Experimental dynamics in magnetic field-driven flows compared to thermoconvective convection

Area of Science:

• Fluid dynamics
• Instability phenomena
• Pattern formation

Background:

• Fluid layers with rotational symmetry are susceptible to instabilities.
• Destabilization can be achieved through various methods, including thermal gradients and electromagnetic forces.
• Understanding pattern dynamics is crucial for controlling fluid behavior.

Purpose of the Study:

• To compare the dynamic behaviors of fluid instabilities in two distinct experimental setups.
• To investigate the role of control parameters in pattern formation and evolution.
• To identify similarities and differences in pattern dynamics despite varying destabilization mechanisms.

Main Methods:

• Classical Bénard-Marangoni experiment utilizing temperature gradients for destabilization.
• Liquid metal drop destabilization via oscillating magnetic fields, inducing radial Lorentz forces.
• Analysis of pattern formation, symmetry breaking, and dynamic behaviors (stationary, rotations, transitions).

Main Results:

• Both systems exhibit pattern formation that breaks initial rotational symmetry.
• Azimuthal and radial wavenumbers emerge, dependent on experimental control parameters.
• Observed dynamics include stationary patterns, rotations, transitions between solutions, and cyclic connections.

Conclusions:

• Despite differences in destabilization (temperature vs. magnetic fields), fluid instability dynamics show remarkable similarities.
• Control parameters significantly influence the resulting patterns and their dynamical evolution.
• The study highlights universal aspects of pattern formation in fluid systems.