  The Rayleigh-Taylor Instability (RTI) in compressible flow with
inter-molecular interactions is probed via the Discrete Boltzmann Method (DBM).
The effects of interfacial tension, viscosity and heat conduction are
investigated. It is found that the influences of interfacial tension on the
perturbation amplitude, bubble velocity, and two kinds of entropy production
rates all show differences at different stages of RTI evolution. It inhibits
the RTI evolution at the bubble acceleration stage, while at the asymptotic
velocity stage, it first promotes and then inhibits the RTI evolution.
Viscosity and heat conduction inhibit the RTI evolution. Viscosity shows a
suppressive effect on entropy generation rate related to heat flow at the early
stage but a first promotive and then suppressive effect on entropy generation
rate related to heat flow at a later stage. Heat conduction shows a promotive
effect on entropy generation rate related to heat flow at an early stage.
Still, it offers a first promotive and then suppressive effect on entropy
generation rate related to heat flow at a later stage. By introducing the
morphological boundary length, we found that the stage of exponential growth of
interface length with time corresponds to the bubble acceleration stage. The
first maximum point of interface length change rate and the first maximum point
of the change rate of entropy generation rate related to viscous stress can be
used as a new criterion for RTI to enter the asymptotic velocity stage.
