• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 추계학술대회논문집
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• pp.170-176
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• 2009

Flow control butterfly valve(FCBV) is known to have difficulty in controlling flow rate along valve opening due to its high flow rate. In low opening condition, the butterfly valve also has some shortcomings such as noise, vibration and erosion which are mostly caused by cavitation effects. Therefore, the FCBV requires proper remedies to reduce cavitation effects and to improve flow control performance. Numerical analysis is applied to FCBV flow to find effects of design factors such as seat diameter and valve opening rate. Cases with 3 different sizes of seat diameter and various valve opening rate are selected for the numerical analysis. From the analysis results, it is found that the FCBV with small seat diameter shows better pressure loss performance and reduced cavitation effects.

• 한국전산유체공학회지
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• 제15권1호
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• pp.64-70
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• 2010

Flow control butterfly valve(FCBV) is known to have difficulty in controlling flow rate along valve opening due to its high flow rate. In low opening condition, the butterfly valve also has some shortcomings such as noise, vibration and erosion which are mostly caused by cavitation effects. Therefore, the FCBV requires proper remedies to reduce cavitation effects and to improve flow control performance. Numerical analysis is applied to FCBV flow to find effects of design factors such as seat diameter and valve opening rate. Cases with 3 different sizes of seat diameter and various valve opening rate are selected for the numerical analysis. From the analysis results, it is found that the FCBV with small seat diameter shows better pressure loss performance and reduced cavitation effects.

• 한국전산유체공학회지
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• 제6권1호
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• pp.40-46
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• 2001

Pressure-flow control characteristics of a commercially available cerebrospinal flow(CSF) control shunt valve was studied using flow/structure interaction analyses. Pre-stress of the valve diaphragm(membrane) was accounted for the simulation of an actual valve. The present results were in good agreement with the valve specification listed in the commercially available CSF control valve. The flow/structure interaction analysis of the present study can be effectively used to design a variety of CSF control shunt valves.

• 오토저널
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• 제15권2호
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• pp.53-63
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• 1993

A numerical modeling technique is proposed for computer simulations of high speed valve train dynamic terms in the valve spring reaction forces are calculated using linear vibration theory for given kinematic valve motions. Because the spring dynamics are analyzed before the time stepping integration, spring surge phenomena can be included without using additional computer time. In addition to that, steady state response of the valve dynamics can be obtained by just one cycle simulation. Consequently, valve train dynamics can be simulated very quickly without noticeable errors in accuracy. The experimental result prove the computer model developed here is accurate and also computationally efficient. The model is especially useful for cam profile optimizations.

• 한국정밀공학회지
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• 제23권5호
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• pp.137-142
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• 2006

The muffler which reduce the exhaust noise and vibration from engine influence on the engine performance. Recently, exhaust variable valve has set up in the muffler controls the backpressure in the exhaust system. And the backpressure variation according to the exhaust variable valve opening has developed the engine performance. First, the preceding of structural analysis is needed and simulation experiment is requested for the study on the design factor to influence on the operation of the exhaust variable valve. In this study, setting up the various variables according to each composition element needed for the structural analysis of the exhaust variable valve, it is experimented the analysis on the influence of each design factor with the calculation of stress distribution and the displacement to cause about the backpressure for the valve through parameter study.

• 한국산학기술학회논문지
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• 제13권5호
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• pp.1963-1968
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• 2012

본 논문은 현장에서 사용하고 있는 밸브 수압측정기를 3차원 자동설계 프로그램인 CATiA를 활용하여 설계하였다. 또한 유한요소 해석코드인 ANSYS를 활용하여 설계된 밸브 수압측정기에 대하여 유동해석을 수행하여 내부압력에 따른 유체의 흐름을 구하였다. 이러한 해석결과는 새로운 밸브 수압측정기를 개발하는데 기초자료로 활용될 계획이며 개발예정인 밸브 수압측정기는 밸브 점검 시 시간을 단축하고, 사고를 방지하여 안전성을 향상시킨다.

• Journal of Information Processing Systems
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• 제16권5호
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• pp.1095-1104
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• 2020

This paper introduces a design scheme of intelligent gas valve management and service system based on Internet. This scheme adds sensor and general packet radio service (GPRS) modules to the traditional gas valve and establishes communication connection between gas valve and the server through wireless packet communication technology, which makes the traditional gas valve have the networking ability. Compared with the traditional gas valve management and service business, the method proposed in this paper is more convenient and efficient.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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• pp.221-227
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• 2000

The design of the valve plate is most important to increase efficiency in the oil hydraulic axial piston pump. A theoretical study was carried out to clarify the pressure characteristics at the land of the valve plate in the oil hydraulic axial piston pump. Dynamic pressure acts on the land of the valve plate was computed numerically with discharge pressure, rotational speed and swash plate angle. Pressure distribution between the valve plate and the cylinder block also was obtained with dynamic pressure. The results are applicable to improve the design technique of the valve plate in the oil hydraulic axial piston pump.

• 대한기계학회논문집
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• 제1권2호
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• pp.65-72
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• 1977

Major problems in the design and use of refief valve are (a) chattering because of instability, (b) excessive pressure differential which makes the valves crack far below maximum pressure diminishing useful flow in the system. In this study, A magnet-coupled relief valve is investigated theoretically and experimentally in order to improve the performance of a conventional direct type reliefvalve. A theory is developed to predict the performance, response, and stability of the magnet-coupled valve taking into account the delivery line response. In the experiment, a typical magnet-coupled relief valve is designed on the basis of the analytical results; the discharge rates are measured varying the supply pressure, and both the pressure-time curves and valve displacament-time curves are recorded providing the supply pressures greater than the setting pressure. The measured override characteristic curves are then compared with those of conventional pilot type and direct type releif valves. It is showm that the excessive pressure differential of a magnet-coupled relief valve becomes less than that of a conventional direct type valve. It is also shown that the most important chatacteristic of a magnet-coupled relief valve is to eliminate valve chattering due to instability regardless of the magnitude of setting pressures and discharge rates, which suggests wide applications of the idea of the use of a magnet in the design of hydraulic valves.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1581-1584
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• 2007

The safety valve is the important equipment used to protect the pressure vessel and pressure facilities from overpressure by discharging the operation medium when the pressure of system is reaching the design pressure of the system. Some materials for a safety valve disk are studied in this paper. A studied safety valve has to resist sulfurous acid and nitric acid. etc. Furthermore teflon which is a general material of the valve easily sticks to a disk and a sliding part of the valve by thermal expansion. Therefore both teflon and stainless-steel are used to improve these problems. The analysis of the thermal expansion is conducted with commercial FEM software to improve the problems. Boundary conditions were temperature and load in this study. From the analysis, the thermal expansion of by teflon/stainless steel-made valve is lower than that of teflon-made valve under high temperature. Thus, teflon/stainless steel-made valve is safe and no malfunction by thermal expansion.