浮式风机气动—水动—气弹性耦合响应数值模拟

随着海上风电产业的快速发展，大型浮式风机逐渐从概念设计走向工程应用，但仍面临较大的挑战。一方面，在风、浪等环境载荷的作用下，浮式风机的气动载荷和水动力响应之间存在明显的相互干扰作用；另一方面，风力机大型化使得叶片细、长、薄的特点愈发突出，叶片柔性变形十分显著，这会影响到浮式风机的耦合性能。基于两相流CFD求解器naoe-FOAM-SJTU，结合弹性致动线模型和等效梁理论，建立了浮式风机气动—水动—气弹性耦合响应计算模型，并对规则波和剪切风作用下Spar型浮式风机的气动—水动—气弹性耦合响应进行了数值模拟分析。结果表明，风力机气动载荷使得叶片挥舞变形十分显著，而叶片的扭转变形会明显降低风力机的气动载荷。此外，风力机气动载荷会增大浮式平台的纵荡位移和纵摇角，同时，浮式平台运动响应会导致风力机气动载荷产生大幅度周期性变化。进一步地，叶片结构变形响应会使得浮式风机尾流场的速度损失和湍动能有所降低。

Numerical simulation of coupled aero-hydro-elastic performance of floating offshore wind turbine

With the rapid development of the offshore wind power industry, large floating wind turbines have gradually moved from conceptual design to engineering applications, but they still face greater challenges. On the one hand, there is strong interference effects between the wind turbine and the floating platform. On the other hand, the wind turbine blades become more thin-long-thin. This leads to significant blade deformation, which will affect the coupling performance of the floating wind turbine. In this research, based on the two-phase flow CFD solver naoe-FOAM-SJTU, combined with the elastic actuator line model and the equivalent beam theory, a coupled aero-hydro-elastic calculation model is established for the FOWT. Furthermore, coupled aero-hydro-elastic simulation for the Spar-type floating wind turbine under regular waves and shear wind is performed. The results show that the aerodynamic loads amplify the flap-wise deformation of wind turbine blades, while the torsional deformation leads to a significant decrease of aerodynamic loads. Besides, the surge displacement and the pitch angle of the floating platform are enlarged by the aerodynamic loads, and the aerodynamic loads show periodical change trend with large fluctuation amplitude because of the platform motions. Moreover, the blade deformation makes both the speed loss and the turbulent kinetic energy in the wake field slightly decrease.