[sircorp]

Originally Posted by ghorrocks

Sounds like you need to think about what is really happening. If you apply a defined temperature on the walls then of course you won't get any cooling as you have defined it to be fixed. You need to think about what are appropriate initial and boundary conditions so the correct physics can occur.

I suggest you should consider an initial condition of your fixed temperature, with the wall being a convective boundary condition.

Firstly Thanks a lots for helping me. At last I am up and running.

One quick Question. I have included fluid zones inside the copper pipe and did meshing of whole geometry and all wall are coupled Except Insulation. Pipe is heavily insulated.

I had a 75mm insulation around the pipe.
My Question is ::

Should I use Shell Conduction(Inside Wall Zone -> Then Temperature) and set the insulation parameters for insulation or it is better to include Insulation in the geometry and do the meshing together.

Since I have 75mm Thick Insulation, Mesh size may become too much.

Advice please

Thanks for the help.

With Regards

Shane

[ghorrocks]

I do not know what you are trying to achieve with your model so cannot say what the best form of model is. Have a think about the results you need to know and the physics required to achieve it.

Regarding your comment on thick insulation - you often do not need a very fine mesh in conducting solids. Often a fairly coarse mesh will do. So the thickness of the insulation will probably not be a problem as you can use a coarse mesh.

[sircorp]

Originally Posted by Thomas MADELEINE

Since there is no big change in the flow (except for temperature) the thing you can do is extract the HTC (W/m²/K) from a steady state simulation with a rough temperature at wall. This value should be more or less constant no matter of the wall temperature.
and export it to a mechanical software for a transient run.

It is not the most accurate simulation but you don't have to get all the interfaces right.

2nd choice :
on CFX you can create a solid domain and create interface for only heat flux.
I think the same is available on Fluent but I don't know this software as well as CFX.

Thanks a lot.

From my understanding is Fluent is almost same as CFX.

Shane