Abstract
Dynamic behaviors of Marangoni convection induced at LiBr aqueous solution by addition of a surfactant have been investigated experimentally by using a real-time type laser holographic visualization system. N-octanol was used as a surfactant. The Marangoni convections occurred at/beneath the solution surface in the very beginning of steam absorption were observed in three dimensions. At first, vertical convective motions induced in the LiBr aqueous solution by addition of the surfactant were observed varying the initial surfactant's concentration ranging from 0 to 50000ppm and the liquid layer thickness ranging from 5 to 25mm. And, horizontal convective motions induced at the LiBr aqueous solution by addition of the surfactant were observed varying the initial surfactant's concentration ranging from 0 to 400ppm and the shallow liquid layer thickness ranging from 2 to 5mm. Pentagonal or hexagonal cell patterns were clearly observed at the surface and these cells instantly grew in size from small to large during the 10 milliseconds after the beginning of absorption. Thus, generation and growth processes of the Marangoni convection were revealed from the visualization results. And, spatial-temporal scales of the Marangoni convection were determined experimentally.
