A new formulation is proposed to lubricate tribopairs in extreme conditions where the amount of lubricant small and lubricating region highly confined. It composed non-magnetic solid lubricants dispersed an oil-based ferrofluid. When this inverse ferrofluid (IFF) magnetically activated, particles are subjected magnetophoretic forces. By using appropriate magnetic field gradients, they can be dr...

We present a new class of magnetically shaped deformable liquid mirrors made of a magnetic liquid (ferrofluid). Deformable liquid mirrors offer advantages with respect to deformable solid mirrors: large deformations, low costs and the possibility of very large mirrors with added aberration control. They have some disadvantages (e.g. slower response time). We made and tested a deformable mirror,...

The damped oscillations of liquid-immersed ferrofluid sessile droplets were studied with high-speed imaging experiments and analytical modeling to develop a novel microrheology technique. Droplet oscillations were induced with an external magnetic field, thereby avoiding transients in the resulting vibrational response of the droplet. By following the droplet relaxation with a high-speed camera...

The purpose of this article is to study the heat transfer characteristics of a voice-coil and permanent magnet for a speaker using nano-sized ferrofluid. In order to investigate the temperature characteristics of the speaker, the speaker power ratings, ambient temperatures of the test chamber, chamber sizes and input signals were tested. As a result, the temperatures of the voice-coil and magne...

Measurements of magnetic-field-induced torque in applied uniform rotating magnetic fields are presented and compared to theoretical analyses for waterand oil-based ferrofluids. These experiments measure the viscous torque on the inner wall of a stationary hollow polycarbonate spindle that is completely filled with ferrofluid and attached to a viscometer functioning as a torque meter. The spindl...

In this study, the Brownian motion and thermophoresis effects on the MHD ferrofluid flow over a cone with thermal radiation were discussed. Kerosene with the magnetic nanoparticles (Fe3O4) was considered. A set of transformed governing nonlinear coupled ordinary differential equations were solved numerically using Runge-Kutta based shooting technique. A simulation was performed by mixing ferrou...

in the present attempt, flow behavior and thermal convection of one type of nanofluids in a disc geometry was investigated using computational fluid dynamics (cfd). influence of gravity induced sedimentation also has been studied. the commercial software, fluent 6.2, has been employed to solve the governing equations. a user defined function was added to apply a uniform external magnetic field....

This experimental study investigates the advantage of using Mn–Zn Fe2O4/water ferrofluid subjected to effect a non-uniform magnetic field on thermal efficiency fabricated cylindrical solar collector with receiver in shape helical pipe. Using ASHRAE Standard, this has investigated influence nanoparticles volume fraction (0.0–1.0%), mass flow rate fluid (0.00415–0.033 kg/s), and produced by set p...