symmetry Boundary Conditions

club68512 · April 29, 2010, 06:47

hello every

I have a problem about...symmetry Boundary Conditions,Dose it means no flux of any property across that boundary ?

the flux is heat? or??

thanks!

MuxaB · May 2, 2010, 17:14

This is correct, all fluxes into the boundary are zero, and there is no friction at it.

club68512 · May 3, 2010, 11:43

Quote:

Originally Posted by MuxaB

This is correct, all fluxes into the boundary are zero, and there is no friction at it.

but I set the boundary as symmetry that still has fluid across.

MuxaB · May 5, 2010, 00:55

Is there another mesh block on the other side of that boundary? If so, then this boundary will automatically be set as an inter-block boundary, which allow for a flow through it.

If it is stays a symmetry boundary, then there is definitely no flow through it. What makes you think there is flow?

club68512 · May 7, 2010, 10:50

Quote:

Originally Posted by MuxaB

Is there another mesh block on the other side of that boundary? If so, then this boundary will automatically be set as an inter-block boundary, which allow for a flow through it.

If it is stays a symmetry boundary, then there is definitely no flow through it. What makes you think there is flow?

thanks!! now I see.

I set another mesh block on the side!

club68512 · September 29, 2010, 04:59

I have some problems...

as you say... Is there another mesh block on the other side of that boundary? If so, then this boundary will automatically be set as an inter-block boundary, which allow for a flow through it. do you mean any boundary on the other side ? even P or Wall ?

How do you know about that? I can't find any documents to prove that .

sorry about my poor English~

stefmascio · September 29, 2010, 10:47

yes, whatever you set, if two boundaries are connected, the connected boundaries are automatically switched to a special type called "inter-block" as soon as you run the simulation.

This happens for linked blocks and for nested blocks too. In this second case, clearly, only the boundaries of the inner block will be converted to the inter-block type.
If you have two linked blocks, not of the same dimensions, the part of the boundary not connected to the other block will automatically become a wall.

hhh · August 30, 2012, 10:05

Dear friends,
i am doing 3D wing analysis, i have doubt on boundary conditions in fluent ie both symmetry and periodic, anybody have the answer please let me know briefly,for what kind of purpose to use symmetry & periodic boundary conditions, please tell any example with problem.

April 29, 2010, 06:47	symmetry Boundary Conditions	#1
club68512 New Member liang liam Join Date: Nov 2009 Location: Taiwan Posts: 28 Rep Power: 17	hello every I have a problem about...symmetry Boundary Conditions,Dose it means no flux of any property across that boundary ? the flux is heat? or?? thanks!

August 30, 2012, 10:05	boundary condition (symmetry vs periodic doubt)	#8
hhh Senior Member kunar Join Date: Nov 2011 Posts: 117 Rep Power: 15	Dear friends, i am doing 3D wing analysis, i have doubt on boundary conditions in fluent ie both symmetry and periodic, anybody have the answer please let me know briefly,for what kind of purpose to use symmetry & periodic boundary conditions, please tell any example with problem.

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May 2, 2010, 17:14		#2
MuxaB Senior Member michael barkhudarov Join Date: Mar 2009 Location: Sante Fe, New Mexico, USA Posts: 337 Rep Power: 18	This is correct, all fluxes into the boundary are zero, and there is no friction at it.

May 5, 2010, 00:55		#4
MuxaB Senior Member michael barkhudarov Join Date: Mar 2009 Location: Sante Fe, New Mexico, USA Posts: 337 Rep Power: 18	Is there another mesh block on the other side of that boundary? If so, then this boundary will automatically be set as an inter-block boundary, which allow for a flow through it. If it is stays a symmetry boundary, then there is definitely no flow through it. What makes you think there is flow?

September 29, 2010, 04:59		#6
club68512 New Member liang liam Join Date: Nov 2009 Location: Taiwan Posts: 28 Rep Power: 17	I have some problems... as you say... Is there another mesh block on the other side of that boundary? If so, then this boundary will automatically be set as an inter-block boundary, which allow for a flow through it. do you mean any boundary on the other side ? even P or Wall ? How do you know about that? I can't find any documents to prove that . sorry about my poor English~

September 29, 2010, 10:47		#7
stefmascio Member Stefano Join Date: Mar 2009 Posts: 59 Rep Power: 17	yes, whatever you set, if two boundaries are connected, the connected boundaries are automatically switched to a special type called "inter-block" as soon as you run the simulation. This happens for linked blocks and for nested blocks too. In this second case, clearly, only the boundaries of the inner block will be converted to the inter-block type. If you have two linked blocks, not of the same dimensions, the part of the boundary not connected to the other block will automatically become a wall.