[NesrineB]

Hello,

I'm running a CHT simulation which includes solid-solid conduction then solid-liquid conduction. The flow is laminar.

Is it required to use the under relaxation factor ?

[lcarasik]

Originally Posted by NesrineB

Hello,

I'm running a CHT simulation which includes solid-solid conduction then solid-liquid conduction. The flow is laminar.

Is it required to use the under relaxation factor ?

It is very likely you will need to keep under relaxating even for laminar flow. You can always test it by setting it higher and higher until it won't solve. (It meaning the various applicable relaxation factors that apply to your case.)

[NesrineB]

Thank you for responding.
One more question: Should I activate it from the first iteration and keep it till the last one ?

[lcarasik]

Originally Posted by NesrineB

Thank you for responding.
One more question: Should I activate it from the first iteration and keep it till the last one ?

What's your reasoning for modifying it to begin with?

[NesrineB]

I think I got this point. My simulation is not converging due to other problems.

I posted another question earlier do you have an idea how to do it ? I'm posting it again:

'I'm modeling a geometry with CCM+. I have a circular tube in which circulates a hot fluid. The hole tube is covered by a solid layer. So I have solid- solid condction then solid-fluid conduction. I set up the physics for the solid layer which is heated with 38 C but my question is how can I set up the physics for the inner layer of the tube ? Should I set the thermal specification as Temperature ? Because I think that's not correct since the wall of the tube will have variable temperate and will transfer heat to the fluid.
Thank you