Abstract
The purpose of this study is to obtain basic knowledge of the heat and mass transfer processes as affected by interfacial disturbance induced by addition of surfactants. We apply a nonflowing bulk absorption model and assume that interfacial disturbance occurs randomly. Four governing equations-for continuity, laminar momentum, energy, and diffusion-are solved numerically to obtain the unsteady temperature and concentration distribution during vapor absorption with interfacial disturbance for various aspect ratios δ(D/L = thickness of absorbent solution/length of model cell) and random numbers of interfacial disturbance points. In this study, surface tension between the surfactant ( n-octanol) and absorbent solutions (H2O/LiBr) is considered to be constant during the vapor absorption (i. e., independent of concentration changes in the absorbent solution). The influence on the occurrence of random interfacial disturbance is quantified in terms of mean Sherwood number and Nusselt number for severalδ(=0.1, 0.3, 0.5, 1) and with variations in the number of random disturbance points (1 to 5) where disturbance randomly occurs on the model cell surface. As a result of these calculations, the absorption enhancement ratio (amount of vapor absorption with surfactant addition/amount of vapor absorption without surfactant addition) is obtained by comparison between surfactant-added and nonadded conditions, for the same calculation parameterδ.
