Numerical Simulation Of Wind Turbine Wake Based On Large Eddy Simulation

Nowadays,as energy and environment issues have become the most urgent ones concerning the sustainable development of all human beings,exploiting a clean and renewable resource like wind energy is critical to our kind.Wind farm is the main and widely used approach to transform wind energy into electricity.However,the efficiency of the wind farm will be largely affected by the wake effect of the air entering the turbine,which increases the operation cost and weakens the acquisition of the wind.In an engineering point of view,this research about the wake effect of the wind turbines is evidently practical.There are several main methods to help us research into wind turbine wake: Wind Tunnel Experiments,Theoretical Modelling and Numerical Simulation.In this article,the numerical simulation is carried out by ANSYS FLUENT.More profound research is undertaken by combining this numerical simulation with the theoretical model and the fan interference effect.The fundamental research layout is as following:(1)The introduction of the aerodynamic principle based on the momentum-blade element theory.The configuration of the forces on the turbine is formed and then solved by an auto computer programming code.The result is verified by comparing with the results of the software(2)The introduction of the basic theory of the large-eddy simulation.By adopting the actuator disk model and the large-eddy simulation combined with the blade element momentum method,the numerical simulation of the wake of a single turbine is built,during which the detailing of the computation area,grid mesh and boundary conditions is illustrated thoroughly.The accuracy is guaranteed by the comparison between the numerical model and the experiment results.Furthermore,the analysis of the influence of the interaction of parameters provide certain evidence to our research.For example,how the thrust coefficient and ambient turbulence intensity will influence the average wake speed and the flow field variables such as turbulence.(3)For dual turbines,the computational fluid dynamics method based on the large-eddy simulation and the blade element momentum method is applied to obtain the results of numerical simulations.The liability of these results of two turbines can be verified by comparing with the expected values from the theoretical wake model.Further on,these results shade light on the interference effect between the wake of two turbines,therefore to optimize the layout of the turbines in practice.