Suppose that we have an edge as a blade as a rotational wall (2d problem), it rotates about its center.

Radius of this blade= 10 m

Rotational speed= 1 rad/ s

I used moving reference frame, and I set the speed of rotational wall 0 (relative).

Originally, the velocity magnitude in the top of the blade has to be 10 m/s. but I get it 7.8 m/s

In fact the wall don't obey from:

V=R.Omega
also velocity magnitude in the axis is not zero m/s.

What's the problem??? What's your idea??