axis Boundary conditions
 

Hi
I need some help,how can i define the axis when it is out of domain in case of 2D annular flow in circular duct it is axsi symetric and the only mesh(annular domain ) is importes in fluent how can i do???

good question...
*Did you try to import your mesh in the 2d-axisymetric solver?Check your solver's specifications for axis BC (for instance in Fluent it has to be x>0 and your domain should belong to xy postive quarter (x&y>0))
In this case if your domain is in (xy)>0 and no cells at y=0, maybe fluent will automatically treat it right (go and display your grid with symmetries to check if Fluent reflects your grid around x)

*I never tried it, but you can also try that: in 2d you can mesh a solid domain in which your axis will be meshed. Define the solid region as solid and export

*Else you can try a workaround by switching in 3d and using symmetries.

thank you-mAx-
I think ,i'll try the second case with meshing the solid domain,i tried with importing mesh in the 2d-axisymetric solver but the results were wrong.