عنوان مقاله English
نویسندگان English
In this paper, steady creeping motion of non-Newtonian falling drop through a viscous fluid is investigated analytically. Here, the Upper Convected Maxwell model (UCM) is used for drop phase and Newtonian model is considered for external fluid. The perturbation technique is used to solve both exterior and interior flows and Deborah number that indicated the elastic effect is considered as the perturbation parameter. The present solution is derived up to second order of perturbation parameter so the present solution has a suitable accuracy for drops that made from dilute polymeric solutions. We found that the Newtonian drop has a spherical shape during the creeping motion but the non-Newtonian drop loses this shape and takes an oblate form. By increasing the elastic effect, a dimple at the rear end of the drop is created and developed. Here, it is shown that the present results have more agreement with experimental data than the previous analytical studies. The origin of drop deformation is also considered and it is proofed that the elastic property of drop phase creates a concentrated normal stress at the rear end of the drop that causes the dimple shape in this region.
کلیدواژهها English
