Reynolds number scaling of influence of boundary layers on the global behavior of laboratory quasi-Keplerian flows

TL;DR

This study investigates how boundary conditions affect the behavior of quasi-Keplerian flows in a Taylor-Couette setup, revealing the importance of boundary layers and Reynolds number scaling in achieving ideal flow conditions.

Contribution

It identifies specific boundary conditions that produce self-similar, near-ideal quasi-Keplerian flows and explains deviations caused by boundary-induced Ekman circulation.

Findings

Boundary conditions crucial for ideal flow behavior

Reynolds number scaling influences flow self-similarity

Ekman circulation impacts angular momentum transport

Abstract

We present measurements of quasi-Keplerian flows in a Taylor-Couette device that identify the boundary conditions required to generate near-ideal flows that exhibit self-similarity under scaling of the Reynolds number. These experiments are contrasted with alternate boundary configurations that result in flows that progressively deviate from ideal Couette rotation as the Reynolds number is increased. These behaviors are quantitatively explained in terms of the tendency to generate global Ekman circulation and the balance of angular momentum fluxes through the axial and radial boundary layers.