G051055 傾斜板上での液膜流の破断に対する液物性による影響([G051-05]流体工学部門,一般セッション : 液膜・液滴)

抄録

The liquid film flow applied for the separating technology, for example CO_2 absorbers, is required to increase its interfacial surface with gas in order to improve the separation efficiency, furthermore the smaller liquid flow rate is favorable for the economy. The liquid film flow with low liquid loading, however, breaks up to rivulet flow and reduces its interfacial surface. The present study focuses on detailed descriptions of the transition phenomena between film flow and rivulet flow by changing liquid flow rate and the influences of liquid properties, inclined angle of wall and wall surface texture treatments on the interfacial surface. Results of Computation Fluid Dynamics (CFD) with the Volume of Fluid (VOF) model, which is validated by the lab-scale experiments, show that the pattern of the film flow varies with the kind of liquid, especially liquid viscosity and contact angle. Correlation equations for the wetted area ratio are derived as functions of the dimensionless parameters, Weber number, Reynolds number, Froude number and the liquid contact angle. The wavy surface is more sensitive to the liquid viscosity and the liquid flow rate while it is effective to prevent the film flow from breaking.