• Title/Summary/Keyword: Three-dimensional heat transfer analysis

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A Study on Heat Transfer Characteristics of Laser Cutting for the CSP 1N Sheet Using High-power CW Nd:YAG Laser (고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 박판 절단공정의 열전달 특성 분석)

  • Ahn, Dong-Gyu;Kim, Min-Su
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.1
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    • pp.51-58
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    • 2006
  • The objective of this research work is to investigate into heat transfer characteristics of the laser cutting of CSP 1N sheet using high power CW Nd:YAG laser. In order to investigate the heat transfer characteristics, three dimensional quasi stationary and steady-state heat transfer analysis has been carried out. The laser heat source is assumed as a volumetric heat source with a gaussian heat distribution in a plane. Through the comparison of the results of analyses with those of experiments, the proper finite element model has been obtained. In addition, characteristics of the three-dimensional heat transfer and temperature distribution have been estimated by the finite element model. Finally, the minimum temperature at the center for cutting of the material has been estimated.

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Three Dimensional Heat Transfer Analysis of a Thermally Stratified Pipe Flow (열성층 배관 유동에 대한 3차원 열전달 해석)

  • Jo Jong Chull;Kim Byung Soon
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.103-106
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    • 2002
  • This paper presents an effective numerical method for analyzing three-dimensional unsteady conjugate heat transfer problems of a curved pipe subjected to infernally thermal stratification. In the present numerical analyses, the thermally stratified flows in the pipe are simulated using the standard $k-{\varepsilon}$turbulent model and the unsteady conjugate heat transfer is treated numerically with a simple and convenient numerical technique. The unsteady conjugate heat transfer analysis method is implemented in a finite volume thermal-hydraulic computer code based on a non-staggered grid arrangement, SIMPLEC algorithm and higher-order bounded convection scheme. Numerical calculations have been performed far the two cases of thermally stratified pipe flows where the surging directions are opposite each other i.e. In-surge and out-surge. The results show that the present numerical analysis method is effective to solve the unsteady flow and conjugate heat transfer in a curved pipe subjected to infernally thermal stratification.

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ANALYSIS OF HEAT TRANSFER OF INCLINED IMPINGING JETS ON A CONCAVE SURFACE (엇갈리게 기울어진 충돌제트들에 의한 오목면 상의 열전달 성능해석)

  • Heo, M.W.;Lee, K.D.;Kim, K.Y.
    • Journal of computational fluids engineering
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    • v.16 no.2
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    • pp.11-16
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    • 2011
  • Numerical analyses have been carried out to analyze the three-dimensional turbulent heat transfer by impingement jet on a concave surface with variation of geometric configurations. Three-dimensional Reynolds averaged Navier-stokes equations have been calculated using the shear stress transport turbulent model. The numerical results for heat transfer rate were validated in comparison with the experimental data. The distance between jet nozzles and angle of inclined jet nozzle were selected as the geometric variables. Area-averaged Nusselt numbers on concave surface are evaluated to find the characteristics of heat transfer with the two geometric variables. The heat transfer increases as the distance between jet nozzles increases, and the inclined impinging jets show much better heat transfer performance than the vertical impinging jet.

Three-dimensional heat transfer analysis of laser cutting process for CSP 1N sheet using high power CW Nd:YAG laser (고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 냉연강판 절단 공정의 3 차원 열전달 해석)

  • Kim M.S.;Ahn D.G.;Lee S.H.;Yoo Y.T.;Park H.J.;Shin H.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.162-165
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    • 2005
  • The objective of this research work is to investigate into the three-dimensional temperature distribution using quasi steady-state heat transfer analysis fur the case of the laser cutting of CSP 1N sheet using high power CW Nd:YAG laser. The laser heat source is assumed as a volumetric heat source with a gaussian heat distribution in a plane. Through the comparison of the results of analyses with those of the experiments, the optimal finite element model is obtained. Finally, characteristics of the three-dimensional heat transfer and temperature distribution have been estimated by the optimal finite element model.

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Three Dimensional Analysis for the Performance of the Corrugated Louver Fin for a Vehicle Heat Exchanger (차량용 열교환기의 주름진 루터 휜에 대한 3차원 성능해석)

  • 박봉수;조재헌;한창섭
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.2
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    • pp.116-126
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    • 2002
  • A three dimensional numerical analysis of the corrugated louver fin for a vehicle heat exchanger was performed. The heat transfer rate and the air pressure drop of the corrugated louver fins for a slim heater were compared with experimental results at the same operating conditions. As for the slim heater fin, we found an optimum fin pitch at certain operating conditions. As the fin pitch increased, the air pressure drop decreased. The vertical or flat top fin was superior to the common declined fin in the aspect of heat transfer performance. As the louver length increased, both the heat transfer rate and the air pressure drop increased.

HEAT-TRANSFER ANALYSIS OF A COOLING CHANNEL WITH INCLINED ELLIPTICAL DIMPLES (기울어진 타원형 딤플이 부착된 냉각 유로에 대한 열전달 성능해석)

  • Kim, H.M.;Moon, M.A.;Kim, K.Y.
    • Journal of computational fluids engineering
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    • v.17 no.1
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    • pp.1-7
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    • 2012
  • This paper deals with a parametric study on inclined elliptical dimples to enhance heat transfer in a channel. Three-dimensional Reynolds-averaged Naiver-Stokes equations are solved to estimate flow and heat transfer in dimpled channel. As turbulence closure, the low-Re shear stress transport model is employed. Two non-dimensional geometric variables, dimple ellipse diameter ratio and angle of main diameter to flow direction are selected for the parametric study. The inclined elliptical dimples show higher heat-transfer performance but with higher pressure drop compared to the circular dimples. And there is an optimum inclination angle that gives the maximum heat transfer.

Analysis of Temperature and Total Heat of Heated Glass through Experimental Measurement and Three-Dimensional Steady-State Heat Transfer Analysis (실측실험과 3차원 정상상태 열전달 해석을 통한 발열유리의 온도 및 전열량 분석)

  • Lee, Do-Hyung;Yoon, Jong-Ho;Oh, Myeong-Hwan
    • KIEAE Journal
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    • v.15 no.1
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    • pp.111-116
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    • 2015
  • Heat loss from windows and condensation occuring on its surface due to its lower insulation value causes much discomfort to occupants. In this study, Heated glass was used to make a basic study on prevention of condensation on glass surface for its heating functionality through experimental measurement and simulation analysis of total heat flux on the interior and exterior surface of glass. Error between experimental results and three dimensional steady-state heat transfer analysis were caused firstly, beacuse in the experimental chambers, cold chamber and steady temperature and humidity chamber, air temperature setting was not constant but rather ON/OFF control, and secondly, due to error rate in heat flux meter due to heat flux direction even in stable conditions.

Stress Intensity Factor Analysis of Nozzle Considering Pressure and Heat Transfer on Crack Face (균열면에 작용하는 내압과 열전달의 영향을 고려한 노즐부의 응력확대계수 해석)

  • Jeong, Min-Jung;Kim, Yeong-Jin;Gang, Gi-Ju;Beom, Hyeon-Gyu;Pyo, Chang-Ryul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2252-2258
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    • 2000
  • In order to investigate the effect of nozzle on stress concentration in pressure vessels, three dimensional finite element analyses were performed. The results were compared with those for corresponding two dimensional axisymmetric finite element analyses. A three dimensional finite element model with a surface crack was also designed to evaluate the effect of internal pressure and heat transfer on crack face, and the resulting stress intensity factors from the finite element analyses were compared with those for ASME Sec. XI and Raju-Newman's stress intensity factor solution. As a result, the validity of currently available stress intensity factor solutions for a surface crack was reviewed in the presence of geometrical complexity, heat transfer and internal pressure.

Analysis of turbulent heat transfer over V-shaped ribs (V-형 사각리브에 의한 난류열전달 해석)

  • Lee, Young-Mo;Kim, Kwang-Yong
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.169-172
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    • 2005
  • Numerical analysis of turbulent flow in three-dimensional channel with V-shaped ribs extruded on both walls has been carried out. Reynolds-averaged Navier-Stokes are calculated for analysis of fluid flow and heat transfer. Shear stress transport (SST) turbulence model is used as a turbulence closure. Computational results for heat transfer rate show good agreements with experimental data.

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Three-Dimensional Beat Transfer Analysis on Tilting-Pad Thrust Bearings (3차원 열전달을 고려한 틸팅패드 스러스트 베어링의 해석)

  • Kim Ho-Jong;Choi Sung-Pil;Ha Hyun-Chun
    • Tribology and Lubricants
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    • v.22 no.4
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    • pp.173-181
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    • 2006
  • In the present study, we developed a numerical analysis software to predict performance of tilting-pad thrust bearings. The finite element method was adopted to compute lubricant film pressure and temperature. Three-dimensional heat transfer equations were solved simultaneously for the lubricant film, pad, and runner. Groove temperature was assumed with two different models. From application of the software to a thrust bearing, it has been seen that the three-dimensional analysis predicts higher temperature than the average temperature analysis. It has also been found that the groove model with a hot-oil-carry-over factor predicts higher temperature.