• Title/Summary/Keyword: Two-dimensional temperature distribution

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Distribution Analysis of Local Critical Temperature and Current Density in YBCO Coated Conductors using Low-temperature Scanning Laser Microscopy (저온 주사 레이저 현미경(LTSLM)을 이용한 YBCO 초전도 선재의 국소적 임계 온도 및 전류 밀도 분포 분석)

  • Park, S.K.;Cho, B.R.;Ri, H.C.
    • Progress in Superconductivity
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    • v.12 no.1
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    • pp.17-22
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    • 2010
  • Distribution of local critical temperature and current density in $YBa_2Cu_3O_{7-\delta}$ (YBCO) coated conductors was analyzed using a Low-temperature Scanning Laser Microscopy (LTSLM). We prepared YBCO coated conductors of various bridge types to study the spatial distribution of critical temperature and current density in single and multi bridges. An LTSLM system was modified for a detailed two-dimensional scan without shifting of the sample. We observed a spatial distribution of the critical temperature from the bolometric response, which arises from a focused laser beam at the sample near the superconducting transition. Also we studied the relation between the critical temperature and the current density.

Prediction of Fiber Content Distribution of Long Fiber-Reinforced Thermoplastic Sheet for Nonisothermal Compression Molding (장섬유강화 열가소성고분자 복합판의 비등온 압축성형에 있어서 섬유함유율 분포의 예측)

  • 김석호;백남주;김이곤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.2
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    • pp.393-398
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    • 1990
  • A method is proposed which can be used to obtain the fibesr content distribution of compression molded long fiber-reinforced thermoplastic sheet for nonisothermal state. The fiber is modelled to be a sphere. Once the one-dimensional unsteady state heat conduction equation in solved, the mean temperature in defined across the thickness direction. The viscosity of matrix is determined with the mean temperature. Using the obtained viscosity, two-dimensional sheet0like part compression molding is simulated with the finite element method. Comparison with experiments shows that the method accurately predicts the distribution.

The Thermal Analysis of Brake Disc using the Solid Model and 2D Coupled Model (솔리드모델과 2D 연성모델을 사용한 브레이크 디스크의 열해석)

  • 강상욱;김창진;이대희;김흥섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.6
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    • pp.93-100
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    • 2003
  • This paper describes the thermoelastic instability arising from friction heat generation in braking and proposes the finite element methods to predict the variation of temperature and thermal deformation. In a conventional disc brake analysis, heat generation is only related with wheel speed and friction material and the interface pressure between disc and pad is assumed constant. But under dynamic braking conditions, the frictional heat causes the thermoelastic distortion that leads to more concentrated contact pressure distribution and hence more and more non-uniform temperature. In this paper, to complete the solution of the thermomechanically coupled problem, the linear relation model between pressure and temperature is proposed and demonstrated in examples of a simple two dimensional contact problem. And the two dimensional model has been extended to an annular three dimensional disc model in order to consider more realistic geometry and to provide a more accurate critical speed for automotive brake systems.

The Effect of Tandem Cooling on Welding Thermal Stress (Tandem Cooling이 용접열응력(熔接熱應力)에 미치는 영향(影響))

  • J.E.,Park;B.Y.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.14 no.4
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    • pp.15-22
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    • 1977
  • In this paper, two dimensional theoretical solutions of temperature distribution and thermal stress due to tandem cooling in an infinite plate were studied. Temperature distribution and thermal stress were calculated by numerical integration. Calculated temperature distributions were in good agreement with the result of the experiments by Park, and calculated thermal stresses were in good agreement with physical phenomena. This solutions could be applied to the practical tandem cooling operations.

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Behavior of frost formed on heat exchanger fins (열교환기 휜에서의 착상 거동)

  • Kim, Jung-Soo;Lee, Kwan-Soo
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2334-2339
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    • 2008
  • This paper proposes an improved mathematical model for predicting the frosting behavior on a two-dimensional fin considering the heat conduction of heat exchanger fins under frosting conditions. The model consists of laminar flow equation in airflow, diffusion equation of water vapor for frost layer, and heat conduction equation in fin, and these are coupled together. In this model, the change in three-dimensional airside airflow caused by frost growth is accounted for. The fin surface temperature increased toward the fin tip due to the fin heat conduction. On the contrary, the temperature gradient in the airflow direction(x-dir.) is small throughout the entire fin. The frost thickness in the direction perpendicular to airflow, i.e. z-dir., decreases exponentially toward the fin tip due to non-uniform temperature distribution. The rate of decrease of heat transfer in the airflow direction is high compared to that in the z-direction due to more decrease in the sensible and latent heat rate in x-direction.

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Numerical Analysis on Cooling Characteristics of Electronic Components Using Convection and Conduction Heat Transfer (대류와 전도 열전달을 이용한 전자부품의 냉각특성 수치해석)

  • Son, Young-Seok;Shin, Jee-Young
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.390-395
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    • 2001
  • Cooling characteristics using convection and conduction heat transfer in a parallel channel with extruding heat sources are studied numerically. A two-dimensional model has been developed for numerical prediction of transient, compressible, viscous, laminar flow, and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The considered assembly consists of two channels formed by two covers and one PCB which has three uniform heat source blocks. Five different cooling methods are considered to find efficient cooling method in a given geometry and heat source. The velocity and temperature fields, local temperature distribution along surface of blocks, and the maximum temperature in each block are obtained.

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Thermomechanical interactions in a transversely isotropic magneto thermoelastic solids with two temperatures and rotation due to time harmonic sources

  • Lata, Parveen;Kaur, Iqbal
    • Coupled systems mechanics
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    • v.8 no.3
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    • pp.219-245
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    • 2019
  • The present research deals in two dimensional (2D) transversely isotropic magneto generalized thermoelastic solid without energy dissipation and with two temperatures due to time harmonic sources in Lord-Shulman (LS) theory of thermoelasticity. The Fourier transform has been used to find the solution of the problem. The displacement components, stress components and conductive temperature distribution with the horizontal distance are calculated in transformed domain and further calculated in the physical domain numerically. The effect of two temperature are depicted graphically on the resulting quantities.

Thermal property evaluation of semiconductor laser (반도체 레이저의 열적 특성 평가)

  • 박경현
    • Proceedings of the Optical Society of Korea Conference
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    • 1990.02a
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    • pp.79-81
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    • 1990
  • Temperature distribution of laser diode chip mounted on ideal heat kink was calculated by numerical analysis. In numerical analysis, infinite difference method and Gauss-Scidel iteration was adopted on the basis of two dimensional heat conduction phenomena. As a result, temperature increase of active medium of laser diode driven at 60mA was calculated to be 1.47$^{\circ}C$

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A Numerical Analysis to Predict the Temperature Distribution around a Cold Storage Cavern (지하암반 냉동저장고 주변의 온도분포 예측을 위한 수치해석)

  • 이규상;이정인
    • Tunnel and Underground Space
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    • v.14 no.4
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    • pp.287-294
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    • 2004
  • To predict the temperature distribution around a underground rock storage cavern, two- and three- dimensional numerical analysis using FLAC was conducted. The effects of groundwater and latent heat on thermal properties were considered in numerical calculation. The temperature estimated by FLAC are compared with the temperature measured for 5-year operation at Gonjiam storage cavern. Estimated and measured temperatures showed great discrepancy when thermal properties from laboratory tests were used and showed good agreement when the effects from 20% of volumetric water fraction and latent heat were considered. However, the discrepancy still increased with operation time due to the heat flow from ground surface. Three-dimensional numerical models were established to closely approximate the boundary condition of the test site, and numerical results better agreement when groundwater and latent heat effects were considered.

Distribution Analysis of the Local Critical Temperature and Current Density in YBCO Coated Conductors using Low-temperature Scanning Laser and Hall Probe Microscopy (저온 주사 레이저 및 홀소자 현미경을 이용한 YBCO 초전도 선재의 국소적 임계 온도 및 전류 밀도 분포 분석)

  • Park, S.K.;Cho, B.R.;Park, H.Y.;Ri, H.C.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.28-33
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    • 2011
  • Distribution of the local critical temperature and current density in YBCO coated conductors were analyzed using Low-temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared YBCO coated conductors of various bridge types to study the spatial distribution of the critical temperature and the current density in single and multi bridges. LTSLHPM system was modified for detailed linescan or two-dimensional scan both scanning laser and scanning Hall probe method simultaneously. We analyzed the local critical temperature of single and multi bridges from series of several linescans of scanning laser microscopy. We also investigated local current density and hysteresis curve of single bridge from experimental results of scanning Hall probe microscopy.