Report KD 484 in which the VIRYA-3B3 rotor is described, is reviewed. A photo of the drawing with drawing number 1201-01 has been added in appendix 2. KD 484 can be copied for free from my website:
www.kdwindturbines.nl. As the drawing is originally made on A1 format, a print of the photo on A4 format will be too small to read the measures but the measures can be read on the computer screen if the scale is enlarged. Manufacture of the wooden blades of the VIRYA-3B3 is rather easy as the blade have a constant chord and no twist. I have added the photo of the VIRYA-3B3 drawing as attachment. If this rotor is used in combination with the 38-pole PM-generator as described in report KD 648, the hub has to be provided with a 28 mm cylindrical hole with key groove.
Wind tunnel tests at the University of Delft have shown that the characteristics of a small rotor with a constant chord are even better that of a rotor with the same design tip speed ratio and diameter and tapered and twisted blades. This might be caused by Reynolds effects and by the fact that the scale model of the rotor with a constant chord could by made accurately but that accurate manufacture of the scale model with tapered and twisted blades was very difficult. The tests were performed by Nienke Hosman to get her Msc degree.
