• 전기학회논문지
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• 제58권4호
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• pp.801-805
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• 2009

This paper reports on a flexible flap valve actuated by electromagnetic force under a constant pressure source. The flexible flap valve consists of the three main components: a flexible flap with a steel disk embedded in PDMS, an electromagnetic actuator and two glass plates with inlet and outlet. The flap valve is fabricated by SU-8 mold process, the EDM process and oxygen plasma treatment. The dimension of an assembled flap valve is $12[mm]{\times}20[mm]{\times}28[mm]$. The stroke volume of the flap valve is measured for various pressures. And the time of the applied input voltage is varied to change the open time of the valve. When the input voltage of 30[V] is applied for 0.25[s], the minimum stroke volume of the flap valve is $40[{\mu}L]$ at 70 [kPa].

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1476-1477
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• 2008

This paper reports on a flexible flap valve actuated by electromagnetic force under a constant pressure source. The flexible flap valve consists of the three main components: a flexible flap with a steel disk embedded in PDMS, an electromagnetic actuator and two glass plates with inlet and outlet. Sealing lip structures for improving the valve characteristics are added on the outlet of the bottom glass substrate. The flap valve is fabricated by the spin-coating process, the EDM process, SU-8 mold process and oxygen plasma treatment. The dimension of an assembled flap valve is $12mm{\times}20mm{\times}28mm$. The stroke volume of the flap valve is measured for various pressures and open times. When the input voltage of 30 V is applied for 0.33 s, the minimum stroke volume of the flap valve is 70 ${\mu}L$ at 50 kPa.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1992년도 춘계학술대회
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• pp.123-126
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• 1992

In this paper, a numerical simulation of steady laminar and turbulent flow in a two dimensional model for the total artificial heart is presented. A trileaflet polyurethane valve was simulated at the outflow orifice while the inflow orifice had a trileaflet or a flap valve. The numerical solutions of the simulated model show that regions of relative stasis and trapped vortices were smaller wi thin the ventricular chamber wi th the flap valve at the inflow orifice than that with the trileaflet valve. The predicted Reynolds stresses distal to the inflow valve within the ventricular chamber were also found to be smaller with the flap valve than with the trileaflet valve. Analysis of the numerical solutions suggests that geometries similar to the flap valve(or a tilting disc valve) results in a better flow dynamics within the total artificial heart chamber compared to a trileaflet valve.

• 대한의용생체공학회:의공학회지
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• 제13권2호
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• pp.87-96
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• 1992

In thIns paper, a numerical simulation of steady laminar and turbulent flow in a two dimensional model for the total artificial heart is'presented. A trlleaflet polyurethane valve was simulated at the outflow orifice while the Inflow orifice had a trileaflet or a flap valve. The finite analytic numerical method was employed to obtain solutions to the governing equations in the Cartesian coordinates. The closure for turbulence model was achieved by employing the k-$\varepsilon$-E model. The SIMPLER algo rithm was used to solve the problem in primitive variables. The numerical solutions of the slulated model show that regions of relative stasis and trapped vortices were smaller within the ventricular chamber with the flap valve at the Inflow orifice than that with the trileaflet valve. The predicted Reynolds stresses distal to the inflow valve within the ventricular chamber were also found to be smaller wlth the flap valve than with the trlleaflet valve. These resu1ts also suggest a correlation be- tween high turbulent stresses and the presence of thrombus In the vicinity of the valves in the total artificial hearts. The computed velocity vectors and trubulent stresses were comparable with previ ously reported in vitro measurements in artificial heart chambers. Analysis of the numerical solo talons suggests that geometries similar to the flap valve(or a tilting disc valve) results in a better flow dynamics within the total artificial heart chamber compared to a trileaflet valve.

• 한국기계가공학회지
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• 제15권4호
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• pp.16-22
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• 2016

This study is a structural analysis of 3" Cryogenic Safety Breakaway Coupling using a manufactured product from KLAW Company. Breakaway coupling is very important in the pipe system, especially when transporting fuel or gas in the pipeline. For the analysis of the patent infringement target, Dover and KLAW Company's technologies (US 08127785, EP 0764809) were analyzed. Finally, the flip-flap valve overlap was measured after combining the breakaway coupling through 3D modeling, and the valve overlap had a 0.7mm measurement value from the height gauge. The safety breakaway coupling consisted of a total of 62 pieces (body: 42, valve module: 21).

• 항공우주시스템공학회지
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• 제13권4호
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• pp.50-59
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• 2019

플랩제어시스템의 주요 구성품인 주제어밸브의 설계는 실제 제작 경험을 바탕으로 반복-오차 방법에 의존하여 수행하였다. 본 논문에서는 모델 기반의 부품 설계 방법을 제안하였다. 플랩제어시스템은 주제어 밸브, 고장-안전 밸브, 솔레노이드 밸브, LVDT, 구동 모터 등으로 구성된다. 주제어밸브는 주로 스풀과 슬롯으로 구성된다. 주제어밸브의 중요한 설계변수는 슬롯의 폭 (Slot Width), 오버 랩(Overlap) 및 간극(Clearance)이다. AMESim을 활용하여 주 제어 밸브의 유로를 모델링하고 해석하였다. 제안된 설계절차를 적용한 결과 허용된 가공오차 범위 내에서 요구 성능을 충족함을 확인하였다.

• 한국생산제조학회지
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• 제21권3호
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• pp.355-361
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• 2012

Though a micro pump is a crucial element in miniaturized bio-fluidic systems or drug delivery systems, it has some intrinsic disadvantages such as backward flow, pulsation of flow, low repeatability and producibility, and high cost. To overcome these limitation, a PZT disc actuated micro pump including a novel ring-shaped multi-flap check valve is introduced. To enhance the performance of the micro pump, the static behaviour of flap valve module and the micro fluidic behavior of fluids are numerically modelled and analyzed. As results of the numerical analysis, the optimal dimension and configuration of the ring-shaped multi flap valve are $1{\times}0.05$ mm and 2 (inlet side)${\times}1$ (outlet side) type. The obtained maximum flow rates and flow resolution are about 90 ml/min and 30 ${\mu}l$/stroke respectively.

• Journal of Korean Neurosurgical Society
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• 제43권1호
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• pp.51-53
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• 2008

The syndrome of the sinking skin flap was introduced to explain the phenomenon of neurological deterioration after decompressive craniectomy. A 37-year-old man was admitted with acute subdural hematoma and traumatic intraparenchymal hematoma. After decompressive craniectomy, the patient suffered from hydrocephalus for which a ventriculoperitoneal (V-P) shunt was inserted. Following this procedure, the depression of the skin flap became remarkable and his mentation was deteriorated. The patient recovered uneventfully after temporary elevating of valve pressure and cranioplasty. We present a patient who was successfully managed with elevation of valve pressure and cranioplasty for the syndrome of the sinking scalp flap with review of a pertinent literature.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권6호
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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.

• International Journal of Aerospace System Engineering
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• 제4권1호
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• pp.13-21
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• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.