摘要
本文采用格子Boltzmann气固两相流模型模拟了扩散机制下椭圆截面纤维非稳态捕集颗粒过程,包括颗粒枝簇结构的形态和生长过程,并定量分析了纤维周围流场压降和扩散捕集效率随沉积颗粒质量的动态变化规律。当扩散机制主导时,初始阶段颗粒会比较均匀地沉积在椭圆截面纤维表面,后面随着沉积颗粒的枝簇结构长大,改变了流场的分布以及捕集面积,颗粒会更多地在迎风端沉积。对于系统压降的动态变化,不同条件下均满足标准化压降随颗粒沉积质量增加呈指数变化关系。对于椭圆截面纤维捕集效率的动态变化,当增长速度稳定后,不同条件下均满足标准化效率随颗粒沉积质量增加呈线性增长的规律。
In this article, we use a lattice Boltzmann-cellular automata(LB-CA) probabilistic model to simulate the non-steady-state particle filtration process of elliptical fibers for the diffusion dominant regime including the growth process of the clusters and the cluster structures. The dynamic changes of pressure drop and collection efficiency for the diffusion dominant regime are investigated. When the diffusion mechanism dominated, particles deposit on the elliptical fiber surface uniformly at the initial stage, followed by the clusters grow up, which change the flow field and capture area, and more particles will deposit on the windward side later. Dynamic changes of the standardized pressure drop is exponential to the particle deposition quality at different operation conditions. When the growth rate stabilized, dynamic changes of the standardized capture efficiency is proportional to the particle deposition quality at different operation conditions.
引文
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