Experimental and numerical study for the cross-flow around four cylinders in an in-line square configuration

2007 ◽  
Vol 21 (9) ◽  
pp. 1338-1343 ◽  
Author(s):  
K. Lama ◽  
L. Zou
Keyword(s):  
Numerical Study ◽  
Cross Flow ◽  
The Cross ◽  
Square Configuration ◽  
Four Cylinders

scholarly journals Numerical Study on Heat and Mass Transfer of the Cross-flow Liquid Desiccant Regenerator

2017 ◽  
Vol 205 ◽  
pp. 2647-2654 ◽  
Author(s):  
Yang Li ◽  
Zhibo Fu ◽  
Xiaohu Yang ◽  
Lianying Zhang ◽  
Qunli Zhang ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Numerical Study ◽  
Cross Flow ◽  
Liquid Desiccant ◽  
The Cross

scholarly journals Design and Numerical Study of Micropump Based on Induced Electroosmotic Flow

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Kai Zhang ◽  
Lengjun Jiang ◽  
Zhihan Gao ◽  
Changxiu Zhai ◽  
Weiwei Yan ◽  
...  
Keyword(s):  
Electroosmotic Flow ◽  
Stokes Equations ◽  
Numerical Study ◽  
Cross Flow ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Driving Mode ◽  
Electric Driving ◽  
Induced Charge ◽  
The Cross

Induced charge electroosmotic flow is a new electric driving mode. Based on the Navier–Stokes equations and the Poisson–Nernst–Planck (PNP) ion transport equations, the finite volume method is adopted to calculate the equations and boundary conditions of the induced charge electroosmotic flow. In this paper, the formula of the induced zeta potential of the polarized solid surface is proposed, and a UDF program suitable for the simulation of the induced charge electroosmotic is prepared according to this theory. At the same time, on the basis of this theory, a cross micropump driven by induced charge electroosmotic flow is designed, and the voltage, electric potential, charge density, and streamline of the induced electroosmotic micropump are obtained. Studies have shown that when the cross-shaped micropump is energized, in the center of the induction electrode near the formation of a dense electric double layer, there exist four symmetrical vortices at the four corners, and they push the solution towards both outlets; it can be found that the average velocity of the solution in the cross-flow microfluidic pump is nonlinear with the applied electric field, which maybe helpful for the practical application of induced electroosmotic flow in the field of micropump.

scholarly journals Mixing Performance of a Passive Micro-Mixer with Mixing Units Stacked in Cross Flow Direction

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1530
Author(s):  
Makhsuda Juraeva ◽  
Dong-Jin Kang
Keyword(s):  
Numerical Study ◽  
Volume Flow Rate ◽  
Flow Direction ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
High Concentration ◽  
Mixing Performance ◽  
Wall Impingement ◽  
The Cross ◽  
Micro Mixer

A new passive micro-mixer with mixing units stacked in the cross flow direction was proposed, and its performance was evaluated numerically. The present micro-mixer consisted of eight mixing units. Each mixing unit had four baffles, and they were arranged alternatively in the cross flow and transverse direction. The mixing units were stacked in four different ways: one step, two step, four step, and eight step stacking. A numerical study was carried out for the Reynolds numbers from 0.5 to 50. The corresponding volume flow rate ranged from 6.33 μL/min to 633 μL/min. The mixing performance was analyzed in terms of the degree of mixing (DOM) and relative mixing energy cost (MEC). The numerical results showed a noticeable enhancement of the mixing performance compared with other micromixers. The mixing enhancement was achieved by two flow characteristics: baffle wall impingement by a stream of high concentration and swirl motion within the mixing unit. The baffle wall impingement by a stream of high concentration was observed throughout all Reynolds numbers. The swirl motion inside the mixing unit was observed in the cross flow direction, and became significant as the Reynolds number increased to larger than about five. The eight step stacking showed the best performance for Reynolds numbers larger than about two, while the two step stacking was better for Reynolds numbers less than about two.

Numerical Study of the Cross Flow in a Non-isothermal Open Cavity

2016 ◽  
pp. 3-13
Author(s):  
G. E. Ovando-Chacon ◽  
S. L. Ovando-Chacon ◽  
J. C. Prince-Avelino ◽  
A. Rodriguez-León ◽  
A. Servin-Martínez
Keyword(s):  
Numerical Study ◽  
Cross Flow ◽  
Open Cavity ◽  
The Cross

Numerical Simulation of Cross-Flow around Four Cylinders in a Square Configuration Using Lattice Boltzmann Method

2013 ◽  
Vol 405-408 ◽  
pp. 3259-3262 ◽  
Author(s):  
Wei Zhang ◽  
Hui Hua Ye ◽  
Jian Hua Tao
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Lattice Boltzmann Method ◽  
Vortex Shedding ◽  
Lattice Boltzmann ◽  
Cross Flow ◽  
Spacing Ratio ◽  
Square Configuration ◽  
Boltzmann Method ◽  
Four Cylinders

The flow around four cylinders in a square configuration with a spacing ratio 4 and Reynolds number of 200 are investigated using lattice Boltzmann method for angles of incidence α=0 and 45º, respectively. The results show that no biased flow occurs and the flow pattern is symmetrical at α=0, and the vortex shedding exists after the upstream cylinders which is completely different from the experimental results. It is hard to explain the discrepancy at present. The phenomenon of vortex shedding in-phase observed in the experiment reappears in the numerical simulation at α=45º.

A Numerical Study on Mixing In Turbulent Flow Behind a Backward-Facing Step

2005 ◽  
Author(s):  
R. Veturi ◽  
K. Aung
Keyword(s):  
Turbulent Flow ◽  
Mass Concentration ◽  
Numerical Study ◽  
Velocity Ratio ◽  
Cross Flow ◽  
Backward Facing Step ◽  
Computational Fluid Dynamics Analysis ◽  
Circular Jets ◽  
Contour Plots ◽  
The Cross

Present work studies the mixing in turbulent flow behind a backward-facing step, which is a classical example of mixing of jet in cross flow. In this study the cross flow was an unconfined cross flow flowing through a duct, which has geometry of backward-facing step with varying cross section. Three jet geometries, a slot jet, a single circular jet and three circular jets with different injection angles were studied. Spatial unmixedness based on helium mass concentration was used as an indicator for determining the degree of mixing. Velocity ratio, defined as ratio of jet velocity to the cross flow velocity, was varied during the analysis. Three different values of velocity ratio were considered during the study. Computational fluid dynamics analysis was performed using commercial CFD software CFX 5.6. Results were extracted in the form of helium mass concentration fields, concentration profiles, concentration contour plots and velocity vector plots. From the results obtained it can be concluded that, angle of jet inclination is the important controlling parameter in mixing in flow behind a backward-facing step. Single jet geometry gives better mixing for the given conditions.

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