Conjugate Heat transfer in CFX
 

Hi

I am trying to model a conjugate heat transfer problem in cfx. I went through the tutorial on CHT that came with the help files. It is on transfer of heat from solid coil to the flowing fluid. In my case, it is the reverse of that. A solid web is moving horizontally and hot air is coming in from the top and bottom of the web perpendicular to the web motion.

I modeled this similar to the procedure described in the tutorial. I create the solid domain inside the fluid domain used enclosure. generated the mesh. applied interfaces and boundary conditions. I ran the simulation and its running. But after my first run, I noticed that there is no heat transfer into the web.

Am I missing something here ? Do I need to change anything ?

P.S: I am new to CFD.

Thankyou

Shyam

Hi

I was going through some more threads here in the forum and found this. There one of the possible approaches mentioned was to get the heat transfer coeff from the cfd simulation and use it on the boundary of the solid and calculate the heat transfer in the solid.

Can this process be applied in my case. If yes can someone tell me how exactly i do it?

Is your case stationary or transient?

I am not sure what you meant but im trying to simulate steady state with the solid domain moving at a constant velocity.

Hi, I am new to CFD also, where can I find the tutorial files?

I need to model a CHT problem as well, internal flow through a certain solid structure which will generate heat. Any idea where to find relevant tutorial files?

Also, which is better to model CHT, CFX or Fluent? Thanks!! :)

Hi

The tutorial files are located in the directory where you have installed openfoam. there is a directory named tutorials.

I dont have Fluent. But I tried my case in CFX. The simulaton setup was pretty straight forward. But it was not useful for my case since I dont know how to setup motion to the solid domain. But for you it should work just fine.

OF is simple to setup and all but the solvers available right now will do only the following
Compressible----transient and steady state
Incompressible--- transient.

Hope this helped you.

Shyam

Hi Shyam,

I am running CFX in Ansys 12.1, I've found the tutorials.

By the way, what is OpenFoam??

Hi

Sorry, I got confused a bit. I was trying to solve this problem both in CFX and OpenFoam (its an opensource CFD software).


Shyam

I was learning CHT in CFX using the heating coil example from the tutorial. The tutorial uses calcium carbonate at the interface between solid and fluid. In my case, I do not have this "thin material", how should I define my interface ?
Thanks.

I am not sure how that is done. I am waiting for some help myself.

Did you try doing the opposite? Keeping the web steady and moving the fluid (i.e. switching to frame of reference of solid).
Also, you need to make sure you have enabled the thermal model (instead of isothermal) in solver setup.
If your interface is setup correctly (i.e. selected solid-fluid in interface properties, and specified a surface from solid and a surface from fluid), then you should have no problem getting heat transfer.

Hi

I am successful in runing a simulation with a stationary web. Its similar to the case in the tutorial.
But my case involves both fluid and web moving.
Yes, I have enabled the Heat Transfer model to thermal energy for both web and the fluid.

Shyam