A unified analytical prediction for steady-state behavior of confined drop with interface viscosity under shear flow

In this Letter, we fill in the blanks in the theory of drops under shear flow by unifying analytical predictions for steady-state behavior proposed by Flumerfelt [R. W. Flumerfelt, J. Colloid Interface Sci. 76, 330 (1980)] for unconfined drops with interface viscosity with the one of Shapira & Haber [M. Shapira and S. Haber, Int. J. Multiph. Flow. 16, 305 (1990)] for confined drops without interface viscosity. Our predictions for both steady-state drop deformation and inclination angle are broadly valid for situations involving confined/unconfined drops, with/without interface viscosity and viscosity ratio, thus making our model so general that it can include any of the above conditions.