• Computational Structural Engineering
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• v.10 no.3
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• pp.67-73
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• 1997

CFD 연구를 초고속선 선형개발에 활용한다면 선체주위의 유동장 계산결과로부터 압력 및 속도, 자유표면 파고분포 등 초고속선의 설계 및 기본계획 단계에서 필요한 저항 및 추진성능 자료를 얻을 수 있다. 이러한 기능을 더욱 개선 발전시키면 선형개발에 더 많은 적용이 예상된다. 또한 항주 시간에 따른 초고속선의 운동특성을 고려할 수 있게 된다면 앞으로 항주자세제어 및 내항성능과 승선감의 추정도 CFD 연구를 통해서 가능하리라 믿는다. 이제 국내 조선소를 중심으로, 21세기에 도래할 것으로 예측되는 고속 해상수송 수단에 대한 수요에 대응하고 조선기술의 우위확보를 위해 고부가가치, 고성능이 요구되는 초고속선 기술개발에 연구를 집중해야겠다.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.288-290
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• 2003

Artificial heart is divided by pulsation flow type and continuous flow type according to blood circulation pattern. Axial flow blood pump is a kind of continuous flow type artificial heart. Axial flow blood pump would be different pump performance according to impeller's shape and rotating velocity. Pump performance be able to compare by flow rate according to differential pressure and Impeller's rotating velocity. It confirms Impeller model of better efficiency according to compare Pump performance of axial flow blood pump using CFD with actual experiment result.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.39-44
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• 2022

Using a CFD (computational fluid dynamics) simulation tool, we have offered a design guideline of a slot-die head having a simple T-shaped cavity through an analysis of the fluid dynamics in terms of cavity pressure and outlet velocity, which affect the uniformity of coated thin films. We have visualized the fluid flow with a transparent slot-die head where poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) is injected. We have shown that the fluid dynamics inside the slot-die head depends sensitively on the cavity depth, cavity length, land length, and channel gap (i.e., shim thickness). Of those, the channel gap is the most critical parameter that determines the uniformity of the pressure and velocity distributions. A pressure drop inside the cavity is shown to be reduced with decreasing shim thickness. To quantify it, we have also calculated the coefficient of variation (CV). In accordance with Hagen-Poiseuille's laws and electron-hydraulic analogy, the CV value is decreased with increasing cavity depth, cavity length, and land length.

• Proceeding of EDISON Challenge
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• 2012.04a
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• pp.65-68
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• 2012

본 연구에서는 XFOIL을 사용하여 설계된 30% 두께를 가지며 팁에서의 두께가 코드의 1.5%인 풍력터빈용 에어포일의 공력 특성을 해석하였다. 받음각에 따른 양력 항력 곡선 및 양항비를 XFOIL에서 얻어낸 결과와 EDISON_CFD 해석 결과를 상호 비교 하였다. EDISON_CFD에서의 해석을 위한 격자의 형태를 격자균일성을 생각하여 큰 타원과 작은 타원을 합쳐 만들었다. 수치 기법으로 Roe의 FDS를 선택하여 데이터를 수집하였다. 그 결과로 나타낸 압력계수와 양항비 그래프를 보면 선형 구간에서 양력은 XFOIL 해석 결과와 잘 일치하는 결과를 보여주었다. 그러나 항력에서 약1.5배 정도 EDISON_CFD의 결과가 크게 나옴으로써 양항비의 차이를 보이는 것으로 나타났다. 실속이후에서는 XFOIL의 신뢰도가 떨어지는 경향이 있어 특히 실속이후에서는 CFD의 해석결과가 필요한 것으로 보인다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.72-80
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• 2018

With the ever increasing advances in computers and their computing power, computational fluid dynamics(CFD) has become an essential engineering tool in the design and analysis of engineering applications. Accordingly, many universities have developed and implemented a course on CFD for undergraduate students. On the other hand, many professors have used industrial examples supplied by computational analysis software companies as CFD examples. This makes many students think of CFD as difficult and confusing. This paper presents a simple CFD example used in the department of mechanical design engineering of Kangwon National University and shows its effectiveness. Most students answered that a simple CFD example is more comprehensive than an industrial example. Therefore, it is necessary to develop simple computational analysis problems in the engineering education field.

• Clean Technology
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• v.20 no.3
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• pp.263-268
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• 2014

Using the CFD method, the pressure drop in 6 cyclone dust collectors of different shape were calculated. And the results were compared with results of the conventional theories. Equations of Shepherd and Lapple (1939, 1940), First (1950), Alexander (1949), Stairmand (1949), Barth (1956) were used in the theoretical calculation. In CFD calculations, we used standard k-epsilon model for analysis of turbulent flow, fluid is $25^{\circ}C$ air, the velocity at inlet is 10 m/s and the temperature is $25^{\circ}C$. In CFD analysis results, the pressure distributions along the flow showed similar patterns in different cyclone shapes. But the pressure drop distributions estimated on the conventional theories had big difference in different cyclone shapes. Only First's theory and CFD analysis showed similar results.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.606-611
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• 2018

City natural gas is classified flammable hazardous gas and should be secured according to explosion risk assessment determined by Industrial Standard KS C IEC. In this study, leak size, ventilation grade and effectiveness were adopted to the KS C IEC for risk assessment in natural gas supply system. To evaluate the applicability of the computational fluid dynamics (CFD), the risk assessment was studied for four different conditions using hypothetical volume($V_z$) valuesfrom gas leak experiments, KS C IEC calculation, and CFD simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.1
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• pp.43-51
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• 2001

Metacomputing system is the environment, which helps the users easily and promptly deal with their jobs. with integration of the distributed computing resources and visualization device. In this research, we have developed a prototype of a special-purpose metacomputing system for simulation in CFD(Computational Fluid Dynamics) field. This system supports the automatic remote compilation, transparent data distribution, the selection of appropriate computing resource, and the realtime visualization. This research can be summarized as following: a study on selecting resource and the integration of component systems. In the research of selecting computing resource, we use the property of CFD algorithm. In the research of realtime visualization. we modify a popular visualizer.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1080-1087
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• 2019

For a risk analysis in a chemical process, it is important to reflect correctly the characteristic properties of the target process. In this study, computational fluid dynamics (CFD) was adopted for the advanced risk analysis in a residual hydro desulfurization (RHDS) process by considering operation condition, layout of instruments and facilities, atmospheric condition, and wind direction. Release and explosion simulations for the RHDS by using FEA (Finite Element Analysis) and CFD showed the applicability of 3D scanning methods for estimation of release hole size and release amount.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.659-662
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• 2014

본 연구에서는 전산유체 해석프로그램인 EDISON_CFD를 이용하여 Clark-Y 에어포일의 공력특성 변화를 수치해석하고, 여러 가지 받음각의 변화를 통해 양력계수, 항력계수, 양항비 등을 도출하였다. 공력해석을 위한 조건으로 압축성 Navier-Stokes 방정식에 난류 유동조건을 적용하였다. 해석 결과는 에어포일 공력해석 툴로 널리 알려져 있는 XFOIL을 이용하여 비교 검토하였다.