Counterflow-Induced Inverse Energy Cascade in Three-Dimensional Superfluid Turbulence

TL;DR

This paper demonstrates that counterflow in three-dimensional superfluid turbulence can induce an inverse energy cascade, leading to a transition from 3D turbulence to a quasi-2D state with a split cascade, through extensive numerical simulations.

Contribution

It reveals a novel counterflow-induced inverse energy cascade in 3D superfluid turbulence and characterizes the transition to a quasi-2D regime, expanding understanding of quantum turbulence dynamics.

Findings

Inverse energy cascade emerges with increased counterflow.

Transition from 3D turbulence to quasi-2D state observed.

Potential for new experimental studies of superfluid turbulence.

Abstract

Finite-temperature quantum turbulence is often described in terms of two immiscible fluids that can flow with a non-zero mean relative velocity. Such out-of-equilibrium state is known as counterflow superfluid turbulence. We report here the emergence of a counterflow-induced inverse energy cascade in three-dimensional superfluid flows by performing extensive numerical simulations of the Hall-Vinen-Bekarevich-Khalatnikov model. As the intensity of the mean counterflow is increased, an abrupt transition, from a fully three-dimensional turbulent flow to a quasi two-dimensional system exhibiting a split cascade, is observed. The findings of this work could motivate new experimental settings to study quasi two-dimensional superfluid turbulence in the bulk of three-dimensional experiments. They might also find applications beyond superfluids in systems described by more than one fluid component.