Influence of setting condition on characteristics of Savonius hydraulic turbine with a shield plate

Abstract

The aim of this investigation was to improve power performance of Savonius hydraulic turbine utilizing small stream for electric generation. An attempt was made to increase the power coefficient of runner by the use of flat shield plate placed upstream of the runner. The difference of the power coefficient is discussed in relation to clearance between the runner and the bottom wall and the rotation direction of the runner. The flow field around the runner was also examined visually to clarify influences of setting conditions on the power performance. From this study it was found that the power coefficient is achieved for 0.47 by only using a flat shield plate, the increase is up to 80% over the runner without the plate. Moreover, it is the proper condition that clearance ratio is 0.73 in this study.

Performance parameters of Savonius type hydrokinetic turbine – A Review

“…For rivers, this technology is referred as river current turbines (RCT) or river current energy conversion system (RCECS) [36,37]. Similar to wind turbines, there are several types of hydrokinetic turbine designs available in the literature [6,18,32,[36][37][38][39]. Based on rotor axis orientation with regard to water flow direction, turbines are broadly classified into two categories i.e.…”

“…Gorlov helical water turbine, having diameter of 1 m and height of 2.5 m was installed by GCK technology limited (USA) in the coast of Korea [18]. Gorlov vertical axis turbine [39] having helical blades of reduced relative diameter and increasing the length of blade was investigated and found the coefficient of power as 0.35. Different types of rotors can be hybridized (such as Darrieus-Savonius hybrid) in order to achieve better performance features [42].…”

“…The angular acceleration of Savonius turbine increases, while the rotor moment, M, and inertia of the turbine decrease with increase of the aspect ratio [50]. There are a number of studies for the wind as well as for water as working fluid which reveal that aspect ratio ranging from 1.0 to 2.0 also exhibits good performance of Savonius rotors [39,47,[55][56][57][58][59][60][61][62][63].…”

Upstream Flow Control for the Savonius Rotor under Various Operation Conditions

“…As for the case documented in [32], the power coefficient with the deflector is more than twice of the original value. A considerable improvement of rotor performance is also found in the case studied in [29], which is featured by the introduction of the shield plate. In this connection, apart from the auxiliary device, there are other factors that influence rotor performance, such as rotor blade size, blade shape, blade surface roughness and tip-speed ratio, any of them can outweigh the others in the contribution to the torque or energy coefficient.…”

“…A shield plate was mounted upstream of the Savonius rotor as the rotor was used to absorb the kinetic energy of water [29]. With such a scheme, an increase in the power coefficient was proved.…”