Improved lumped models for transient combined convective and radiative cooling of multi-layer composite slabs

Abstract

Improved lumped parameter models were developed for the transient heat conduction in multi-layer composite slabs subjected to combined convective and radiative cooling. The improved lumped models were obtained through two-point Hermite approximations for integrals. Transient combined convective and radiative cooling of three-layer composite slabs was analyzed to illustrate the applicability of the proposed lumped models, with respect to different values of the Biot numbers, the radiationconduction parameter, the dimensionless thermal contact resistances, the dimensionless thickness, and the dimensionless thermal conductivity. It was shown by comparison with numerical solution of the original distributed parameter model that the higher order lumped model ðH 1;1 =H 0;0 approximationÞ yielded significant improvement of average temperature prediction over the classical lumped model. In addition, the higher order ðH 1;1 =H 0;0 Þ model was applied to analyze the transient heat conduction problem of steel-concrete-steel sandwich plates.

Lumped models for transient thermal analysis of multilayered composite pipeline with active heating

“…Transient heat transfer in multilayered composite plates, cylinders and spheres are of great interest in a number of engineering applications [4,5,6,7,8,9,10,11,12]. The use of composite media is necessary when the thermal and mechanical properties of a single layer is not sufficient as to fulfill both thermal and mechanical requirements.…”

A Pragmatic and High-Performance Radiative Cooling Coating with Near-Ideal Selective Emissive Spectrum for Passive Cooling

“…Therefore, passive cooling could have a significant impact on global energy consumption for its ability to cool without external energy. Efficient radiative cooling devices are expected to exhibit a thermal radiative peak within 8 to 13 µm, which is known as the atmospheric window, in order to transfer the heat directly to outer space [4][5][6]. Radiative cooling technologies have been extensively investigated in the last decades [7][8][9].…”

“…If an efficient radiative material can be applied to the market for large-scale application (for example, buildings, curtains, and tents), the following characteristics should be exhibited [10,11]: (1) it has a near-ideal emittance profile, (2) it has a good cooling effect, (3) the substrate should be rigid or flexible, (4) it can be put into extensive production, and (5) the price is affordable.…”

“…The P(VDF-HFP) composite coating exhibits excellent optical properties to meet the characteristics (1,2). To satisfy the characteristics (3)(4)(5), PET aluminized film is selected as the coating substrate due to being flexible, cheap, and mass-manufactured, and its ability to be applied to various fields. The composite coating was made into a cubic box to test its space cooling performance on a rooftop.…”

Improved Lumped Models for Transient Combined Convective and Radiative Cooling of Multilayer Spherical Media

“…The proposed lumped models are obtained through two-point Hermite approximations for the average temperature and heat flux in each layer [17,18]. This approach has been shown to be efficient in a great variety of multilayer applications [19][20][21][22][23][24]. For the average temperature, the plain trapezoidal rule ( 0,0 approximation) is employed in all layers, except for the innermost layer, where the second-order two-side corrected trapezoidal rule ( 2,1 approximation) is utilized.…”