Flow Simulations on Blades of Hydro Turbine

Abstract

One of the renewable energy is hydroelectric power generation. Hydro turbine is a rotary engine that extracts energy from a fluid flow by transferring the potential energy to electricity generation. Depending on head and water flow rate, variation of pressure and momentum cause the runner blades to rotate. This research studied the effects of pressure and velocity of fluid flow on blades which help in improving the hydro turbine efficiency. The computational Fluid Dynamics (CFD) was used to simulate the pressure and velocity distributions on blades of hydro bulb turbine, which consists of runner with five blades and rotating at 980 rpm, by using Fluent Software. The LES model of turbulence flow, under the practical condition of unsteady and incompressible fluid flow, was conducted in order to study the effects of blade angles on hydro turbine installed at Huai Kum Dam drainage pipeline. At the average head of 21 m, blade twist angle of 25^o and the blade camber angle of 32^o, the simulation was applied on varying guide vane angle at different angles of 60^o, 65^o and 70^o respectively for comparing the maximum and minimum pressure on blades. The simulation showed that, at guide vane angle of 60^o, 65^o and 70^o, the maximum pressures at leading pressure side are 213 kPa, 217 kPa and 207 kPa and the minimum pressures at leading suction side are -473 kPa, - 465 kPa and -581 kPa, respectively. By adjusting the guide vane angle, it clearly affects the pressure distribution and the efficiency of the hydro turbine. This case study will serves as the guideline for blade design of hydro bulb turbine for the improvement of turbine efficiency.