|
[Sponsors] |
![]() |
![]() |
#1 |
Senior Member
Join Date: Mar 2013
Location: Germany
Posts: 357
Rep Power: 14 ![]() |
Hi All
I am doing a quasi 2D simulation in CFX. So my domain is 1mm thick in the z direction and when I check the streamlines along the center plane (2D Surface Streamline) I can see some recirculations and when I see the 3D streamlines I dont see them . Ofcourse in 3D streamlines I am saying the starting position as the flow inlet position. And within 1mm thickness do you think there will be difference in the flow pattern in the Z direction ? Why is the streamlines look different ? Which one can we trust then ? Or what is their significance ? |
|
![]() |
![]() |
![]() |
![]() |
#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,816
Rep Power: 144 ![]() ![]() ![]() ![]() |
There is a recirculation in your 3D simulation. You just have not put a streamline in it. It looks pretty similar to the 2D results to me.
Whether there will be a difference in 2D and 3D results depends on which flow regime you are in. Have a look at flow over a cylinder - it goes through many flow regimes depending on the Reynolds number, going from 2D to 2D transient to 3D transient to 3D steady state.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
|
![]() |
![]() |
![]() |
![]() |
#3 |
Senior Member
Gert-Jan
Join Date: Oct 2012
Location: Europe
Posts: 1,885
Rep Power: 27 ![]() |
You should use the inlet AND the outlet as starting point for your streamlines. And then calculate 'Forward and backward'.
|
|
![]() |
![]() |
![]() |
![]() |
#4 |
Senior Member
Join Date: Mar 2013
Location: Germany
Posts: 357
Rep Power: 14 ![]() |
Ah ok now I see it ..So its the same for both surface streamline or the 3D streamline.
Thanks both of you.. |
|
![]() |
![]() |
![]() |
|
|