A new chapter 3 has been added to report KD 416 about drag machines. Chapter 3 gives the Cp-lambda curve for only the cup which is moving in the direction of the wind.
KD 601 reviewed
Report KD 601 about a self starting Darrieus rotor has been reviewed. The estimated Cp-lambda and Cq-lambda curves given at chapter 5 have been changed. For very low lambda values, the rotor works as a drag machine and the Cq-lambda curve now has a small positive Cq value for values of lambda smaller than 0.3. The maximum Cp has been reduced from 0.35 up to 0.3.
KD 416 reviewed
Table 1 out of report KD 416 about drag machines has been extended. The Cp-lambda and Cq-lambda curves have been added in figure 2 and figure 3.
KD 599 reviewed
A new link to the report: “Wind tunnel blockage corrections: an application to vertical-axis wind turbines” has been added as point 2.8 in report KD 599: “Measurements of Savonious rotors available in the Internet”.
KD 679 added, certain reports cancelled and certain reports and folders reviewed
Report KD 679 has been added to the menu-KD reports. The tittle of this report is: “Development of an 8-pole, 3-phase axial flux permanent magnet generator for the VIRYA-1 windmill using a bicycle hub and 8 neodymium magnets size round 25 * 12 mm and a stator made out of galvanised steel sheet”. Report KD 679 replaces report KD 608 which is cancelled. Report KD 626 in which the VIRYA-1.25AF rotor is described is cancelled too because the matching in between rotor and generator isn’t good enough for the measured generator characteristics. The generator characteristics are given in report KD 678 which has been reviewed. Report KD 672 has been reviewed too. The extended specification and the folders of the free VIRYA designs which are given at the menu KD-folders have been reviewed too.
KD 678 reviewed
A new chapter 6, “Generator measurements”, has been added to report KD 678. A teacher of a technical school has built the 8-pole generator of the VIRYA-1.02 and I have measured this generator on my test rig for a 12 V battery load. The torque level of the generator appeared to be lower than expected but the matching in between rotor and generator is still acceptable. The maximum electrical power for the rated wind speed of 8 m/s is about 24 W.
Folder Kragten Design reviewed
The folder about Kragten Design at the menu “Home” has been slightly modified.
KD 670 reviewed
Some small mistakes have been removed from report KD 670 about the VIRYA-5.2.
KD 599 reviewed
The link in this report to the report: “Wind Tunnel Performances Data for Two- and Three-bucket Savonius rotors” has been changed as the original link is no longer working.
KD 137 (in Dutch) beschikbaar
Rapport KD 137 kan gratis gekopieerd worden van het menu “No wind energy”. De titel van dit Nederlandstalige rapport is: “De dubbelzuigervoetpomp”. Dit rapport werd al in 2003 geschreven. Pagina 3 werd in Juli 2019 enigszins aangepast zodat nu naar courante andere KD-rapporten verwezen wordt. Dit rapport staat niet onder het menu KD-reports omdat het niet over windenergie gaat maar over een pomp die met de voeten aangedreven wordt. In figuur 1 van KD 137 wordt een gedetailleerde tekening van de pomp gegeven.