基于CFD模拟卷烟烟气扩散过程的影响因素

Factors influencing diffusion process of cigarette smoke by CFD-based simulation

为了研究卷烟烟气的径向扩散和轴向流动过程,采用计算流体力学(CFD)技术中SIMPLEC算法、二阶迎风算法以及组分运送方法,结合粒子图像测速法(PIV),以CO作为代表组分分析了卷烟烟气通过卷烟纸的径向扩散,以及卷烟烟气由点燃端通过烟丝流向吸入端的轴向流动。结果表明:(1)烟支的变短会使从卷烟纸侧壁流出烟气中CO的百分含量增加,并趋向稳定;(2)卷烟纸孔隙率在0.415~0.482之间时,孔隙率增加对从卷烟纸侧壁流出烟气中CO的百分含量没有明显影响,但会使从吸入端流出烟气中CO的百分含量增加;(3)卷烟纸的平均孔径与吸入端压力的增加都会使从吸入端和卷烟纸侧壁流出烟气中CO的百分含量增加。

In order to study the radial diffusion and axial flow processes of cigarette smoke, SIMPLEC algorithm, secoild-order upwind algorithm and component transport method in computational fluid dynamics （CFD） combined with particle image velocimetry （PIV） were used. By taking CO as a representative component, the radial diffusion through cigarette paper and the axial flow of cigarette smoke were analyzed. The results showed that： 1） The shortening of cigarette increased the percentage of CO in cigarette smoke diffused through the cigarette paper. 2） Within the porosity range of 0.415-0.482, the increase of cigarette paper porosity did not obviously affected the percentage of CO in cigarette smoke diffused through the cigarette paper, but it would increase CO level in cigarette smoke at the mouth end. 3） The increase of either the mean pore diameter of cigarette paper or the pressure at the mouth end increased the percentage of CO in cigarette smoke diffused through the cigarette paper and that come out of the mouth end.