Field function for translation
 

Dear all,

I have created a filed function for oscillation of a cylinder on free surface and then was trying to provide reference of the field function in translation. I am getting an error during this operation.

Cannot evaluate expression $$WallVelocity on Simulation>MotionManager>TranslatingMotion("Transl ation")>VectorPhysicalQuantity>InlineFieldFunction ("InlineFieldFunction")
Command: SetProperties

My field function name is WallVelocity

I have defined it as

[(($Time<0.05) ?
(1*$$Position(“wall”) [1]) :
(0.1*sin(360./6.2831853*$Time)*$$Position(“wall”) [1])), 0, 0]

a simple SHM with amplitude of 0.1 and frequency of 1 rad/s.

This does not show any syntax error.

Then i refer the field function using $$WallVelocity in my translation motion and i get the error specified above?

Can anyone guide me where things are going wrong?

Thanks

Regards
Arun

Did you set the type and function name in the properties window?

Did you use a Tools>Motions, to define a Translation Motion with you field function at the Translation Velocity?

Hello Andrew,
I did assign type as velocity and function name as WallVelocity and Translation velocity was assigned $$WallVelocity.

Thanks
Regards
Arun

Also this is a problem of free surface with VOF definition. To specify calm water condition with no velocity, i have defined VOF waves and given 0.0 amplitude.
Is it possible to have a wall condition and symmetry planes all around and still define VOF waves?I am getting an error.

Can you please tell me how to specify a calm water condition with the motion of this cylinder on free surface?

If you could just guide.

Regards
Arun

You should be able to define a flat wave, use the hydrostatic and volume fraction definitions for your initial condition and then oscillate it. You may want to make the bottom a zero velocity inlet and the top a pressure outlet.

I'm not sure about your wall velocity function. You might want to try and implement the motion through a grid velocity applied to the top and bottom with the morpher.

Thanks a lot.
Will try your suggestions.

Regards
Arun