中和颗粒可压缩性颗粒层模型

本文针对可压缩颗粒层建立了二维数值模型.首先利用颗粒层中颗粒间的相互位置关系,建立了每一个颗粒的力平衡方程,获得了每一个颗粒的受力大小,然后提出了颗粒层坍塌判据,在此基础上,建立了描述颗粒层的沉积-压缩-沉积的动态过程的可压缩颗粒层模型,模型计算结果表明,颗粒层压缩现象主要发生在下部区域,过滤速度越高、范德华力越小,颗粒层越易坍塌,并且颗粒层的压降出现了脉动,模型结果符合已知的实验结果.

MODELING ON THE FORMATION OF COMPACTIBLE CAKE

In this work,a two dimension simulation model on the filtration of the compactible cake is improved.This study considered the collapse of the cake carefully,which was not paid enough attention in the previous studies.From the forces equilibrium equations,the forces acting on every particle are calculated.Then a collapse criterion is established.Especially,this study developed a detailed model to describe the collapse process of the cake.Simulation results show that the collapses mainly occur in the lower layers of the cake.And under low filtration velocity,the pressure drop tends to increase linearly,while high velocity the pressure drop increases irregularly.These results have good agreement with known experimental data.