• 항공우주기술
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• 제6권2호
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• pp.29-34
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• 2007

본 논문에서는 엔진고공환경 시험설비의 엔진 입구 덕트에서 측정한 전압력과 전온도를를 통해 실시간으로 공기유량을 계산하고, 압력프로파일을 이용하여 경계층 레이크를 장착하지 않았을 경우에도 공기유량을 예측할 수 있는 방법을 기술하였다. 또한, 엔진입구배관에 걸친 덕트 연결부를 통한 압력손실을 예측하고, 이를 통해 공기유량을 보정함으로써, 고공환경시험설비에서의 공기유량측정의 신뢰도를 향상시키고 설비유지측면에서 운용성을 보고자 하였다.

• 한국수소및신에너지학회논문집
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• 제27권3호
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• pp.311-317
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• 2016

This paper presents the flow characteristics of a ball valve used for a gas pipeline. Understanding of the internal flow of a ball valve is an important to analyze the physical phenomena of the valve. Present experimental study was performed by IEC 60534-2-3, the international standard for an industrial control valve testing procedure. Pressure measured at upstream and downstream of the valve, flow-rate and gas temperature passing the inside of the gas pipeline were measured with respect to valve opening rates. Throughout the experimental measurement of the ball valve, empirical equation of the pressure drop between the ball valve according to the mass flow rates is successively obtained using a polynomial curve fitting method. In addition, flow coefficient for determining the valve capacity is also analyzed with respect to valve opening rates using the curve fitting method.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 12th Asian Congress of Fluid Mechanics
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• pp.44.5-45
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• 2008

• 동력기계공학회지
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• 제19권1호
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• pp.19-23
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• 2015

The swirling flow fields of a gun-type gas burner(GTGB) without a combustion chamber were measured by a straight-type five-hole pressure probe(FHPP) under the cold flow condition. The three kinds of velocity components and the static pressure were calculated by using a non-nulling calibration method covering the velocity reduction performance of the effective flow attack angle of ${\pm}80^{\circ}$. As a result, the velocity and static pressure measured by a FHPP comparatively shows the better performance on the swirling flow of a GTGB than those measured by X-probe.

• 한국가시화정보학회지
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• 제11권1호
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• pp.34-40
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• 2013

Gas/liquid two-phase ejector is a device without moving parts, in which liquid is used to drive gas of a low-pressure source. In this paper, the hydrodynamic characteristics of a vertical down type two-phase ejector were studied using an air-water loop system. Entrained air flow rates were measured with inlet and outlet pressures of the ejector with varying water flow rate. Homogeneous bubbly flows in the discharge pipe were confirmed by the high speed flow visualization method. Quantitative measurements of void fraction were made using a newly developed fiber optic probe system.

• 한국전기전자재료학회논문지
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• 제21권12호
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• pp.1096-1100
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• 2008

This report examines the variations on structural properties of $SnO_2$ thin films deposited by using thermal chemical vapor deposition techniques with different oxygen flow gas. TEM showed some of the interface to be atomically rough. The aspects of the boundary shape and growth behavior agree well with the theory of interface growth. The electron diffraction showed that the roughness was changed as the different oxygen flow gas increased. These measurement results suggested that the number of interface facet and abnormal grain growth were related oxygen flow gas.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1742-1756
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• 2023

The hydrogen behavior in a nuclear containment vessel is a significant issue when discussing the potential of hydrogen combustion during a severe accident. After the Fukushima-Daiichi accident in Japan, we have investigated in-depth the hydrogen transport mechanisms by utilizing experimental and numerical approaches. Computational fluid dynamics is a powerful tool for better understanding the transport behavior of gas mixtures, including hydrogen. This paper describes a Large-eddy simulation of gas mixing driven by a high-buoyancy flow. We focused on the interaction behavior of heat and mass transfers driven by the horizontal high-buoyant flow during density stratification. For validation, the experimental data of the Containment InteGral effects Measurement Apparatus (CIGMA) facility were used. With a high-power heater for the gas-injection line in the CIGMA facility, a high-temperature flow of approximately 390 ℃ was injected into the test vessel. By using the CIGMA facility, we can extend the experimental data to the high-temperature region. The phenomenological discussion in this paper helps understand the heat and mass transfer induced by the high-buoyancy flow in the containment vessel during a severe accident.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1512-1516
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• 1994

FLIC(Fluid in cell) method has been used for analyzing a cold gas flow field in an interrupter of a circuit treater since 1970s. In this paper FLIC method is applied to calculation of a cold gas flow and then combined with the simple are analysis method in order to investigate the flow field characteristics in a puffer type interrupter rated at 145kV 40kA. The results for a cold gas flow agree with the experimental measurement well. The other results such as pressure rise, arc temperature, post-arc current and so forth am also reasonable and show the possibility that the combined program can be applied to the design of UHV interrupters.

• 한국유체기계학회 논문집
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• 제6권2호
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• pp.47-53
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• 2003

The piston prover was developed and the flow measurement uncertainty of this piston prover was evaluated according to ISO/IEC 17025. The laser interferometer, instead of the optical sensors used in the typical provers, was employed in this prover to measure accurately the testing time and the moved distance of the piston. Uncertainty was calculated with evaluation of various uncertainty factors affecting flow measurement. The expanded uncertainty (U) of the piston prover was $1.3{\times}10^{-3}$ (at the confidence level of $95\%$). This evaluation example will be useful in the flow measurement uncertainty determination of other gas flow measurement system.