颗粒床孔隙率与渗透率的关系

Relationship between porosity and permeability of the particles packed bed

孔隙率和渗透率是土壤科学，能源动力工程，化学工程，土木工程以及环境工程研究中的基本物性参数。采用小流量和低压差实验研究了非固结颗粒床的渗透率和孔隙率关系。研究表明，给定颗粒介质的渗透率ｋ与孔隙率的关系是唯一确定的；流量和压差成正比的达西渗流定律和通常的层流流动规律表现出一致性，但发生在毛细多孔介质内的渗流流动并不同于常规的槽道流动。渗透率不是颗粒或流道几何尺度平方的函数。对粒度ｄ为１００～４５０μｍ，粒径比为１．２５∶１的窄筛分砂土的渗透率建议采用如下带单位的公式计算：ｋ／μｍ２＝１．７２×１０４（ｄ／ｍｍ）１．４６５４．６９。

Porosity and permeability of the particle packed bed are both important properties for soil science, petroleum physical principle, civil and environment engineering, chemical industry and materials engineering. The relationship between permeability k and porosity φ of the particle packed bed was measured by passing little flow with little pressure drop. The repeated experimental results show that, for a given unconsolidated porous medium, the permeability porosity relationship is unique. The relationship between the flow rate and pressure drop in the capillary porous media following linearity recovered by Darcy's law is consistent with that of the layer flow in ordinary pipes and channels. However, the conventional hydrodynamic theory and dimensional analysis are not sufficiently applied to the penetrate flow in the porous media. The permeability can not be expressed by a linear function of the square of the particle size. For the screened sand whose particle size rangesd from 100μm to 450μm and size ratio is 1∶1.25, the permeability can be estimated from the formula: k/ μm 2=1.72×10 4 ( d /mm) 1.465 φ 4.69 .