• 한국기계가공학회지
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• 제7권4호
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• pp.76-81
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• 2008

A cryogenic butterfly valve is used to transfer the liquefied natural gas (LNG) which temperature is $-162^{\circ}C$. This valve is core part in the piping system using LNG. This paper performed coupling analysis using FEM to evaluate safety of cryogenic butterfly valve. Flow analysis is calculated numerically the CAE and CFD methods are useful to predict the thermal matter and the inner flow field of the valve. Thermal analysis and structural analysis used ANSYS Workbench.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.68-74
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• 2011

Recently, thanks to the advanced computational power and numerical methods, it is made possible to analyze the flow around moving bodies using computational fluid dynamics techniques. In those simulations, moving mesh techniques should be able to represent both the body motion and boundary deformation, which are frequently encountered in fluid-structure interaction and/or six degree-of-freedom problems. In the present study, the staggered loosely coupling algorithm was used for fluid-structure interaction and the Laplacian operator based technique was used for moving mesh. For the verification of the developed computational method, the flow around a two-dimensional cylinder was simulated and analyzed.

• 한국해양공학회지
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• 제25권4호
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• pp.36-41
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• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• 드라이브 ㆍ 컨트롤
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• 제16권4호
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• pp.65-73
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• 2019

In this study, flow analysis and fluid-solid interaction analysis were conducted on a hollow fiber membrane module used for analysis of dehumidification characteristics. To ensure the reliability of the flow analysis results, the dehumidification experiment was performed under the temperature of 30℃ and relative humidity of 30% RH. The results of the dehumidification experiments were compared with the flow analysis results. The results of dehumidification experiments and flow analysis had a difference of approximately 5%. A 1-Way fluid-solid interaction analysis with various materials was conducted. From the results, it was found that the baffle with the largest shape deformation (polyethylene material) was subjected to 2-way fluid-solid interaction. The analysis of fluid flow and dehumidification characteristics were analyzed according to the shape deformation of the baffle.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5371-5376
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• 2013

메인스타팅 에어밸브는 선박에서 최초 시동을 위해 장착되는 요소로서 운전 시에는 공기를 차단하는 역할을 한다. 본 연구에서는 기 개발된 50A 메인스타팅 에어밸브의 형상을 기초로 80A 메인스타팅 에어밸브의 기초설계를 제시하였고, 80A 메인스타팅 에어밸브의 개념설계는 CATIA를 이용하여 완성되었다. 그리고 압력분포 및 속도분포등의 유동특성을 검토하기 위해서 유동해석을 수행하였고, 이어서 FSI를 이용한 구조해석을 수행하였다. 이상의 수치해석을 위하여 ANSYS 및 ANSYS CFX 프로그램을 이용하였다. 밸브 몸체의 과도한 중량은 인접 구조요소의 강도를 저해시킬 수 있고 유동특성에도 좋지 못한 영향을 줄 수 있다. 본 논문에서는 80A 밸브의 경량화 설계를 강도성능의 요구조건을 고려하여 제시하였다. 최종 제시한 밸브는 7kg의 경량화를 이루었고 최대응력도 설계기준을 만족시켰다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.482-487
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• 2001

Leaf type foil bearings have been used successfully in many aerospace applications such as air cycle machines, turbocompressors and turboexpander. These applications are characterized by light loads, constant speeds and low to moderate temperatures. But, as system on start-up or shutdown, sliding contact between the shaft and foil surfaces cause wear. So, in present study, to understand pressure-flow characteristics and deformation of foil bearing, flow/structure interaction analysis was used. and using this method, 2D and 3D calculation was peformed for shape of foil bearing to know circumferential direction flow and leakage flow characteristics of axial direction.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.113-119
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• 2017

An investigation on aerodynamic performance of a highly-loaded axial fan has been conducted to find the effects of tip injection and casing groove on aerodynamic performance in this study. Three-dimensional Reynolds-averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence model were used to analyze the fluid flow in the fan with Fluid-Structure Interaction (FSI) analysis. The hexahedral grid was used to construct computational domain, and the grid dependency test drew the optimal grid system. FSI analysis was also carried out to predict the deformation of rotor and stator blades, and the effect of deformation on the aerodynamic performance of axial fan was analyzed compared to the performance predicted without FSI analysis.

• 한국기계가공학회지
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• 제20권3호
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• pp.107-112
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• 2021

Pressure, which is a dynamic characteristic of a floodgate, is predicted using an FSI analysis method. A fluid analysis model and a hydrology analysis model were used as analysis models. As a result of the analysis, we found that a warped model has smaller acceleration than a square model. Additionally, this numerical analysis technique was applied to the actual hydrology, and the analysis results were compared with the results of the vibration tests. As a result, we confirmed that there is a small difference between the results of the vibration tests and the results of the FSI analysis. Through this analysis, the applicability and reliability of the FSI analysis method were verified. We concluded that the pressure of a floodgate can be measured through an FSI analysis method.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 춘계학술대회 및 창립 30주년 심포지엄(논문집)
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• pp.349-354
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• 2006

본 연구는 풍하중이 컨테이너 크레인에 작용할 때, 풍향에 따라서 컨테이너 크레인의 유동장을 분석하였다. 본 연구를 위해 사용된 모델은 50ton급 컨테이너 크레인으로 현재 항만시설에 가장 많이 사용되는 모델이다. 유동장은 원통으로 모델링하였으며, 직경, 300m 높이 200m로 설정하였다. 본 연구는 멱급수를 적용하여 풍속 50m/s의 설계 기준에서 고도에 따라 풍속을 고려하였다. 또한 풍향은 $0^{\circ}{\sim}180^{\circ}$ 를 $30^{\circ}$ 간격으로 적용하였으며, CFX-10을 사용하여 전산유동해석을 수행하였다. 본 연구에서는 풍향에 따른 풍압력을 분석하였으며, 향후 유동 연성 해석을 통한 컨테이너 크레인의 구조 안정성 평가를 할 것이다.

• 한국항공우주학회지
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• 제37권8호
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• pp.744-750
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• 2009

본 논문에서는 압전 작동기로 구동되는 무밸브 마이크로 펌프의 펌프 성능을 계산하였다. 선행연구에서 개발된 마이크로 펌프는 4층의 경량 압전 복합재료 작동기, PDMS로 된 챔버와 2개의 디퓨져로 이루어져 있다. 유한요소 해석은 압전 영역, 구조 영역 및 유체 영역을 완전 연성하여 수행되었다. 구조 및 압전 영역의 해석은 ANSYS를 사용하였으며, 유체영역의 해석은 ANSYS CFX를 사용하여 수행하였다. 작동 주파수가 10 Hz와 40 Hz인 경우에 대한 해석을 수행하여 작동 주파수가 유동 특성에 미치는 영향을 고찰하였다. 또한 300 Hz까지의 유동 해석을 통하여 작동 주파수에 따른 유량을 계산하였다.