Stationary and transient heat conduction in a non homogeneous material
Tóm tắt
An apparent thermal conductivity for inhomogeneous materials is widely used. In this paper it is demonstrated that the apparent thermal conductivity for stationary heat conduction is not sufficient to describe the transient heat response of an inhomogeneous medium. In the geometry we used the heat transfer is estimated too high when the stationary thermal conductivity is employed. A numerical solution of the equation of thermal diffusion has been used to check several approximations. For short and for long times a separate approximate analytic expression can be used.
Tài liệu tham khảo
De Jong, A. G.; Hoogendoorn, C. J.: Improvement of heat transport in paraffines for latent heat storage systems. In: den Ouden, C. (ed.): Thermal storage of solar energy. The Hague, Martinus Nijhoff Publ. 1981, pp. 123–133
Russell, H. W.: Principles of heat flow in porous insulators. J. Am. Ceram. Soc. 18 (1935) 1–5
Mattarolo, F.; di Filippo, F.; Sovrano, M.: Recherches sur les propriétés thermiques des mousses de polyuréthane rigide expansées. I.I.F.-I.I.R., Commission B2, Trondheim 1966
Crane, R. A.; Vachon, R. I.: A prediction of the bounds of the effective thermal conductivity of granular Materials. Int. J. Heat Mass Transfer 20 (1977) 711–723
Bart, G. C. J.; Schaareman, P. B. J.; Hoogendoorn, C. J.: Finite differences solution of transtient heat conduction in composite materials with phase change. In: Morgan, K. (ed.): Proc. 4th Int. Conf. Numerical Methods in Thermal Problems. Swansea: Pineridge Press 1985