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 StefanG April 20, 2012 08:14

Symmetry Boundary Condition

Dear all,

I'm sorry I didn't find an explanation to my question in the ANSYS Help, so I have to ask here:

When I'm using a symmetry boundary condition in my simulation, which divides my geometry in two equal parts, will I have to impose half of the mass flow or anyway the full mass flow as my boundary condition?

Best regards,
Stefan

 Far April 20, 2012 09:52

specify half

 lffabiani April 20, 2012 10:13

Yes, Far is right.

The mass flow must be proportional to the partion, meaning that if you divide the domain in two parts, the mass flow must be 1/2 of what it would be on the whole domain. If you divide it in 6 parts, it should be 1/6 of the total mass flow, etc...

 Lance April 23, 2012 02:18

http://en.wikipedia.org/wiki/Intensi...ive_properties

 StefanG May 1, 2012 02:17

 hhh August 30, 2012 09:06

boundary condition (symmetry vs periodic doubt)

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.

 bratzinger August 31, 2012 04:25

Hi
Quote:
 Originally Posted by hhh (Post 379501) Dear friends, ...for what kind of purpose to use symmetry & periodic boundary conditions, please tell any example with problem.
if u have e.g. a large cooler with periodic elements or pipes where u don't want to simulate large inflow regions to have the desired velocity profiles, u can simulate relative small meshes and that reduces the amount of time to process -> especially useful if u want to simulate lots of parameter variations(e.g. in a DoE project)

if your 3D-wing isn't symetric at all, then ... ;)

 ghorrocks August 31, 2012 06:56

Mathematically a symmetry boundary is zero normal velocity and zero normal gradient on all other terms, and periodic boundaries have all values equal on the equivalent locations on both boundaries.

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