Computational and experimental investigation of runner for gravitational water vortex power plant

The gravitational water vortex power plant (GWVPP) is a new type of low head turbine system in which a channel and basin structure is used to form a vortex, where the rotational energy from the water can be extracted through a runner. This study is focused on the optimization of the runner to improve the efficiency of the GWVPP. Computational fluid dynamics (CFD) analysis is carried out on three different runner designs with straight, twisted and curved blade profiles. ANSYS CFX was used to analyze the fluid flow through the channel, basin, turbine hub and blade, and results were used to evaluate the efficiency of each of the runner designs. The CFD analysis showed curved blade profile to be the most efficient profile, with a peak efficiency of 82%, compared to 46% for the straight blade runner and 63% for the twisted blade version. An experimental test of the turbine system was carried out to validate the runner analysis, in a scale version of the GWVPP. The testing showed that the runner behaved as predicted from the CFD analysis, and had a peak efficiency point of 71% at 0.5m head.