ISPH modeling of Rayleigh–Taylor instability

This paper presents a Smoothed Particle Hydrodynamics (SPH) solution to a Rayleigh-Taylor Instability (RTI) problem in an incompressible viscous two-phase immiscible fluid with an interfacial tension. The evolution of the fluid-fluid interface is numerically investigated for four different density ratios. The simulation outcomes are compared with existing results in literature. Three stages of instability, namely the exponential growth rate, the formation of circular form at the crest of spike and the appearance of the final shape of instability, are discussed for different density ratios. It is shown that the numerical algorithm used in this work is capable of capturing the complete physics behind the RTI, such as interface evolution, growth rate and secondary instability accurately, and successfully.