Computational fluid dynamic predictions on effects of screw number on performance of single blade Archimedes screw turbine

Abstract

One of the alternative solutions to reduce the impact of electricity crisis in Aceh and other isolated areas in Indonesia is by the construction of small-scale hydro power plants that can work efficiently on the heads lower than 10 meters. One suitable type of turbine applied to the head below 10 meters is the Archimedes screw turbine. Due to the lack of information about the application of low head power plants, resulting in applications of this type of turbine is still less in Indonesia. This paper examined the appropriate turbine model. Before experimental turbine testing, turbines were designed theoretically first and then analyzed numerically. The flow velocity and pressure patterns within the turbine were analyzed using ANSYS CFD (Computational Fluid Dynamic) software under design conditions for 7, 9 and 11 screw numbers for single blade turbine. Based on the results of pressure analysis, speed and turbulent kinetic energy, it found that turbine performance using 11 blades is better among the three turbines. However, the highest average speed was obtained on the turbine using 7 screws, which maximum pressure obtained on a turbine 7 screws of 1406 Pa, on 9 screws on plane 1301 Pa and at 11 screws of 1175 Pa. Based on the results of the analysis, it showed that the smaller the distance between the channel and turbine blades, the results were more efficient due to the absence of wasted streams. Therefore, the flow pressure in the inlet position all directly leaded to the tip off the blade to produce a momentum.