Yan Weng

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Alex Moutsoglou


A study was conducted to compare the performance of a Benesh rotor to that of a Savonius rotor as a wind power generating device. Tests were conducted for each rotor in two different setups in 1992 and 1993, respectively. Each of the rotor-shaft assemblies was tested at the exit of the 1992 and 1993 wind tunnels. The steady air flow velocity was over 14 mph. Each rotor was slowly loaded by adding weights to the upstream side of a pulley attached to the rotating shaft. The reaction force on the other side of the pulley was then measured. At each loading, the corresponding torque and power coefficients were calculated and plotted as a function of the tip speed ratio. In the 1993 tests, at 24 inches from the ground the Benesh rotor provided an average maximum power coefficient Cp,max of 0.32 at a Reynolds number of 1.6x105. The corresponding average Cp,max for the Savonius rotor was 0.26 at a Reynolds number of 1.51x105. At a height of approximately 14 inches from the ground the Benesh rotor resulted at an average Cp,max of 0.31 at a Reynolds number of 1.59x105. The corresponding Cp,max for the Savonius rotor was 0.277 at a Reynolds number of 1.53x105. In all the tests, the maximum power coefficient for the Benesh rotor occurred at lower tip speed ratios than that for the Savonius rotor. Finally, the present data compared very favorably with the experimental data of the Sandia report (16).

Library of Congress Subject Headings

Rotors -- Testing
Wind power
Wind turbines




South Dakota State University



Rights Statement

In Copyright