Analytical solution to heat transfer for mixed electroosmotic and pressure-driven flow through a microchannel with slip-dependent zeta potential

2021 ◽  
Vol 181 ◽  
pp. 121989
Author(s):  
Debanjan Banerjee ◽  
Sumit Kumar Mehta ◽  
Sukumar Pati ◽  
Pankaj Biswas
Keyword(s):  
Heat Transfer ◽  
Analytical Solution ◽  
Zeta Potential ◽  
Flow Through ◽  
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 Temperature rise in a verging annular die

2016 ◽  
Vol 36 (7) ◽  
pp. 735-750 ◽  
Author(s):  
Georges R. Younes ◽  
A. Jeffrey Giacomin ◽  
Peter H. Gilbert
Keyword(s):  
Analytical Solution ◽  
Velocity Profile ◽  
Temperature Rise ◽  
Pressure Profile ◽  
Viscous Heating ◽  
Maximum Throughput ◽  
Flow Through ◽  
Pressure Driven Flow ◽  
Analytical Expressions ◽  
Pressure Driven

AbstractPlastic pipes, tubes or catheters are extruded by pressure-driven flows through annular dies. Whereas die lands are straight, the section connecting the die land to the extruder either converges or diverges, converging when the product is smaller than the extruder barrel, and diverging when larger. In this paper, we carefully consider the converging or diverging connecting flows, in spherical coordinates, for the most common configuration: the Newtonian pressure-driven flow through the annulus between two coapical coaxial cones. We derive theexactanalytical solution for the velocity profile, and then use this to arrive at theexactanalytical solution for the temperature rise caused by viscous heating. We care about this rise because it often governs maximum throughput, since pipe makers must protect the melt from thermal degradation. We find that both the velocity profile, and the temperature profile, peak over the same conical surface and this surface is nearer the inner die wall. We also provide analytical expressions for the nonlinear pressure profile and the die cooling requirement. We find that this cooling requirement is always higher on the inner cone.

Mixed Electroosmotic Pressure Driven Flow and Heat Transfer of Power Law Fluid in a Hydrophobic Microchannel

2017 ◽  
Author(s):  
Ainul Haque ◽  
Ameeya Kumar Nayak
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Joule Heating ◽  
Scientific Data ◽  
Channel Height ◽  
Flow And Heat Transfer ◽  
Power Law Fluids ◽  
Hydrophobic Microchannel ◽  
Pressure Driven Flow ◽  
Pressure Driven

In this paper, a mathematical model has been developed to analyze the combined electroosmotic and pressure driven flow of power law fluids in a micro channel in the presence of Joule heating effects. The effects of Navier slip boundary condition and thermal radiation is examined for effective heat transfer in a hydrophobic microchannel. The analytical treatment has been performed for fluid flow and heat transfer effects in terms of flow governing parameters. This study highlights the effect of channel height to the electric double layer thickness and observed the flow variation due to heat transfer effect with the available scientific data. For a pure EOF, velocity slip have more significant role to get a maximum flow rate as expected. For both pseudo-plastic and dilatent fluids Nusselt number is decreased with the increment of the hydrophobic parameter and dimensionless pressure gradient where as increment in Joule heating effect enhance the heat transfer rate.

scholarly journals Rheology and microstructural evolution in pressure-driven flow of a magnetorheological fluid with strong particle–wall interactions

2012 ◽  
Vol 23 (9) ◽  
pp. 969-978 ◽  
Author(s):  
Murat Ocalan ◽  
Gareth H. McKinley
Keyword(s):  
Microfluidic Devices ◽  
Magnetorheological Fluid ◽  
Time Dependent ◽  
Mr Fluid ◽  
Flow Through ◽  
Fluid Particles ◽  
And Performance ◽  
Pressure Driven Flow ◽  
Actuator Design ◽  
Pressure Driven

The interaction between magnetorheological (MR) fluid particles and the walls of the device that retain the field-responsive fluid is critical as this interaction provides the means for coupling the physical device to the field-controllable properties of the fluid. This interaction is often enhanced in actuators by the use of ferromagnetic walls that generate an attractive force on the particles in the field-on state. In this article, the aggregation dynamics of MR fluid particles and the evolution of the microstructure in pressure-driven flow through ferromagnetic channels are studied using custom-fabricated microfluidic devices with ferromagnetic sidewalls. The aggregation of the particles and the time-dependent evolution in the microstructure is studied in rectilinear, expansion and contraction channel geometries. These observations help identify methods for improving MR actuator design and performance.

Sign in / Sign up

Export Citation Format

Share Document