Numerical reproduction of the spiral wave visualized experimentally in a wide-gap spherical Couette flow

TL;DR

This study numerically reproduces the experimentally visualized spiral wave in a wide-gap spherical Couette flow, confirming the flow pattern and phase velocities through computational modeling aligned with experimental observations.

Contribution

The paper presents a numerical method to reproduce and visualize spiral waves in spherical Couette flow, matching experimental results and advancing flow pattern analysis.

Findings

Numerical reproduction of spiral wave matches experimental visualization.

Phase velocities of the spiral wave are accurately predicted.

Flow pattern analysis is validated through comparison with experimental data.

Abstract

SCF experiments were conducted according to the work of Egbers and Rath [Acta Mech. 111 pp. 125--140 (1995)]. Through visualization using aluminium flakes drifting on a horizontal plane illuminated by a laser sheet, the flow was identified as a spiral wave with azimuthal wavenumber $m=3$, using the experimentally obtained and numerically deduced comparison between phase velocities. By solving the equation of motion for the infinitesimal planar particles advecting in the flow field of the spiral wave, a visual distribution of reflected light was reproduced virtually, which is in good agreement with the picture obtained experimentally.