[Emris]

Hello.
I have such a problem.

Let's say
There is a square bath of conductive liquid (metal)
Permanent magnets rotate around it, stirring the metal.

The Ansys apdl package solved the electromagnetic problem.
That is, I got the forces acting on each element at any given time fx, fy, fz

I imagine I can solve a stationary hydrodynamic problem

I simply create a subdomain, and as a source I specify the user function, which consists of fx, fy, fz for each element

Now the main question is...
but how to make a user function file change (at each moment it should be different, according to the results of solving an electromagnetic task)

or how I can substitute a new file at every step of the way (new distribution of Lorenz forces acting on the melt) .

Thank you very much in advance.

And excuse my bad English.

[ghorrocks]

You appear to be trying to develop a coupling between ANSYS APDL doing electromagnetics FEA and CFX doing CFD. In that case you should use the existing coupling between these softwares. Have a look at the Fluid-Structure interaction in the documentation and tutorial examples. While these examples are based on structural models, the same principles should apply to any ANSYS APDL model.

[Emris]

Thank you very much for the answer, I have read about Fluid-Structure interaction, I can't combine these two tasks in this way (since Ansys apdl doesn't have a volumetric force solution for the centroid (element)).

When I did a stationary task, I did this:
I solved an electromagnetic problem in ANSYS apdl and then formed a table:
coordinates of the center of each element - force components
[m], [m], [m] fx, fy, fz
Further on, in the CFX package itself, I open Tools->initialize profile data
and create a user function that I use as a source on the subdomain.
and it all works fine.

The problem is this
I want to solve the transient problem
i.e.
for each step of time I have a new file with volumetric forces.

Can I somehow substitute them (at each step a new file).
whether it is possible to control the load step and change the source for subdomain
or are there any other mechanisms

thank you so much in advance.

[AtoHM]

Hm, I dont know how huge these profile data files are allowed to be, but you could group all of the time steps within one file.

Just append all the timesteps to the profile data file and add a column for time.


fx, fy, fz, time
0, 1, 0, 1 //first time step

1, 0, 0, 1
...
0, 1, 0, 2 //2nd time step

1, 0, 0, 2
...
and so on. Just add time as additional dependency in your source term expression.

If there is no size limitation, I don't see why it shouldn't work.

[evcelica]

AtoHM's advice sounds like it would work.
though, I didn't know you could make a table like this with more than 4 columns.



Can you use a rotating coordinate system for the source term expression? If that work out?