Effects of surface topography on low Reynolds number droplet/bubble flow through a constricted passage

This paper is an attempt to study the effects of surface topography on flow a droplet (or bubble) in low Reynolds number regime. Multiphase flows through constricted passage find many interesting applications chemistry and biology. The main parameters which determine properties such as rate pressure drop, govern complex multiphase phenomena drop coalescence, break-up snap-off straight channel are viscosity ratio, size ratio viscous forces tension (denoted by Capillary number). But passage, addition above-mentioned parameters, various other geometric constriction length shape constriction, phase angle, spacing between constrictions also start playing important role. Most studies done problem have aimed understand role physical with some extending their analysis variation one or two parameters. no could be found explicitly evaluates topography. An has been made unify current literature well analyze effect understanding physics mechanisms involved. non-dimensional numbers this then identified using scaling analysis.