金属泡沫固体复合材料的周期性非稳态热响应特性  

Periodically unsteady thermal response of metal-foam solid composite

作　　者：殷英 徐会金[1,2] 赵长颖[2] 

机构地区：[1]中国石油大学(华东)储运与建筑工程学院,青岛266580 [2]上海交通大学工程热物理研究所,上海200240

出　　处：《科学通报》2016年第36期3964-3972,共9页Chinese Science Bulletin

基　　金：国家自然科学基金(51406238);山东省优秀中青年科研奖励基金(BS2014NJ009);中国博士后科学基金(2015M570363)资助

摘　　要：金属泡沫是一种高导热性多功能材料,内部传热有明显的局部非热平衡特性,而在导热中的热响应特性与外界环境密切相关.本文基于两方程模型研究了填充固体石蜡的金属泡沫复合材料在非稳态过程中的热响应特性.结果表明,金属泡沫与石蜡间存在局部非热平衡效应,需采用两方程模型计算.当环境温度随时间作周期波动时,金属泡沫内温度场也呈周期波动,并且,随环境温度波动周期的增大,局部非热平衡效应先增大后减小,即存在一个共振周期使得局部非热平衡效应最明显.在外界温度波动幅度一定时,金属泡沫内温度振幅随波动周期的增大呈对数趋势增大,不同位置振幅的衰减程度不同,距加热面越远衰减越多.本文还详细讨论了金属泡沫的孔隙率、孔密度、热扩散率,以及石蜡中含纳米颗粒添加物对复合材料热响应特性的影响程度.在实际应用中,应综合考虑这些影响因素,从而使该复合材料的换热性能达到最优.本文揭示了金属泡沫导热中金属骨架相和填充固体相的温度差异,对于多孔介质非稳态热传导的局部非热平衡特性具有直接的科学意义.With the development of materials and manufacturing techniques, using highly conductive metallic porous materials, such as metal foam, metal fiber felt, lattice-frame material, and so on, to enhance heat transfer becomes possible. As a highly-conductive multi-functional material, metal foam owns many good features including high porosity, light weight, large surface area, high strength, etc. To date, the thermal response characteristics of porous media with transient heat transfer have been investigated to some extent. For metal foam, the local thermal non-equilibrium（LTNE） effect can be found during the unsteady heat conduction process. However, for the unsteady heat conduction of the highly-conductive metal foam saturated with solid with a low thermal conductivity, the LTNE effect exists, but the thermal response characteristics of the metal foam and the infill solid with the periodically changing thermal boundary condition are rarely investigated. In this paper, based on the two equations model, the thermal response of the composite material which is made up of the metal foam and the saturated paraffin wax was numerically investigated with the periodic fluctuating temperature boundary condition, in which the temperature difference between metal foam and the infill paraffin wax was considered. The finite volume method（FVM） was used to discrete the coupled governing equations including the porous solid equation for metal foam and the infill solid equation for paraffin wax. The governing equations were solved by Gauss-Seidel iteration method. The present simulation method was validate by comparing with the analytical results under a constant temperature boundary. Then, the effects of various parameters on the thermal response characteristics were discussed. It was found that the LTNE effect exists in the metal foam and paraffin wax and thus the two equations model must be employed. When the ambient temperature periodically fluctuates with time, the temperature field inside the metal foam also reflects the

关 键 词：多孔介质 传热 数值分析 波动周期 纳米颗粒 

分 类 号：TB33[一般工业技术—材料科学与工程]