On flow length requirement for stress-induced polymer migration in fine capillaries

Abstract

The development of macromolecular concentration gradient caused by the stress induced migration phenomenon in capillary flows has been studied numerically. It is shown that for reaching a given level of flow enhancement, the capillary lengths required are considerably less than those expected from prior analyses, which have neglected the strong interdependence between the flow field and the resulting concentration profiles. The implications of the present findings in terms of detection of macromolecular migration in capillary flows and also the influence on transport rates have been discussed critically.