating in a wake will require advanced numerical modeling and simulations. Existing simulation tools, however, mostly focus on non-stratified, uniform flow conditions over flat surfaces interacting with rigid-body wind turbine structures due to highly-turbulent stratified flow with large Reynolds number and complex multi-physics coupling. At the same time the problem is amplified by presence of the components in a relative motion superimposed on elastic deformation of the blades, geometric and material nonlinearity of the multilayer composite structures and large problem size. Motivated by the above challenges, the proposed research program focuses on the development of a predictive FSI framework for computation of wind turbines at full scale and with full geometrical complexity subjected to realistic atmospheric conditions. The advanced multiphysics simulations will improve our understanding of the turbulence dynamics in the ABL over complex terrain under different atmospheric stability regimes and how it affects the aerodynamic and blade structural response. The first-of-a-kind FSI simulations of multiple wind turbines with full geometric and material complexity will shed more light on wake-turbine interaction and how it affects fatigue life. The proposed novel numerical framework can improve design and optimization process of wind turbines and prevent failure of main turbine components by providing high-fidelity outputs for quantities of interest for which measurements are not readily available. It will serve as a valuable tool for developing sophisticated wind turbine control strategies to maximize power output. The proposed interdisciplinary research program will also create a valuable dataset that can be used by other researchers for numerical tools validation. Using this program the prospective highly qualified personnel will develop strong expertise in multiphysics simulations of complex engineering problems that is in increasing demand in industry, national laboratories, and academia in Canada and worldwide.