Scaling of the turbulence transition threshold in a pipe

TL;DR

This paper presents an experimental study on the transition to turbulence in pipes, revealing a new scaling law that the perturbation amplitude needed for transition scales inversely with Reynolds number.

Contribution

The study uncovers a novel scaling law linking perturbation amplitude to Reynolds number, connecting experimental results with modern turbulence transition theories.

Findings

Perturbation amplitude scales as O(Re^{-1})

Transition threshold varies over an order of magnitude in Re

Experimental results support the new scaling law

Abstract

We report the results of an experimental investigation of the transition to turbulence in a pipe over approximately an order of magnitude range in $Re$. A novel scaling law is uncovered using a systematic experimental procedure which permits contact to be made with modern theoretical thinking. The principal result we uncover is a scaling law which indicates that the amplitude of perturbation required to cause transition scales as $O(Re^{-1})$.