Performance analysis of spherically curbed hydrokinetic turbine arranged in ln-line array in a closed conduit

Abstract

The present study aims to explore the applicability of hydrokinetic turbine (HKT) in a closed conduit. Spherically curbed Savonius HKT (SSHKT) was designed to calculate turbine performance (CP). Pipe flow velocity (V) is kept as 1.0, 2.0 and 3.0 m/s. Turbine performance declines as velocity increases, due to obstruction created by the turbine in the flow passage, flow instability, and separation. Performance of multiple SSHKTs was investigated installed in inline array. These turbines were arranged at varying distance of 2.5D, 3D, 3.5D, 4D, 4.5D and 5D, where D is the turbine diameter. The SSHKTs performed best at 3.5D irrespective of flow velocity. The number of the turbines increase the power production; however, efficiency of the system doesn't increase in that proportion. The CP of the first SSHKT was always higher compared to the next one along the array. In the pipeline, for single turbine, the high flow velocity causes a more significant pressure drop than the low flow velocity. At V = 1.0 m/s, the pressure drop for a single SSHKT is 8.52 %; whereas, at V = 2.0 m/s, the pressure drop is 28.69 %. Due to more blocked places in the arrayed turbines, the percentage pressure loss is greater.