Magnetorheological Fluids Behaviour in Oscillatory Compression Squeeze: Experimental Testing and Analysis

Abstract This article deals with experimental testing of magnetorheological fluid (MRF) behaviour in the oscillatory squeeze mode. The authors investigate and analyse the influence of excitation frequency and magnetic field density level on axial force in MRFs that differ in particle volume fraction. The results show that, under certain conditions, the phenomenon of self-sealing can occur as a result of the magnetic field gradient and a vacuum in the working gap of the system.

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Experimental and numerical study on surface roughness of magnetorheological elastomer for controllable friction

Friction ◽

10.1007/s40544-017-0309-0 ◽

2019 ◽

Vol 8 (5) ◽

pp. 917-929 ◽

Cited By ~ 1

Author(s):

Rui Li ◽

Xi Li ◽

Yuanyuan Li ◽

Ping-an Yang ◽

Jiushan Liu

Keyword(s):

Magnetic Field ◽

Surface Roughness ◽

Surface Morphology ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Rubber Matrix ◽

Magnetorheological Elastomer ◽

Particle Volume ◽

Simulation Results ◽

The Magnetic Field

Abstract Magnetorheological elastomer (MRE) is a type of smart material of which mechanical and electrical properties can be reversibly controlled by the magnetic field. In this study, the influence of the magnetic field on the surface roughness of MRE was studied by the microscopic modeling method, and the influence of controllable characteristics of the MRE surface on its friction properties was analyzed by the macroscopic experimental method. First, on the basis of existing studies, an improved mesoscopic model based on magnetomechanical coupling analysis was proposed. The initial surface morphology of MRE was characterized by the W-M fractal function, and the change process of the surface microstructures of MRE, induced by the magnetic interaction between particles, was studied. Then, after analyzing the simulation results, it is found that with the increase in the magnetic field and decrease in the modulus of rubber matrix, the surface of MRE changes more significantly, and the best particle volume fraction is within 7.5%–9%. Furthermore, through experimental observation, it is found that the height of the convex peak on the surface of MRE decreases significantly with the action of the magnetic field, resulting in a reduction in the surface roughness. Consistent with the simulation results, a particle volume fraction of 10% corresponds to a maximum change of 14%. Finally, the macroscopic friction experiment results show that the friction coefficients of MREs with different particle volume fractions all decrease with the decrease in surface roughness under the magnetic field. When the particle volume fraction is 10%, the friction coefficient can decrease by 24.7% under a magnetic field of 400 mT, which is consistent with the trend of surface roughness changes. This shows that the change in surface morphology with the effect of the magnetic field is an important factor in the control of MRE friction properties by magnetic field.

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Pre-Yield Shearing Regimes of Magnetorheological Fluids

Volume 2: Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Bio-Inspired Materials and Systems; Energy Harvesting ◽

10.1115/smasis2012-8047 ◽

2012 ◽

Cited By ~ 1

Author(s):

Waad Nassar ◽

Xavier Boutillon ◽

José Lozada

Keyword(s):

Magnetic Field ◽

Shear Stress ◽

Shear Strain ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Initial Response ◽

Magnetic Pole ◽

Particle Volume ◽

Average Shear ◽

The Magnetic Field

We analyzed experimentally the pre-yield regime of some MRFs. The hearing response is ruled by two successive regimes and limited by an interfacial phenomenon. The initial response is pseudo-elastic and independent from the magnetic field and of the particle volume fraction. The shear-stress limit of this regime is proportional to the square of the magnetic field and to the particle volume fraction. In the next regime, the shear strain is not uniform in the fluid. The increase in average shear stress varies linearly with the increase in average shear strain. The variation coefficient is proportional to the square of the magnetic field and decreases with the particle volume fraction. Finally, a loss of adhesion of the magnetic aggregates with the shearing plate or the magnetic pole occurs. The corresponding shear stress is proportional to the square of the magnetic field and to the particle volume fraction.

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Dusty Nanofluid Past a Centrifugally Stretching Surface

Mathematical Problems in Engineering ◽

10.1155/2020/9163081 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16 ◽

Cited By ~ 2

Author(s):

Wubshet Ibrahim ◽

Dachasa Gamachu

Keyword(s):

Magnetic Field ◽

Differential Equations ◽

Velocity Profile ◽

Ordinary Differential Equations ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Stretching Surface ◽

Particle Volume ◽

Magnetic Field Parameter ◽

The Magnetic Field

This communication reports, the flow of Cu-water dusty nanofluid past a centrifugally stretching surface under the effect of second order slip and convective boundary conditions. The coupled nonlinear ordinary differential equations are get hold of from the partial differential equations which are derived from the conservation of momentum and energy of both nanofluid and dusty phases. Then, using apt resemblance transformation these ordinary differential equations were altered into a dimensionless form and then solved by bvp5c solver in Matlab software. The variation in velocity and temperature profiles of fluid and dusty phases for different parameters are thrash out in depth by figures and tables. The outcomes exhibit that the velocity profile of both fluid and dusty phases boot as the values of the dust particle volume fraction parameter is enlarged. Besides, the magnetic field parameter has similar effect on the velocity profile of both fluid and dusty phases. Also, the results illustrated that temperature profile of both Cu-water nanofluid and dusty particle phases are improved within an enhancement in the values of the temperature relaxation parameter, Cu-particle volume fraction, and Biot number. The results also confirm that for greater values of the magnetic field parameter the values of skin friction coefficient are enlarged for all values of the velocity ratio parameter.

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Thermophoresis and suction/injection roles on free convective MHD flow of Ag–kerosene oil nanofluid

Journal of Computational Design and Engineering ◽

10.1093/jcde/qwaa031 ◽

2020 ◽

Vol 7 (3) ◽

pp. 386-396

Author(s):

Himanshu Upreti ◽

Alok Kumar Pandey ◽

Manoj Kumar

Keyword(s):

Magnetic Field ◽

Mass Transfer ◽

Heat And Mass Transfer ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Mass Transfer Rate ◽

Brownian Diffusion ◽

Particle Volume ◽

Ohmic Dissipation ◽

Surface Mass

Abstract In this article, the mass and heat transfer flow of Ag–kerosene oil nanofluid over a cone under the effects of suction/injection, magnetic field, thermophoresis, Brownian diffusion, and Ohmic-viscous dissipation was examined. On applying the suitable transformation, PDEs directing the flow of nanofluid were molded to dimensionless ODEs. The solution of the reduced boundary value problem was accomplished by applying Runge–Kutta–Fehlberg method via shooting scheme and the upshots were sketched and interpreted. The values of shear stress and coefficients of heat and mass transfer were attained for some selected values of governing factors. The obtained results showed that when the amount of surface mass flux shifts from injection to the suction domain, the heat and mass transfer rate grew uniformly. However, they have regularly condensed with the rise in the magnitude of the magnetic field and particle volume fraction. Several researches have been done using cone-shaped geometry under the influence of various factors affecting the fluid flow, yet, there exists no such investigation that incorporated the response of viscous-Ohmic dissipation, heat absorption/generation, suction/blowing, Brownian diffusion, and thermophoresis on the hydro-magnetic flow of silver-kerosene oil nanofluid over a cone.

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Synthesis of magnetorheological fluid and its application in a twin-tube valve mode automotive damper

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420720925497 ◽

2020 ◽

Vol 234 (7) ◽

pp. 1001-1016 ◽

Cited By ~ 1

Author(s):

Rangaraj Madhavrao Desai ◽

Subash Acharya ◽

Mohibb-e-Hussain Jamadar ◽

Hemantha Kumar ◽

Sharnappa Joladarashi ◽

...

Keyword(s):

Magnetic Field ◽

Rheological Properties ◽

Smart Materials ◽

Dynamic Range ◽

Experimental Testing ◽

Testing Machine ◽

Magnetorheological Fluid ◽

Magnetorheological Damper ◽

Geometrical Parameters ◽

The Magnetic Field

The change in rheological properties of smart materials like magnetorheological fluid when brought under the influence of a magnetic field can be utilized to develop magnetorheological devices where the output has to be continuously and quickly varied using electronic control interface. In the present study, magnetorheological fluid is synthesized and used as a smart fluid in a twin-tube magnetorheological damper operating in valve mode. The behavior of the magnetorheological fluid is experimentally characterized in a rheometer and mathematically modeled using Herschel–Bulkley model. The parameters of the Herschel–Bulkley model are expressed as polynomial functions of strength of the magnetic field in order to find the shear stress developed by the magnetorheological fluid at any given strength of the magnetic field applied. The magnetorheological damper, which was designed for application in a passenger van, is tested in the damper testing machine. The performance of the damper at different damper velocities and current supplied is studied. The range of values for the parameters of the experimental testing are chosen to emulate the actual conditions of operation in its intended application. Nondimensional analysis is performed, which links magnetorheological fluid rheological properties and geometrical parameters of magnetorheological damper design with the force developed by the damper. Finite element method magnetics is used to find the strength of the magnetic field at the fluid flow gap. Analytical methods are used to calculate the damper force developed due to the field-dependent yield stress and compared with experimental force values. The resulting dynamic range of the magnetorheological damper is also assessed.

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Radiation and non-uniform heat sink/source effects on 2D MHD flow of CNTs-H2O nanofluid over a flat porous plate

Multidiscipline Modeling in Materials and Structures ◽

10.1108/mmms-08-2019-0153 ◽

2019 ◽

Vol 16 (4) ◽

pp. 791-809

Author(s):

Himanshu Upreti ◽

Sawan Kumar Rawat ◽

Manoj Kumar

Keyword(s):

Magnetic Field ◽

Heat Sink ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Porous Plate ◽

Mhd Flow ◽

Particle Volume ◽

Content Type ◽

Uniform Heat ◽

The Impact

Purpose The purpose of this paper is to examine the velocity and temperature profile for a two-dimensional flow of single- and multi-walled nanotubes (CNTs)/H2O nanofluid over a flat porous plate, under the impact of non-uniform heat sink/source and radiation. The influence of suction/blowing, viscous dissipation and magnetic field is also incorporated. Design/methodology/approach The solution of the PDEs describing the flow of nanofluid is accomplished using Runge–Kutta–Fehlberg approach with shooting scheme. Findings Quantities of physical importance such as local Nusselt number and skin friction coefficient for both types of nanotubes are computed and shown in tables. Also, the impact of copious factors like Prandtl number, magnetic field, Eckert number, porosity parameter, radiation parameter, non-linear stretching parameter, injection/suction, heating variable, particle volume fraction and non-uniform heat sink/source parameter on temperature and velocity profile is explained in detail with the aid of graphs. Originality/value Till date, no study has been reported that examines the role of radiation and non-uniform heat sink/source on MHD flow of CNTs‒water nanofluid over a porous plate. The numerical outcomes attained for the existing work are original and their originality is authenticated by comparing them with earlier published work. This problem is of importance, as there are many applications of the fluid flowing over a flat porous plate.

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THE RESPONSE TIME OF A ROTOR SYSTEM WITH A DISK-TYPE MAGNETORHEOLOGICAL FLUID DAMPER

International Journal of Modern Physics B ◽

10.1142/s0217979205030517 ◽

2005 ◽

Vol 19 (07n09) ◽

pp. 1506-1512 ◽

Cited By ~ 8

Author(s):

CHANGSHENG ZHU

Keyword(s):

Response Time ◽

Magnetic Particle ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Magnetorheological Fluid ◽

Rotor System ◽

Rapid Response ◽

Particle Volume ◽

Magnetorheological Fluid Damper ◽

Fluid Damper

The response time of a rotor system supported upon a disk-type magnetorheological fluid damper operating on shear mode is measured experimentally. The effects of rotating speed, step current and magnetic particle volume fraction, on the response time are dealt with. It is shown that the dynamic response can be described by first 10% response time and rapid response time. Generally, the first 10% response time and the rapid response time are in order of less than 0.1 second and 0.1~0.4 second. The magnetic field strength, magnetic particle volume fraction and power supply have a great effect on the response time. The response time in dropping step current is several times longer than that in applying step current. There is a zero initial delay time at either applying or dropping the current, which is caused by the magnetizing or de-magnetizing process.

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Effects of magnetic field inclination and internal heat sources on nanofluid heat transfer and entropy generation in a double lid driven L-shaped cavity

Thermal Science ◽

10.2298/tsci190217325c ◽

2019 ◽

pp. 325-325 ◽

Cited By ~ 2

Author(s):

Ali Chamkha ◽

Zeinab Abdelrahman ◽

Mohamed Mansour ◽

Taher Armaghani ◽

Ahmed Rashad

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Heat Source ◽

Mixed Convection ◽

Entropy Generation ◽

Volume Fraction ◽

Particle Volume Fraction ◽

Internal Heat ◽

Performance Criteria ◽

Particle Volume

Mixed convection has been one of the most interesting subjects of study in the area of heat transfer for many years. The entropy generation due to MHD mixed convection heat transfer in L-shaped enclosure being filled with Cu-water nanofluid and having an internal heating generation is explored in this investigation by the finite volume technique. Lid-motion is presented by both right and top parts of walls to induce forced convection and the cavity is under an inclined uniform magnetic field along the positive horizontal direction. The statistics concentrated specifically on the impacts of several key parameters like as the aspect ratio of the enclosure, Hartmann number, nano-particle volume fraction, and heat source length/location on the heat transfer inside the L-shaped enclosure. Outcomes have been manifested in terms of isotherm lines, streamlines, local and average Nusselt numbers. The obtained results show that addition of nanoparticles into pure fluid leads to increase of heat transfer. The maximum value of local Nusselt pertaining to the heat source occurs when L=0.1. Impacts of heat source size and location, internal heat generation absorption, angle of magnetic field on heat transfer and entropy generation are completely analyzed and discussed. The best configuration and values of important parameters are also presented using thermal performance criteria.

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