考虑反弹行为的单纤维过滤稳态捕集效率的数值模拟

Numerical Simulation of Stationary Collection Efficiency of a Single Fiber Filtration Considering the Rebounding Behavior

采用稳态单纤维表面粉尘树枝生长随机模拟,并考虑纤维过滤中气溶胶粒子碰撞反弹行为,讨论稳态下斯托克斯数(St)与哈梅克常数(H)对粒子运动轨迹的影响,计算分析了St与H对稳态单纤维捕集效率的影响.研究结果表明:当H值一定时,考虑反弹的捕集效率与不考虑反弹的捕集效率可以按斯托克斯数临界值St_c为分界点写成分段函数,通常1.0≤St_c≤3.5,在St≤St_c的阶段,考虑反弹的捕集效率与不考虑反弹的捕集效率相等,且与文献研究结果基本吻合;在St>St_c阶段,考虑反弹的捕集效率小于不考虑反弹的捕集效率,需对文献研究结果进行修正,修正结果为文献研究结果乘以反弹系数k,k是St、拦截系数Rp、填充率c及H的函数.

By using stochastic simulation technique in the growing process of particle dendrites on a single fiber and considering the behavior of aerosol particles collision,adhesion and rebound on surface of fibers,the effects of Stokes number（St）and Hamake constant（H）on particle trajectories in steady state were investigated.The effects of St and H on stationary collection efficiency of a single fiber were examined.The results show that when His a fixed value,the relationship between rebounding collection efficiency and no-rebounding collection efficiency can be written as a piecewise function which the demarcation point is Stc,these two are equal in the stage of the value of St is less than or equal to St_c,and the findings are consistent with the literature;when St is greater than St_c,rebounding collection efficiency is less than no-rebounding collection efficiency,the research results are revised,multiplied by rebounding coefficient k,kis a function of St,intercept coefficient Rp,filling rate Cand H.