High aspect ratio in viscous sublayer?

Marius

Because I don't want to use wall functions (because I want to get a correct idea of the flow separation) I have to model the viscous sub and buffer layer, I am using a structured grid. So the spacing normal to the wall, close to the wall, is really fine. This gives in my viscous sublayer extremely high aspect ratio's for the hex elements, over 1000. I know normally this is not required, but is this also valid for the viscous sublayer, because else I have to increase the number of cells dramatically? Who can help me, thanks in advance.