Experimental study of submerged liquid metal jet in transverse magnetic field

TL;DR

This experimental study investigates how a submerged liquid metal jet behaves in a square duct under a transverse magnetic field, revealing flow instabilities, the influence of magnetic parameters, and the transition to quasi-two-dimensional vortex structures.

Contribution

It provides new experimental insights into the flow dynamics, stability, and structure of liquid metal jets in magnetic fields at high Reynolds and Hartmann numbers.

Findings

Flow is unsteady with high-amplitude fluctuations due to jet instability.

Magnetic field suppresses three-dimensional perturbations at moderate Stuart numbers.

At high Stuart numbers, flow transitions to a quasi-two-dimensional asymmetric vortex.

Abstract

A liquid metal flow in the form of a submerged round jet entering a square duct in the presence of a transverse magnetic field is studied experimentally. A range of high Reynolds and Hartmann numbers is considered. Flow velocity is measured using electric potential difference probes. A detailed study of the flow in the duct's cross-section about seven jet's diameters downstream of the inlet reveals the dynamics, which is unsteady and dominated by high-amplitude fluctuations resulting from instability of the jet. The flow structure and fluctuation properties are largely determined by the value of the Stuart number N. At moderate N, the mean velocity profile retains a central jet with three-dimensional perturbations increasingly suppressed by the magnetic field as N grows. At higher values of N, the flow becomes quasi-two-dimensional and acquires the form of an asymmetric macrovortex, with high-amplitude velocity fluctuations reemerging.