Study on Open Cross-Flow Runner for Environmentally Friendly Nano-Hydraulic Turbine Utilizing Waterfall (Influence of Waterfall Thickness on the Runner Performance)

The aim of this investigation is to develop an open type cross-flow runner for environmentally friendly nano-hydraulic turbine utilizing extremely low head waterfalls. The waterfall condition is strongly affected by weather, so flow rate changes frequently. It causes a decrease in runner performance because it does not have any flow adjusting mechanisms. It is, therefore, important to evaluate the runner performance against the change of flow condition for stable power generation. This study focused on the influence of waterfall flowing position and its thickness on the runner performance. An open type cross-flow runner was applied for waterfall generation. As a result, we found that the runner characteristic varied with the waterfall condition. In particular, the waterfall thickness has great influence on the runner performance. The value of C_Pmax reaches the highest value of 0.61 at Q = 3.0×10⁻³ m³/s.