The aim of my subject is the enhancement of the heat transfer inside a hot rotating tank which contains a hot rotating blade and a cold fluid. I am using Ansys Fluent but i couldn't find how can i give the initial temperature for the fluid?
Best regards
In FLUENT, under solution methods, you can change the reference conditions for temperature.
Thanks a lot Mr. Shashwat Agarwal for your response but i need more clarifications if you can.
Reference values do NOT initialize the flow field for CFD simulation. Reference values are just for calculating normalized variables and dimensionless groups for the output. No influence on CFD simulation itself.
Explicit temperature initialization can of course be done in Standard initialization (not hybrid initialization). Alternatively the flow field can be initialized using patching method. There a temperature field can be specified as well. And last but not least (but this is the least convenient way) is to write your own UDF for temperature field initialization, if you like to prescribe a more complex temperature pattern.
Thanks a lot for your response Mr. Thomas Frank but when i put the same temperature for the rotating tank and the blade the fluid take this value of temperature even i use another value in the initialization, Patch or UDF.
Although when i use different value of the temperature for the tank and the blade the software calculate automatically the initial temperature of the fluid.
Thanks
This should not happen, if you chose to take the option of Standard initialization with a user prescribed temperature. This option is for exactly this purpose, where the user wants to prescribe fluid temperature. Same for patching (than without initialization, because patching is replacing it). Everything else I would judge as an erroneous behavior of the program. But I would not wonder too much in the case of Fluent so.... In Fluent everything needs to be verified by the user before seriously using it. And that version by version again.
Hi,
I was a bit worried about your comments and so I did a quick setup for my favorit case - the CFX Static Mixer ;-)) . I setup the case with a hot wall (360K), fluid is air with low temperature of 283K at inelt1 and 303K at Inlet2. The fluid is initialized with hot temperature of 303K using the Standard Initialization in Fluent. In the result, after this initialization the domain should be filled with hot air at the beginning of the simulation. And with progressing simulation this hot air should become replaced by the cold fluid from both inlets, with the exception of the heated air close to the Static Mixer walls.
In the two attached images you can see the the flow result after standard initialization and 2 (pseudo-transient) steady-state iterations and the 2nd image shows the final temperature distribution.
My conclusion: everything works as expected.
Thanks a lot for your response Mr. Thomas Frank and sorry for the delay.
In my case there is no inlet and outlet i have a closed system which contains a hot rotating cylinder and inside this cylinder there are:
1- A hot blade rotates with transient velocity.
2- A cold fluid.
The aim of the subject is the study with Ansys Fluen the enhancement of the heat transfer between the wall of the cylinder/blade and the fluid.
In Ansys Fluent I can fix the temperature of the blade and the cylinder but i can't give an initial temperature for the fluid even i tried to use Standard initialization, patching method.
NB: I m using Ansys Fluent 15.0.
Best regards.
As you could see, with ANSYS Fluent 19.x it worked well. So most likely you need to use a more contemporary version of ANSYS Fluent or you need to write an fluid temperature initialization UDF for your case.
hi Boubakeur Benlaib,
I wonder if you were able to complete your simulation ?. Do you enter the temperature of the fluid in what way?
thanks
Hey Boubakeur, have you solved your problem ? Because i am also encountering same problem.
Hello Boubakeur
You can simply patch regions of interest like this:
/solve/patch ()
where Id1 is the Id name of the Zone.
You can patch multiple regions Id1 Id2 Id3, etc...
You can use Zone name instead of Id of zone.
At the end of the Id list you have to put this simbol "()".
In your case variable is temperature.
I hope this helps.
Best regards.
Vincenzo
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