Navier number and transition to turbulence

21st Fluid Mechanics Conference

物理学;力学

Ziólkowski, P.^1,2 ; Badur, J.^1

Energy Conversion Department, Institute Fluid-Flow Machinery PAS-ci, Fiszera 14, 80-231 Gdan´sk, Poland^1

Conjoint Doctoral School, Faculty of Mechanical Engineering, Gdansk University of Technology, Gdan´sk, Poland^2

关键词: Friction resistance;    Laminar to turbulent transitions;    Mass flow rate;    Momentum transports;    Navier numbers;    Transition to turbulence;    Turbulence transition;    Universal model;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/530/1/012035/pdf
DOI  :  10.1088/1742-6596/530/1/012035

学科分类：力学，机械学

来源: IOP

【 摘 要 】

The motivation behind this article is to explain a role of the Navier number (Na - dimensionless slip-length) in prediction of closures for laminar to turbulent transition undergoing via eddies detachment from the slip layer in nano-cannals. Additionally the role of the Navier number Na in universal modeling of phenomenon of enhanced mass flow rate reported in micro- and nano-channels has been explained. The Na number should be treated as a ratio of internal viscous to external viscous momentum transport and therefore this notion cannot be extended onto whole friction resistance phenomena. Our proposal for unique expressing of a critical point in turbulence transition is that on a plane of fD- Re one needs two coordinates. The second critical coordinate has been discovered by Stanton and Pannell and is known to be the Stanton-Pannell number StPa. Finally dependence of the Stanton-Pannell number StPa on Navier number Na and Reynolds number Re is presented.