Savonius wind turbine

About: Savonius wind turbine is a research topic. Over the lifetime, 333 publications have been published within this topic receiving 6521 citations.

Performance and wake measurements of a Savonius wind turbine

Abstract: In this study, the performance, drag and wake characteristics of a vertical axis Savonius wind turbine are investigated experimentally. The turbine is drag driven and has a helical configuration, making the top rotated 180 degrees relative to the bottom. All experiments were conducted in the wind tunnel at the Norwegian University of Science and Technology. The rotor wake was captured using two Cobra probes produced by Turbulent Flow Industries (TFI). These are 4-holed dynamic pressure probes capable of measuring all three velocity components in turbulent conditions. Both performance and wake measurements were conducted in four different inflow conditions, using Reynolds numbers of ReD ⇡ 1.6 ⇥ 105 and ReD ⇡ 2.7 ⇥ 105 and turbulence intensities of 0.6% and 5.7%. The efficiency of the turbine was found to be highly dependent on the Reynolds number of the incoming flow. In high turbulent inflow, the efficiency was only reduced in the case of high Reynolds number. Hence, greater levels of turbulence results in a weaker Reynolds number dependency of the rotor performance. The drag of the turbine was shown to be independent of the turbines rotational speed over the range tested, and it was slightly lower in high turbulent inflow. The wake was captured for the described inflow conditions in both optimal and suboptimal operating conditions by varying the rotational speed of the turbine. Measurements were conducted in a horizontal plane at the center height of the turbine, spanning 2.3 turbine diameters in both lateral directions relative to the turbine center-line, and up to 11.6 diameters downstream of the turbine. Results show an asymmetrical wake formation in optimal operating conditions where the velocity deficit is greatest behind the returning turbine blade. In sub-optimal conditions, the wake is more symmetric. Regarding levels of turbulent kinetic energy in the wake, a proportionality with the inflow turbulence intensity was observed. The levels of lateral entrainment in the far wake (above 8 diameters downstream) are found to increase in high turbulence, This leads to more turbulent mixing and faster recovery of the far wake. In low Reynolds number flow, higher inflow turbulence intensity increase the wake width compared to the case of almost uniform inflow. This is in contrast to the wakes of horizontal axis wind turbines. The opposite effect was however observed in high Reynolds number flow. Based on the findings from the wake measurements, some recommendations on where to place supplementary turbines.

Pengaruh Pemasangan Sudu Pengarah dan Variasi Jumlah Sudu Rotor terhadap Performance Turbin Angin Savonius

Abstract: The objectives of research were to understand the influence of the installation of guide vane on the performance of Savonius wind turbine and to acknowledge the number of rotor blade which produces the most maximum performance. There are three variations for the number of rotor blade, which are 2, 3 and 4 blades on the range of wind speed are 4-7 m/s. Result of research indicated that rotor with three blades can give better performance than rotor with two and four blades. Rotor with guide vane has produced better performance in power coefficient rate for 0,3638 at wind speed 5 m/s, while rotor without guide vane can only provide power coefficient for 0,2595 at similar wind speed 5 m/s.

Savonius wind turbine with curved vane

Abstract: PROBLEM TO BE SOLVED: To provide a structure which increases output without sacrificing the characteristics of a Savonius wind turbine with simple structure, and prevents breakage of the impeller to be caused by overspeed in strong wind. SOLUTION: In a position close to an outer end of a curved vane of the Savonius wind turbine, the vane is curved in an inverted-Z shape or a Z shape so that a portion close to the outer end of the vane is relatively shifted on a wind receiving recessed curved face side. Hence, the strength is increased, and a wind force received by an outer face of a step plate connecting a vane face close to a rotational center with a vane face close to the outer end sandwiching the stepped part therebetween, acts to assist the wind power received by an original recessed curved face. As a result, a rotative force of the Savonius wind turbine is increased to increase the output torque. Although wind flowing around on a recessed curved face side of the other curved vane hits on an inner face of the step plate and acts in a direction pushing back the vane, since the torque is smaller than the assist torque, net torque increase and output increase are achieved. COPYRIGHT: (C)2010,JPO&INPIT

A Numerical Study of a Newly Developed of Savonius Wind Turbine Style on Increasing the Performance of Savonius Wind Rotor

Abstract: In the present study, a new model of Savonius wind turbine has been designed to increase the low performance of the Savonius wind rotor, a type of vertical-axis wind rotor, and the effect of wind speed on the static rotor performance has been analyzed numerically using solid-work flow simulation (SWFS). SWFS is based on the Reynolds Averaged Navier-Stokes (RANS) equations with the standard k-e turbulence model. These equations were solved by a finite volume discretization method. Further, the effects of rotor geometries and end plate on static torque are also discussed. In order to clarify the new designed of the rotor, static torque was measured with various blade sizes and end plate shape. From the study, found that the use of both upper and lower end plats significantly increase the torque by 40% compared with no end plates. Additionally, it was also observed that the torque of rotors increases proportionally to blade size and end plate shapes. Moreover, the results showed that model 2 has produced more torque compared to other models.