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CFX heat transfer not working

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Old   October 8, 2018, 07:41
Angry CFX heat transfer not working
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  1. I'm trying to do simple transient simulation of cooling copper tube with initial temperature of 100 C with water @20 degree that flowing inside the tube.
  2. The result not making any sense
  3. At final time the tube and water are at temperature of 20 C
  4. The dimensions of the copper tube is D1=30, D2=20, L =150
  5. The water velocity is 50 mm/s
  6. At inlet the temperature is 20 C
  7. No heat flow to the tube from the outside (adiabatic)
  8. Total time 100 s
  9. Ansys version is 19.2
  10. Can any one check my files
  11. https://drive.google.com/open?id=1dI...iKi2mg0jEiz6Da
  12. Or tell me whats wrong
  13. Or make the simple simulation and sent me

Many Thanks
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Old   October 8, 2018, 07:55
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Did you make all the needed interfaces and turned on heat transfer in the second tab in the interface settings?
You need to specify fluid-solid connections otherwise these are not connected
...
(..later in time)
Ok I see you have made connections
Outlet could be just pressure opening
And I am not sure jet why there is no trn.files created
..
(..later in time)
Ok it is working now
I have decreased the mesh size from 4mm to 2mm as it was really coarse
It would be good to add some inflation layers on the fluid walls
I have merged both bodies into one part to obtain a conformal mesh at the interface
Changed the outlet to opening
Initialize the velocity of water to 50mm/s in the correct direction
I have set solid timescale factor to 100

Last edited by urosgrivc; October 8, 2018 at 08:59.
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Old   October 10, 2018, 09:37
Default Initial temperature of the copper pipe
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I made the changes that you suggested
and it seem that the initial condition of the pipe isn't set, i.e the pipe start at final temperature of the water 20 C, and not in it initial temperature 90 C
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Old   October 10, 2018, 18:25
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Glenn Horrocks
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Setting initial conditions is very basic stuff. Have a look at the CFX tutorials for how to set up initial conditions.
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