I am ritired now for some years and I no longer need substantial income out of my activities for Kragten Design. Therefore I have halved the licence fees for the bigger VIRYA wind turbines for which a licence is required. The new licence fees can be found on the folder “Extended specification VIRYA windmills” which you find at the menu “VIRYA-folders”.

The VIRYA-3.18 with a Chinese axial flux generator and a 2-bladed steel rotor with a design tip speed ratio of 7 is cancelled. This is done because experiences with the 2-bladed steel rotor of the VIRYA-1.65 have shown that too much noise is produced for steel rotors with 7.14 % cambered blades if the design tip speed ratio is that high.

Report KD 532 gives the rotor calculations of a 3.1 m diameter, 2-bladed rotor made out of Roofmate and glass fibre. A new chapter 6 has been added in which it is checked if this rotor matches with the Chinese axial flux generator of Hefei Top Grand type TGET260-0.5KW-350R. As generator characteristics for a 24 V battery load are not available, these characteristics were estimated from the given specification of the manufacturer.

Report KD 595 with the measurements of a Chinese axial flux generator has slightly been reviewed. A reference 4 to the VIRYA-1.5 rotor has been added.