Wang Tongguang

Large-eddy simulation of aerodynamic performance and wake characteristics of two inline wind turbines

A series of simulations are carried out to investigate the aerodynamic characteristics and model the wake interactions of two aligned wind turbines in low turbulence uniform inflow, using Large-Eddy Simulation (LES) technique with the actuator-line method (ALM). Turbulence is treated via four different subgrid-scale (SGS) models in LES. The aerodynamic performance of the two rotors, the mean velocity and Reynolds stress of the wake agree well with the measurements. The downstream turbine shows much lower power coefficient and thrust coefficient when fully covered in the wake of the upstream turbine, with the highest power coefficient being only 25% of the upstream one. The turbulence intensity of the wake increases a lot compared to the low level turbulence in the inflow. From the comparison of the results from different SGS models, we conclude that the choice of different SGS models has little influence on both the load prediction and the wake description in the ALM-LES combined method.

Wind turbine design and its aerodynamic issues

A multi-objective design framework is presented based on Pareto theory for complicated multiple variables, multiple objectives and multiple constraints in wind turbine optimization. The basic features of the integrated optimization design are discussed through a 1.5 MW large-scale wind turbine blade design as an example. Key issues in both the wind turbine aerodynamic calculation methods and the unsteady aerodynamic modeling are then introduced with a summary of the complexity of wind turbine aerodynamics, followed by a brief review on progress and challenges in the aerodynamic calculations and models one by one.