基于非圆球模式的大气超细颗粒物在沉积和凝并共同作用下的动力学模型研究

数值模拟了封闭环境内非球形超细颗粒物的动力学演化,以探讨颗粒物的沉积和凝并行为.采用泰勒展开方法导出了描述颗粒物动力学这两种行为共同作用的矩方程.通过与实验结果对比表明:本文得出的矩方程相对于传统的矩方程模型更适于刻画颗粒物的扩散和重力沉积,能够精确地预测它们的动力学演变过程.通过将颗粒形状参数(分形维数,Df)纳入原始动力学方程,使得颗粒物凝并模型可以较为准确地描述真实情况下非球形颗粒的凝并行为.此外在高颗粒物浓度条件下,得出颗粒物的演变主要受到凝并作用的影响,沉积作用则相对较弱.

Research on dynamic model of non-spherical ultrafine particles considering both deposition and coagulation

This paper numerically investigates a dynamical evolution of ultrafine nonspherical particles in closed environments so as to explore their deposition and coagulation processes. The moment equations describing the dynamical behavior together considering both of above processes of the particles are derived from the Taylor expansion. Numerical results show that by comparing with the experimental data, the current equations are more suitable than the traditional ones to describe the diffusion and deposition of these particles and can accurately predict their dynamical evolution process. The coagulation model proposed in the paper is able to precisely describe coagulative behaviors of those nonspherical particles due to introduction of fractal dimension (D_f) of the particles to the dynamical equations. In addition, in the case of high particle concentration, the particle evolution is mainly affected by the coagulation rather than the deposition.