Lagrangian quantum turbulence model based on alternating superfluid/normal fluid stochastic dynamics

Queen Mary University of London, School of Mathematical Sciences - Mile End Road, London E1 4NS, UK

Received: 9 August 2014
Accepted: 30 October 2014

Abstract

Inspired by recent measurements of the velocity and acceleration statistics of Lagrangian tracer particles embedded in a turbulent quantum liquid we propose a new superstatistical model for the dynamics of tracer particles in quantum turbulence. Our model consists of random sequences S/N/S/… where the particle spends some time being trapped on vortex lines of the superfluid (S) and some time in the normal liquid (N). This model leads to a superposition of power law distributions generated in the superfluid and Gaussian distributions in the normal liquid, in excellent agreement with experimental measurements. We include memory effects into our analysis and present analytic predictions for probability densities and correlation functions.