• Title/Summary/Keyword: one-dimensional

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심야전력이용 냉방시스템용 캡슐형 빙축열조에 대한 1차원 모델 축방냉 성능 시뮬레이션 (Performance Simulation of One-Dimensional Ice Storage Tank Model for Refrigeration System Using Night Electricity)

  • 이경호;주용진;최병윤
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1999년도 춘계 학술발표회 논문집
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    • pp.193-196
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    • 1999
  • This paper describes one dimensional transient modeling of encapsulated ice storage tank and its experimental validation. This model simulates the performance of tile tank for charge and discharge process with brine mass flow operating conditions.

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1.2MW급 산업용 가스터빈 원심압축기 개발(1)- 공력설계해석 - (Development of Centrifugal Compressors in an 1.2MW Industrial Gas Turbine(I)-Aerodynamic Design and Analysis-)

  • 조규식;이헌석;손정락
    • 대한기계학회논문집B
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    • 제20권8호
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    • pp.2707-2720
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    • 1996
  • The aerodynamic design of the two-stages of centrifugal compressors in an 1.2MW industrial gas turbine is completed with the application of numerical analyses. The final shape of an intake, the axial guide vanes and a return channel is determined using several interactions between design and two-dimensional turbulent flow analysis, focused on the minimum loss of internal flows. The one-dimensional turbulent flow analysis, focused on the minimum loss of internal flows. The one-dimensional design and prediction of aerodynamic performances for the compressors are performed by two different methods; one is a method with conventional loss models, and the other a method with the two-zone model. The combination methods of the Betzier curves generate three-dimensional geometric shapes of impeller blades which are to be checked with a careful change of aerodynamic blade loadings. The impeller design is finally completed by the applications of three-dimensional compressible turbulent flow solvers, and the effect of minor change of design of the second-stage channel diffuser is also studied. All the aerodynamic design results are soon to the verified by component performance tests of prototype centrifugal compressors.

충만 디스크의 면내 진동 해석을 위한 1차원 환상 평판 요소 (A One-dimensional Annular Plate Element for In-plane Vibration Analysis of Full Disks)

  • 곽동희;임정기;김창부
    • 한국소음진동공학회논문집
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    • 제19권12호
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    • pp.1338-1346
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    • 2009
  • We present a one-dimensional annular plate element with which the in-plane vibration of full disks can be analyzed efficiently and accurately by using the FEM. Its elementary mass matrix and stiffness matrix are derived, respectively, from the virtual work by effective forces and the virtual strain energy. The static deformation modes obtained from an integration of the differential equilibrium equations of the annular plate are used as interpolation functions of the one-dimensional annular plate element. The in-plane natural vibration characteristics of a 2-step full disk and a uniform full disk are analysed. Its results are compared with the results obtained by utilizing two-dimensional 8-node quadrilateral plane elements and cyclic symmetry of the disk. And also, by comparing with the theoretical results of previous researchers, the efficiency and accuracy of the presented element are verified.

Current Conservation Factors for Consistent One-Dimensional Neutronics Modeling

  • Lee, Kibog;Joo, Han-Gyu;Cho, Byung-Oh;Zee, Sung-Quun
    • Nuclear Engineering and Technology
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    • 제32권3호
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    • pp.235-243
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    • 2000
  • A one-dimensional neutronics formulation is established within the framework of the nonlinear analytic nodal method such that it can result in consistent one-dimensional models that produce the same axial information as their corresponding reference three-dimension81 models. Consistency is achieved by conserving axial interface currents as well as the planar reaction rates of the three-dimensional case. For current conservation, flux discontinuity is introduced in the solution of the two-node problem. The degree of discontinuity, named the current conservation factor, is determined such that the surface averaged axial current of the reference three-dimensional case can be retrieved from the two-node calculation involving the radially collapsed group constants and the discontinuity factor. The current conservation factors are derived from the analytic nodal method and various core configurations are analyzed to show that the errors in K-eff and power distributions can be reduced by a order of magnitude by the use of the current conservation factor with no significant computational overhead.

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축소 유로내의 두 평행 유동에 대한 해석 (Analysis on Two Parallel Flows in Convergent Channel)

  • 권진경;김태욱;김진현;김재열
    • 한국추진공학회지
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    • 제10권4호
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    • pp.11-18
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    • 2006
  • 축소 유로에서의 두 평행 유동의 합류에 의한 복합유동과 그 초킹 현상이 일차원 등엔트로피 모델과 완전혼합 모델에 의해 계산되었다. 아음속-아음속의 복합유동에 대해 압력측정과 광학 측정이 실시되었으며 그 결과를 일차원 계산의 결과와 비교하였다. 결과적으로 복합유동의 한쪽 유동의 입구조건은 다른 유동의 거동과 초킹 조건에 영향을 미침을 알 수 있었으며 본 실험의 결과는 일차원 계산 결과와 비교적 잘 일치함을 알았다.

One-dimensional consolidation with asymmetrical exponential drainage boundary

  • Mei, Guo-Xiong;Lok, Thomas M.H.;Xia, Jun;Wu, Sheng Shen
    • Geomechanics and Engineering
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    • 제6권1호
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    • pp.47-63
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    • 2014
  • In this paper, asymmetric drainage boundaries modeled by exponential functions which can simulate intermediate drainage from pervious to impervious boundary is proposed for the one-dimensional consolidation problem, and the solution for the new boundary conditions was derived. The new boundary conditions satisfy the initial and the steady state conditions, and the solution for the new boundary conditions can be degraded to the conventional solution by Terzaghi. Convergence study on the infinite series solution showed that only one term in the series is needed to meet the precision requirement for larger degree of consolidation, and that more terms in the series for smaller degree of consolidation. Comparisons between the present solution with those by Terzaghi and Gray are also provided.

속도기전력을 갖는 전자력 방정식의 유한요소 해석 (Finite Element Analysis of Electromagnetic Field Equation with Speed E.M.E)

  • Hahn, Song-Yop
    • 대한전기학회논문지
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    • 제36권4호
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    • pp.252-258
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    • 1987
  • Time periodic finite element solutions for sinusoidally excited electromagnetic field problems in moving media are presented. Solutions by the Galerkin method contain spurious oscillations when grid Peclet number is more than one. To suppress these oscillations an upwind finite element method using two different time periodic test functions is introduced. One is multiplied to second and first-order space derivative terma and the other to the time derivative term. Test functions are obtained from trial functions by adding or subtracting quadratic bias functions with appropriate scaling factors. Phase differences are considered between trial functions and bias functions. For simple interpretations of the phase differences, complex scaling factors are used. The proposed method is developed to give nodally exact solutions for uniform grid spacing in one dimensional problems. Based on the one dimensional results, a two dimensional upwinding scheme is also derived.

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