I was wondering if anyone has built a test bed to figure out the torque vs rpm curves on any of windy nations blades? If it has not been done I am thinking of doing this myself. Any info on this would be helpful.
We'd definitely appreciate if you went ahead and did that! We're happy to distribute your results when you have them. We would do this, but it's on a list of about 103,417 things we need to do!
Wondering if the torque vs. RPM graph or chart is completed? If not, what is the max RPM limits and what wind speed does it relate to? I think we need a blade capable of 600 RPM and produce 200ftlb of torque, what blade would you recommend?
We have no torque vs. RPM charts. At what wind speed to do you need to reach 600 rpm? Is that a loaded rpm? What are the specifications of the generator you are using. If you supply detailed information, then it will be much easier to advise you on which blades would be best for your set-up.
Could this be calculated quite accurately from wind power equation P=0,5*air_density*rotor_area*wind_speed^3 if we knew the blade coefficient and the tip speed ratio. I think 0,4 and 7 could be quite close for 3 blade wind grabbers.