# Periodic boundary condition in 2 directions

 Register Blogs Members List Search Today's Posts Mark Forums Read

 June 20, 2008, 18:50 Periodic boundary condition in 2 directions #1 arash Guest   Posts: n/a Hi! can anyone anwser me please? i am modeling a rotating channel and i have to define periodic boundary condition in two directions ,one in x and another in z direction , the channel is rotaing around y axes, i can make the 2 different periodic zones , but how can i set the periodic conditions for the both directions? because at the menu Defin/periodic condition i can just set the condition for one direction. thanks

 June 21, 2008, 13:18 Re: Periodic boundary condition in 2 directions #2 Phil Guest   Posts: n/a You should make the 2 seperate periodic boundaries first in the pre-processor, then define each seperate in fluent. You don't supply a direction in fluent just whether it is rotational or translational. From what I gather your x is rotational, and your z translational. Hope this helps Phil abdi mohamed1 likes this.

 June 22, 2008, 06:13 Re: Periodic boundary condition in 2 directions #3 arash Guest   Posts: n/a any idea?

 June 22, 2008, 06:18 Re: Periodic boundary condition in 2 directions #4 arash Guest   Posts: n/a tnx ,but my problem is that , i should give a pressure gradiant in x direction ,but zero pressure gradiant in z direction , i can make the two periodic zones , but in periodic condition theres is nothing to choose one of this zones !and i think when i give a pressure gradiant it will assigned to both zones.

 June 22, 2008, 08:04 Re: Periodic boundary condition in 2 directions #5 Phil Guest   Posts: n/a To be honest I'm unsure what you mean by pressure gradient but it sounds like maybe one of them should be symmetry instead of periodic?

 June 23, 2008, 04:37 Re: Periodic boundary condition in 2 directions #6 Paolo Lampitella Guest   Posts: n/a if you carefully check the panel periodic boundary conditions under define (after you defined the two couples of periodic boundaries) you will see a blank for the specification of the pressure gradient and something (i don't remember actually) for specifying the direction of the pressure gradient

 June 24, 2008, 09:29 Re: Periodic boundary condition in 2 directions #7 arash Guest   Posts: n/a thanks for your reply , but as i have mentioned before i have to define two seperate periodic boundary conditions one with pressure gradient and another with zero pressure gradient, but in pannel which you mentioned there is no option for choosing the appropriate boundary condition zone ,then i think when i give a pressure gradient it will be set for both periodic zones which is not correct.

 June 24, 2008, 13:10 Re: Periodic boundary condition in 2 directions #8 Paolo Lampitella Guest   Posts: n/a sorry, i did not understood (my poor english) very well, but maybe could works also in your case. For example, in my turbulent channel flow i have the flow along the positive x axis (streamwise) and the z axis is the transverse direction (the y axis is perpendicular to the walls). If i want the flow goes along the x axis i just put this as direction. The faces perpendicular to the z axis will have just the same gradient that will be parallel to those faces. However this works just in non-rotating channel with the two couples of sides being perpendicular to each other. If your domain is a rectangular channel you could apply a source term to simulate the rotation and use this method to apply periodic boundary conditions. Hope this helps

 August 6, 2015, 03:31 #9 New Member   Derek Chung Join Date: Aug 2015 Posts: 1 Rep Power: 0 Hi, I was wondering if anyone knows how to solve this problem as I encounter the same problem. I would like to set translational periodic boundary conditions in the streamwise direction with specified flow rate as well as in the spanwise direction with zero pressure gradient. If I set the periodic conditions for the streamwise direction with a mass flow rate, it sets the same periodic conditions to the other periodic boundary which in this case, the spanwise direction. How do I define two different periodic boundary conditions separately in Fluent? I am relatively new to Fluent. Any advise will be greatly appreciated.

 August 7, 2015, 13:05 #10 Senior Member   Lucky Tran Join Date: Apr 2011 Location: Orlando, FL USA Posts: 1,339 Rep Power: 20 You need to specify the periodic boundary pair with the zero pressure gradient as an interface.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post jaysree FLUENT 0 December 18, 2007 07:51 Sima Baheri Phoenics 5 October 20, 2007 09:20 elyyan FLUENT 4 April 21, 2006 16:30 ap CFX 1 March 6, 2006 15:16 david FLUENT 0 April 1, 2002 07:24

All times are GMT -4. The time now is 15:18.