The role of the blades number and pitch angles to the capability of self-start the Darrieus wind turbine

Abstract

Darrieus is classified as a vertical axis wind turbine that has a simple construction. It is widely used for small-scale domestic needs in rural or aquaculture areas. As with other types of vertical axis wind turbines, Darrieus have low efficiency. There is resistance on one side of the blade which aggravates the shaft rotation. Another problem is the low ability to self-starting. Some even need help from an external source to start. This is certainly detrimental in terms of energy conversion. The purpose of this study is to obtain information on the wind speed needed for a Darrieus to self-starting on variations in the number of blades and pitch angles. The blade profile used is NACA 6412. Variations in the number of blades are 2,3,4 and 5 and pitch angles of -10°, -5°, 0°, 5°, and 10°. Data retrieval was carried out experimentally using the wind tunnel. It is shown that the self-start wind speed was strongly influenced by the number of turbine blades. The number of blades 5 requires the lowest average self-start wind speed. The pitch angle has a different effect on the wind self-starting speed depending on the number of blades.