|
[Sponsors] |
October 11, 2012, 04:10 |
symmetry and wall (free slip) BC
|
#1 |
Senior Member
Hamed Abdul Majeed
Join Date: May 2012
Location: New Orleans, LA, US
Posts: 147
Rep Power: 14 |
Hi,
What is the difference between symmetry and free slip wall boundary conditions in ANSYS CFX. |
|
October 11, 2012, 06:56 |
|
#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,871
Rep Power: 144 |
This is described in the documentation.
Symmetry enforces zero normal gradient to all parameters, and a slip wall does not necessarily do this. But for most normal simulations they are equivalent. And a symmetry plane is required to be planar, but a slip wall can be any shape. |
|
August 20, 2015, 14:31 |
|
#3 |
Senior Member
|
@ghorrocks : Some body showed a case of cylindrical shape domain and he has applied symmetry condition for the 60 deg sector. In my understanding symmetry condition reflect the solution around the mirror plane which in my understating can only be applied to two planes in 3-d case. I suggested him the periodic bc instead.
What do you think? |
|
August 20, 2015, 14:47 |
|
#4 |
Super Moderator
Alex
Join Date: Jun 2012
Location: Germany
Posts: 3,427
Rep Power: 49 |
I did not double-check if this is true in CFX. Another difference between the two boundary types should show up when using a turbulence model.
Near a free-slip wall, the turbulence kinetic energy is zero while at a symmetry boundary condition its normal gradient is zero. |
|
August 20, 2015, 14:54 |
|
#5 | ||
Senior Member
|
Quote:
This is taken from CFX help : Quote:
|
|||
August 20, 2015, 19:16 |
|
#7 | |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,871
Rep Power: 144 |
Quote:
That is the key difference to keep in mind for symmetry versus periodic. |
||
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
slip wall boundary condition | mb.pejvak | Main CFD Forum | 5 | May 24, 2014 07:49 |
Radiation interface | hinca | CFX | 15 | January 26, 2014 18:11 |
Wall functions with symmetry | moser_r | OpenFOAM Running, Solving & CFD | 9 | August 30, 2012 10:11 |
Modelling free surfaces using no slip wall, and other general queries | andy_mckay88 | Main CFD Forum | 1 | November 18, 2010 06:54 |
wall and symmetry boundary conditions | malik | FLUENT | 2 | April 22, 2008 08:48 |