基于LBM多孔介质复合腔体交界面热滑移效应的研究

Study of heat slip effect on porous medium and fluid interface by lattice Boltzmann method

中文关键词: 实际多孔介质复合腔体  格子Boltzmann方法  热滑移效应  自然对流  交界面

英文关键词: cavity partially filled with actual porous media  lattice Boltzmann method  heat slip effect  natural convection  porous/fluid interface

中文摘要:

      本文采用格子Boltzmann方法对真实多孔介质复合腔体内的对流换热进行研究，分析了不同Ra数、多孔介质高度Y和厚度δ条件下交界面处的热滑移效应，并确定热滑移系数。利用X-CT技术对真实多孔介质材料进行断层扫描，获得实际材料内部结构图片，并进行图片处理，再导入格子Boltzmann模型中进行求解。计算结果表明：等效热滑移系数随高度Y的影响较大，靠近壁面或固体表面的系数偏大，而间隙处的系数偏小，但两处各自的值基本相同；Ra数和厚度δ的变化对等效热滑移系数的作用较小。

英文摘要:

      The model on natural convection in a cavity partially filled with an actual porous layer was studied and solved numerically by lattice Boltzmann method. The heat slip effect at the porous/fluid interface was analyzed under different Ra number, height and thickness conditions of the porous medium. The images of real porous structure obtained by X-ray computed tomography technique and processed were imported into the lattice Boltzmann model for solving. The numerical results showed that the equivalent heat slip coefficient impacts with height is greater, in the near wall or solid surface the coefficient is larger and the gap is small, but the values are basically same, respectively; and varies with increasing Ra number and thickness is less.