On slip velocity boundary conditions for electroosmotic flow near sharp corners

2008 ◽  
Vol 20 (4) ◽  
pp. 043603 ◽  
Author(s):  
Thomas J. Craven ◽  
Julia M. Rees ◽  
William B. Zimmerman
Keyword(s):  
Boundary Conditions ◽  
Electroosmotic Flow ◽  
Slip Velocity ◽  
Sharp Corners

STRESS BEHAVIOR IN THE NEIGHBORHOOD OF SHARP CORNERS

Geophysics ◽  
1964 ◽  
Vol 29 (3) ◽  
pp. 360-369 ◽  
Author(s):  
Frank C. Karal ◽  
Samuel N. Karp
Keyword(s):  
Stress Field ◽  
Boundary Conditions ◽  
Practical Reasons ◽  
Elastic Media ◽  
Elastic Wedge ◽  
Arbitrary Angle ◽  
Free Boundary Conditions ◽  
Stress Behavior ◽  
Sharp Corners ◽  
Stress Free Boundary

Knowledge of the behavior of the stress field in the neighborhood of cracks and sharp corners is important for many theoretical and practical reasons. In an earlier paper the authors examined the behavior of the stress field near the edge of an elastic wedge of arbitrary angle with stress‐free boundary conditions prescribed on both surfaces (Karp and Karal, 1962). Other types of boundary conditions, such as those representing rigid and lubricated boundaries, were not considered. In the present paper these boundary conditions are now studied, and the behavior of the stress field in the neighborhood of the tip is determined. In addition, the stress behavior is examined when two different elastic media meet at a sharp edge.

Determining the Optimum Arrangement of Micromixers in a Microchannel Filled with CuO-Water Nanofluid via Minimizing Entropy Generation

2017 ◽  
Vol 378 ◽  
pp. 39-58 ◽  
Author(s):  
Ahmad Ababaei ◽  
Mahmoud Abbaszadeh ◽  
Ali Akbar Abbasian Arani
Keyword(s):  
Boundary Conditions ◽  
Parallel Plate ◽  
Slip Velocity ◽  
Temperature Jump ◽  
Volume Fraction ◽  
Reynolds Numbers ◽  
Governing Equations ◽  
Simpler Algorithm ◽  
Optimum Arrangement ◽  
Volume Method

In this study, the flow of CuO-water nanofluid in a parallel-plate microchannel in the presence of several micromixers is examined to find optimum arrangements of the micromixers. The governing equations, which are accompanied with the slip velocity and temperature jump boundary conditions, are solved by the Finite Volume Method and SIMPLER algorithm. The study is conducted for the Reynolds numbers in the range of 10 ≤ Re ≤ 100, Knudsen numbers ranging of 0 ≤ Kn ≤ 0.1 and volume fraction of nanoparticles ranging of 0 ≤ ϕ ≤ 4%. The results show that the optimum arrangements of the micromixers belong to cases in which the heights of micromixers are smaller, the distance between them is lower, and their numbers are more.

scholarly journals Solution of Time Periodic Electroosmosis Flow with Slip Boundary

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Qian Sun ◽  
Yonghong Wu ◽  
Lishan Liu ◽  
B. Wiwatanapataphee
Keyword(s):  
Boundary Conditions ◽  
Exact Solutions ◽  
Solid Surface ◽  
Electroosmotic Flow ◽  
Mixing Enhancement ◽  
Slip Boundary Conditions ◽  
Slip Boundary ◽  
Flow Problems ◽  
Micrometer Scale ◽  
Time Periodic

Recent research confirms that slip of a fluid on the solid surface occurs at micrometer scale. Slip on solid surface may cause the change of interior material deformation which consequently leads to the change of velocity profile and stress field. This paper concerns the time periodic electroosmotic flow in a channel with slip boundary driven by an alternating electric field, which arises from the study of particle manipulation and separation such as flow pumping and mixing enhancement. Although exact solutions to various flow problems of electroosmotic flows under the no-slip condition have been obtained, exact solutions for problems under slip boundary conditions have seldom been addressed. In this paper, an exact solution is derived for the time periodic electroosmotic flow in two-dimensional straight channels under slip boundary conditions.

A PIV Study of AC-Electroosmotic Flow in Microchannels

2008 ◽  
Author(s):  
Yangyang Wang ◽  
Sangmo Kang ◽  
Yongkweon Suh
Keyword(s):  
Numerical Simulation ◽  
Electroosmotic Flow ◽  
Slip Velocity ◽  
The Other ◽  
Grey Level ◽  
Frequency Increase ◽  
Ac Electroosmosis ◽  
Velocity Increase ◽  
Small Channel ◽  
Piv Technique

Microscale mixing is difficult because the small channel-dimensions lead to low Reynolds number and the mixing is due to the diffusion only. This study focus on mixing in a microchannel based on AC electroosmosis by using a PIV technique. The zig-zag electrodes are attached at the bottom of the channel. In the experiment, polymer microspheres red fluorescing particles are used to measure the slip velocity and streamlines of the AC electroosmotic flow. At first, the slip velocity at bottom of the electrodes is measured. We find that when the frequency increase, the slip velocity increase too. The slip velocity of short electrode is faster than the other side. And the maximum slip velocity is about 250 micrometer/s. Then, an velocimetry method is presented now, which can give the vertical dimension from the diffraction pattern variations with the defocusing distances of small particle locations. At first, the lowest grey values of points are recorded. Then, the numerical simulation is done, in which the slip velocity is treated as a subsection function approach to the experiment result. And based on the streamline of the numerical simulation, a easy relationship between the lowest grey level of the particle’s pattern and Z coordinate is built successfully.

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