Recent Advances in Renewable Energy

1. INTRODUCTION Due to the rising costs incurred in the experimental studies of the design process of the cross-flow rotors, researchers have adopted numerical methods, such as the CFD (Computational Fluid Dynamics) technique. The CFD method offers the possibility to visualize the turbulent properties and the water comportment upstream and downstream a hydraulic turbine, which are tough to be examined through experimental techniques. For example, a computational investigation of a Savonius hydraulic turbine, which was characterized by spiral vanes with various...

1. INTRODUCTION The water turbines can be classified into two major kinds: the axial-flow rotors (AFR) and the cross-flow rotors (CFR). The simplicity of the blade shapes and the independence of the water current direction give the advantage to the CFR for the generation of small-scale hydropower with regard to the AFR. With the aim of performance enhancement of CFR, numerous computational and experimental tests were conducted recently. For example, Moghimi and Motawej (2020) carried out a computational test of a twisted Darrieus water rotor (TDWR). They investigated the impact of the twist angle on the operational parameters of the TDWR. In conclusion, the lowest coefficient of power value was obtained with...

1. INTRODUCTION Nowadays, various studies have shown different methods to enhance the efficiency of the Savonius turbine (ST) and Darrieus turbine (DT) based on computational and experimental techniques, such as the variation of the design parameters of the turbine. The aspect ratio (AR), the gap distance, the vanes profile, and the number of the vanes are the prime parameters that affect the performance of ST and DT. Patel et al. (2017) presented an experimental investigation of a Savonius water turbine. They studied the impact of the AR, the gap distance and the end disk. They investigated various gap distances (From 0 to 0.174). For a piece gap distance, they tested different ARs. In conclusion, they noted that the performance parameters of the ST could be enhanced using end disks.....