On the motion of Newtonian and non-Newtonian liquid drops

In the present study, the motion of newtonian and non-newtonian liquid drops has beeninvestigated experimentally. in order to investigate the effect of bulk fluid on drops, we have used waterand air, as two fluids with different properties, and various industrial and biological applications. imageprocessing is utilized to analyze the images obtained by a high speed camera. the research has beenseparated into two parts. the first part has been devoted to the experiments in which air is the bulkfluid, and the second is related to the experiment carried out in water. the range of reynolds number is,approximately, 50 < re < 500. the major concern of the present study is the size variation of drops andits effect on the drag coefficient. it is proved that the period of size variation of a drop does not vary withproperties. rheological aspects of the problem have also been considered. in air with small density andviscosity, addition of non-newtonian characteristics to the fluid causes the behavior of the drop to undergodramatic changes. however, in water, a denser and more viscous bulk fluid, the behavior of newtonianand non-newtonian drops (at least for shear thinning fluids) looks the same.