We investigate quantum vortex ring dynamics at scales smaller than theinter-vortex spacing in quantum turbulence. Through geometrical arguments andhigh resolution numerical simulations we examine the validity of simpleestimates of the mean free path and the structure of vortex ringspost-reconnection. We find that a large proportion of vortex rings remaincoherent objects where approximately $75\%$ of their energy is preserved. Thisleads us to consider the effectiveness of energy transport in turbulenttangles. Moreover, we show that in low density tangles, appropriate for theultra-quantum regime, ring emission cannot be ruled out as an importantmechanism for energy dissipation. However at higher vortex line densities,typically associated with the quasi-classical regime, loop emission is expectedto make a negligible contribution to energy dissipation, even allowing for thefact that our work shows rings can survive multiple reconnection events. Hencethe Kelvin wave cascade seems the most plausible mechanism leading to energydissipation.
展开▼
