Chain-induced effects in the Faraday instability on ferrofluids in a horizontal magnetic field

Abstract

The linear stability analysis of the Faraday instability on a viscous ferrofluid in a horizontal magnetic field is performed. Strong dipole-dipole interactions lead to the formation of chains elongated in the field direction. The formation of chains results in a qualitative new behaviour of the ferrofluid. This new behaviour is characterized by a neutral stability curve similar to that observed earlier for Maxwell viscoelastic liquids and causes a significant weakening of the energy dissipation at high frequencies. In the case of a ferrofluid with chains in a horizontal magnetic field, the effective viscosity is anisotropic and depends on the field strength as well as on the wave frequency.

Magnetic fluid rheology and flows

“…The initially flat free surface of the fluid becomes unstable at a critical intensity of the vertical vibrations. The Faraday instability has been used to study the rheological properties of ferrofluids caused by strong dipole interactions that lead to the formation of magnetic particle chains elongated in the direction of the horizontal magnetic field [147]; and used with a vertical oscillating magnetic field to parametrically excite standing surface waves with no mechanically imposed vertical vibrations together with a vertical DC magnetic field to tune the fluid parameters [148]. Later work used both a vertical DC magnetic field with a mechanical exciter to vertically shake the test cell [149] to obtain a novel pattern of standing twin peaks due to the simultaneous excitation of two different wave numbers.…”

Electric Current of Ferrofluid Depending on Temperature

“…When the polarized light perpendicular to the field direction propagation through MF placed in a field, the birefringence and dichronism phenomena could be observed [8][9][10]. If MF samples are placed in magnetic field direction, and the polarization light propagation paralleled to the magnetic field the Faraday affect may be appeared [11][12][13]. Due to the many interesting characteristics of MF, it has already used extensively at temperature sensor designing [14], photonic crystal magnetic field sensor designing [15], lubricant [16], generator [17], et al The electrical conductivity of MF in vary field is carrying out nowadays.…”