Numerical analysis of combined electroosmotic-pressure driven flow of a viscoelastic fluid over high zeta potential modulated surfaces

2021 ◽  
Vol 33 (1) ◽  
pp. 012001
Author(s):  
Bimalendu Mahapatra ◽  
Aditya Bandopadhyay
Keyword(s):  
Numerical Analysis ◽  
Zeta Potential ◽  
Viscoelastic Fluid ◽  
Pressure Driven Flow ◽  
Pressure Driven

Numerical Simulation of Heat Transfer in Mixed Electroosmotic Pressure-Driven Flow in Straight Microchannels

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Amir Shamloo ◽  
Arshia Merdasi ◽  
Parham Vatankhah
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Zeta Potential ◽  
Electric Potential ◽  
Uniform Heat Flux ◽  
Electric Potentials ◽  
Circular Flows ◽  
Flow Through ◽  
Pressure Driven Flow ◽  
Pressure Driven

This paper investigates two-dimensional, time-independent elecroosmotic pressure-driven flow generated by a direct current electric potential with asymmetrical and symmetrical zeta potential distributions along the microchannel walls. Fluid flow through the horizontal microchannel is simulated using a numerical method. Two different cases are proposed to study the effect of electric potential on the flow field. First, negative electric potential is applied on the microchannel walls. In this case, large segments with negative electric potential are initially placed on the first half of the microchannel walls with two different arrangements. Afterward, smaller segments with negative electric potential are placed on the microchannel walls. Next, negative electric potential is replaced by positive electric potential on the microchannel walls in the similar manner. It is shown that applying positive potential on the walls contributes to the localized circular flows within the microchannel. The size of these vortices is also proved to considerably vary with the applied zeta potential magnitude. Finally, the effect of wall zeta potential on heat transfer was studied for all the four types of microchannels by imposing a constant uniform heat flux on the walls. The Nusselt number plots indicate how heat transfer varies along the microchannel walls. The Nusselt number fluctuation can be observed where the positive and negative electric potentials are located.

scholarly journals On the cross-streamline lift of microswimmers in viscoelastic flows

Soft Matter ◽  
2021 ◽  
Author(s):  
Akash Choudhary ◽  
Holger Stark
Keyword(s):  
Viscoelastic Fluid ◽  
Fluid Model ◽  
Second Order ◽  
The Self ◽  
Current Work ◽  
Viscoelastic Flows ◽  
The Cross ◽  
Pressure Driven Flow ◽  
Pressure Driven

The current work studies the dynamics of a microswimmer in the pressure-driven flow of a weakly viscoelastic fluid. Employing the second-order fluid model, we show that the self-propelling swimmer experiences...

scholarly journals Electroviscous effect on fluid drag in a microchannel with large zeta potential

2015 ◽  
Vol 6 ◽  
pp. 2207-2216 ◽  
Author(s):  
Dalei Jing ◽  
Bharat Bhushan
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Electrical Potential ◽  
Slip Condition ◽  
Double Layers ◽  
Electroviscous Effect ◽  
Fluid Drag ◽  
Pressure Driven Flow ◽  
Effect Of Surface ◽  
Pressure Driven

The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson–Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier–Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough.

scholarly journals Molecular dynamics study of pressure-driven water transport through graphene bilayers

2016 ◽  
Vol 18 (3) ◽  
pp. 1886-1896 ◽  
Author(s):  
Bo Liu ◽  
Renbing Wu ◽  
Julia A. Baimova ◽  
Hong Wu ◽  
Adrian Wing-Keung Law ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
Water Transport ◽  
Layered Structures ◽  
Water Molecules ◽  
Flow Rates ◽  
Ultra High Pressure ◽  
Pressure Driven Flow ◽  
Pressure Driven

Water molecules form layered structures inside graphene bilayers and ultra-high pressure-driven flow rates can be observed.

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