Learning Forum

[SURAJGOUDA POLICEPATIL]

In vertical axis wind turbine part 1 tutorial, its said that if we enter an exact rotational velocity of the turbine then the coeff of moment (cm) curve would be zero. 

The entered speed in tutorial is 40m/s and we get some repulsoins in the cm graph. In lesson 7 its said that if 80m/s is entered then we would get a cm curve as 0 (a horizontal line in the graph). I have tried entering the 80m/s value, even then I am not getting cm graph as zero. Still I am getting repulsions in the graph.

 

Kindly suggest me about the issue.

[Rob]

Where does it say 80m/s in that text? 

[SURAJGOUDA POLICEPATIL]

Sorry the units are in rpm, not m/s. If I enter 40rpm Im getting fluctuations as per the tutorial. But if I enter 80rpm as suggested in the text in last sentence, Im not getting cm curve as zero. 

[Rob]

It does say "about", so how far off are you from a zero value?