Simulating a heat source inside a shell box

[nvvvnoliveira]

I am modelling a thermal load applied on a shell box (6 shell faces closed as a 'shoe box') in ABAQUS and I have a few doubts on model conception.

Basically, the idea is to simulate heat coming from the inside of the box to the outside. So I have to assign an inner temperature to 'simulate' an heat source inside and a outer temperature (ambient temperature) and then run a heat step with heat flux as output. Bsically I want to simulate heat coming from inside to the outside the box.

So, in ABAQUS this is not exactly a thermal load (at least from what I understand) so none of the options worked (surface heat flux, body heat flux and concentrated heat flux). I have tried to assign two boundary temperatures (inside and outside) but its not possible with temp bc.

I am looking at interactions to see if I can model this, but I am a bit lost.

Any idea from a conceptual point of view on how to build this thermal simulation in ABAQUS?

Thank you very much

 

[FEA way]

How does the heat propagate from the internal source to outer surfaces of the box ? Is the box filled with air or other medium (convective heat transfer) ? Or is there just vacuum inside (radiative heat transfer) ? What generates the heat ? The key is what physical system you want to model.

 

[nvvvnoliveira]

Hello

- Heat propagates through thermal diffusion and convection (radiation is not considered)
- Yes, there is air inside the box and that is my main doubt, how to simulate air inside the box in abaqus?
- Heat can be generated by two ways, either assigning an internal temperature or placing a solid inside the shell that can generate a heat flux to the outside.

Thank you very much

 

[FEA way]

You can model the air inside the box using solid heat transfer elements (there's even a special type of them that allows you to account for forced convection if needed). Then it will be quite easy to place a heat source in the middle.

 

[nvvvnoliveira]

Can you give me any tips on the abaqus commands to use to model air inside the box please?

 

[FEA way]

You should create a solid model of the inside of the box first. Mesh it with heat transfer elements and assign thermal properties of air. There’s no need to model the walls as solids connected to the air domain (unless you are interested in the flow of heat inside the walls). You can just use a skin feature to represent the walls. Then assign proper loads and interactions - heat source inside and film condition outside. If it’s transient analysis then you should also define initial temperature.