• Title/Summary/Keyword: Numerical experiment

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Shoaling and Breaking Characteristics of Fully Nonlinear Boussinesq Model (완전비선형 Boussinesq 모형의 천수 및 쇄파 특성)

  • YOON JONG-TAE;PARK SEUNG-MIN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.2 s.63
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    • pp.29-33
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    • 2005
  • The accuracy of predicting wave transformation in the nearshore is very important to wave hydrodynamics, sediment transport, and design of coastal structures. Numerical experiments are conducted to identify the shoaling and breaking characteristics of a fully nonlinear Boussinesq equation-based model. Simulated shoaling showed good agreement with the Shouto's formula, and the results of the breaking experiment agreed well with experimented data, over several beach profile.

Investigation on vapor-cooled current leads operating in pulse mode (펄스 모드로 작동하는 증기냉각 전류 도입선에 관한 연구)

  • 인세환;정상권
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.66-72
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    • 2002
  • This paper describes numerical modeling for thermal characteristic of vapor-cooled current leads under pulse operation. The transient thermal analysis considers the temperature difference between a helium gas (low and a copper lead and temperature dependent properties of helium gas, copper and stainless steel. This numerical modeling was compensated and validated by an experiment with commercially available 100 A vapor-cooled current leads. A proper overloading factor was suggested for the current leads under pulse operation through this modeling, which can significantly reduce heat input to a cryostat.

A Study on the Surge Tank (수압조절수조(Surge Tank)에 관한 연구)

  • 남선우
    • Water for future
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    • v.6 no.1
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    • pp.29-35
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    • 1973
  • For the simplicity in the analytical solution, the simple surge tank has been chosen for the test where an unsteady flow is porduced by suddenly closing the valve controlling the discharge. The valve is loated immediately downstream from the surge tank. Momentumn equations in the penstock and in the surge column are measured recored on the oscillograph and then the calibration of surge column heights and scale readings on the oscillograph trace are made. The diameter of the penstock are determined by the trial and error method. The water levels in the surge column are computed by numerical integration of the differential equation of the surge tank. The relationships between the results from the experiment and numerical computation are figured, compared and discussed.

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A numerical model for combustion process of single coal particle in hot gas (고온 유동장 내 석탄 단입자 연소과정의 특성화를 위한 수치적 연구)

  • Niu, Xiaoyang;Lee, Hookyung;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.301-304
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    • 2015
  • With the experiment observation of single particle combustion, this model is built for the numerical analysis of the process. It's about the single coal particle combustion process under different conditions with reasonable assumptions. The model can express the mass, radius, density, temperature changing with different particle sizes, oxygen concentration and gas temperature. It also includes the flame sizes change in different condition and the diffusion of each species. The result shows the characters of the combustion.

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A Comparative Study on Hydraulic Characteristics of Curved Channel by Hydraulic Model Experiments and Numerical Analysis (수리모형과 수치해석을 통한 만곡부 하천의 수리학적 특성 비교 고찰)

  • Seo, Dong-Il;Choi, Han-Kuy
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.85-94
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    • 2007
  • This study, regarding curved channel, was performed to compare and analyze hydraulic characteristics and the speed of water and water level for left bank and right bank through hydraulic model experiments and numerical analysis. Real channels that had characteristics of curved channel were selected as objectives. In order to easily operate one and two dimensional numerical analysis and comparison for total 2.4Km model channel, measuring point was set up as 200m. HEC-RAS model was applied as one dimensional numerical analysis program and SMS model was used as two dimensional numerical analysis program. In respect of speed of water, the average speed of water for right bank recorded 8.33m/s in a model experiment and 3.08m/s, 8.57m/s were average speed of water for right bank in one dimensional and two dimensional numerical analysis. The average speed of water of two dimensional numerical analysis was quite similar to that of model experiments. Also, as for water level, maximum observational errors between one and two dimensional numerical analysis for right and left bank of model experiments were 0.66m, 0.84m and 0.28m, 0.48m for each. It was found that two dimensional numerical analysis had a similar result to hydraulic model experiments. Accordingly, from the result of this study, two dimensional numerical analysis should be used rather than one dimensional numerical analysis, when numerical analysis for curved channel is conducted.

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Numerical Study on Performance of Centrifugal Compressor Volute (원심 압축기 볼루트 성능 해석)

  • Kim, Woo-June;Oh, Chang-Hoon;Cho, Kyung-Seok
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.539-542
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    • 2006
  • A volute (or scroll) of a centrifugal compressor collects the flows from impeller or diffuser, and passes it to a pipe at the exit. This flow still contains some kinetic energy which is not converted into pressure at diffuser, thus volute designer must concern the way to minimize losses. This study defines some variables which determine the shape of volute, and carry out computational analysis based on Design of Experiment to optimize the performance of volute.

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An Evaluation of Welded Drying Equipment (건조장치 제작 및 사용성능 평가)

  • Choi Gwang
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.146-147
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    • 2006
  • In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Rotary dryer is a good apparatus to treat them. The rotary dryer is the way that is to make substance transmission and heat using hot air between sludge particle and heated gas. In this paper, a numerical analysis was performed for the structural analysis of the 3-pass rotary dryer through the finite elemeny method and an experiment was done for the structural stability. And reasonable relation was found between analysis and experiment.

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Effective Teaching of Deflation using Computer Practice (실습을 통한 수축방법의 효과적인 이해)

  • Lee, Gyou-Bong
    • Communications of Mathematical Education
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    • v.20 no.4 s.28
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    • pp.575-586
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    • 2006
  • Both theory and experiment are very important parts in sciences. Especially in mathematics, theory seems to be very important, but experiment or practice doesn't. Numerical analysis of many parts in mathematics needs practice in computer. In this paper, I suggest that computer-practicing in teaching power method, inverse power method and deflation to calculate eigenvalues and eigenvectors is good in understanding the theory. It also makes students sure that mathematics is helpful.

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A Study on Numerical Analysis Using the Two Phase Flow in Alkaline Water Electrolysis Stacks (알카리 수전해 스택에서 수소기포의 2상유동 수치해석에 관한 연구)

  • HAN, JINMOK;BAE, YOOGEUN;SEO, YOUNGJIN;KIM, SEWOONG;JUNG, YOUNGGUAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.2
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    • pp.155-162
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    • 2018
  • In this paper, the reliability of the numerical analysis using the two phase flow on the behavior of the hydrogen bubbles in the alkali electrolysis stacks was investigated by comparing the results obtained from numerical analysis and flow visualization experiments. As the results, through comparison with results gotten to visualization experiments, it is possible to approximate analysis for the flow of hydrogen bubbles in the stacks by numerical analysis using the two-phase flow. Also, the flow of hydrogen bubbles around the electrodes could be similarly analyzed by numerical analysis using the two-phase flow.