Influence of the concentration of a dispersed phase and of the magnetic field on the attenuation of ultrasonic waves in magnetic fluids

Acoustical properties of magnetorheological fluids under applied magnetic field

“…It should be noted that the former dependencies of MRF’s acoustical properties on H and φ are predominantly similar to dependencies obtained when MF has instable structure or subjected before to the magnetic field during some days (Baev et al, 2007; Polunin, 2008). In this case, sizes of the formed aggregates of particles are close to particles or aggregates which are in MRFs.…”

“…Dynamic effects caused by complicated interaction of magnetic field with such structure (previously formed large aggregates) may initiate a new non-local mechanism of relaxation processes. Partially, there are theories (Baev et al, 2007; Gogosov et al, 1987b; Lipkin, 1985) which give explanation of the decrease in velocity in MFs when field is normally applied to cell’s acoustical axis. They include the peculiarities of dipole–dipole interaction, magnetostriction, and some other effects.…”

“…There are a lot of works devoted to the theoretical and experimental study of acoustical properties of MFs in which acoustical anisotropy has been found (Baev et al, 1999, 2007; Gogosov et al, 1987a, 1987b; Lipkin, 1985; Patsegon and Popova, 1996; Polunin, 2008; Skumiel, 2004; Sokolov, 1997; Tarapov, 1973). Formally, this class of colloidal solutions is more close to the class of MRF.…”

“…As theoretical analysis shows (Allegra and Harly, 1970; Baev et al, 2007; Gogosov et al, 1987a, 1987b; Lipkin, 1985; Polunin, 2008; Tarapov, 1973), there are different mechanisms of UW interaction with structure which cause dynamic and dissipative processes and change in C and δ under applied field. These mechanisms are of non-Kneser or (non-local) nature and include the following: thermal and viscous effects, Raleigh scattering, magnetic diffusion, magnetocaloric, magnetostatic, magnetostriction processes, and so on.…”

Energy of stratified magnetic fluid on a porous basis in the environment

“…, where ⃗ -is the normal vector to the interface of two layers of the magnetic fluid; At the interface of two layers of a magnetic fluid z=ℎ 1 + 1 ( , , ), the normal vector ⃗ to the surface f(x, y, z, t) = z − h 1 − ξ 1 (x, y, t) = 0 can be written in the form [2]:…”