Kinetic energy spectra and flux in turbulent phase-separating symmetric binary-fluid mixtures

Abstract: We conduct direct numerical simulation (DNS) of the Cahn-Hilliard-Navier-Stokes (CHNS) equations to investigate the statistical properties of the turbulent phase-separating symmetric binary-fluid mixture. Turbulence causes an arrest of the phase-separation which leads to the formation of a statistically steady emulsion. We characterize turbulent velocity fluctuations in an emulsion for different values of the Reynolds number and the Weber number. Our scale-by-scale kinetic energy budget analysis shows that the interfacial terms in the CHNS provide an alternate route for the kinetic energy transfer. By studying the probability distribution function (PDF) of the energy dissipation rate, the vorticity magnitude, and the joint-PDF of the velocity-gradient invariants we show that the statistics of the turbulent fluctuations do not change with the Weber number.