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Contenuto archiviato il 2022-12-23

Magnetic fluids; structural transformations and hydrodynamic instabilities

Obiettivo

The objectives of the project are: - To investigate the internal structure of magnetic fluids due to dipole-dipole and van der Waals interparticle interactions as well as to an influence of external a.c. and d.c. magnetic fields; - To determine the possible forms of particles associations and their influence on the macroscopic properties of ferrocolloids (magnetization, static and dynamic susceptibility and viscosity); - To study the internal structure transformations and phase separation processes in chain aggregated magnetic fluid; - To study the surface instabilities of the rotating ferrofluid drops and their stability regions at the plane frequency - magnitude of external magnetic field for arbitrary values of magnetic permeability; - To investigate the convective instability of magnetized ferrofluids with allowance for the magnetophoresis and the internal microstructure; - To study the effects of flow vorticity on the non-Newtonian properties of ferrofluid and the stability of ferrofluid flow under longitudinal ac magnetic field. The research activity includes: - The development of statistical mechanics of liquids by means of the Born-Mayer cluster expansion, by the perturbation theory and by the Frenkel expansion on physical groups; - The calculation of macroscopic properties (magnetization, static and dynamic susceptibility and viscosity) of ferrocolloids with aggregates; - The calculation of structural transformations in magnetic fluids within the framework of three approaches proposed; - The fulfilment of different kinds of measurements of magnetic fluids, including magnetic, rheological, light and neutron scattering techniques; - The Monte Carlo modelling of polydisperse magnetic fluids; - The fulfilment of experiments with rotating drops floating in immiscible nonmagnetic fluid as well as levitating in air and the determination of their equilibrium forms and the conditions of their break-up; - The theoretical and experimental investigation of the thermo- and electrical convective stabilities of magnetic fluid with developed microstructure; - The fulfilment of the simulations of hydrodynamics of ferrofluid pipe flow and the investigation of its stability in the presence of longitudinal a.c. magnetic field. The expected results are: - The description of microstructure of polydisperse magnetic fluids in external magnetic field and its influence on macroscopic properties; - The establishing of conditions of formation of different kinds of aggregates and their transformations; - The description of surface instabilities and breakup of rotating ferrofluid drops; - The description of the peculiarities of convection of magnetic fluids with developed microstructure and its experimental discovering; - The studying of temporal evolution of ferrofluid in the case of oscillating and parametric convection; - The establishing of the conditions of appearance of non-Newtonian properties of ferrofluid in alternating magnetic field.

Argomento(i)

Invito a presentare proposte

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Meccanismo di finanziamento

NoE - Network of Excellence

Coordinatore

Universite Paris VI
Contributo UE
Nessun dato
Indirizzo
Tour 13, Case 78, UPMC, pl. Jussieu 4
75252 Paris Cedex 05
Francia

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Costo totale
Nessun dato

Partecipanti (5)