• Title/Summary/Keyword: Heat conduction

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Object-oriented Development of Computer Code for Inverse Heat Conduction Problem

  • Kim, Sun-Kyoung
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.1
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    • pp.59-65
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    • 2007
  • This paper suggests a method for developing computer code that can solve inverse heat conduction problem, The concept of the object-oriented development is employed to implement the computer code in an efficient and flexible fashion. The software design is conducted based on the unified modeling language. Furthermore, this paper also explains how to implement the deliverable computer code using the existing software development tools.

ON THREE SPECTRAL REGULARIZATION METHODS FOR A BACKWARD HEAT CONDUCTION PROBLEM

  • Xiong, Xiang-Tuan;Fu, Chu-Li;Qian, Zhi
    • Journal of the Korean Mathematical Society
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    • v.44 no.6
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    • pp.1281-1290
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    • 2007
  • We introduce three spectral regularization methods for solving a backward heat conduction problem (BHCP). For the three spectral regularization methods, we give the stability error estimates with optimal order under an a-priori and an a-posteriori regularization parameter choice rule. Numerical results show that our theoretical results are effective.

PHRAGMEN-LINDELOF AND CONTINUOUS DEPENDENCE TYPE RESULTS IN GENERALIZED DISSIPATIVE HEAT CONDUCTION

  • Song, Jong-Chul;Yoon, Dall-Sun
    • Journal of the Korean Mathematical Society
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    • v.35 no.4
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    • pp.945-960
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    • 1998
  • This paper is concerned with investigating the asymptotic behavior of end effects for a generalized heat conduction problem with an added dissipation term defined on a three-dimensional semi-infinite cylinder. With homogeneous Dirichlet conditions on the lateral surface of the cylinder it is shown that solutions either grow exponentially or decay exponentially in the distance from the finite end of the cylinder. In particular, to render decay estimate explicit, we pattern after the analysis of Payne and Song [13, 15]. The continuous dependence effect of perturbing the equations parameters is also investigated.

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Investigation of Local Convective Heat Transfer around a Circular Tube in Cross Flow of Air (원관 주위로 공기의 국소 대류 열전달에 대한 연구)

  • 이억수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.6
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    • pp.546-555
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    • 2004
  • With circular tube heated directly or indirectly placed in a cross flow, heat flows circumferentially by conduction due to the asymmetric nature of the fluid flow around the perimeter of the circular tube. The circumferential heat flow affects the wall temperature distribution to such an extent that in some cases. The effects of circumferential wall heat conduction on local convective heat transfer is investigated. The wall heat conduction parameter which can be deduced from the governing energy equation should be used to express the effect of circumferential heat conduction. Two-dimensional temperature distribution is presented through the numerical analysis. The comparison of one-dimensional and two-dimensional solutions is demonstrated on graph of local Nusselt numbers.

Effects of Thermal-Carrier Heat Conduction upon the Carrier Transport and the Drain Current Characteristics of Submicron GaAs MESFETs

  • Jyegal, Jang
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 1997.11a
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    • pp.451-462
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    • 1997
  • A 2-dimensional numerical analysis is presented for thermal-electron heat conduction effects upon the electron transport and the drain current-voltage characteristics of submicron GaAs MESFETs, based on the use of a nonstationary hydrodynamic transport model. It is shown that for submicron GaAs MESFETs, electron heat conduction effects are significant on their internal electronic properties and also drain current-voltage characteristics. Due to electron heat conduction effects, the electron energy is greatly one-djmensionalized over the entire device region. Also, the drain current decreases continuously with increasing thermal conductivity in the saturation region of large drain voltages above 1 V. However, the opposite trend is observed in the linear region of small drain voltages below 1 V. Accordingly, for a large thermal conductivity, negative differential resistance drain current characteristics are observed with a pronounced peak of current at the drain voltage of 1 V. On the contrary, for zero thermal conductivity, a Gunn oscillation characteristic is observed at drain voltages above 2 V under a zero gate bias condition.

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Conjugated heat transfer on convection heat transfer from a circular tube in cross flow (원관 주위의 대류 열전달에 대한 복합 열전달)

  • 이승홍;이억수;정은행
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.5
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    • pp.523-534
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    • 1998
  • The convection heat transfer on horizontal circular tube is studied as a conjugated heat transfer problem. With uniform heat generation in a cylindrical heater placed in a cross flow boundary condition, heat flow that is conducted along the wall of the heater creates a non-isothermal surface temperature and non-uniform heat flux distribution. In the present investigation, the effects of circumferential wall heat conduction on convection heat transfer are investigated for the case of forced convection around horizontal circular tube in cross flow of air and water. Non-dimensional conjugation parameter $ K^*$ which can be deduced from the governing energy differential equation should be used to express the effect of circumferential wall heat conduction. Two-dimensional temperature distribution$ T({\gamma,\theta})$ is presented. The influence of circumferential wall heat conduction is demonstrated on graph of local Nusselt number.

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Analysis of Nano-Scale Heat Conduction in the Quantum Dot Superlattice by Ballistic Diffusive Approximation (Ballistic Diffusive Approximation에 의한 Quantum Dot Superlattice의 나노열전달 해석)

  • Kim, Won-Kap;Chung, Jae-Dong
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1376-1381
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    • 2004
  • Understanding the thermal conductivity and heat transfer processes in superlattice structures is critical for the development of thermoelectric materials and optoelectronic devices based on quantum structures. $Chen^{(1)}$ developed ballistic diffusive equation(BDE) for alternatives of the Boltzmann equation that can be applied to the complex geometrical situation. In this study, a simulation code based on BDE is developed and applied to the 1-dimensional transient heat conduction across a thin film and transient 2-dimensional heat conduction across the film with heater. The obtained results are compared to the results of the $Chen^{(1)}$ and Yang and $Chen^{(1)}$. Finally, steady 2-dimensional heat conduction in the quantum dot superlattice are solved to obtain the equivalent thermal conductivity of the lattice and also compared with the experimental data from $Borca-Tasciuc^{(2)}$.

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A boundary element method based on time-stepping approximation for transient heat conduction in anisotropic solids

  • Tanaka, Masa;Matsumoto, T.;Yang, Q.F.
    • Structural Engineering and Mechanics
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    • v.4 no.1
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    • pp.61-72
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    • 1996
  • The time-stepping boundary element method has been so far applied by the authors to transient heat conduction in isotropic solids as well as in orthotropic solids. In this paper, attempt is made to extend the method to 2-D transient heat conduction in arbitrarily anisotropic solids. The resulting boundary integral equation is discretized by means of the boundary element with quadratic interpolation. The final system of equations thus obtained is solved by advancing the time step from the given initial state to the final state. Through numerical compuation of a few examples the potential usefulness of the proposed method is demonstrated.

AN IMPROVED MONTE CARLO METHOD APPLIED TO THE HEAT CONDUCTION ANALYSIS OF A PEBBLE WITH DISPERSED FUEL PARTICLES

  • Song, Jae-Hoon;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • v.41 no.3
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    • pp.279-286
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    • 2009
  • Improving over a previous study [1], this paper provides a Monte Carlo method for the heat conduction analysis of problems with complicated geometry (such as a pebble with dispersed fuel particles). The method is based on the theoretical results of asymptotic analysis of neutron transport equation. The improved method uses an appropriate boundary layer correction (with extrapolation thickness) and a scaling factor, rendering the problem more diffusive and thus obtaining a heat conduction solution. Monte Carlo results are obtained for the randomly distributed fuel particles of a pebble, providing realistic temperature distributions (showing the kernel and graphite-matrix temperatures distinctly). The volumetric analytic solution commonly used in the literature is shown to predict lower temperatures than those of the Monte Carlo results provided in this paper.

Analysis for computing heat conduction and fluid problems using cubic B-spline function (3차 B-spline 함수를 이용한 열전도 및 유체문제의 해석)

  • Kim, Eun-Pil
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.1-8
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    • 1998
  • We make use of cubic B-spline interpolation function in two cases: heat conduction and fluid flow problems. Cubic B-spline test function is employed because it is superior to approximation of linear and non-linear problems. We investigated the accuracy of the numerical formulation and focused on the position of the breakpoints within the computational domain. When the domain is divided by partitions of equal space, the results show poor accuracy. For the case of a heat conduction problem this partition can not reflect the temperature gradient which is rapidly changed near the wall. To correct the problem, we have more grid points near the wall or the region which has a rapid change of variables. When we applied the unequally spaced breakpoints, the results show high accuracy. Based on the comparison of the linear problem, we extended to the highly non-linear fluid flow problems.

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