LES-based fluid-structure interaction analysis of wind turbines: Wake interference effects and blade surface aerodynamics under variable spacing configuration

The wind power industry has developed rapidly with the rapid increase in global energy demand. The rapid growth in turbine size has led to significant blade aeroelasticity issues, making accurate fluid–structure interaction simulations of wind turbines crucial. This study employs a Large Eddy Simulation and introduces a reliable fluid–structure interaction method to analyze the aerodynamic performance of downstream turbine blades under different wind conditions, upstream turbine spacing, and turbine structural flexibility. The changes in the streamline distribution, mean pressure coefficient, and fluctuating pressure coefficient on the blade surface were analyzed. The presence of upstream turbine wakes significantly reduced the formation of stagnation points on the downstream blade surface. When considering turbine flexibility, the stagnation points on the blade surface are more easily dissipated owing to blade vibrations. The presence of upstream turbine wakes can significantly reduce the number and magnitude of the peak fluctuating pressure coefficient on the blade surface. Under the influence of the wake, fluid–structure interaction simulations consistently predicted higher peak fluctuating pressures. Specifically, for uniform wind conditions, the peak pressures increased by 55.1 % and 107.0 % for the two turbine spacings, whereas for atmospheric boundary layer wind conditions, the increases were 16.9 % and 6.7 %, respectively.