What the different between the symmetry boundary and periodical boundary

- November 20, 2017 at 7:38 am
  
  Jimmyhan
  Subscriber
  
  Hi, I am Jimmy. there is a problem in my simulation, When I used solver there is a warring stop my simulation. it told me something wrong in symmetry boundary setting. So I followed the suggestion to check the reason. But till now I can not find it out. So I try to use another way. I change the cross-section setting to a periodical boundary. It is work! I would like to know this interesting thing. 1. What the difference between the symmetry boundary and periodical boundary? 2. What kind of situation the symmetry boundary (or periodical boundary) have to be used? 3. How can I understand the symmetry and periodical boundary warning and the suggestion clear?Maybe you can give me some advice directly on my problem. Thank you!
- November 20, 2017 at 12:28 pm
  
  Min Zhang
  Subscriber
  
  The two figures listed below may help.
- November 20, 2017 at 10:57 pm
  
  Jimmyhan
  Subscriber
  
  Your reply was such great and clear. But can you give me some advice, Why I change symmetry boundary to periodical boundary the solver was no warning? Symmetry boundary recognize there no plane or axial, but periodical boundary was ok. is there some limitation in boundary setting?Thank you so much.
- November 20, 2017 at 11:17 pm
  
  Min Zhang
  Subscriber
  
  Sorry, I do not know your geometry. Maybe you can refer to the information on this website:
  
  https://www.cfd-online.com/Forums/cfx/65276-symmetry-boundary-conditions-cfx-3.html
- November 21, 2017 at 1:57 am
  
  Jimmyhan
  Subscriber
  
  Thank you, Your suggestion really helps!