• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1047-1052
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• 2008

The aim of this paper is that studies on the characteristics of the liquid-gas ejector. Could get data about various model using numerical analysis. Compare and analyze result that get by an experiment and numerical analysis. And studied Characteristics of the ejector. In this paper, Numerical analysis model is gotten divided according to each Throat ratio as three types. Each throat ratio is 0, 4 and 7.5. According to the result that analyze basic model, pressure became lower causing the volume flow rate increase. In CFD studies, Fixed volume flow rate by these result and analyzed ejector performance. As a result, there was no change of pressure to Throat's Enterance, and pressure became low while pass the throat. Since, pressure recovered while passing diffuser. The outer flow velocity did not change greatly to change of volume flow rate. This research expects that is utilized to data for performance elevation hereafter.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.339-342
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• 2004

It is research about special quality of ozone gas concentration and dissolved ozone concentration that show according to change of flow rate when liquefied ozone gas in water. If increase flow rate of ozone gas, ozone concentration increases being proportional and amount to fixed flow rate, dissolved ozone concentration was measured low. When ozone concentration How rate 1000 [ppm], dissolved ozone concentration smelted to flow rate 1.5[Q] for 28 [min] is $0.1740{\sim}0.8020[mg/l]$. Could know that half-life is most short by 3 minutes 8 seconds in flow rate 1.5 [Q]. And ozone smelted 20 minutes later after half-life measurement became disjointing all.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.480-486
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• 1995

The change in discharge current of a glow discharge has been shown the potential sensitive detector for gas chromatography. To investigate the effect of carrier gas on the electrical characteristics of the discharge and the peak response, the discharge pressure, gas flow rate, and discharge gap have been studied. The discharge gas included the Ar, He, and N$_{2}$. The gas flow rate has been found one of the important parameters to affect both the electrical characteristics and the peak response.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1023-1025
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• 1998

This paper presents the fabrication of a micro pump consisting of a pair of Al f1ap wave and a phase change actuator. The phase change actuator is composed of a heater, a silicone rubber diaphragm and a working liquid chamber. The diaphragm is actuated by the evaporation and the condensation of the working liquid. The actuator pumps fluid through the valves. The micro pump is fabricated by the anisotropic etch, the boron deposition and the metal evaporation. The forward and the backward flow characteristics of the f1ap valves were obtained. Also, the flow rate of the micro pump has been measured. When the square wave input of 12 V, 60% duty ratio and 0.2 Hz is applied, the average flow rate is $0.15{\mu}{\ell}/sec$ for zero pressure difference.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.6
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• pp.360-366
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• 2000

This paper presents the fabrication and test of a micropump consisting of a pair of Al flap valves and a phase-change type actuator. The actuator is composed of a heater, a silicone rubber diaphragm and a working fluid chamber. The diaphragm is actuated by the vaporization and the condensation of the working fluid. The micropump is fabricated by the anisotropic etching, the boron diffusion and the metal evaporation. The forward and the backward flow characteristics of the flap valves illustrate the appropriateness as a check valve. Also, the flow rate of the micropump is measured. When the square wave input voltage of 8 V, 70% duty ratio and 2 Hz is applied to the heater, the maximum flow rate of the micropump is $97\muell/min$ for zero pressure difference.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.272-276
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• 2007

In this paper, we researched a parametric study in flow control system using louver with numerical method. Generally, for the large fans with constant rotational speed, the louver can be used to control the flow rate. The opening and closing of louver can make a some change of flow properties generated by a large fan. To develope the relation between the opening angle of louver and flow rate(or pressure difference), we simulated the flow past the modelled louver installed in a virtual wind tunnel. For the various angles, the mean flow properties are investigated and parameterized with a given boundary condition. The research result can be used directly to design the flow control system of large constant-speed fans, which are often applied to petrolic refinery system.

• Journal of the Korean Society of Visualization
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• v.19 no.2
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• pp.63-73
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• 2021

It is essential to accurately predict the change in water level, velocity, and flow rate for each passage of the grit chamber according to the operating conditions of the pump. In this study, VOF multiphase flow analysis was performed, and the flow characteristics of the grit chamber were predicted. As a result of simulations, the sedimentation phenomenon after the entrance of the grit chamber channel is expected to occur on the side walls. When 6 channels are used, the average speed of the channels is about 52% of the design standard, and when 4 channels are used, the value increases to 74% of the design standard. The average water level in the channels tends to decrease as the flow velocity increases, and the water level in the absorption well with a larger flow rate is maintained lower than that in the absorption well with a smaller flow rate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.11
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• pp.834-839
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• 2009

A three-dimensional computational fluid dynamics (CFD) analysis is performed to investigate flow characteristics in the anode channels and manifold of the internal reforming type molten carbonate fuel cell (MCFC). Considering the computational difficulties associated with the size and geometric complexity of the MCFC system, the polyhedral meshes that can reduce mesh connectivity problems at the intersection of the channel and the manifold are adopted and chemical reactions inside the MCFC system are not included. Through this study, the gas flow rate uniformity of the anode channels is mainly analyzed to provide basic insights into improved design parameters for anode flow channel design. Results indicate that the uniformity in flow-rate is in the range of ${\pm}$1% between the anode channels. Also, the mal-distributed inlet flow-rate conditions and the change in the size of the manifold depth have no significant effect on the flow-rate uniformity of the anode channels.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3120-3124
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• 2008

A three-dimensional computational fluid dynamics (CFD) analysis is performed to investigate flow characteristics in the anode channels and manifold of the internal reforming type molten carbonate fuel cell (MCFC). Considering the computational difficulties associated with the size and geometric complexity of the MCFC system, the polyhedral meshes that can reduce mesh connectivity problems at the intersection of the channel and the manifold are adopted and chemical reactions inside the MCFC system are not included. Through this study, the gas flow rate uniformity of the anode channels is mainly analyzed to provide basic insights into improved design parameters for anode flow channel design. Results indicate that the uniformity in flow-rate is in the range of ${\pm}1%$ between the anode channels. Also, the mal-distributed inlet flow-rate conditions and the change in the size of the manifold depth have no significant effect on the flow-rate uniformity of the anode channels.

• Journal of Welding and Joining
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• v.27 no.1
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• pp.71-78
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• 2009

In the circumferential welding of pipe, welding phenomenon changes with the position of pipe. Especially in the overhead position, back bead of vertical-up position would be sunk. To investigate the size of back bead and keyhole with the change of the flow rate of pilot and shield gas at each position, bead-on plate welds were conducted on 6mm thickness SS400 with inclined-up position. When the rest of welding conditions remained constant, the width of back bead was increased as the flow rate of pilot gas was increased. And back bead tended to convex as the flow rate of shield gas was increased.