Effect of radiative heat transfer on determining thermal conductivity of semi-transparent materials using transient plane source method
Effect of radiative heat transfer on determining thermal conductivity of semi-transparent materials using transient plane source method
复制标题
辐射传热对瞬态平面源法测定半透明材料导热系数的影响
DOI：
10.1016/j.applthermaleng.2016.11.208
复制
发表时间：
2017-03-05
影响因子：
6.4
通讯作者：
Tao, Wenquan
中科院分区：
文献类型：
--
作者：
Zhang, Hu;Li, Yueming;Tao, Wenquan
暂态平面源法的理论基础是适用于不透明介质的非定常热传导微分方程。极低密度的材料，如气凝胶和发泡材料在高温下对热辐射不是不透明的。对于这些半透明材料，辐射会参与热传递过程。采用瞬态平面源法测量半透明材料的导热系数时，材料内部是否存在热辐射会影响测试精度。本文用数值方法研究了辐射传热对瞬态平面源法测定半透明材料导热系数的影响。结果表明，在温度高于600 K、消光系数小于2000 m（-1）且以辐射传热为主的情况下，瞬态平面源法测量的半透明材料导热系数会被高估。对于消光系数为500 m（-1）的材料，在1000 K时偏差达到19.6%。说明瞬态平面源法测量半透明材料的导热系数时，考虑了材料内部辐射传热的部分影响。(C) 2016 Elsevier Ltd.版权所有。
The theoretical basis of transient plane source method is the unsteady differential equation of heat conduction which is suitable for opaque medium. Extremely low density materials such as aerogels and foaming materials are not opaque for thermal radiation at high temperature. For these semi-transparent materials, radiation will participate in the thermal transport process. When applying transient plane source method to measure the thermal conductivity of semi-transparent materials, the existence of thermal radiation within the materials will affect the test accuracy. In present study, the effect of radiative heat transfer on determining thermal conductivity of semi-transparent materials using transient plane source method is numerically studied. The results show that the thermal conductivity of semi-transparent materials measured by transient plane source method will be overestimated at temperature higher than 600 K and extinction coefficient less than 2000 m(-1) where radiative heat transfer is dominant. The deviation increases with temperature and reaches to 19.6% at 1000 K for materials with extinction coefficient of 500 m(-1). It illustrates that the thermal conductivity of semi-transparent materials measured by transient plane source method has taken into account part of the influence of radiative heat transfer within the materials. (C) 2016 Elsevier Ltd. All rights reserved.