# Phase Slip Solutions in Magnetically Modulated Taylor-Couette Flow

## TL;DR

This paper numerically studies magnetically modulated Taylor-Couette flow, revealing phase slip events and bifurcations leading to various vortex solutions, with implications for understanding flow dynamics under magnetic fields.

## Contribution

It introduces new insights into phase slip phenomena and vortex formation in magnetically influenced Taylor-Couette flow, expanding understanding beyond previous geometrical ramp studies.

## Key findings

- Phase slip events cause vortex pairs to form and drift outward.
- Bifurcations lead to symmetric and asymmetric vortex solutions.
- Different phase slip types occur at various Reynolds numbers.

## Abstract

We numerically investigate Taylor-Couette flow in a wide-gap configuration, with $r_i/r_o=1/2$, the inner cylinder rotating, and the outer cylinder stationary. The fluid is taken to be electrically conducting, and a magnetic field of the form $B_z\approx(1 + \cos(2\pi z/z_0))/2$ is externally imposed, where the wavelength $z_0=50(r_o-r_i)$. Taylor vortices form where the field is weak, but not where it is strong. As the Reynolds number measuring the rotation rate is increased, the initial onset of vortices involves phase slip events, whereby pairs of Taylor vortices are periodically formed and then drift outward, away from the midplane where $B_z=0$. Subsequent bifurcations lead to a variety of other solutions, including ones both symmetric and asymmetric about the midplane. For even larger Reynolds numbers a different type of phase slip arises, in which vortices form at the outer edges of the pattern and drift inward, disappearing abruptly at a certain point. These solutions can also be symmetric or asymmetric about the midplane, and co-exist at the same Reynolds number. Many of the dynamics of these phase slip solutions are qualitatively similar to previous results in geometrically ramped Taylor-Couette flows.