英文摘要 |
Non-Newtonian multiphase flows are almost ubiquitous in chemical, biochemical, petroleum and polymer processing industries. Many chemical and processing industries are plagued by bubbles, and many polymeric solutions exhibit non-Newtonian rheological properties. A level set method is used in this study to analyze the rise and deformation of droplets in power-law, and Carreau model non-Newtonian fluid. This simulation is compared to previously published numerical and experimental data to show that the moving droplet interface is viable. The computational geometries used in these comparisons are the same as those reported in the respective literatures. There is good agreement between the current droplet deformation properties and those found in the literature. Computing fluid dynamics-based solver COMSOL Multiphysics 4.3 is used to explore the settling and deformation characteristics of spherical and spheroidal (oblate and prolate) droplets in stagnant air. A two-phase flow system is considered in which the continuous phase is Newtonian medium (air) and the dispersed droplet phase is considered to be both Newtonian fluids (water), Carreau fluid (Emkarox) and the power law fluid (n -0.4). Volume fraction images of spherical and spheroid droplets reveal substantial distortion in the early stages, which gradually decreases as the droplet approaches the channel's bottom. The drag coefficient of a moving droplet is calculated over time to comprehend non-Newtonian droplet settling velocity. |