  We present a numerical study of emulsions in homogeneous and isotropic
turbulence at $Re_\lambda=137$. The problem is addressed via Direct Numerical
Simulations (DNS), where the Volume of Fluid (VOF) is used to represent the
complex features of the liquid-liquid interface. We consider a mixture of two
iso-density fluids, where fluid properties are varied with the goal of
understanding their role in turbulence modulation, in particular the volume
fraction ($0.03<\alpha<0.5$), viscosity ratio ($0.01<\mu_d/\mu_c<100$) and
large scale Weber number ($10.6<We_\mathcal{L}<106.5$). The analysis, performed
by studying integral quantities and spectral scale-by-scale analysis, reveals
that energy is consistently transported from large to small scales by the
interface, and no inverse cascade is observed. Furthermore, the total surface
is found to be directly proportional to the amount of energy transported, while
viscosity and surface tension alter the dynamic that regulates energy
transport. We also observe the $-10/3$ and $-3/2$ scaling on droplet size
distributions, suggesting that the dimensional arguments which led to their
derivation are verified in HIT conditions.
