Aqueous magnetic fluids instabilities in a Hele-Shaw cell
M. RĂCUCIU1,*
Affiliation
- “Lucian Blaga” University, Faculty of Science, Dr.Ratiu Street, No.5-7, Sibiu, 550024, Romania
Abstract
In this study, it was investigated the interface patterns of two immiscible, viscous fluids into the geometry of a horizontal
Hele-Shaw cell, considering that one of the fluids is an aqueous magnetic fluid. In general, the total energy of a magnetic fluid
system consists of three components: gravitational, surface, and magnetic. For a magnetic fluid into a horizontal Hele-Shaw
cell, the gravitational energy is constant and can be inessential, thus leaving only the surface and magnetic energies. The
interface between two immiscible fluids, one of them with a low viscosity and another with a higher viscosity, becomes
unstable and starts to deform. Dynamic competition in such confined geometry leads finally to the formation of fingering
patterns of a magnetic fluid in a Hele-Shaw cell. The computational study upon the interface instabilities patterns in aqueous
magnetic fluids was accomplished evaluating fractal dimension in finger-type instabilities. Between the fractal dimension and
experimental instability generation time a correlation was established.
Keywords
Magnetic fluid, Hele-Shaw cell, Viscous finger instability.
Citation
M. RĂCUCIU, Aqueous magnetic fluids instabilities in a Hele-Shaw cell, Optoelectronics and Advanced Materials - Rapid Communications, 3, 2, February 2009, pp.132-134 (2009).
Submitted at: Jan. 30, 2009
Accepted at: Feb. 13, 2009