Learning Forum

[Milne Ando]

G'day,

Due to Karman vortex street forming behind the cylinder, properties(velocity, pressure profile)of the outlet must be not uniform. In this case, pressure outlet is used and I wonder that

1. what is pressure profile multiplier? (user guide doesn't explain it much)
2. how many time the diameter of the cylinder is far enough away from the outlet to the cylinder?(at least)
3. for backflow pressure specification, I have no idea which one is suitable. Any suggestion?

Hope someone can help me out, thank you.

[Amine Ben Hadj Ali]

Details about the options for pressure outlet to be found in the Fluent User's Guide. If not using profile the profile multiplier is not used at all.

You should place the outlet at least 10-20 times the diameter of  our pipe. The best place is really where you can provide reasonable backflow stagnation quantities if reversa flow is expected to occur or best where no reversal flow is expected.  I would say free stream gauge pressure is the way to go.