Effect of building diffusers on aerodynamic performance for building augmented vertical axis wind turbine

Abstract

Considering the fact that the architecture environment is rich in wind resources, the building integrated wind turbine (BIWT) has been widely applied to obtain the wind energy with high quality. In order to take advantage of the height of the building and the building diffuser's wind gathering effect, the building augmented vertical axis wind turbine (BA-VAWT), which is composed of a vertical axis wind turbine placed between different building diffusers, is put forward as a type of BIWT. The aerodynamic performance of the BA-VAWT with different building diffusers and their shape parameters is investigated through numerical simulation, which is calculated by Reynolds Averaged Navier–Stokes equations using the transition shear-stress transport SST k–ω turbulence model in this paper. In addition, the computational model and method are validated to be reasonable by comparing the experimental data with the numerically calculated value of the clean BA-building augmented wind turbine. The results show that the building diffusers have a great influence on the aerodynamic performance of BA-VAWT. The trapezium building diffuser has the most effective wind gathering effect with the result of the BA-VAWT presenting a power coefficient as high as 1.56 at the optimal tip-speed ratio of 4.62. Furthermore, the spacing and width of the trapezium building diffuser's effect on BA-VAWT appear more obvious with the increasing tip-speed ratio; meanwhile, the average torque coefficient and the load fluctuation also change significantly in the larger tip-speed ratios due to the existence of many large-scale vortex structures in the wake area.