[StefanG]

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?

Thank you in advance for your reply.

Best regards,
Stefan

[Far]

specify half

[lffabiani]

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]

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

[StefanG]

Thank you for your help!

[hhh]

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]

Hi

Originally Posted by hhh

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]

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.

[ns778]

Hi, is this the same for velocity? if I model half the model, should I half the inlet velocity? I am guessing pressures remain the same because they're defined per unit area?

[Opaque]

Nope.

You may have to half the system mass flow, but the velocity remains the same.

You only halved the cross-section, not the flow conditions