• Journal of computational fluids engineering
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• v.12 no.1
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• pp.16-21
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• 2007

This paper presents numerical results of fluid flows and mixing in a microfluidic device with AC electroosmotic flows (AC-EOF) around coplanar electrodes attached on the top and bottom walls. To obtain the flow and mixing characteristics, numerical computations are performed by using a commercial code, CFX10. Experiment was performed to confirm the generation of the drift velocity around the electrodes. It was found that near the coplanar electrodes 3-D complex flows are generated. The AC-electroosmotic flow on the electrodes plays an important role in mixing the liquid.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.434-440
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• 2004

The electro-rheological fluids for semi-active suspension system are a class of colloidal dispersion which exhibit large reversible changes in their rheological behavior when they are subjected to external electrical fields. This paper presents Bingham properties of ER fluids subjected to temperature variations. In addition, an appropriate size of the ER damper for a passenger car is proposed to investigate the effects of Bingham characteristics on the damping performance. The filed-dependent damping forces are evaluated according to the temperature variation and sedimentation ratio.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.61-66
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• 2001

Electro-Rheological(ER) fluids undergo a phase-change when subjected to an external electric field, and this phase-change typically manifests itself as a many-order-of magnitude change in the rheological behavior. This paper presents experimental results on material properties for an ER fluids of arabic gum components subjected to electrical fatigues. As a first step, ER fluids are made of arabic gum 25% of particle weight-concentration. Following the construction of test mechanism for estimated durability of ER fluid, the dynamic yield stress, shear stress and current density of the ER fluids are experimentally distilled as a function of DC electric field. The durability estimation of operated ER fluids are distilled and compared with those of unused ER fluids. In addition, the surface roughness of the employed electrode for copper and aluminum are evaluated as a function of the number of the electric-field cycles.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.135-140
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• 2011

The battery pack, a main component of NEV(Neighborhood Electric Vehicle), needs cooling system when it is charging or discharging to prevent the degradation of the battery charging efficiency. The purpose of this study is to analyse the effects of cooling methods, changing positions of inlet and outlet and changing area ratios of inlet and outlet. It has been observed that in the point of uniform cooling suction from the exit side is more efficient than blowing from the inlet. And there is a suitable inlet/outlet area ratio in maximizing the mass flow rate. The numerical analyse using a commercial code STAR-CCM+ version 4.02 were used for the study.

• Journal of computational fluids engineering
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• v.16 no.3
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• pp.82-87
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• 2011

The battery pack, a main component of NEV(Neighborhood Electric Vehicle), needs cooling system when it is charging or discharging to prevent the degradation of the battery charging efficiency. The purpose of this study is to analyse the effects of cooling methods, changing positions of inlet and outlet and changing area ratios of inlet and outlet. It has been observed that in the point of uniform cooling, suction from the exit side is more efficient than blowing from the inlet. And there is a suitable inlet/outlet area ratio in maximizing the mass flow rate. A commercial code, STAR-CCM+(ver. 4.02), was used for the numerical study.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.703-704
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• 2008

We fabricated and tested porous silicon-based electroosmotic pumps. Compared to other pumping media, porous silicon is beneficial for obtaining comparable flow rates with much lowered electric potential, while maintaining enough mechanical properties. We fabricated porous silicon with two sided-reactive etching processes. We found higher flow rate per electric potential (consistent with previous studies) and we also found asymmetric flow rates for different pumping directions. We plan to utilize this asymmetry for AC pumping applications.

• Journal of computational fluids engineering
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• v.13 no.4
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• pp.58-65
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• 2008

In the present study, a numerical analysis on electrohydrodynamics (EHD) of the flow and the collection mechanisms inside a electrostatic precipitator with a spiral spike electrode were investigated. The phenomena of the electrostatic precipitator include complex interactions between the electric field, the fluid flow and the particle motion. To validate the numerical method, the numerical computation for the electric field of a simple wire-pipe type electrostatic system having an analytic solution were performed. Using this numerical method, the electric field of the spiked electrostatic precipitator was simulated. And the fluid flow and the particle motion inside the spiked electrostatic precipitator were numerically analyzed.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.27-30
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• 2005

In a microfluidic chips pressure driven flow or electro-osmotic flow has been usually employed to deliver bio-samples. Flow in the chips is usually slow and the mixing performance is poor. A micro-mixer with a rapid mixing is important for practical applications. In this study a newly designed and electro-osmotic driven micro-mixer is proposed. This design is comprised of a channel and a series of metal electrodes periodically attached on the side surface. In this configuration electro-osmotic flows and the stirring effects are simulated three-dimensionally using a commercial code, CFD-ACE. Focus is given the effect on the electro-osmotic flow characteristics under the local variation of the electric field.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.276-282
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• 2008

In the present study, a numerical analysis on electrohydrodynamics (EHD) of the flow and the collection mechanism inside a electrostatic precipitator were investigated. The phenomena of the electrostatic precipitator include complex interactions between the electric field, the fluid flow and the particle motion. To validate the numerical method, the numerical computation for the electric field of a simple wire-pipe type electrostatic system having an analytic solution were performed. Using this numerical method, the electric field of the spiked electrostatic precipitator was simulated. And the fluid flow and the particle motion inside the spiked electrostatic precipitator were numerically analyzed.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.276-282
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• 2008

In the present study, a numerical analysis on electrohydrodynamics (EHD) of the flow and the collection mechanism inside a electrostatic precipitator were investigated. The phenomena of the electrostatic precipitator include complex interactions between the electric field, the fluid flow and the particle motion. To validate the numerical method, the numerical computation for the electric field of a simple wire-pipe type electrostatic system having an analytic solution were performed. Using this numerical method, the electric field of the spiked electrostatic precipitator was simulated. And the fluid flow and the particle motion inside the spiked electrostatic precipitator were numerically analyzed.