Experimental and numerical study of screw rotors efficiency with different geometric parameters as turbines in micro-HPP

This paper reports on the investigation of the features of using screws as turbines in free-flow floating and submerged micro-HPP with different geometric parameters by optical diagnostics (particle image velocimetry) and numerical simulation (large eddy simulation). The numerical simulation shows the good agreement with the experimental results. Change of screw pitch lead to significant effect on the structure of the flow downstream of the screw rotor. Screw rotor with a screw pitch equal to half the length of the rotor has the good energy characteristics and shows the best hydrodynamic flow structure.