• Title/Summary/Keyword: Chimera

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A Study of Parallel Implementations of the Chimera Method using Unsteady Euler Equations (비정상 Euler 방정식을 이용한 Chimera 기법의 병렬처리에 관한 연구)

  • Cho K. W.;Kwon J. H.;Lee S.S
    • Journal of computational fluids engineering
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    • v.4 no.3
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    • pp.52-62
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    • 1999
  • The development of a parallelized aerodynamic simulation process involving moving bodies is presented. The implementation of this process is demonstrated using a fully systemized Chimera methodology for steady and unsteady problems. This methodology consists of a Chimera hole-cutting, a new cut-paste algorithm for optimal mesh interface generation and a two-step search method for donor cell identification. It is fully automated and requires minimal user input. All procedures of the Chimera technique are parallelized on the Cray T3E using the MPI library. Two and three-dimensional examples are chosen to demonstrate the effectiveness and parallel performance of this procedure.

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Overexpression of GFP-AFP Chimera Protein using Recombinant Escherichia coli and Analysis of Anti-freezing Characteristics (재조합 대장균을 이용한 GFP-AFP Chimera 단백질 과량발현 및 특성 파악연구)

  • Ko, Ji-Seun;Hong, Soon Ho
    • KSBB Journal
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    • v.28 no.5
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    • pp.310-314
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    • 2013
  • Antifreeze peptide from Myoxocephalus octodecemspinosus was overexpressed and purified in Escherichia coli. Green fluorescence protein-AFP chimera was constructed by integrating gfp and afp genes. Produced GFP-AFP chimera protein was purified using polyhistidine tag which was inserted at C-terminus. By addition of GFP-AFP chimera protein, freezing point of elution buffer was decreased from $-13^{\circ}C$ to $-20^{\circ}C$. This result suggested that GFP-AFP chimera can be considered as a potential candidate of novel inhibitor for gas hydrates.

Analysis of the flow field around an automobile with Chimera grid technique (Chimera 격자기법을 이용한 자동차 주위의 유동장 해석)

  • An, Min-Gi;Park, Won-Gyu
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.39-51
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    • 1998
  • This paper describes the analysis of flow field around an automobile. The governing equations of the 3-D unsteady incompressible Navier-Stokes equations are solved by the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror. To validate the capability of simulating the flow around a ground vehicle, the flows around the Ahmed body with 12.5$^{\circ}$ and 30$^{\circ}$ of slant angles are simulated and good agreements with experiment and other numerical results are achieved. To validate Chimera grid technique, the flow field around a cylinder was also calculated. The computed results are also well agreed with other numerical results and experiment. After code validations, the flow phenomena around the ground vehicle are evidently shown. The flow around the side-view mirror is also well simulated using the Chimera grid technique.

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Development of Euler/Navier-Stokes Solver using Chimera Grid Method (Chimera 격자계를 이용한 Euler/Navier-Stokes Solver의 개발)

  • Lee S.;Park M.;Cho K. W.;Kwon J. H.
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.141-146
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    • 1998
  • An Euler/Navier Stokes solver has been developed for the analysis of steady and unsteady flows. The $q-{\omega}$ turbulent model has been incorporated into the solver in strongly coupled manner for stability and robustness. A new Chimera hole cutting algorithm, Cut-paste algorithm, has been devised for automatic Chimera hole cutting. Number of viscous/inviscid numerical computations demonstrate the accuracy and the versatility of the solver.

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A Study of Parallel Implementations of the Chimera Method (Chimera 기법의 병렬처리에 관한 연구)

  • Cho K. W.;Kwon J. H.;Lee S.
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.35-47
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    • 1999
  • The development of a parallelized aerodynamic simulation process involving moving bodies is presented. The implementation of this process is demonstrated using a fully systemized Chimera methodology for steady and unsteady problems. This methodology consist of a Chimera hole-cutting, a new cut-paste algorithm for optimal mesh. interface generation and a two-step search method for donor cell identification. It is fully automated and requires minimal user input. All procedures of the Chimera technique are parallelized on the Cray T3E using the MPI library. Two and three-dimensional examples are chosen to demonstate the effectiveness and parallel performance of this procedure.

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Numerical Flow Simulations Around High Speed Train Using CHIMERA Grid Technique (CHIMERA 격자기법을 이용한 고속전철 주위의 전산유동해석)

  • Choi S. W.;Kim I. S.
    • Journal of computational fluids engineering
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    • v.1 no.1
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    • pp.81-87
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    • 1996
  • The aerodynamic charateristics of high speed train can be improved by well-designing of its fore-body shape. In this paper, as a way of the design a fore-body shape which has optimal aerodynamic charasteristics, 9 models of fore-body shapes are proposed and the change of aerodynamic charateristics is studied through calculations of flow field around high speed train for each fore-body shape. The flow field around high speed trains are calculated using Thin-Layer Navier-Stokes equation and Chimera grid technique. The application of Chimera grid technique to these flow calculations over high speed train which has ground plane under the train makes grid generation easily. As a computaional algorithm, Pulliam and Chaussee's Diagonal algorithm, the modified form of the Beam and Warming's AF scheme which operates on block-tridiagonal matrices, is selected to reduce computaional time. Introducing hole points flag concept to this Diagonal algorithm. a algorithm for Chimera grid is generated. The variational trends of aerodynamic characteristics are studied from the results of flow calculations around high speed trains for 9 fore-body shapes.

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Characteristics of 'Hongrou Taoye', a Grafted Chimera in Sweet Orange and Satsuma Mandarin

  • Zhang, Min;Xie, Zongzhou;Deng, Xiuxin;Liao, Shengcai;Song, Wenhua;Tan, Yong
    • Horticultural Science & Technology
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    • v.33 no.3
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    • pp.390-395
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    • 2015
  • The synthesis of chimeras is a breeding approach for horticultural crops. In our breeding program, a new diploid citrus chimera, named 'Hongrou Taoye' (Citrus sinensis [L.] Osbeck + Citrus unshiu Marc.), was found arising at the junction where a 'Taoye' sweet orange (C. sinensis) scion was grafted onto Satsuma mandarin (C. unshiu). As an artificial chimera, its fruit traits derived from the L1 cell layer, with juice color and carotenoid complement, in which ${\beta}$-cryptoxanthin accumulated predominantly, similar to those of Satsuma mandarin. By contrast, traits originating from the L2/L3 cell layer, including pollen, seed, and rind aroma characteristics, were the same as those of 'Taoye' sweet orange (the scion). SSR and cpSSR analyses showed that both nuclear and chloroplast genomes of the chimera were a combination of both donor parents. 'Hongrou Taoye' thus combined the valuable traits of both donor plants, and therefore has good potential in citrus fresh market.

Numerical Analysis on Separation Dynamics of Multi-stage Rocket System Using Parallelized Chimera Grid Scheme (병렬화된 Chimera 격자 기법을 이용한 다단 로켓의 단분리 운동 해석)

  • Ko Soon-Heum;Choi Seongjin;Kim Chongam;Rho Oh-Hyun;Park Jeong-joo
    • 한국전산유체공학회:학술대회논문집
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    • 2002.05a
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    • pp.47-52
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    • 2002
  • The supersonic flow around multi-stage rocket system is analyzed using 3-D compressible unsteady flow solver. A Chimera overset grid technique is used for the calculation of present configuration and grid around the core rocket is composed of 3 zones to represent fins in the core rocket. Flow solver is parallelized to reduce the computation time, and an efficient parallelization algorithm for Chimera grid technique is proposed. AUSMPW+ scheme is used for the spatial discretization and LU-SGS for the time integration. The flow field around multi-stage rocket was analyzed using this developed solver, and the results were compared with that of a sequential solver The speed-up ratio and the efficiency were measured in several processors. As a result, the computing speed with 12 processors was about 10 times faster than that of a sequential solver. Developed flow solver is used to predict the trajectory of booster in separation stage. From the analyses, booster collides against core rocket in free separation case. So, additional jettisoning forces and moments needed for a safe separation are examined.

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Validation of Chimera Grid Method Applied to UMSAPv With Prediction of Carriage Load (장착하중 예측을 통한 UMSAPv에 적용된 중첩 격자 기법 검증)

  • Kang, SeonWook;Ahn, Kyehyun;Lee, Seungsoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.10
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    • pp.669-676
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    • 2022
  • In this paper, the carriage load analyses of stores installed on aircraft are conducted to validate the chimera grid method applied to an unstructured CFD solver, UMSAPv. First, the chimera grid method of UMSAPv is verified for the well-known Eglin Wing/Pylon/Finned store problem. Next, an angle of attack sweep of F/A-18C clean configuration is conducted at a subsonic speed. The computed results are compared with the results of the previous study using MSAPv, a structured CFD solver, to show the validity of Umsapv. Finally, the carriage of F/A-18C JDAM is carried out with a chimera grid as well as a single block grid. The computed results are compared with other computational, experimental and the flight tests.