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Maintaining average temperature at Inlet in cyclic Boundary condition

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Old   May 8, 2018, 03:18
Default Maintaining average temperature at Inlet in cyclic Boundary condition
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Dear all,
I want to maintain the average temperature at the inlet to fixed value of 1 in my cyclic boundary condition. (streamwise periodic heat transfer)
I have seen the fvOption utility patchMeanVelocityForce to fix the average velocity at any patch to desired value.
Is there any utility available in OpenFOAM to fix the average temperature of any patch?

Thanks in advance

Last edited by Luttappy; May 16, 2018 at 06:05.
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Old   May 16, 2018, 06:01
Default Maintaining average temperature at Inlet in cyclic Boundary condition
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Since i am not dealing with actual temperature and my temperature range is from 0 to 1, this can be implemented in OpenFOAM very easily by following way.
  1. Find the average temperature (Tavg) at INLET after every time step after solving energy equation.
  2. Divide the temperature field of whole computational domain by Tavg (T=T/Tavg)
  3. Proceed to next time step

In some cases people suggest this procedure after every N time step rather than every time step. This N can be found by trial and error.

If we don't fix average temperature at INLET to a constant value, temperature value inside the domain can go to very very low value (Cold walls + hot fluid entering case) or very very high value (Hot walls + cold fluid entering case). This is because of the cyclic boundary condition applied at INLET and OUTLET.

Please correct me if i am wrong
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Old   June 1, 2018, 15:14
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Hello Luttappy,


did you find out how to set the value for the temperatur with a cyclic inlet boundary condition?


Greetings
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Old   June 21, 2018, 02:04
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Quote:
Originally Posted by SamuelPei View Post
Hello Luttappy,


did you find out how to set the value for the temperatur with a cyclic inlet boundary condition?


Greetings
I resolved it in this way.

Quote:
Originally Posted by Luttappy View Post
Since i am not dealing with actual temperature and my temperature range is from 0 to 1, this can be implemented in OpenFOAM very easily by following way.
  1. Find the average temperature (Tavg) at INLET after every time step after solving energy equation.
  2. Divide the temperature field of whole computational domain by Tavg (T=T/Tavg)
  3. Proceed to next time step

In some cases people suggest this procedure after every N time step rather than every time step. This N can be found by trial and error.

If we don't fix average temperature at INLET to a constant value, temperature value inside the domain can go to very very low value (Cold walls + hot fluid entering case) or very very high value (Hot walls + cold fluid entering case). This is because of the cyclic boundary condition applied at INLET and OUTLET.

Please correct me if i am wrong
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Old   September 11, 2018, 15:44
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Quote:
Originally Posted by Luttappy View Post
I resolved it in this way.
Hi Luttappy, could you please share your code for this? Maybe your .C files would help. Thanks.
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Old   September 25, 2018, 04:27
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Me too please!
I have a non-uniform cross section periodic channel that this may work for.
Sharing your solution would be very helpful...

Regards
Peter
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