The effect of large-scale forcing on small-scale dynamics of incompressible turbulence

The subtle but crucial effects of large-scale forcing on the small-scale velocity-gradient (VG) dynamics is examined using direct numerical simulation (DNS) data incompressible turbulence. interplay among forcing, inertia, pressure and viscous characterised as a function local streamline geometry VG magnitude (Frobenius norm). When conditioned topology, forcing: (i) counteracts inertial action in strain-dominated nodal topologies; (ii) balances rotation-dominated unstable focal topologies. Unexpectedly, acts to reduce magnitudes regions strong dissipation. In these regions, non-local whereas offsets nonlinear effects. very low dissipation, combines with inertia offset action. With regard probability distribution normalised invariants, primary role nullify certain features (dilatational currents) This results emergence universal statistical (solenoidal that are determined largely by inertia–pressure–viscous interactions. These findings serve enhance our understanding processes turbulence guide model development.