• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.50-55
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• 2008

본 연구는 대구지하철 중앙로 역사 화재사고를 모델로 하여 FDS와 FLUENT를 이용해 화재유동 분석을 하였다. 경계조건으로는 그동안 조사된 대구지하철화재사고의 분석 자료를 이용하였다. 화재해석은 지하승강장 포함 하여 지상 대합실 까지 총 3개의 층을 FLUENT 및 FDS를 이용하여 수행하였으며, 해석 결과는 화재 온도 분포와 CO 데이터를 비교분석 하였다. 총 시뮬레이션 시간은 600s 이며 10s 마다의 결과값을 비교하였다. 이러한 분석결과는 향후 피난시뮬레이션과의 연계를 통해 지하역사 최적설계 기법연구에 기초자료가 될 것으로 생각되어진다.

• 한국기계가공학회지
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• 제17권5호
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• pp.1-7
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• 2018

Flexible track drilling machines are credited with important applications in the area of aircraft manufacturing because of their portability, quick installation capabilities, and high efficiency. However, their structures are special and the constitution principles and motion characteristics are difficult to control, increasing the development costs and research cycle in the context of the technology blockade of foreign companies. The simulation analysis of flexible track drilling machines can be conducted by applying virtual prototypes, shortening the development cycle and reducing the cost. In this paper, a model of a machine is established by using the SolidWorks software and imported into ADAMS to conduct kinematic and dynamic simulation analysis. During the analysis, the feasibility of the configuration is checked, a reasonable driving motion is chosen, potential deficiencies are found, and improvement actions are raised.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.466-477
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• 2021

There are three different well-known methods for predicting the manoeuvrability of ships: (1) free running model test, (2) direct manoeuvring simulation using CFD and (3) system-based manoeuvring simulation. In this paper, the manoeuvrability of the KVLCC2 was estimated using CFD with rigid body motion and body force propeller method. The free running manoeuvre at the different time steps were also simulated. The yaw checking ability and the turning ability of KVLCC2 were predicted using CFD and could have been confirmed that the IMO criteria was satisfied. When the results were compared with the model test and system-based method, the free running simulation showed better agreement to that of the model test. It could also be confirmed that the results vary depending on the time step. Overall, the CFD results using the body force propeller method estimated most accurately the test results.

• 한국염색가공학회지
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• 제34권4호
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• pp.250-260
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• 2022

In this research, a high-elasticity acrylic emulsion binder with core-shell polymerization and self-crosslinking system is mixed with a flame-retardant water-dispersed polyurethane (PUD) binder. In addition, finite element analysis was conducted through virtual engineering software ANSYS by applying three representative nonlinear material models. The most suitable nonlinear material model was selected after the relative comparison between the actual experimental values and the predicted values of the properties derived from simulations. The selected nonlinear material model is intended to be used as a nonlinear material model for computational simulation analysis that simulates the experimental environment of the vibration test (ASTM E1399) and the actual fire safety test (ASTM E1966). When the mass fraction of thermally expandable graphite was 0.7%, the thermal and physical properties were the best. Among the nonlinear material models, the simulation result of the Ogden model showed the closest value to the actual result.

• 한국연소학회지
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• 제13권3호
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• pp.24-32
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• 2008

Steady Laminar Flamelet Model (SLFM) calculation is performed to compare the turbulent combustion characteristics of air combustion and oxy-combustion with $CO_2$ recirculation. Radiative heat loss is considered by the optically thin limit assumption. For more realistic simulation the first-order conditional moment closure(CMC) model is applied to SANDIA PILOTED FLAME D again for the oxidants of air and mixture of $O_2$ and $CO_2$. The chemical kinetic machanism for methane is GRI Mech 3.0. Results show that oxy flames are much more stable than air flames, while comparable stability is maintained with 65% $CO_2$ recirculation. The comparable peak temperature is maintained with 80% $CO_2$ recirculation. Higher the temperature, higher the fractions of intermediate species, CO and OH, due to dissociation.

• 설비공학논문집
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• 제14권5호
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• pp.433-440
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• 2002

Simulations were carried out to investigate the characteristics of $CO_2$ emissions for an electric powered air conditioning system. The $CO_2$ emissions were evaluated for various simulation parameters such as a power source distribution rate, power plant efficiency, power supply efficiency and system performance (COP). It was found that the $CO_2$ emissions were remarkably decreased by increasing the COP of the electric powered air conditioning system with storage tank. The $CO_2$emission per unit refrigeration capacity is 0.6 kg/RTh. And also, as the COP increase by 0.1, the $CO_2$ emissions decrease by 7.2%.

• 터널과지하공간
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• 제18권3호
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• pp.175-184
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• 2008

본 고에서는 온실가스 감축방안으로 배출 $CO_2$를 지하심부에 격리 저장시키는 지중 저장기술의 국내외 기술동향을 살펴보고 지반 및 암반공학적 관련기술로서 $CO_2$ 주입에 따른 대상지층의 역학적 안정성 및 누출경로 평가를 위한 열-수리-역학적 연계해석기술 및 적용사례, 기술개발요소를 소개하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.466-469
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• 2009

The life time of AMOLED displays has been dependent on OLED materials up to this point. In particular, image sticking (burn-in) has been one of the most critical issues for AMOLEDs. This paper proposes image sticking compensation AMOLED pixel circuits to address the problem without requiring process or material improvements to the OLED itself. We verified the performance of those circuits by simulation and actual panel implementation.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.29-33
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• 2007

In order to protect the environment from the refrigerant pollution, the $CO_2$ may be regarded as one of the most attractive alternative refrigerants for an automotive air-conditioning system. Control methods for a $CO_2$ system should be different because of $CO_2$'s unique properties as a refrigerant. Especially, the high-side pressure of a $CO_2$ system should be controlled for the effective operation of the system. In this study, the high-side pressure setpoint algorithm was developed by using a neural network and a Lagrange interpolation method. These methods were compared. Simulation results showed that a Lagrange interpolation method was more effective than a neural network in the respect of its easiness of programming and shorter execution time.

• Journal of Welding and Joining
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• 제26권5호
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• pp.29-35
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• 2008

In this paper concentrate on the comparison of the thermal and mechanical characteristics in Butt joint of ship structure AH32 steel by using hybrid welding and conventional SAW. For this purpose, fundamental welding phenomena of hybrid process using $CO_2$ Laser and MIG is investigated by the experiments and characteristics of thermal and welding residual stress distribution of welded joint in SAW and hybrid welding are understood from the result of FE numerical simulation and experimental values. From the result of this study, it is understood that Laser-MIG hybrid welding have high potential, make substantial saving of time and manufacturing cost and may proves its self robust in the butt joining of thick AH32 steel ship structural plate in the near future.