不同纤维结构特性下纤维集合体过滤性能的DPM数值模拟

DPM Numerical Simulation on Filtration Performance of Fiber Assembly under Different Fiber Structural Characteristics

为了探究过滤风速、纤维直径、纤维固体体积分数、纤维层厚度、纤维排列方式对纤维集合体内部气流速度分布、压力损失、过滤效率的影响,通过观察分析真实滤料结构特征和表面形态,利用Matlab随机算法,Solidworks建模软件生成直径为3-5μm、在空间中随机分布的三维纤维集合体,利用Digimat纤维建模软件生成纤维排列方向平行于X轴的三维纤维集合体,结合计算流体力学方法,基于拉格朗日离散模型和Laminar流场,利用雷诺相似准则对微米纤维模型内部气-固两相流动情况进行数值模拟。结果表明:过滤风速的增大对纤维集合体内部气相流场的影响表现为无规律性,纤维集合体内部压力损失随过滤风速的增大而增大;纤维过滤效率和压力损失随纤维固体体积分数、纤维层厚度的增大而增大;过滤效率和压力损失随着纤维直径的增大而减小;平行于X轴排列的纤维集合体的过滤效率和压力损失较空间随机分布纤维集合体的高。

In order to investigate the effect of inlet airflow speed,fiber diameter,fiber solid volume fraction,fiber layer thickness,and fiber arrangement on the airflow velocity distribution,pressure loss,and filtration efficiency inside fiber assembly,the structural characteristics and surface morphology of the actual fiber filter media were observed and analyzed,and then the geometrical models of the fiber assembly was constructed by using Matlab,Solidworks and Digimat.The Matlab software was used to construct a three-dimensional random structure of fiber assembly,and the Digimat was used to construct a three-dimensional fiber assembly with fiber arrangement parallel to the X-axis.The gas-solid two-phase flow inside the fiber assembly was numerically simulated by combining the computational fluid dynamics methods,Lagrangian discrete model and the laminal flow field,and the Reynolds similarity criterion.The results showed that the increase of inlet airflow speed had an irregular effect on the gas phase flow field inside the fiber assembly,the pressure loss inside the fiber assembly increased with the increase of inlet airflow speed,the filtration efficiency and pressure loss of fiber assembly increased with the increase of fiber solid volume fraction and fiber layer thickness,the filtration efficiency and pressure loss of fiber assembly decreased with the increase of fiber diameter,the filtration efficiency and pressure loss of fiber assembly with a fiber parallel to the X-axis structure was higher than that of fiber assembly with a fiber randomly distributed structure.