Moisture Transport in Unconsolidated Porous Media During Drying

该项目涉及水分输送的实验研究 在粒状多孔介质干燥过程中发生的过程。 在 原理上，其机制很简单--水蒸气在大气中的扩散， 气相由于分压和对流的梯度 由于毛细管力而处于液相中。 最近的视觉研究 已经清楚地表明，局部异质性的影响是 由两个参数主导：Bond数（表面张力比 重力效应）和粒子的方差 粒度分布 为了探索广泛的债券数字， 研究者将使用100至200个玻璃球的填充床， 1000微米 颗粒尺寸变化的影响 将使用球形颗粒的混合物和 碎玻璃颗粒的混合物。

This project involves an experimental study of the moisture transport process that occurs during the drying of granular porous media. In principle, the mechanisms are quite simple--diffusion of water vapor in the gas phase owing to gradients in the partial pressure and convection in the liquid phase owing to capillary forces. Recent visual studies have clearly indicated that the influence of local heterogeneities is dominated by two parameters: the Bond number (ratio of surface tension effects to gravitiational effects) and the variance of the particle size distribution. To explore a wide range of Bond numbers, the investigator will use packed beds of glass spheres ranging from 100 to 1000 microns. The influence of the variance of the particle size distribution will be explored using mixtures of spherical particles and mixtures of crushed glass particles.