CFD to Simulation trouble-shooting

[Anonymous]

Greetings,

I'm fairly new to CFD and Simulate Mechanical, but am questioning some results that I'm getting.

What I intend to happen is to inject 900°F fluid into 400°F flow, and determine the associated thermal stresses associated with this action. Attached you'll find a screenshot of the results from CFD, as well as what the alleged stresses are.

It looks like to me somehow the temperatures are somehow misplaced in the conversion. As the region is relatively low-poly, it appears as 4 blobs around the perimeter of a non-existing injection point.

Any thoughts you have will be appreciated.

Thanks.

[KubliJ]

Hi Michael,

Thermal stress is caused by parts changing temperature compared to how they were originally constrained.  So a part that is not constrained in a way to prevent thermal movement will not generate any stress.  Temperature gradients alone will not cause stress.

Looking at your model, my best guess is that you have at least a symmetry constrain, but how are the ends of the pipe constrained?  Assuming you have them fixed, or constrained in a way to prevent thermal expansion/contraction then I would say there is definitely something wrong with CFD to Mech.  Could you share your model to look at?

Thanks,

James