On the stability of inhomogeneous fluids under acoustic fields

In this work, we present the stability theory for inhomogeneous fluids subjected to standing acoustic fields. Starting from first principles, criterion is established two of different impedance separated by a plane interface. Through and numerical simulations show that, in presence interfacial tension, relocation high-impedance fluid anti-node node occurs when force overcomes tension force, which agreement with recent microchannel experiments. Furthermore, establish an Bond number that characterizes stable (Bo_a < 1) > regimes. Remarkably, it found critical energy density required can be significantly reduced increasing channel height could help design acoustofluidic devices handle immiscible fluids.