Hi James, this 2:1 ratio has been around for years BUT it takes into account the wind only. You will find that the VAWT has an APPARENT WIND direction and velocity, with wake vortices both internally and externally. How ever the Pure drag type as you have designed here is very powerful and is suitable for things like lifting water and grinding grain because of it's very low RPM and very high torque.
I think your design is good and your presentation is great. Only suggestion I have would be to add supports at the ends of the blades to reduce defliction.
James, if you shape the blades like a symmetrical airplane wing pivoting at about 20% of chord there must also be a version possible whereby the blade arms stay fixed and each blade rotates on its own pitch axis in synch with the wind direction indicator. Together there will be a positively contributing torque. Right?
