scholarly journals Structure of Electrorheological Fluids under an Electric Field and a Shear Flow:  Experiment and Computer Simulation

2006 ◽  
Vol 110 (24) ◽  
pp. 11635-11639 ◽  
Author(s):  
J. G. Cao ◽  
J. P. Huang ◽  
L. W. Zhou
2001 ◽  
Vol 15 (06n07) ◽  
pp. 695-703 ◽  
Author(s):  
S. L. VIEIRA ◽  
M. NAKANO ◽  
S. HENLEY ◽  
F. E. FILISKO ◽  
L. B. POMPEO NETO ◽  
...  

It was reported that under the simultaneous stimulus of an electric field and shear, the particles in an ER fluid form lamellar formations in the direction of shear (adhered to one of the electrodes) which may be responsible for the ER activity more than the strength of the chains. In this way, it would be expected that the shear stress should change consistently with the morphology of the formations. In this work we studied the effect of shearing time, electric field strength and shear rate on the shear stress. We suggest that changes on shear stress with time are due to changes of the morphology of the lamellar formations.


1994 ◽  
Vol 38 (3) ◽  
pp. 453-463 ◽  
Author(s):  
Steven L. Ceccio ◽  
Alan S. Wineman

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Manash Pratim Borthakur ◽  
Binita Nath ◽  
Gautam Biswas

2009 ◽  
Vol 626 ◽  
pp. 367-393 ◽  
Author(s):  
STEFAN MÄHLMANN ◽  
DEMETRIOS T. PAPAGEORGIOU

The effect of an electric field on a periodic array of two-dimensional liquid drops suspended in simple shear flow is studied numerically. The shear is produced by moving the parallel walls of the channel containing the fluids at equal speeds but in opposite directions and an electric field is generated by imposing a constant voltage difference across the channel walls. The level set method is adapted to electrohydrodynamics problems that include a background flow in order to compute the effects of permittivity and conductivity differences between the two phases on the dynamics and drop configurations. The electric field introduces additional interfacial stresses at the drop interface and we perform extensive computations to assess the combined effects of electric fields, surface tension and inertia. Our computations for perfect dielectric systems indicate that the electric field increases the drop deformation to generate elongated drops at steady state, and at the same time alters the drop orientation by increasing alignment with the vertical, which is the direction of the underlying electric field. These phenomena are observed for a range of values of Reynolds and capillary numbers. Computations using the leaky dielectric model also indicate that for certain combinations of electric properties the drop can undergo enhanced alignment with the vertical or the horizontal, as compared to perfect dielectric systems. For cases of enhanced elongation and alignment with the vertical, the flow positions the droplets closer to the channel walls where they cause larger wall shear stresses. We also establish that a sufficiently strong electric field can be used to destabilize the flow in the sense that steady-state droplets that can exist in its absence for a set of physical parameters, become increasingly and indefinitely elongated until additional mechanisms can lead to rupture. It is suggested that electric fields can be used to enhance such phenomena.


2012 ◽  
Vol 61 (4) ◽  
pp. 217-222 ◽  
Author(s):  
M. Inoue ◽  
S. Suzuki ◽  
Z. Akase ◽  
D. Shindo

2020 ◽  
Vol 32 (9) ◽  
pp. 092110
Author(s):  
Binita Nath ◽  
Manash Pratim Borthakur ◽  
Gautam Biswas
Keyword(s):  

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
George S. Georgiev ◽  
Anna A. Tzoneva ◽  
Velin A. Spassov

AbstractIt has been established that the electroviscosity effect of polyzwitterionic (PZI) aqueous solutions is more considerable than and acts in a direction opposite to that of aqueous polyelectrolyte solutions. Temperature and electric field strength influence the electroviscosity of PZI aqueous solutions in parallel, though the reasons for these effects are quite different. The unusual electroviscosity behaviour of PZI solutions is explained by a ‘core-shell’ model for the structural organization of PZI macromolecules, suggesting that cluster formation is due to intensive dipoledipole interactions between monomer units of the same or of different macromolecules.


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