## General Mechanical

#### Help by heat flow analyses in a tube welding simulation

• SvenPG
Subscriber

Hello,

i am new to this forum and need some help with my Ansys Simulation problem. For my master thesis i try to simulate the heat flow in a pre heating process before welding. I have 2 tubes and 2 adapter tubes and want to simulate a direct current amperage from one to the other tube.

As in the picture, my tubes have a temperature of 22°C and i insert an amperage of 1700A. I think i maybe made a mistake in my settings because the solver ends with the note that there is no converging solution to my linear problem. Maybe my thinking on how the amerage works is wrong?

Maybe someone can help me get started right, i need the heat flow for the tubes, especially for the 2 tubes in the middle.

Greetz Sven

• peteroznewman
Subscriber

Hello Sven,

I haven't had a chance to use Thermal Electric before now, so I was curious to build a simple model. It is just two tubes touching at the center. I left the inside wall insulated and the outside wall with convection cooling. I put the current in the two end faces.

What I was interested to try was to add some resistance at the bonded contact at the center to see how that would change the result.

By default, there is no contact resistance and the temperature is uniform along the length of the tube.

After changing the contact definition it looks like the image below:

Here is the change in the Electric Conductance, from Program Controlled to Manual and assigning a value.

Attached is an ANSYS 19.1 archive.

Kind regards,

Peter

• SvenPG
Subscriber

Hello Peter,

thank you very much for your answer. It helped me alot and now my simulations are working! The tip with the electric conductance is pure gold! I really appreciate your time! Have a nice day!

Kind regards,

Sven

• SvenPG
Subscriber

So i simulated a bunch of different calculations and i came to a point where i would appreciate help again! So i try to simulate the same calculation again, but not steady but for 6s time. So as i understand it, i need to perform an thermal-transient calculation. Besides i m not able to give amperage as boundarie conditions, my simulation do not look as i expected. So i tried with heat flow and with heat flow density (hope the words are correct translated from german to ansys english) and got both times the same issue.

and same for the other one

i try to figure out if there is a mistake in the contact area settings but it does not effect the outcome of my simulation.

So my question: Is it possible to do 6 steady simulations and get the result temperature of the previous one as my start temperature for the next one? or maybe if someone knows what did i wrong with my thermal-transient calculations?

Sven

• peteroznewman
Subscriber

Hello Sven,

Good progress!

If you create a Workbench Project Archive .wbpz file from your project, and attach it to your post above, I will be able to take a closer look.  The file size limit for attachments is 120 MB, so Clear Generated Data on the Model to remove the mesh from the file if it is too large.

Kind regards,

Peter

• SvenPG
Subscriber

Hello Peter,

thank you for your help again. It is really appreaciated! I attached two different files on the post above as requested. One Simulation is the succesful steady one, the other is the transient one i m working on recently.

Kind regards,

Sven

Edit: I hope the files are as you requested