Oil (high Pr) flows: Near wall mesh resolution
 

Does anyone have experience with computing heat transfer in oil (or other high Pr fluid) flows? What is the ideal, near wall spacing to use for high Pr flows? While I am able to accurately get the pressure distribution, my Nu distribution is not correct, which of course is due to the thinner thermal BL.

I'm interested in computing the Nu for both laminar as well as turbulent flow regimes in some tube cross-sections carrying oil and the Pr of the flows. I am looking at Pr in the range of 100 - 150.