Impact of swirling on capillary instability of Walter’s B viscoelastic fluid-viscous fluid interface with heat and mass transfer

Abstract

The multifaceted applications of swirling interfaces featuring heat and mass transfer extend across diverse industries, encompassing energy, manufacturing, healthcare, and environmental protection. The present study is concerned with examining the swirling impact on the capillary instability occurring at the interface between a Walter’s B viscoelastic fluid and a viscous fluid, under the influence of heat and mass transfer. The setup consists of two rigid cylinders that form an annular region filled with viscous fluid on the inner side and Walter’s B viscoelastic fluid on the outer side. The outer cylinder rotates at a constant angular velocity, while the inner cylinder remains stationary. The study employs the Walter’s B viscoelastic model, which conforms to the potential flow theory for viscoelastic fluids. The proposed flow theory disregards tangential stresses and balances the difference in normal viscous stresses with the surface force at the free boundary. The perturbed equations yield a quadratic equation in growth rate, which is numerically analyzed. The results show that heat and mass transfer enhance the interface’s stability and swirling makes it more stable. Moreover, it is noteworthy that the Weber number exerts a stabilizing influence on the interface, while the density ratio also plays a role in promoting its stability. The centrifuge number exhibits a counteractive effect by impeding interface growth, thus contributing to its stabilization.