ANSYS Fluent Tutorial | Heat Transfer Through Insulation | Heat Exchange Through Insulation (Part-2)

This video contains ANSYS fluent tutorial for CFD analysis of heat transfer between two pipe with insulation in between them. This is the second part of the tutorial . The viewers would be able to know how to insert a new material property in ANSYS fluent, how set solution parameters and analyzing the results. The first part of this tutorial contains the creation of geometry and meshing . Please comment if have any doubt in this tutorial.

[@zilongzhao2517]

Hi, thanks for your video! I have a question, where did you set the initial temperature of the insulation?

[@AnsysTutor]

i have not set any initial temperature for insulation, its the default atmospheric temperature, while doing standard initializing , the solver generally assigns the default Temperature of 300K to the unassigned walls.

[@danielbowman2321]

I've been following your tutorial but I'm having a problem. When I try to initialize the simulation I get an error "get-thread: invalid thread id (integer) or name (symbol)" I think the problem may be in my boundary conditions as although I followed your tutorial mines look different. Any help would be appreciated.

[@AnsysTutor]

try to reset the setup once,and check if you had defined the boundary surfaces in meshing properly or not, sometimes users do named selection of the same surface twice, it might cause this error.

[@el_vidicovski6657]

Can you please tell me how do we know type of material on the walls in boundary conditions when the wall are two side (borders between two regions). For example wall-innerpipe1-insulation. Is the the material steel or polyurethane?

[@AnsysTutor]

see adjacent cell zones to find what is the near by region, for that click on boundary conditions window for that wall there you can see that adjacent cellzone.

[@el_vidicovski6657]

what about shadow zones.. I see that they have to be from same materials as it original walls, because when i change it, the material of its original (non shadow wall) also change d but their adjacnet zone are different...Also I noticed that in my case adjacent zone of wall-innerpipe1-insulation is insulation and in yours innerpipe1.. So should I put polyurethane as material or not?...Thank you very much Sir!

[@edwardwonder9258]

Great Video. May I ask what if I want to simulate a conductor inside the pipe filled with air. The current in the conductor will produce heat. Is it doable in Fluent?

[@AnsysTutor]

Yes you can do it , you have to calculate the heat that will generate by the current, and put that value as heat flux in boundary conditions.

[@edwardwonder9258]

@@AnsysTutor Thank you for your answer. I was aware that, however, the value is not constant and it is related to the temperature of the conductor. Do you know if there is any variable like "T" I can use in the setting? For example, I want to put P=I^2*R(T) in the heat flux, will the Ansys know that the "T' means the temperature of the boundary?

[@AnsysTutor]

for this you can use UDF (user defined function)

[@kasmerdem2707]

Hi, I have a problem although i have tried same process at twice.
Energy is decreasing 11.iteration (9.1207e-07) and then always increasing (1.8055e-02).
Please can you tell me how i can solve this problem?

[@AnsysTutor]

check the mesh and boundary conditions etc

[@kas5857]

Why is there very high temperature within the pipe insulation 300+ k. I thought the insulation is meant to insulate and stop heat transfer?

[@AnsysTutor]

The insulation material (polyurethane) has assigned a conductivity of 0.0207W/mK ,due to which there is a heat conduction from pipe 1(top one) which has also shown in results, that there is a slight increase in temperature of pipe 2 .As the insulating material is in between these two pipe so its tempr gets increased due to this conduction heat transfer. You can compare different insulating material by changing the insulating material properties, and see the heat transfer between these two pipe.

[@el_vidicovski6657]

Thank you very much for a great video. It helped me a lot but I have a problem because energy is growing all the time. Does anybody know what might be te problem. Everything else is like in your case.

[@AnsysTutor]

increase the mesh. is there any divergence?

[@el_vidicovski6657]

there is no divergence. I made a calculation for 1000 iterations and energy falls at the beggining , than rises and becomes constant. Other lines decrase and become constatnt. Results finally have no sense. I made the mesh just like you.. what elese should I do. Thank you very much for help.

[@el_vidicovski6657]

Please do you have any idea what might be wrong. I put infaltionlayers near solid-liquid interfaces and it still doest work because energy rises after few iterations and I have also temperature limitations warnings in all zones. Any suggestio how to solve this problem?

[@AnsysTutor]

Temperature limitations warning cames if there is any problem in meshing. I think you should check the mesh . and if its possible then increase the no of elements.

[@AnsysTutor]

what is the no of elements in meshing?