TITLE:
Trajectory Analysis of Particle Motions in Superfluid Helium-4 Using PTV Method
AUTHORS:
Lizhu Chen, Yoshiyuki Tsuji
KEYWORDS:
Superfluid, He II, Counterflow, Particle Tracking Velocimetry
JOURNAL NAME:
Journal of Flow Control, Measurement & Visualization,
Vol.10 No.2,
April
27,
2022
ABSTRACT: This paper describes the use of particle tracking velocimetry to analyze the Lagrangian acceleration of small particles in superfluid helium with varying time increments, . The probability density of acceleration exhibits Gaussian properties for ,but displays a lognormal distribution for ,where is the migration time characterizing the particle motion. The particle trajectories are well characterized by the Hurst exponent H. For smaller time scales than , the trajectories exhibit linear motion (), but have certain fractal properties with for time scales larger than .