Experimental Investigation of Runner Design Parameters on the Performance of Vortex Turbine

Abstract

The vortex turbine (VT) is a micro-hydro turbine that extracts power from a water vortex that is artificially generated in a conical or cylindrical cross-section basin. The former cross-section gives rise to a stronger vortex than the latter, meaning it has more potential for power generation. For this reason, the present study experimentally analyzed the effect of sensitive geometric parameters on the VT performance, i.e., the rotor to basin diameter ratio (RB) and runner’s position in the conical basin (CB). The results show that the ideal runner in terms of RB for the best performance of VT is a runner with RB = 0.6, which has a maximum potential for the utilization of the forced vortex region of the Rankine vortex. Moreover, the best position for the installation of a VT runner is the location at the bottom near the orifice, as the strong vortex tangential velocity and maximum head drop at the mid-position is not a feasible option. Blades with a tilt in the vertical plane are suggested for use in the power extraction at the bottom of CB whereas crossflow blades suit the rotational flow region near the top of CB, i.e., the surface vortex.