Numerical Investigation of Drop Impact on Immiscible Liquid-Liquid Interfaces

In this paper, we numerically investigate the levitation behaviors of a drop impacting an immiscible liquid-liquid interface, disregarding the influence of gravitational acceleration. Through energy budget analysis, we elucidate that the phenomenological model proposed by Sanjay et al. (J. Fluid Mech., 2023, vol. 958, p A25) and Jha et al. (Soft Matter. 2020, vol. 16, pp 7270-7273) is partially applicable to drop impact on liquid-liquid interfaces. Specifically, the magnitude of energy transferred from the impacting drop to the liquid film remains unchanged despite a two-orders-of-magnitude variation in the density of the surrounding liquid. Additionally, the normalized maximum film deflection exhibits a significant two-stage growth characteristic with increasing liquid film thickness under conditions of relatively high liquid film viscosity or an interfacial tension coefficient ratio. When the liquid film thickness is relatively low, the energy transfer from the impacting drop to the liquid film is also insensitive to changes in the interfacial tension coefficient ratio.