Abstract: The schlieren system was used to capture the onset of transition to turbulence and the interfacial turbulence in desorbing surface of tension-lowering solutes from aqueous solution. Convective structure in ethanol-water solution, isopropanol-water solution and acetone-water solution was alike. When the mass transfer process started, a rapidly growing turbulent region was observed on the surface. Several small round cells appeared on the edge of the expanding turbulent region. These small cells gradually developed into polygon structures as reported by many investigators. After the short instability process, the structures changed into ring-like shapes. In ethyl acetate-water solution, the structures remained clustered shape, and turbulence intensity was stronger. Structural features and turbulence intensity of interfacial convection depended on experimental operating conditions and physical properties of the system.

Key words: schlieren system, organics aqueous solution, desorption, interfacial turbulence, Rayleigh-Marangoni effect

摘要： 通过纹影光路,捕捉到低表面张力溶质从水中解吸导致的气液界面失稳过程及后续的对流结构图像.乙醇、异丙醇和丙酮水溶液中的现象相似:传质开始进行时,界面出现一个迅速变大的湍动区,湍动区扩张的同时,其边缘区域产生很多圆形的小胞,这些小胞逐渐演化成多边形,短暂的界面失稳过程之后,界面对流结构逐步发展为环形;但在乙酸乙酯体系中,界面对流结构一直都是团状的,而且湍动强度更为剧烈.结果表明,界面对流结构特点和剧烈程度取决于实验条件和体系的物理性质.

关键词: 纹影系统, 有机物水溶液, 解吸, 界面湍动, Rayleigh-Marangoni效应