Application of Liutex for Analysis of Complex Wake Flows Characteristics of the Wind Turbine

Abstract

To further understand the complicated wake characteristics of the wind turbine under various conditions, the Liutex vector is applied to identify the vortex in the turbine wake. The actuator line model is used to predict the aerodynamic performance of wind turbine. By combining the actuator line model and finite element method, the aeroelastic responses of wind turbine are obtained. Moreover, the actuator line model is embedded into in-house CFD code naoe-FOAM-SJTU to predict the coupled aero-hydrodynamic performance of the FOWT. Different vortex identification methods including the Vorticity method, Q method and Liutex method are adopted to visualize the wake characteristics. The wake characteristics of wind turbine calculated from different simulations are discussed in detail. Several conclusions can be drawn from the simulation results and discussions. Compared with the Vorticity method and Q method, the Liutex vector can better describe the complex wake characteristic of wind turbine in various conditions. The wake vorticity distribution behind the wind turbine is found to be asymmetric. In addition, the wake characteristics of the FOWT become more uneven when the platform motions are taken into consideration, and significant wake expansion phenomenon is observed.