A Novel Explicit Equation for Friction Factor in Smooth and Rough Pipes


AVCI A., KARAGÖZ İ.

JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME, vol.131, no.6, 2009 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 131 Issue: 6
  • Publication Date: 2009
  • Doi Number: 10.1115/1.3129132
  • Journal Name: JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Keywords: boundary layer turbulence, channel flow, friction, pipe flow, rough surfaces, TURBULENT PIPE, CHANNEL FLOWS, WALL

Abstract

In this paper, we propose a novel explicit equation for friction factor, which is valid for both smooth and rough wall turbulent flows in pipes and channels. The form of the proposed equation is based on a new logarithmic velocity profile and the model constants are obtained by using the experimental data available in the literature. The proposed equation gives the friction factor explicitly as a function of Reynolds number and relative roughness. The results indicate that the present model gives a very good prediction of the friction factor and can reproduce the Colebrook equation and its Moody plot. Therefore, the new approximation for the friction factor provides a rational, accurate, and practically useful method over the entire range of the Moody chart in terms of Reynolds number and relative roughness.