Experimental and numerical investigations on a new developed Savonius turbine for in-pipe hydro application

Abstract

Due to limitation of energy resources, a large body of research activities has been turned to investigate potential alternative avenues to supply energy. In this regard, the renewable sources, which can provide the sustainable and cleaner energy production, have increasingly become attractive. Hydropower has the highest proportion of the renewable energy sources. Availability and high efficiency are the undeniable advantages of the hydro potentials. In this paper, hydro-energy extraction from pipelines by a new designed vertical axis turbine is studied experimentally and numerically. The turbine scheme is inspired by the Savonius rotor turbine, which includes two semicircular blades that is built by the 3D printer and installed vertically in a 100 mm transparent pipe. A sloped block is used just before the turbine blades to concentrate the flow and enhance the efficiency. In experiments, flow rate ranges from 2.7 × 10−3 m3/s to 7.3 × 10−3 m3/s and pressure drop that occurs through the turbine is less than 10.5 kPa. Numerical results show an acceptable agreement with experiments and assure that numerical method is reliable. Following successful validation, numerical studies are expanded, in order to study more details on the new turbine performance. According to the numerical results, the characteristic curves of the new turbine are depicted and described. In numerical simulation, for different turbine rotational speeds, the flow rate and the pressure difference examined are up to 12 × 10−3 m3/s and 30 kPa, respectively. Using the obtained results, investigations and studies are performed to describe turbine behavior under the effects of changing the clearance and flow field conditions. Finally, cyclic variations of turbine flow rate, torque and minimum pressure on the turbine blade are described by velocities streamlines. This approach might preform design improving for such a turbine.