Effect of gap thickness on the viscoelasticity of magnetorheological fluids / Lopez-Lopez Modesto T.,Rodriguez-Arco Laura,Zubarev Andrey,Iskakova Larisa,Duran Juan D. G. // JOURNAL OF APPLIED PHYSICS. - 2010. - V. 108, l. 8.

ISSN/EISSN:

0021-8979 / 1089-7550

Type:

Article

Abstract:

In this work, the effect of confinement distance on the magnetorheological (MR) properties of a conventional MR fluid, constituted by 30 vol \% of iron microparticles dispersed in a liquid carrier, is studied. With this aim a commercial magnetorheometer supplied with parallel-plate geometry was used. The distance between the upper and the lower plate (gap thickness) was tuned from 10 to 400 mu m. The steady-state and the dynamic regimes of the MR fluid in the presence of applied magnetic fields were studied as a function of the gap length. The experimental results show that in the preyield regime there is a strong increase in the magnitude of the viscoelastic moduli and the shear stress as the gap thickness is increased. The physical reason for this effect might be the influence of gap thickness on the particle structures induced by the field. This hypothesis is corroborated by microscopic observations in diluted systems. These experiments show that the aspect ratio (length/diameter) of the field-induced structures increases with the gap thickness. Theoretical analysis shows that the increase in the storage modulus with gap thickness can be explained by a decrease in the demagnetizing factor of these structures and, as a consequence, by an increase in the restoring torque, acting on them. The dissipation effects in the suspension under oscillating flow are rather produced by contact friction between the particles in the dense structures. (C) 2010 American Institute of Physics. {[}doi: 10.1063/1.3498804]

Author keywords:

ELECTRORHEOLOGICAL FLUIDS; SUSPENSIONS; DENSITIES; STRESS; MRF

DOI:

10.1063/1.3498804

Web of Science ID:

ISI:000283745100020

Соавторы в МНС:

Другие поля

Поле	Значение
Month	OCT 15
Publisher	AMER INST PHYSICS
Address	1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Language	English
Article-Number	083503
EISSN	1089-7550
Keywords-Plus	ELECTRORHEOLOGICAL FLUIDS; SUSPENSIONS; DENSITIES; STRESS; MRF
Research-Areas	Physics
Web-of-Science-Categories	Physics, Applied
Author-Email	modesto@ugr.es
ResearcherID-Numbers	Lopez-Lopez, Modesto T/K-7327-2012 Zubarev, Adrey/B-4752-2014 Lopez-Duran, Juan de Dios/M-2774-2014 Rodriguez-Arco, Laura/K-6056-2014
ORCID-Numbers	Lopez-Lopez, Modesto T/0000-0002-9068-7795 Lopez-Duran, Juan de Dios/0000-0002-5586-1276 Rodriguez-Arco, Laura/0000-0002-5527-7547
Funding-Acknowledgement	Junta de Andalucia, Spain {[}P08-FQM-3993, P09-FQM-4787]; MICINN, Spain {[}FIS2009-07321]; Russian Fund of Fundamental Investigations {[}10-01-96002-Ural, 10-02-96001, 10-02-00034, 08-02-00647]; Russian Federal Education Agency {[}2.1.1/2571, 2.1.1/1535]; Russian Federal Target Program {[}02.740.11.0202, 02-740-11-5172, GK 330, NK-43P(4)]; University of Granada (Spain)
Funding-Text	This work has been supported by Project Nos. P08-FQM-3993 and P09-FQM-4787 (Junta de Andalucia, Spain) and Project No. FIS2009-07321 (MICINN, Spain), by the Russian Fund of Fundamental Investigations, Grant Nos. 10-01-96002-Ural, 10-02-96001, 10-02-00034, and 08-02-00647, grants of the Russian Federal Education Agency, Project Nos. 2.1.1/2571 and 2.1.1/1535, by the Russian Federal Target Program, Grant Nos. 02.740.11.0202, 02-740-11-5172, GK 330, and NK-43P(4). M.T.L.-L. and L.R.-A. also acknowledge financial support by the University of Granada (Spain).
Number-of-Cited-References	37
Usage-Count-Since-2013	9
Journal-ISO	J. Appl. Phys.
Doc-Delivery-Number	674LJ