Experimental Determination of Optimum Design Configuration for Micro Wind Turbines at Low Wind Speeds

Abstract

This paper reports experiments and theory on some small wind turbines of rotor diameter 100 cm and less. Discrepancies in power performance have been found from predictions of blade element theory. Wind tunnel experiments showed that performance depends on the solidity of the fixed diameter rotor due to the dependence of Reynolds number on chord length. In particular, power output is lower than theory predicts on wind speed less than about 10m/s. For turbine rotors of constant diameter, output depends on solidity. In general, at low wind speeds, rotors with greater solidity give a higher output than with less solidity. This is due to the difference in Reynolds number, which itself is associated with chord length. The optimum value of Reynolds number for such small turbines is 100,000.

Parametric study of a fan-bladed micro-wind turbine

“…Several small wind turbine designs have been studied in the past decade. Tokuyama et al [12] selected the NACA 4418 aerofoil shape as the blade profile of a wind turbine with a fixed blade number but variable rotor solidity for their experimental study. They reported a maximal power coefficient of about 0.3 and recommended a rotor solidity of about 0.5 for small wind turbines having rotor diameter less than 80 cm.…”

Experimental Study on a Model of a Commercial Windpumping Rotor

“…Small scale wind rotor models have been tested as described in Kentfield (1996) and more recently by Tokuyama and et al (2002). These experimental results help small windpump design and the improvement of existing designs.…”