高速气流加速下雾粒的传质(英文)  

Mass Transfer of Micro Droplet Instantaneously Accelerated by High-speed Gas Stream

作　　者：关国强[1] 朱家骅[1] 夏素兰[1] 杨雪峰[1] 

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《四川大学学报（工程科学版）》2003年第3期42-48,共7页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(29976026);教育部博士点基金资助项目(20010610027);高速水力学国家重点实验室资助项目(2007)

摘　　要：针对高分散气雾两相流动体系,提出了一种新的传质理论表达式,其传质系数用Kolmogoroff长度时间尺度进行关联,并开发出基于MonteCarlo和CFD的联合模拟方案。运用该传质表达式和模拟方案,成功地模拟了氢氧化钠与二氧化碳的气雾两相射流中和反应体系。结果表明:相间传质时间尺度(1.6×10-4s)远小于弛豫时间尺度(4.5×10-4s),进一步研究说明尽管气雾相间传质的速率很快,但相间传递量是主要通过速度滑移实现的,相间传质对雾粒相的运动行为影响甚小,因而在工程上对于雾粒相运动行为的描述可以忽略传质的影响。由激光多普勒测速仪得到的实验数据证实了模拟结果,表明模拟能正确预测此类输运现象。A novel theoretical expression of mass transfer in highly dispersed gas droplet system is presented in which mass transfer coefficient is correlated with the Kolmogoroff length to time scale. Based on the idea of Monte Carlo and CFD coupling, a corresponding simulation scheme is developed to simulate a gas droplet (sodium hydroxide and carbon dioxide) neutralization reactive jet system, considering the crucial procedure of interfacial mass transfer. The results show that the rate of mass transfer is much faster than that of hydrodynamic respondence because the temporal scale of mass transfer, 1.6×10 -4 s, is less than the relaxation time, 4.5×10 -4 s. It also shows that the great interfacial transfer magnitude is mainly caused by the velocity slip and it is justified to neglect the effect of mass transfer in description of droplet motional behavior. It provides a path of simplification in engineering. The experimental data measured by laser Doppler velocimeter are used to validate the simulation results. It shows that the simulation is able to predict these unique transport phenomena.

关 键 词：传质 气雾两相射流反应 MONTE Carlo和CFD联合模拟 

分 类 号：TQ027.3[化学工程]