• 제목/요약/키워드: CFD 해석

검색결과 2,611건 처리시간 0.031초

Numerical modeling of ICP-nitriding system using CFD-ACE+ (CFD-ACE+를 이용한 ICP-nitriding system의 수치 모델링)

  • Ju, Jeong-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 한국표면공학회 2009년도 춘계학술대회 논문집
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    • pp.268-268
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    • 2009
  • 고밀도 유도 결합 플라즈마를 이용한 연료 전기 분리판용 질화 장치를 플라즈마를 모사할 수 있는 3차원 전산 유체 역학 프로그램인 CFD-ACE+를 이용하여 해석하였따. 내장형 안테나 타입의 유도 결합 플라즈마의 전자 온도, 밀도 균일성, 가스 유동, 얇은 기판이 촘촘히 적재 되었을 경우의 플라즈마 특성을 모사하였다.

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Characteristics of Flow Field at Curved Section of Oil Fence using PIV Measurements and CFD Simulations (PIV 계측과 CFD 해석을 통한 오일펜스 만곡부 단면에서의 유동장 특성)

  • Kim, Tae-Ho;Jang, Duck-Jong;Na, Sun-Chol;Bae, Jae-Hyun;Kim, Dae-An
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제17권1호
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    • pp.29-37
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    • 2011
  • PIV measurements of the velocity field, pressure field, vorticity, and turbulent intensity in the rear of curved section of an oil fence with current speed showed that the flow directions in the rear of flow boundary area were similar to those in the front of it. As the current speed increased, the patterns of pressure distribution were changed, and the turbulent flow became more irregular. CFD simulations under the same conditions as the PIV tests showed that the flow patterns of the wake were similar to those by PIV tests in speed of 0.3 m/s and less, but were distinctively deviated from those in 0.4 m/s due to the flexibility of the oil fence, which was not properly taken care of in CFD modeling.

Viscous Flow Analysis around a Blade Section by a Hybrid Scheme Combining a Panel Method and a CFD Method (패널법과 전산유동해석법의 결합을 이용한 날개단면 주위 점성유동 해석)

  • Oh, Jin-An;Lee, Jin-Tae
    • Journal of the Society of Naval Architects of Korea
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    • 제50권5호
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    • pp.355-363
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    • 2013
  • Panel methods are essential tools for analyzing a fluid-flow problem around complex three dimensional bodies, but they lack ability to solve viscous effects. On the other hand, CFD methods are considered as powerful tools for analyzing fluid-flow characteristics including viscosity. However, they also have short falls, requiring more computing time and showing different results depending on the selection of turbulence models and grid systems. In this paper a hybrid scheme combining a panel method and a CFD method is suggested. The scheme adopts a panel method for far-field solution where viscous effects are negligible and a CFD method for the solution of RANS equations in near-field where viscous effects are relatively strong. The intermediate region between the far-field and near-field is introduced where the calculated field point velocities by the panel method are given as boundary velocities for the CFD method. To verify the scheme, calculated results, by a panel method, a CFD method and the hybrid scheme, for a two dimensional foil section are compared. The suggested hybrid scheme gives reasonable results, while computation time and memory can be dramatically reduced. By using the hybrid scheme efforts can be concentrated for the local flow near the leading and trailing edges, by providing more dense grid system, where detailed flow characteristics are required.

Comparison of Design Concepts for Four Different Entrained-Bed Coal Gasifier Types with CFD Analysis (CFD 해석을 통한 4종의 건식 분류층 석탄가스화기 설계개념 비교)

  • Yun, Yongseung;Ju, Jisun;Lee, Seung Jong
    • Applied Chemistry for Engineering
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    • 제22권5호
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    • pp.566-574
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    • 2011
  • Coal gasifier is a key component for achieving high efficiency in integrated gasification combined cycle and indirect coal liquefaction. Although there have been several successful coal gasifiers that were commercially proven, many different design configurations are still possible for a simple and reliable gasifier operation. Four different gasifier design concepts of dry-feeding were compared in terms of residence time, exit syngas temperature and syngas composition. First, cold-flow simulation was applied to pre-select the configuration concepts, and the hot-flow simulation including chemical reactions was performed to compare the concepts at more actual gasifier operating conditions. There are many limitations in applying CFD method in gasifier design, particularly in estimating slag behavior and slag-tap design. However, the CFD analysis proved to be useful in comparing the widely different gasifier design concepts as a pre-selection tool.

A CFD Study for Rocket Exhaust Flow using Single Species, Unreacted Flow Model (단일화학종 비반응 해석 모델을 사용한 로켓 연소후류 유동해석 연구)

  • Kang, Sun-Il;Huh, Hwan-Il
    • Aerospace Engineering and Technology
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    • 제11권1호
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    • pp.126-134
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    • 2012
  • The Single Species, Unreacted Flow Model which is effectively applicable on the computational analysis of rocket exhaust flow is introduced in this paper. The basic concept of this model had been originated from chemically frozen analysis of hot air but it was complemented by compensating molecular weight and specific heat which was obtained CEA code analysis of exhaust plume. Comparing single species, unreacted model with the finite chemistry model, unreacted model can reduce calculation time to 1/5 while it makes similar simulation results.

Development of Analysis Technique for a High Voltage Circuit Breaker Using the CFD-CAD Integration (CFD-CAD 통합해석을 이용한 초고압 가스차단기 설계 기술 개발)

  • Lee, J.C.;Oh, I.S.;Min, K.S.;Kim, Y.J.
    • Proceedings of the KSME Conference
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.523-528
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    • 2001
  • There are many difficult problems in analyzing the flow characteristics in a high voltage circuit breaker such as shock wave and complex geometries, which may be either static or in relative motion. Although a variety of mesh generation techniques are now available, the generation of meshes around complicated, multicomponent geometries like a gas circuit breaker is still a tedious and difficult task for the computational fluid dynamics. This paper presents the computational method for analyzing the compressible flow fields in a high voltage gas circuit breaker using the Cartesian cut-cell method based on the CFD-CAD integration, which can achieve the accurate representation of the geometry designed by a CAD tools. The technique is frequently satisfied, and it will be almost universally so in the future, as the CFD-CAD traffic increases.

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다양한 레이놀즈수에서 원형실린더 주변 유동 특성 연구

  • Lee, Ji-Hyeon;An, Chang-Hwan
    • Proceeding of EDISON Challenge
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    • 제6회(2016년)
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    • pp.27-34
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    • 2016
  • 본 연구에서는 EDISON CFD의 2D_Incomp_P 해석자를 이용하여 0.16부터 1,000,000까지 다양한 레이놀즈수에서 실린더의 유동 특성을 연구하였다. 임계 레이놀즈수 이하에서 실험값과 유사한 압력분포도를 제작하여 해석 결과의 타당성을 검증하였다. 레이놀즈수에 따른 항력계수의 그래프를 제작하여 항력계수의 값이 레이놀즈수의 변화에 대해 선형적으로 변화하는 것을 연구하였다. 같은 속도장일 때 특성길이에 따른 유동장의 차이점도 연구하기 위하여 특성길이에 변화를 주어 해석을 진행하였고, 특성길이가 길수록 박리가 빠르게 발생하는 것을 알게 되었다.

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