Numerical simulation of tower shadow effect of upwind horizontal axis wind turbine

Abstract

The tower-blade interaction is one of key reasons that would seriously affect the wind turbine aerodynamic performance. Simulation of tower shadow effect for a three-bladed, upwind offshore wind turbine using STAR-CCM+ software is researched. The model of national renewable energy laboratory (NREL) 5 MW baseline wind turbine is used in this simulation by computational fluid dynamics (CFD) method. Based on the reynolds averaged navier-stokes (RANS) equations and the shear-stress transport (SST) k - ω turbulence model, aerodynamic simulations for NREL 5 MW turbine have been studied. Model validation and grid-independence verification are conducted in order to have more accurate results. The aerodynamic simulations of wind turbine model with tower and rotor model without tower are carried out separately. The impacts of tower shadow effect on aerodynamic performance are obtained by comparison of two models. The method of blade element momentum (BEM) is also used to study tower shadow effect, and two research methods are compared. Simulation results demonstrate that the tower shadow effect is remarkable. Mutation caused by tower shadow effect of aerodynamic performance is emerged and it will cause some adverse results for blades and tower. Impact of tower shadow effect on average value of wind turbine aerodynamic load is not significant. As is shown by simulation results, average thrust of wind turbine is declined by 0.46% and average power is declined by 0.87%. This paper could also provide some references for further research about the influence of tower shadow effect on aerodynamic performance.