• 한국전산유체공학회지
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• 제18권2호
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• pp.41-48
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• 2013

Ice accretion on the solid surface is an importance factor in assessing the performance of aircraft and wind turbine blade. Changes in the external shape due to ice accretion can greatly deteriorate the aerodynamic performance. In this study, a three-dimensional upwind-type second-order positivity-preserving finite volume CFD scheme based on the unstructured mesh topology is developed to simulate two-phase flow in atmospheric icing condition. The code is then validated by comparing with NASA IRT experimental data on the sphere. The present results of the collection efficiency are found to be in close agreement with experimental data and show improvement near the stagnation region.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1997년도 추계 학술대회논문집
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• pp.106-112
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• 1997

The effects of radiative heat transfer are investigated in a turbulent combustion flow field with highly non-adiabatic flames. Turbulent combustion is modeled by the $k-{\varepsilon}-g$ model and a one step irreversible reaction scheme for the combustion chemistry. The radiative trasport equation is solved by the finite volume method considering the radiative transfer from $CO_2,\;H_{2}O$ and soot only. Gray gas is assumed to calculate the radiative properties of $CO_2\;and\;H_2O$. A two-equation soot formation model is applied to predict soot volume faction distribution. All equations are solved in a coupled manner and the numerical results are compared with available experimental data.

• 한국유체기계학회 논문집
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• 제9권4호
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• pp.27-35
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• 2006

A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate are carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1996년도 춘계 학술대회논문집
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• pp.33-39
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• 1996

An incompressible flow stover based on the unstructured finite volume method has been developed. The flow domain is discretized by triangles in 2D or tetrahedra in 3D. The convective and viscous fluxes are obtained using edge connectivities of the unstructured meshes. The pressure-velocity coupling is handled by the artificial compressibility algorithm due to its computational efficiency associated with the hyperbolic nature of the resulting equations. Laminar test flow problems are computed and presented with a comparison against other numerical solutions or experimental results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 추계 학술대회논문집
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• pp.31-36
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• 2003

A field reconstruction scheme for a cell centered finite volume method on unstructured meshes is developed. Regardless of mesh quality, this method is exact within a machine accuracy if the solution is linear, which means it has full second order accuracy. It does not have any limitation on cell shape except convexity of the cells and recovers standard discretization stencils at structured orthogonal grids. Accuracy comparisons with other popular reconstruction schemes are performed on a simple example.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 추계학술대회논문집
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• pp.211-217
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• 2009

The numerical program has been developed for the purpose of the complicate geometries application using CIP method. The non-staggered, non-orthogonal, and unstructured grid system can be also used for the various geometries in the program. For validating CIP solver, the lid-driven cavity flow and solitary wave propagation flow are carried out. Test results show a good agreement with the verified results. The dynamic solver was used for the behavior of moving body. Interface process between the two solvers is introduced. The research was performed on the flow problem around torpedo and log and the flow problem in a tank in order to analyze the three phase flow problem Although the comparison to the verified results was not quantitatively performed, the trend of the results was reasonable.

• 한국전산유체공학회지
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• 제19권4호
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• pp.52-60
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• 2014

Recently, coastal structures have been built to protect coastal areas. However, if a tidal wave caused by an earthquake hits the coast, it would cause catastrophic damages. It is important to analyze the basics and the characteristics of a tsunami to reduce damages caused by natural disasters. In this study, a tsunami passing over different topographical changes is simulated with VOF method based on FVM(Finite Volume Method). The reduction of both scale and velocity is accomplished by similarity analysis, and an initial energy is generated by increasing the water level as needed to create a tsunami as if it is caused by a crustal movement. It is found that the present method is appropriate to simulate the tsunami with its mechanism.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1988-1991
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• 2005

A micro fluid actuator driven by electromagnetic force at MEMS(Micro Electro Mechanical System) level has been designed. The operation of the actuator was simulated in three steps. First, fluid flow analysis has been performed to determine the actuator load. With the load, dynamic behavior of the actuator structure has been analysed. Finally, fluid-structure interaction analysis has been performed to predict the performance of the actuator. To avoid excessive amount of computation, axisymmetric and plane strain 2-D models were used.

• 대한의용생체공학회:의공학회지
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• 제22권1호
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• pp.59-68
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• 2001

유체-고체 상호작용을 고려하여 다양한 복부대동맥류 모델에 대해서 맥동유동 및 구조를 동시에 해석하였다. 동맥류의 확장부 크기와 혈관벽 두께에 따라서 총 여덟 개의 축대칭 동맥류 모델을 선정하였다. 유한체적법 및 압력기반의 유한차분법을 이용하여 유동을 해석하였으며, 유한요소법을 이용하여 구조해석을 수행하였다. 동맥류의 확장부위가 클수록 최대응력은 최대확장부위와 변곡점에 해당하는 동맥류의 입구 및 출구 부분에 집중되었으며, Von Mises 응력은 최대확장부위 뿐만 아니라 동맥류의 근위부와 원위부($\pm$1D)에서도 현저하게 증가하였다. 또한 더욱 확장된 모델일수록 혈관벽은 직경방향의 변위보다 축방향의 변위가 지배적이었으며, 동맥류 원위부보다 근위부에서 큰 축방향 변위를 나타냈다. 동맥류 입구부의 미약한 와류는 한 주기동안 그 크기와 강도를 더해가며 동맥류 원외부로 이동하였고, 동맥류의 내부 유동은 압력차이가 감소하는 기간동안 더 큰 영향을 받았다. 확장정도가 심할수록 동맥류 내부에 더 크고 강한 와류가 관찰되었다. 압력차이가 최소가 된 직후 동맥류의 근위부와 원위부동맥 벽 근처에서의 역방향 유동이 관찰되었다. 대체로 혈관벽 두께가 감소한 모델과 더욱 확장된 모델일수록 벽전달률은 감소하였다. 혈관벽의 탄성에 의하여 압력차이와 벽전달률 사이에 위상차가 존재함이 확인되었다. 유체-고체의 상호작용을 고려한 연구는 다른 심혈관계를 이해하는데도 매우 유익할 것으로 생각된다.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.606-611
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• 2018

산업현장과 열병합발전 등 다양한 장소에 사용되는 도시가스는 산업안전보건법 정의에 따라 인화성 가스에 해당되며 한국산업표준 KS C IEC에 의해 가스 폭발위험장소가 설정되어 안전하게 관리가 되어야 한다. 본 연구에서는 일반 화학공장에 적용되는 KS C IEC 표준을 저압 도시가스 사용설비 폭발위험성 예측에 합리적으로 적용하기 위해누출공 크기, 환기 등급, 환기 유효성 등의 주요 변수를 도입하였다.CFD 시뮬레이션 적용의 타당성을 평가하기 위해 전산유체역학 (CFD) 시뮬레이션, 가스누출실험, KS C IEC 표준 계산 통해 얻어진 폭발하한계가상 체적을 이용하여 네 가지 다른 조건에서 폭발 위험성을 평가하였다.