Turbulence Intensity Scaling: A Fugue

TL;DR

This paper investigates how different definitions of turbulence intensity scale with Reynolds number and friction factor in pipe flows, providing a unified approach for smooth and rough walls based on experimental data.

Contribution

It introduces a scaling relationship for turbulence intensity with Reynolds number and friction factor, and identifies the most effective definitions for smooth and rough pipe flows.

Findings

Turbulence intensity scales with the friction factor.

Best turbulence intensity definitions are identified.

A calculation procedure based on Reynolds number and roughness is proposed.

Abstract

We study streamwise turbulence intensity definitions using smooth- and rough-wall pipe flow measurements made in the Princeton Superpipe. Scaling of turbulence intensity with the bulk (and friction) Reynolds number is provided for the definitions. The turbulence intensity scales with the friction factor for both smooth- and rough-wall pipe flow. Turbulence intensity definitions providing the best description of the measurements are identified. A procedure to calculate the turbulence intensity based on the bulk Reynolds number (and the sand-grain roughness for rough-wall pipe flow) is outlined.