Investigation of Cavitation in Micro Hydro Turbines

By the year 2020, 70% of the dams in the United States will be at least 50 years old and will need repair. In addition, the World Energy Council estimates that there are ~200,000 gigawatt hour (GWh) per year of unused power available in low head locations, making now a perfect time to develop and design more efficient hydro turbines as the world becomes more reliant on alternative energy sources. Cavitation in turbomachinery is always a threat to the performance and the lifetime of the blades and other components (e.g. casing and draft tube). Working on understanding this phenomenon and the conditions for generation and propagation in a system proposes effective solutions to eliminate or at least diminish the detrimental effects.In the submitted project, cavitation patterns were investigated numerically and experimentally in a scaled model of a Kaplan hydro-turbine. Numerical methods were applied in a computational fluid dynamics (CFD) software to predict the flow behavior through the turbine and study the occurrence of cavitation with the link to the output power. The experimental study comprised of generating a recirculated-water setup to test a 3D-printed 3-inch Kaplan turbine with a maximum head of 9 feet.In this study, the team has demonstrated the cavitation effect with different conditions of the rotor speed and the flow rate