수직축 조류 터빈 발전효율 평가를 위한 유동-터빈 연동 CFD 해석 (II)

Abstract

CFD (computational fluid dynamics) analyses that considered the dynamic interaction effects between the flow and a turbine were performed to evaluate the power output characteristics of two representative vertical‐axis tidal‐current turbines: an H‐type Darrieus turbine and Gorlov helical turbine (GHT). For this purpose, a commercial CFD code, Star‐CCM+, was utilized, and the power output characteristic were investigated in relation to the scale ratio using the relation between the Reynolds number and the lift‐to‐drag ratio. It was found that the power coefficients were significantly reduced when the scaled model turbine was used, especially when the Reynolds number was lower than 105. The power output characteristics of GHT in relation to the twisting angle were also investigated using a three‐dimensional CFD analysis, and it was found that the power coefficient was maximized for the case of a Darrieus turbine, i.e., a twisting angle of 0°, and the torque pulsation ratio was minimized when the blade covered 360° for the case of a turbine with a twisting angle of 120°.