• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.176-181
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• 2000

Acoustic modal characteristics are investigated on the passenger compartment and trunk coupled system. One-dimensional theoretical model is proposed and the validity of the model is verified by experiment on a simplified compartment model. The theoretical model identifies the occurrence of a new low frequency compartment mode, which does not exist in the uncoupled passenger compartment. The effect of the hole size on the compartment modes is analytically and experimentally examined.

• 대한의용생체공학회:의공학회지
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• 제23권5호
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• pp.341-349
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• 2002

본 논문에서는 혈중 목표 농도 자동 조절기(Target-controlled infusion system. TCI)를 개발하는 것으로써, 마취의가 혈중 목표 농도를 설정하면 사용약제의 약동학적 모델링에 의해서 주입속도를 자동적으로 계산하여 마취의 깊이를 예측하는 약동학적 모델의 수립과 검증 방법을 설명한다. 정확한 약동학적 모델의 구축은 시스템의 성능에 큰 영향을 미치므로 먼저 PART 1에서는 약동학적 모델을 구축하되 3-콤파트먼트 모델과 4-콤파트먼트 모델로 해석하였다. 기존의 TCI에서 사용하고 있는 3-콤파트먼트 모델에 가상의 효과처 구획(Effect Site Compartment)을 만들고 이를 네 버내 구획으로 가정한 4-콤파트먼트 모델(Four-Compartment Model)을 수립하였고, matlab 5.0을 이용하여 비교 분석하였다. 모델은 혈중 목표 농도 주입(Plasma Targeting)과 효과처 목표 농도 주입(Effect Site Targeting), 혈중 농도 유지를 위한 주입율 계산과 기타 마취 상태를 추정하는 정보를 포함한다. 시뮬레이션의 결과를 바탕으로 4-콤파트먼트 모델을 디지털 z-변환을 거쳐 디지털시그널프로세서에 프로그램하고 TCI시스템의 적용가능성을 평가하였다. 정맥 마취용 TCI는 오동작에 대한 검증이 반드시 요구되므로 구축한 모델링에 대한 시뮬레이션의 평가 방법을 설정하였다. 기존의 TCI시스템과는 달리 약동학적 약물 전달 속도 상수(k-파라미터)를 독립적으로 조절할 수 있는 기능이 추가되어 다양한 약제의 사용이 가능할 뿐만 아니라 새로운 약동학적 모델의 개발과 평가에 기여하게 되고, 환자의 체형과 병명에 따른 약동학적 모델의 변화에 대응할 수 있게 하였다.

• 한국전산유체공학회지
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• 제15권4호
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• pp.67-75
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• 2010

Hydrogen safety is one of important issues for future public usage of hydrogen. When hydrogen is released in a compartment, the occurrence of detonation must be prohibited. In order to evaluate the possibility of DDT (Deflagration to Detonation Transition) in the compartment with the hydrogen release, sigma-lambda criteria which were developed from experimental data are commonly used. But they give a little conservative results because they do not consider the detailed geometrical effect of the compartment. This is the main reason of the need to mechanistic combustion model for evaluation of hydrogen flame propagation and acceleration. In this study, sigma-lambda criteria and combustion model were systematically applied to evaluate a possibility of DDT in a IRWST compartment of APR1400 nuclear power plant during a hypothetical accident. A combustion model in an open source CFD code OpenFOAM has been applied for analyses of hydrogen flame propagation. The model was validated by evaluating the flame acceleration tests conducted in FLAME facility. And it was applied to evaluate the characteristics of a hydrogen flame propagation in the IRWST compartment of APR1400.

• Nuclear Engineering and Technology
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• 제37권4호
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• pp.385-390
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• 2005

The effect of the Wolsong Tritium Removal Facility on the change of tritium concentration in the soil water was assessed by introducing a dynamic compartment model. For the mathematical modeling, the tritium in the environment was thought to come from two different sources. Three global tritium cycling models were compared with the natural background concentration. The dynamic compartment model was used to model the behavior of the tritium from the nuclear power plants at the Wolsong site. The source term for the dynamic compartment model was calculated with the dry and wet deposition rates. The area around the Wolsong nuclear power plants was represented by the compartments. The mechanisms considered in deriving the transfer coefficients between the compartments were evaporation, runoff, infiltration, hydrodynamic dispersion, and groundwater flow. We predicted what the change of the tritium concentration around the Wolsong nuclear power plants would be after future operation of the tritium removal facility to show the applicability of the model. The results showed that the operation of the tritium removal facility would reduce the tritium concentration in topsoil water quickly.

• 대한기계학회논문집
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• 제16권1호
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• pp.13-21
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• 1992

본 연구에서는 구조-음향모드 연성계수를 이용하여 심각한 소음문제가 발생하 는 경우의 효과적인 소음저감 방안을 제시하고, 제작된 차실모델에 대한 소음저감 시 뮬레이션을 수행한 후 그 결과를 실험치와 비교함으로써 수립된 소음저감 방안의 신뢰 도와 유용성을 확인하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.234-241
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• 2002

In this study, the car crash analysis that simulates the crushing behavior of car forestructure during a frontal impact is carried out. The analysis model for front impact of a car consists of the lumped mass and the spring model. The characteristics value of masses and springs is obtained from the static analysis of a target car. The deceleration-time curve obtained from the simulation are compared with NCAP test data from the NHTSA. They show a good agreement with frontal crash test data. The deceleration-time curve of passenger compartment is classified into 3 stages; beginning stage, middle stage, and last stage. And the behavior of masses at each stage is explained. The effect of stiffness variation on deceleration of passenger compartment is resolved. The maximum loaded peak-time of torque box and dash is the main factor to control the passenger compartment's maximum deceleration.

• 방사성폐기물학회지
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• 제18권3호
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• pp.395-405
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• 2020

Compartment fire tests were performed using kerosene and Jet A-1 as fire sources to evaluate the relationship between flame temperature and opening size. The tests were performed for a fire caused by the release of kerosene owing to vehicle impact, and for a fire caused by the release of Jet-A-1 owing to airplane collision. The compartment fire tests were performed using a 1/3-scale model of a metal storage cask when the flame temperature was deemed to be the highest. We found the combustion time of Jet-A-1 to be shorter than that of kerosene, and consequently, the flame temperature of Jet-A-1 was measured to be higher than that of kerosene. When the opening was installed on the compartment roof, even though the area of the opening was small, the ventilation factor was large, resulting in a high flame temperature and long combustion. Therefore, the position of the opening is a crucial factor that affects the flame temperature. When the metal storage cask was stored in the compartment, the flame temperature decreased proportionally with the energy that the metal storage cask received from the flame.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.158-165
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• 1996

The knowledge of air flow in an engine room has become more and more important in recent car design. The fluid flow in the engine compartment was investigated by numerical analysis. Due to the complex geometry of the engine compartment, mesh generation is a time-consuming job. In this research, the "ICEM" code was used to generate meshes by the Cartesian mesh model. The Reynolds-averaged Navier Stokes equations, together with the porous flow model for radiator and condenser, were solved. Computation was performed for the steady, incompressible, and high speed viscous flow, adopting the standard K-ε turbulence model. The "STAR-CD" code was used as a solver. The effect of car front openning area on the flow in engine room was also investigated.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.193-200
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• 1997

Flame spread and heat release properties and incident heat flux of interior materials subject to an igniter heat flux in a compartment are investigated and compared by using computer model. A comer fire ignition source is maintained for 10 minutes at 100 kw and subsequently increased to 300kw. In executing the model, base-line material properties are selected and one is changed for each run. Also 4 different igniter heat flux conditions and examined. Results are compared for the 12 different materials tested by the ISO Room Comer Test (9705). The time for total energy release rate to reach 1MW is examined. The parameters considered include flame heat flux and thermal inertia, lateral flame spread parameter, heat of combustion and effective heat of gasfication. The model can show the importance of each property in causing fire growth on interior Hnish materials in a compartment. The effect of ignitor heat flux and material property effects were demonstrated by using dimensionless parameters a, b and Tb. Results show that for b greater than about zero, flashover time in the ISO Room-Corner test is principally proportional to ignition time and nothing more.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1660-1664
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• 2008

Extra-corporeal Life Support System (ECLS) is the device used in emergency cases to substitute a extracorporeal circulation in open heart surgery, cardiac arrest or in acute cardiopulmonary failure. To obtain the effect of counter-pulsation on hemodynamic response in the ECLS quantitatively, we developed cardiovascular model which consists of 12 compartment model of heldt et al. and 3 compartment model of Schreiner et al. based on windkessel approximation. We compared coronary perfusion, arterial pulse pressure, cardiac output, and left ventricular pressure-volume diagram according to flow configuration such as counter-pulsation, copulsation, and continous flow. When counter-pulsation was applied, 5% higher coronary perfusion, 26% lower pulse pressure, and 2% higher cardiac output than copulsation condition were calculated. We conclude that counter-pulsation configuration in the ECLS is hemodynamically more stable than copulsation and influences the positive effect to recover ventricles.