UDF for Rotation
 

i'm looking for a function that allows to rotate the body between two corners according to the flow.
i'ts a dynamic mesh whith smoothing and remeshing.
the time step is 0.001
end the center of rotation is (0,0)
this is the 6dof function

Now i need to rotate betwen 55° and 5° .
this is the error that fluent gives me end what appens to the mesh
Attachment 35275

Please help me ! :(

Please, anyone can help me? thanks in advance...

Did you tried to reduce under relaxation factor? It's might take longer running time, but might solve the problem

which particular parameter i have to reduce ?

I think the problem that causes negative volumes is due to the fact that I don't have imposed a limit on the rotation as the cells at the edges deform excessively. Anyone knows how to do it ?

i posted the image of the initial condition of the valve, and what i want to do it
and what happens instead.
Attachment 35382
Attachment 35381

Now i'm able to make the simulation without volume errors . but i'm not able to define the angle limits on rotations.

I thought, bypassing the problem, to describe the boundaries on the translation of the center of gravity of the wing so that when it reaches one of the limits of this interval, have v = 0 .. but what macro should i use end how?

could you describe your solution on how to solve the negative volume?