Han Yafen, Li Shuai, Liu Haidong, Li Yucong
School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132013, China.
Nanomaterials (Basel). 2022 Sep 29;12(19):3424. doi: 10.3390/nano12193424.
In order to deeply study the heat conduction of nanoporous aerogel, a model of gas-solid heat conduction was established based on the microstructure of aerogel. The model was divided into two subdomains with uniform mesh because of the different gas-solid characteristics, and simulation was performed on each domain using the lattice Boltzmann method. The value of temperature on the boundaries of subdomains was determined by interpolation. Finally, the temperature distribution and the thermal conductivity were maintained. It can be concluded that when the gas-phase scale was fixed, the temperature distribution of the solid phase became more uniform when the scale increased; when the solid-phase scale was fixed, the temperature jump on the gas-solid interface decreased with the increase in the gas-phase scale; and the thermal conductivity of gas-solid coupling varied with the scale of the gas phase or solid phase, showing a scale effect in varying degrees.
为深入研究纳米多孔气凝胶的热传导，基于气凝胶微观结构建立了气固热传导模型。由于气固特性不同，该模型被划分为具有均匀网格的两个子域，并使用格子玻尔兹曼方法对每个域进行模拟。子域边界上的温度值通过插值确定。最后，得到了温度分布和热导率。可以得出结论，当气相尺度固定时，随着尺度增加，固相温度分布变得更加均匀；当固相尺度固定时，气固界面处的温度跃变随气相尺度增加而减小；气固耦合热导率随气相或固相尺度变化，呈现出不同程度的尺度效应。
