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Sima Baheri November 18, 2006 04:52

periodic boundary condition?
 
Hi every one

I use ICEM-CFD as a grid generation software for PHOENICS. My geometry is very complex so I use multi-block method. It's a turbomachinery problem so I need periodic boundary condition but cyclic boundary condition in main menu/sources) doesn't work in this case. I'd be grateful if you help me.

Regards, Sima Baheri


Carlos November 28, 2006 20:14

Re: periodic boundary condition?
 
Hi Sima,

For PHOENICS, cyclic boundary conditions are not periodic boundary conditions. I do think that the only way to stablish periodic boundary conditions is writing a ground or a inform code. Does anybody know any other way?

You will find at inform lessons all you need to write a customized boundary condition. You will just have to write down your "periodic" equation for your boundary.

By the way, at \\phoenics\d_polis\d_enc\CYCLIC.htm you will find what is cyclic boundary conditions for PHOENICS:

"The variable XCYCLE is used to activate cyclic boundary conditions in the x-direction. If a cyclic boundary at x=0 is not required, XCYCLE is left at its default setting of F; if it is set T, the whole x=0 boundary is treated as cyclic. This option is active for any one-, two- or three-dimensional problem in which the x-direction is present; that is, whenever NX is greater than one.

Cyclic boundary conditions are required whenever the two ends of the calculation domain in the x-direction join up with one another. This can occur in a one-dimensional single- loop calculation, or in a polar-coordinate calculation in which the whole angular extent from 0 to 360 degree is to be considered. It is because of this latter application, that the x- direction (which is, as explained earlier, the circumferential direction when polar coordinates are used) is chosen to be the one in which cyclic boundary conditions are provided."

I hope I could help you.

Regards,

Carlos.


vikas menghwani February 26, 2007 05:18

Re: periodic boundary condition?
 
can you plwase explain a translational periodic boundary condition??

Steven October 17, 2007 15:39

Re: periodic boundary condition?
 
See J. Heat Transfer Vol. 129 pp. 601-605. Example was done with Inform.

Sima October 20, 2007 03:57

Re: periodic boundary condition?
 
Dear Steven

Thank you for your help, but which year?

Regards, Baheri

Steven October 20, 2007 09:20

Re: periodic boundary condition?
 
This year (2007). There's also discussion on the subject on CHAMs web site, e.g. http://www.simuserve.com/phoenics/d_polis/d_enc/fdf.htm and elsewhere (I'd need to search for more).

Actually people have been doing periodic bcs in PHOENICS from the early days (staring with Chandra Prakash in the '90's). The only catch is to make the boundary in the x-direction. Unfortunately you cannot readily do it in the y or z directions.


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