Abstract:The wind turbine wakes impact the efficiency and lifespan of the wind farm. Therefore, to improve the wind plant performance, research on wind plant control is essential. The actuator line model (ALM) is proposed to simulate the wind turbine efficiently. This research investigates the National Renewable Energy Laboratory 5 Million Watts (NREL 5-MW) wind turbine wakes with Open Field Operation and Manipulation (OpenFOAM) using ALM. Firstly, a single NREL 5-MW turbine is simulated. The comparison of the power and thrust with Fatigue, Aerodynamics, Structures, and Turbulence (FAST) shows a good agreement below the rated wind speed. The information relating to wind turbine wakes is given in detail. The top working status is proved at the wind speed of 8 m/s and the downstream distance of more than 5 rotor diameters (5D). Secondly, another case with two NREL 5-MW wind turbines aligned is also carried out, in which 7D is validated as the optimum distance between the two turbines. The result also shows that the upstream wind turbine has an obvious influence on the downstream one.

The scale of a wind turbine is getting larger with the development of wind energy recently. Therefore, the effect of the wind turbine blades deformation on its performances and lifespan has become obvious. In order to solve this research rapidly, a new elastic actuator line model (EALM) is proposed in this study, which is based on turbinesFoam in OpenFOAM (Open Source Field Operation and Manipulation, a free, open source computational fluid dynamics (CFD) software package released by the OpenFOAM Foundation, which was incorporated as a company limited by guarantee in England and Wales). The model combines the actuator line model (ALM) and a beam solver, which is used in the wind turbine blade design. The aeroelastic performances of the NREL (National Renewable Energy Laboratory) 5 MW wind turbine like power, thrust, and blade tip displacement are investigated. These results are compared with some research to prove the new model. Additionally, the influence caused by blade deflections on the aerodynamic performance is discussed. It is demonstrated that the tower shadow effect becomes more obvious and causes the power and thrust to get a bit lower and unsteady. Finally, this variety is analyzed in the wake of upstream wind turbine and it is found that the influence on the performance and wake flow field of downstream wind turbine becomes more serious.

The deformation and vibration of wind turbine blades in turbulent environment cannot be ignored; therefore, in order to better ensure the safety of wind turbine blades, the study of air-elastic response of wind turbine blades under turbulent wind is indispensable. In this paper, the NREL 5MW wind turbine blades are modeled with accurate 3D lay-up design, firstly, based on the joint simulation of commercial software STAR CCM+ and ABAQUS, the two-way fluid-solid coupling technology, the wind turbine under uniform wind condition is simulated, and the results from thrust, torque, structural deformation and force perspective and FAST are compared with good accuracy and consistency below the rated wind speed. Secondly, the aerodynamic performance, flow field distribution and structural response of turbulent winds with different turbulence strengths at 10 m/s were studied. The results show that the turbulence intensity has a greater impact on the amplitude of the wind turbine blade, and the stress distribution of the blade is more concentrated, which in turns affects the stability and safety of the wind turbine blade and is not conducive to the normal operation of the wind turbine.

No abstract

No abstract