Performance Enhancement of Hydraulic Axial Turbine Rotor Using Enclosure at Upstream and Downstream Side

Abstract

The demand for electricity is increasing tremendously globally with the development of countries. To fulfill the supply of electricity, many countries have already adopted renewable energy sources. The production of electricity from hydraulic energy sources is one of the oldest methods. The axial flow water turbine can efficiently generate energy from the water flow with a very low head. The current investigation is focused on enhancing the performance of the axial turbine by providing an enclosure around the rotor. The initial experiments were carried out with only the upstream enclosure. The optimized upstream enclosure was taken with different lengths of downstream enclosure for further investigations. The current investigation concluded that the maximum efficiency using only an upstream enclosure is 89.48%, which is around 3.20% higher compared with the bare turbine. The optimum efficiency was found at upstream-side length ratio (ULR)=0.46 (upstream enclosure length LU=40 mm). With using the optimum ULR=0.46, the maximum efficiency for the downstream enclosure was found at downstream-side length ratio (DLR)=0.23 (downstream enclosure length LD=20 mm). The highest efficiency value for this axial runner was obtained at 90.89%, which is 4.83% higher compared with the bare turbine.