粗糙多孔保温层的热质耦合传递分形研究

粗糙多孔保温层内部的热质耦合传递过程广泛存在于能源利用、机械隔热等工程中，为了更加真实地体现该热质耦合传递过程，将粗糙的孔隙通道描述为短周期正弦变化的毛细管道，根据达西定律、能量守恒定律和牛顿冷却定律，同时考虑粗糙度和粗糙密集度两个影响因素，提出了粗糙毛细管道的渗流系数和对流换热系数模型，分析了粗糙表面对渗流系数和对流换热系数的影响。结果表明，渗流系数模型的理论预测值与实验数据相吻合；渗流系数与面积分形维数、粗糙密集度呈正相关，与迂曲分形维数、粗糙度呈负相关；对流换热系数与渗流系数、粗糙度和粗糙密集度呈正相关，与面积分形维数、迂曲分形维数呈负相关。

Fractal study of heat and mass coupled transfer in a rough porous insulation layer

The heat and mass coupled transfer process in a rough porous insulation layer is widely used in energy utilization, mechanical heat insulation engineering and other projects. In order to reflect the heat and mass coupled transfer process more truly, the rough pore channel can be described as a short-period sinusoidally changing capillary channel. According to Darcy's law, the conservation of energy and Newton's law of cooling, and considering the roughness and roughness density at the same time, models for the seepage coefficient and convective heat transfer coefficient of a rough capillary channel are proposed. The influence of the rough surface on the seepage coefficient and convective heat transfer coefficient is analyzed. The results show that the theoretical prediction value of the seepage coefficient is consistent with the experimental data. The seepage coefficient is positively correlated with the area fractal dimension and roughness density, and is inversely correlated with the tortuous fractal dimension and roughness. The convective heat transfer coefficient is positively correlated with the seepage coefficient, roughness and roughness density, and is inversely correlated with the area fractal dimension and tortuous fractal dimension.