• Title/Summary/Keyword: 복합 무차원 계수$ K^*$

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Effect of Interface on the Properties of Cord-Rubber Composites (코드섬유-고무 복합재료의 물성치에 대한 계면의 영향)

  • Lim, Hyun-Woo;Kim, Jong-Kuk;Yum, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.5
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    • pp.583-588
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    • 2010
  • The nonlinearity and high deformability of rubber make accurate analysis of the behavior of cord-rubber composites a challenging task. Some researchers have adopted the third phase between cord and rubber and have carried out three-phase modeling. However, it is difficult to determine the thickness and properties of the interface in cord-rubber composites. In this study, a two-dimensional finite-element method (2D FEM) is used to investigate the effective and normalized moduli of cord-rubber composites having interfaces of various thicknesses; this model takes into account the 2D generalized plane strain and a plane strain element. The neo-Hookean model is used for the properties of rubber, several interface properties are assumed and three loading directions are selected. It is found that the properties and thickness of the interface can affect the nonlinearity and the effective modulus of cord-rubber composites.

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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