Wall functions
 

hi,

I wonder if k-w models also use wall functions? I heard that they were not using so our analysises should have y+ values between 1-10. But I couldn't find if k-w uses wall functions or not from the user guide. So I can't decide whether to hold y+ values between 1-10 or 30-90. Can anyone help me solving the situation?

Regards

Taskin

Re: Wall functions
 

Did you read the User Guide? In Chapter 10, Modeling Turbulence, Sections 10.5, 10.8, 10.9 you can find the description.

Good luck

zhang

Re: Wall functions
 

I think fluent automatically does it. Near the walls it used the wall functions

-H

Re: Wall functions
 

If you use the transition option with k-w, you need to have y+ near 1, otherwise it uses wall functions.

Re: Wall functions
 

For my cases, I have done both y+ =1 and y+>30 and at least of the k-e model, the results seem similar. Since the geometry of interest for my case is very small so y+=1 if the way to go.

Re: Wall functions
 

okay thanks, I have built up a mesh that havey+=1 - 4.. its results are quite good with Spalart Allmaras. However drag coefficient is still lower than its real value Taskin

Re: Wall functions
 

I am new to fluent and would want to understand the idea behind this Quick convection scheme. Where in the user manual can find information about it?

Regards, James

Re: Wall functions
 

Try to ask your system administrator about the Fluent manual.