On the difficulty of determining Karman 'constants' from DNS
Fluid Dynamics
2024-04-03 v2
Abstract
The difficulty of determining the slope of the famed logarithmic law in the mean velocity profile in wall-bounded turbulent flows, the inverse of the Karman 'constant' , from direct numerical simulations (DNS) is discussed for channel flow. Unusual approaches, as well as the analysis of the standard log-indicator function are considered and analyzed, leading to the conclusion that a definitive determination of the channel flow from DNS with an uncertainty of, say, 2-3% will require the residue of the mean stream-wise momentum equation in the simulations to be reduced by at least an order of magnitude.
Cite
@article{arxiv.2402.14729,
title = {On the difficulty of determining Karman 'constants' from DNS},
author = {Peter A. Monkewitz},
journal= {arXiv preprint arXiv:2402.14729},
year = {2024}
}