CFD analysis of a ducted spherical helical turbine for micro-hydropower

Abstract

Recently, a micro-hydropower generation system has been introduced for generating electricity by installing a spherical helical turbine in a water pipe line having a circular cross section. In this study, flow analyses through two ducted spherical helical turbines were reviewed to improve the performance of the turbine. The grid generation that determines the accuracy of the solution was performed using ANSYS ICEM-CFD and flow analysis was performed using ANSYS CFX V14.5. For CFD analysis, shear stress transport(SST) turbulence model was used. The performance of spherical helical turbine in water depends on the inlet water velocity of turbine. More fluid energy was concentrated in the turbine than with duct. In addition, flow analysis was performed by designing the same flow rate to compare the circular duct and the rectangular duct. As a result, using rectangular duct over circular duct improved performance by about 4.7%. It was also obtained that the use of the rectangular duct would increase the performance of spherical turbine by approximately 77.3%. Through the vortex structure analysis, it was confirmed that the vortex inside the turbine was reduced due to the use of the duct, thereby improving the performance of the turbine. In the future, it will be necessary to verify the performance of the spherical helical turbine by experiment, and it is expected that the spherical helical turbine with excellent performance will be developed by continuous research. ? TJPRC Pvt. Ltd.