格子波尔兹曼两相流模型模拟椭圆纤维捕集颗粒物过程

Simulation of Particle Capture Process for Elliptical Fibers by Lattice-Boltzmann Two-phase Flow Model

使用LB气固两相流模型模拟椭圆纤维捕集颗粒物过程,考察了在不同捕集机制(包括扩散、惯性和拦截)主导下椭圆纤维的捕集效率以及颗粒在流场中的运动过程。通过与同体积分数圆柱的捕集效率比较发现:椭圆纤维具有更大的捕集范围,因此扩散捕集效率高于圆柱纤维,与长短轴之比成正比;影响惯性和拦截效率的因素则比较多(包括椭圆形状、放置方向甚至是颗粒粒径),在这两种机制主导下,通常椭圆捕集效率仍然高于圆柱纤维(除了椭圆长轴平行于来流方向的情况)。最后通过Levenberg-Marquardt方法对模拟结果进行处理,得到了一系列修正系数,使其与原有的圆柱纤维效率计算公式结合,能够用来计算椭圆纤维的捕集效率。

This paper used LB gas-solid two-phase model to simulate the particle capture process of elliptical fiber, and investigate the capture efficiency by various capture mechanisms （diffusional, interception and inertial impaction mechanism） and motion of particles with distinct properties in the flow field. Through comparing with capture efficiency of cylinder fiber, it can be found that the diffusional capture efficiency of elliptical fiber is greater than that of cylinder fiber because of its larger capture range in proportion to the aspect ratio. There are many factors （such as aspect ratio, place angle and even particle diameter） may affect the capture efficiency of interception and inertial impaction mechanism. When interception or inertial impaction mechanism is dominated, the capture efficiency of elliptical fiber is often higher than cylinder fiber except the situation in which the major axis is parallel to flow direction. A series of correction coefficients was obtained by Levenberg-Marquardt algorithm. The coefficients can be combined with the exist formulas of cylinder fiber to calculate the capture efficiency of elliptical fiber easily.