# Periodic boundary condition

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 May 1, 2003, 04:02 Periodic boundary condition #1 Arif Guest   Posts: n/a I am simulating a flow problem using periodic boundary condition. Two end of a circular tube consider as translational periodic boundary. According to the fluent documentation, we can specify mass flow rate or pressure gradient for periodic boundary condition. In my case I specified mass flow rate. Now I want to calculate pressure loss to compare with standard friction factor correlation. In the article 8.3.2 of user's guide showed that Local pressure gradient =gradient of periodic component of pressure + gradient of linearly-varying component of pressure We can get gradient of a linearly-varying component from periodic condition panel. How can we find the gradient of periodic component of pressure? Any help in this regards is greatly appreciated. Arif

 December 21, 2013, 23:14 Hi Arif #2 New Member   ASHRAF ALFANDI Join Date: Oct 2012 Posts: 17 Rep Power: 13 In this case, the "linearly-varying component = beta" is the actual pressure drop across the your domain in which FLUENT calculates the beta that corresponds to the input mass flow rate. Once the calculation is done, go back to the periodic B.C panel and check "beta" and thats you dp. good luck..... hyugakojiro999 likes this.

 January 17, 2014, 06:48 #3 Member   Join Date: Dec 2013 Posts: 53 Rep Power: 12 Hi everyone!!! I am trying to simulate a 1d heat transfer in a medium confined between two large walls (top and bottom wall). I created a 2d rectangle in icem cfd. For top and bottom lines I have given the boundary conditions as walls. But I am not clear what boundary condition I should use for left and right lines which are not supposed to be present. (I created them only for meshing).. do I have to use periodic condition? Pls reply.

March 9, 2017, 01:18
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soheil
Join Date: Mar 2017
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Quote:
 Originally Posted by ashraf88 In this case, the "linearly-varying component = beta" is the actual pressure drop across the your domain in which FLUENT calculates the beta that corresponds to the input mass flow rate. Once the calculation is done, go back to the periodic B.C panel and check "beta" and thats you dp. good luck.....
hi ashraf
in periodic B.C. it gives your pressure drop per metre...that mean total pressure drop per total length of your domain?
can we calculate pressure with made two line in your domain and the calculate p(in) & p(out) in these line and the calculate pressure drop?