Drag-Type Hydraulic Rotor

The advantages of the drag-type rotor in wind energy utilization have been widely acknowledged. In recent years, the exploitation of water energy in off-shore regions, rivers or even pipes guides the application of the drag-type rotor into a new stage. In this chapter, a drag-type rotor operating in the medium of water is investigated. The water tunnel is used to furnish flow environment for the rotor. Flow patterns near the rotor are measured with particle image velocimetry technique and the wake flow is particularly emphasized. At various rotor setting angles and upstream velocity magnitudes, velocity and vorticity distributions in the wake flows are depicted and compared. The time-dependent torque coefficient of the rotor is calculated based on CFD results.