3 blade turbine

A three blade version. This uses https://wind.nrel.gov/airfoils/Shapes/S835_Shape.html for the airfoil cross section, and a modification of the taper designed by John McCosker http://www.ewp.rpi.edu/hartford/~ernesto/SPR/McCosker-FinalReport.pdf.

The attached python script can be ran in FreeCAD to generate one wing, which I then copied to form all three. Then put a hub in the middle.