中文摘要：

结合Matlab软件和数值计算前处理软件Gambit中的Journal文件建立了随机排列纤维过滤器模型,利用计算流体动力学（CFD）技术对4种随机排列纤维过滤器内部气-固两相流动特性进行数值研究,并将数值计算值和经典模型及实验关联式进行了比较。结果表明：利用论文提出的建模方法可以得到与实际纤维过滤器相似的模型。过滤器压力损失的数值计算预测值和实验关联式吻合较好,误差均在2%以内。不同结构过滤器收集效率的数值计算结果和理论模型的趋势基本一致,且不同粒径范围的颗粒收集机理也不同。对于小粒径颗粒（dp〈0.5μm）,主要由布朗扩散起作用,dp〉1.5μm时,惯性碰撞贡献较大,当0.5μm≤dp≤1.5μm时,2种机理作用都较弱。另外,纤维直径和纤维填充密度分布会影响纤维过滤器的过滤性能,论文中,结构1（纤维直径和填充密度沿气流方向减小）的过滤器和结构3（纤维直径和填充密度沿气流方向增加）的收集效率高于结构2（在气流方向上纤维直径减小而填充密度增大）和4（在气流方向上纤维直径增大而填充密度减小）,而压力损失则恰恰相反。结构1在大颗粒的收集上好于结构3,对于小颗粒则正好相反。结构4对于所有类型的颗粒的收集都要好于结构2。

英文摘要：

The fibrous filter with random structure has been established based on the Matlab program and the Journal file in preprocessing software,Gambit.The gas-solid two phases flow characteristics in four fibrous filters with random structure are simulated by computational fluid dynamics（CFD） technology,and the predicted results are compared with the values of the empirical models.The results indicate that utilization of the modeling method proposed can obtain a filter geometry that is similar to the actual filter.The predicted values of the dropped pressure are in excellent agreement with the experimental correlation,and the error are less than 2%.Meanwhile,the predicted values of the collection efficiencies show a similar tendency as theoretical model,and the capture mechanism changes with different particle sizes.When the particle size is smaller than 0.5 μm,Brownian diffusion plays a significant role in the filtration process,while the inertial impaction becomes an important capture mechanism when the particle size is greater than 1.5 μm.When the particle size is in the range from 0.5 to 1.5 μm,the Brownian diffusion and the inertial impaction are both relatively weak.Additionally,the fiber diameter and the solid volume fraction（SVF） are important geometry parameters in the filter.The collection efficiencies of geometry 1（in which the fiber diameter and SVF are decreased along the gas flow） and geometry 3（in which the fiber diameter and SVF are increased along the gas flow） are higher than those of geometry 2（in which the fiber diameter is decreased and SVF is increased along the gas flow） and geometry 4（in which the fiber diameter is increased and SVF is decreased along the gas flow）,and for the pressure drop,the results are just the contrary.Meanwhile,the four geometries have different collection efficiencies for different particle size.For large particles,the collection efficiency of geometry 1 is higher than that of geometry 3.While for submicron particles,the result is the opposite.As