颗粒型多孔材料孔隙率理论分析和实验研究

Theoretical Analysis and Experimental Study on Porosity of Granular Porous Materials

颗粒型多孔材料中基体颗粒存在多种堆积形式,分为绝对稳定堆积和亚稳定堆积。建立无边界影响的堆积颗粒型多孔材料孔隙率理论模型,获得无边界影响下多孔材料的理论孔隙率。理论分析认为每种堆积形式存在的概率相等,推导获得颗粒型多孔材料的孔隙率为定值0. 377。通过与文献数据对比,发现该数值与文献数据吻合良好。此外,通过实验研究发现,当多孔材料直径与颗粒小球粒径比值增大时,即多孔材料边界效应减弱,实验获得多孔材料孔隙率越接近该数值,从而证明了该数值的正确性。

There are various arrangements in granular porous materials,i. e.,absolute stable state and quasistable state. The porosity model for randomly packed beds of spheres are proposed. It is considered that the overall porosities of granular porous materials are not affected by boundary. The probability of the presence of each configuration is assumed to be identical,a constant of bulk porosity 0. 377 is theoretically proposed. Good agreement is found between the proposed bulk porosity and available data adopted from literature. In addition,experimental investigation is also implemented. The effect of boundary becomes weaker as the increase of ratio between diameters of porous material and spheres. It is found that the experimental porosity approximates to theoretical porosity 0. 377 as the increase of ratio,and good validation is also achieved.