Numerical analysis on the low noise designs of Savonius wind turbines by using phase difference in vortex shedding

와류이탈 위상차를 이용한 사보니우스형 풍력터빈의 소음 저감 설계에 관한 수치적 연구

In this study, low noise designs of a Savonius wind turbines are numerically investigated. From a previous study, it was found that the high harmonic components whose fundamental frequency is higher than the BPF were found to be dominant in noise spectrum of a Savonius wind turbine. On a basis of this observation, S-shaped blade tip is proposed as a low design factors that decrease wind turbine noise by inducing phase differences in vortex shedding. The conventional Savonius and S-shaped turbines are investigated using Hybrid CAA method where flow field around the turbine are computed using CFD techniques and the radiated noise are predicted by applying acoustic analogy to the computed flow data. Noise reductions by these design factors are confirmed by comparing the predicted noise levels from these turbines.