Is Y+ depends on the tubulence model?
 

If we use different turbulence models, the target Y+ will change accordingly?

Does you question mean -
"If you use different turbulence models we should target different Y+ while making grids ?"

Yes Thanks in Advance

These 3 links might be useful -
http://www.cfd-online.com/Forums/mai...ga-models.html
http://www.cfd-online.com/Wiki/RANS-...bulence_models
http://www.kxcad.net/STAR-CCM/online...ulence-15.html

yes, it does

for the turbulence model chosen, a preferable range of Y+ must be obtained to be considered valid the analysis. What drives this range will be the size of the first cell adiacent to the wall.

for example yplus 30 or greater for K epsilon based models and y+1 ~ for the SST, BSL and SA type models. It is the preferable approach.

although we can extend the K epsilon model to yplus = 1 range by using the special damping functions as implemented in the Fluent

similarly SST model can be used with the yplus = 30 mesh


P.S: Yplus = 30 or greater implies we are not solving the viscous sub-layer (yplus 2 or less) and buffer layer (in between 2 and 30). It is also called wall function approach

Yplus = 1 implies we are resolving the viscous sub layer. It is necessary to use the yplus = 1 type mesh if flow is dominated by the separation and reattachment where wall function ceases to be valid

In commercial CFD codes after Yplus = 11.06 wall function approach is activated and below this viscous sub layer approach is used

also check this link http://www.cfd-online.com/Forums/cfx...machinery.html

thanks for your information. now I have some idea about Y+