European Turbulence Conference 14

Full Program »

On the validity of the law of the wall

View File

Existing and new direct numerical simulation (DNS) results are used to examine the effect of flow Reynolds number and pressure gradients on the law of the wall for incompressible wall-bounded turbulence. We find no evidence from DNS against the law of the wall: as the Reynolds number is increased, all sources agree precisely over an increasing range of z+ on the function U+ versus z+. This includes Couette-Poiseuille flows with mild but non-negligible, favorable and adverse, pressure gradients. We consider the law of the wall to be firmly established up to z+ ≈ 400. On the other hand, a logarithmic region (in the sense of constant logarithmic slope equal to the inverse of the von Karman coefficient κ) is not revealed for the Reynolds numbers accessible to DNS today. A constant slope roughly over the range [150,400] is recovered by introducing a shifted origin for z+, but the required value of κ is then near 0.35, which is outside the range of recent proposals, namely [0.38,0.42], let alone the range that prevailed for decades, namely [0.40,0.41].


Gary N Coleman    
United States

Philippe R Spalart    
Boeing Commercial Airplanes
United States


Powered by OpenConf®
Copyright ©2002-2013 Zakon Group LLC