Effects of Hub-To-Tip Ratio and Tip Clearance on Hysteretic Characteristics of Wells Turbine for Wave Power Conversion

<正>A Wells turbine for wave power conversion has hysteretic characteristics in a reciprocating flow. The hysteretic loop is opposite to the well-known dynamic stall of an airfoil. In this paper, the mechanism of the hysteretic behavior was elucidated by an unsteady 3-dimensional Navier-Stokes numerical simulation. It was found that the hysteretic behavior was associated with a streamwise vortical flow appearing near the blade suction surface. The effects of hub-to-tip ratio and tip clearance on the hysteretic characteristics of the Wells turbine have also been discussed in this paper.