Hi. I'm coping with this fact: what should be the extent of the extrusion layer ?

I mean, i'm using a standard k-e model, with a standard wall function (local Re is high), how much space have i to take in account for the boundary layer ?

i thought a 3-layer with a thickness of 0.5(what are these numbers about ? Are maybe referred to the min and max cell lenght of the import geometry?) should be good...

Is there a way to calculate easy the boundary layer thickness ? I tried with the method y+ ='friction velocity * wall distance / dynamic viscosity, but i obtain nothing... any ideas ?

15

15 what ?

furlongs

it's a joke or an elegant way to say that i'm asking too much with too little detail ?

it's a bad joke, it is monday after all.....

yeah, you're right...

If you make the the cell reynolds number 1500 you generally get a decent Yplus for wall functions.

length is near wall cell height velocity is an estimate of the average free stream velocity