Numerical assessment of the effect of different end-plates on the performance of a finite-height Savonius turbine

ABSTRACT

i.e. semi-circular and circular end-plates, and also a new proposed one, which is called quarter-spherical end-plate. The effectiveness of the end plates are measured and compared with the benchmark case, i.e. without end-plate. Computed results show that all end-plates increase the power coefficient of the rotor, among them the circular end-plate does considerably. The rotor with circular end-plate generates positive power coefficient even at tip–speed ratio (TSR) greater than 1.0, whereas the other rotors do not. Circular end-plate increases the power coefficient of the wind turbine by 84% at TSR = 0.6, the TSR corresponding to the greatest power coefficients of all studied rotors, and averagely by 126% in the range 0.4<TSR<0.8. Unfortunately, the rotor with circular end-plate faces with the greatest levels of the drag and lift forces exerting on the rotor shaft. Introducing some designing indices shows that a rotor with quarter-spherical end-plate can be a good alternative for one with circular end-plate.

KEYWORDS:

• Savonius wind turbine
• tip–speed ratio
• end-plate
• power coefficient
• torque coefficient

Nomenclature

Table

Disclosure statement

No potential conflict of interest was reported by the author(s).