Windmill Blade twist

[izax1]

Hi all

We are in the process of developing a novel Windmill blade design. We have most of the design criteria defined but one thing is bit unclear: Where is the rotation center for blade twast? And is it the same rotation center along the blade length?

 

[rb1957]

1) don't double post. you should report the other thread "posted by mistake" and ask the admin to take it down.

2) in the simple (though not ideal) world, the axis of twist is a straight line through the center of the hub.

3) but there's nothing to prevent you from having a curved axis, sweeping aft would be more natural (I think) .

4) this "axis of twist" is presumably the 1/4 chord line (as that is our default for section aerodynamic properties.

5) I'd've thought that this was well written up in windmill design texts ?