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  • Title/Summary/Keyword: 구동압력

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A Study ob Performance with NanofiltrationLinear and Helical Modules (Nanofiltration linear and helical module들의 막투과 성능 비교)

  • ;Belfort, Georges
    • Proceedings of the Membrane Society of Korea Conference
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    • 1997.10a
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    • pp.33-36
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    • 1997
  • 1. 서론 : 압력-구동 막공정을 분리공정에 응용시 커다란 장해는 막표변과 내부에 용존 및 부유물질들의 성장과 침착현상이다. 지난 수년 동안에 여러 연구자들이 유체의 불안정성을 이용하여 농도분극과 오염현상을 효과적으로 제거할 수 있음을 보였다.(생략)

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Crack analysis of mis-matched welding at CRDM(control rod drive mechanism) upper penetration nozzles of RPV(reactor pressure vessel) considering the change of mechanical properties (기계적 물성 변이를 고려한 원자로 압력용기(RPV : reactor pressure vessel) 상부 제어봉 구동 장치(CRDM : control of rod diver mechanism) 관통 노즐 이종재 용접부의 균열해석)

  • Lee, Yong-U;Kim, Jong-Seong;Lee, Gang-Yong
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.241-243
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    • 2005
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Thermal Wave Transfer and Combustion Response of Droplet Perturbed by Acoustic Pressure (압력파에 교란된 액적내부에서의 에너지 파동 및 반응 메커니즘)

  • Lee Cilyong;Yoon Woongsub
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.183-188
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    • 2005
  • This study targets to investigate thermal wave transfer in a droplet strongly coupled with acoustic pressure and its effects on combustion response. The one-dimensional vaporization model uses SRK equation of state and flash calculation method to obtain more accurate thermophysical properties and compute vapor-liquid equilibrium. Calculations of an n-pentane droplet exposed into a perturbing nitrogen gas is carried out in terms of different ambient gas pressures and wave frequencies. The thermal wave is transferred more effectively at lower frequencies, which results in the decrease in the amplitude of the response.

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Experimental Study on the Flow Hysteresis Phenomenon in a Supersonic Nozzle (초음속 노즐에서 발생하는 유동 이력현상에 대한 실험적 연구)

  • Nam, Jong-Soon;Kim, Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.206-212
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    • 2011
  • Hysteresis phenomena in fluid flow systems are frequently encountered in many industrial and engineering applications and mainly appear during the transient processes of change of the pressure ratio. Shock-containing flow field in supersonic nozzles is typically subject to such hysteresis phenomena, but associated flow physics is not yet understood well. In the present study, experimental work has been carried out to investigate supersonic nozzle flows during the transient processes of change in the nozzle pressure ratio. Time-dependent surface wall pressures were measured by a multiple of pressure transducers and the flow field was visualized using a nano-spark Schlieren optical method. The results obtained show that the hysteresis phenomenon is strongly dependent on the nozzle geometry as well as the time scale of the change of pressure ratio.

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Velocity and Pressure Measurement of Channel Cavity Flow by PTV (PTV에 의한 채널캐비티 유동의 속도 및 압력계측)

  • Cho, D.H.;Kim, J.G.;Lee, Y.H.
    • Solar Energy
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    • v.17 no.3
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    • pp.59-66
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    • 1997
  • The present study adopted the PTV method for the velocity acquisition. The system consists of an image grabber built-in a personal computer and a laser-based sheet light projector and particle identification softwares. Velocity vectors are obtained, by PTV and they are used as velocity components for Poisson equation for pressure. Related boundary conditions and no-slip condition at solid wall and the linear velocity extrapolation on the upper side of cavity are well examined for the present study. For calculation of pressure, resolution of grid is basically 40×40 and 2-dimensional uniform mesh using MAC staggered grid is adopted. The result of experiment reveal that, newly suggested measuring method is capable of estimating pressure and velocity distribution of flow field reasonably.

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Improvement on Pressure Drop Performance of Flow Control Disk in Portable Resuscitator (CFD 해석을 통한 인공호흡기 유량조절디스크의 압력 강하 성능개선)

  • Kim, Young-Soo;Kim, Min-Wook;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.1-5
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    • 2016
  • Cases of cardiac arrests due to cardiovascular ailments have increased recently., portable Current portable resuscitators which can be automatically supply oxygen operated by the pressure of supplied oxygen without manual or electronic actuators are now widely used in emergency worldwide. However, reductions in Pressure drop characteristics through the extended use of this type of resuscitator, however, is are not well-known described. This paper describes the reduction in pressure loss drop performance of the various holes in within the flow control disc of with various hole size of the portable resuscitators using on breathing resistance through the CFD simulation, and suggests the an optimum optimal design of the hole shapes for the minimization of alteration in order to minimize this pressure drops.

Control Strategy of Ratio Changing System for a Metal V-Belt CVT Adopting Primary Pressure Regulation (압력제어 방식 금속 벨트 CVT 변속비 제어 전략)

  • 최득환;김현수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.3
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    • pp.201-208
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    • 2002
  • In this paper, the control strategy of ratio changing system for a metal belt CVT adopting primary pressure regulation is developed, and the shirting performance of pressure regulating type CVT with the suggested control strategy is investigated. The control strategy suggested in this study is composed of 2 feedback loop, one is speed ratio feedback and the other is primary pressure feedback. The pressure feedback is adopted to ensure prohibiting a belt slip during transient period in a fast downshift mode. Simulation results show that the system with suggested control strategy gives appropriate response time and tracking Performance for upshift and also gives a proper primary pressure which can prohibit the belt slip. In addition, it is fecund that the given system has an acceptable servo property in tracking the target speed ratio and robustness for the disturbance of line pressure.

압력제어솔레노이드밸브를 이용한 직접구동 방식의 유압회로에 의한 자동변속기의 변속품질 향상에 관한 연구

  • 김정관;한명철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.505-508
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    • 1995
  • This paper suggests new hydraulic circuit to control the pressure of clutches and brakes which has several advantages than conventional hydraulic circuit in automatic transmissions. In conventional hydraulic circuit, the pressures of all friction elements are controlled by only one pressure control valve and accumlators. So, controllable range is limited and it is unable to control the friction elements independently. Therefore, we can not do the fine control of timing between apply clutch and release clutch which is needed in clutch-to clutch shifting automatic transmissions. To overcome these faults, we designed the direct-acting hydraulic circuit where one pressure control valve and pressure control solenoid valve are allocated to each friction element and control that independently. Through this structural improvement of hydraulic circuit, we can achieve elaborate aontrol to clutch pressure. Specially, We can control the timing between apply clutch and release clutch delicately which is needed in clutch-to-clutch shifting.

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압력제어솔레노이드밸브를 이용한 직접구동 방식의 유압회로에 의한 자동변속기의 변속품질 향상에 관한 연구

  • 김정관;한명철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.577-580
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    • 1995
  • This paper suggests direct-acting hydraulic circuit to control clutches and brakes in automatic transmission. As only one pressure control valve controls the pressure of several friction elements with accumulators in conventional hydraulic circuit, the controllable range is limited. In addition, it is difficult to control the fine timing between apply clutch and release clutch. So, we designed new method to control the pressure of clutch which uses ressure control valve and pressure control solenoid valve independently in each friction element. through this structure improvement of hydraulic circuit, we can control the pressure of clutches and brakes finely and fine timing of between apply clutch and release clutch.

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A study of unsteady characteristics on the pintle nozzle (핀틀 노즐의 비정상 특성연구)

  • Lee, Ji-Hyung;Chang, Hong-Been;Ko, Hyun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.662-665
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    • 2011
  • Pintle technology, which is one of the thrust control method for solid rocket motor, can control the thrust by the control of nozzle throat area through the pintle moving. For studying the unsteady flow characteristics of pintle nozzle by needle type pintle moving, cold flow test and numerical analysis were performed. The pressure distribution on the pintle tip was varied for pintle moving and stopping and thrust was varied by this effects.

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