|
[Sponsors] |
November 14, 2009, 07:10 |
Asking Y plus
|
#1 |
Senior Member
teguh hady
Join Date: Aug 2009
Location: Saga, Japan
Posts: 222
Rep Power: 17 |
Dear All,
In simulating airfoil, i use y+ = 1 for thin layer. However, I don't know the correct value of grow ratio b/a and number of row in GAMBIT?? Help me out this problem!!! Thanks teguhtf
__________________
Now Or Never!!! |
|
November 15, 2009, 17:16 |
Problem Dependent.
|
#2 |
Senior Member
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
Blog Entries: 1
Rep Power: 47 |
These are up to the user and are highly problem dependent. If you don't already have a preference, then you should start with a ratio of 1.2 (most common).
As for number of layers, this should be enough to capture the thickness of your boundary layer velocity profile, but not so thick that it causes you too much meshing trouble. Try 5, or try 21, solve, and look at the boundary layer velocity profiles... Which works best for your type of model? You want to see a smoothly transitioning boundary layer profile that goes from 0 at the wall up to the free-stream velocity (should approach asymptoticly )before the top of the prism stack. Was 21 layers overkill or does it look like you need more? |
|
November 21, 2009, 21:11 |
|
#3 |
Senior Member
teguh hady
Join Date: Aug 2009
Location: Saga, Japan
Posts: 222
Rep Power: 17 |
Thank you for your reply,
Well, My problem is How to get Right value of Cd & Cl between experiment and simulation. Can you explain the Y+ value of other boundary condition?? Do you have reference?? Btw, I've try 5 to 10 layers. But it doesn't work!! My simulation is just 2D so i can use prism. Thanks for helping Teguh
__________________
Now Or Never!!! |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|