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UDF for Rotation

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Old   November 18, 2014, 10:52
Default UDF for Rotation
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Giovanni
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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

Quote:
DEFINE_SDOF_PROPERTIES (Rotazione, prop, dt, time, dtime)
{
prop[SDOF_MASS] = 0.01;
prop[SDOF_IZZ] = 0.00833;
prop[SDOF_ZERO_TRANS_X] = TRUE ;
prop[SDOF_ZERO_TRANS_Y] = TRUE ;
prop[SDOF_ZERO_TRANS_Z] = TRUE ;
prop[SDOF_ZERO_ROT_Y] = TRUE ;
prop[SDOF_ZERO_ROT_X] = TRUE ;
printf ("\n2d_Rotazione: Updated 6DOF properties");
}
Now i need to rotate betwen 55° and 5° .
this is the error that fluent gives me end what appens to the mesh
Cattura.jpg

Please help me !
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Old   November 20, 2014, 09:04
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Giovanni
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Please, anyone can help me? thanks in advance...
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Old   November 21, 2014, 07:10
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Linh Tuan The Nguyen
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Did you tried to reduce under relaxation factor? It's might take longer running time, but might solve the problem
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Old   November 21, 2014, 12:22
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Giovanni
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Quote:
Originally Posted by linh nguyen View Post
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.
before.jpg
what appens.jpg
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Old   November 22, 2014, 06:10
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Giovanni
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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?

Last edited by Johnmuddy; November 22, 2014 at 07:18.
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Old   October 25, 2016, 08:44
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Wesley liu
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could you describe your solution on how to solve the negative volume?
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