79 / 168
Abstracts
O3.4
Lagrange trajectory of small particles in super fluid HeII
Wataru Kubo and Yoshiyuki Tsuji
Nagoya University, Department of Energy Engineering and Science, Nagoya city
Japan 464-8603
Small tracer parties in HeII are visualized and their motions are analyzed. The
particles are made of solid hydrogen whose diameter is an order of micron. In a
counter flow, changing the heat flux and bath temperature, Lagrange velocity
and accelerations are computed by analyzing the visualized images through
PTV technique. We studied how the particle sizes affect the statistics of particle
motions. The probability density functions of acceleration shows nearly stretched
exponential shape. But the tail part is significantly affected by the particle sizes.
These are similar characteristics in classical turbulence. We compared the detail
of them and discuss their property.
O3.5
Inhomogeneous quantum turbulence in a channel
Makoto Tsubota, Satoshi Yui, Shinichi Ikawa
Department of Physics, Osaka City University, Osaka 558-8585, Japan
We discuss the numerical simulation of inhomogeneous quantum turbulence in a
square channel. The recent visualization experiments revealed inhomogeneous
flow profile in a channel. We discuss three topics. One is inhomogeneous structure
and dynamics of vortices in thermal counterflow[1]. The second is superfluid
boundary layer in pure normal flow, where we found the logarithmic velocity
profile of superfluid velocity [2]. The last is coflow turbulence. The simulation
finds a novel behavior that vortices are dragged into an attractor by the mutual
friction [3].
[1] S. Yui, M. Tsubota, Phys. Rev. B91, 174504(2015).
[2] S. Yui, K. Fujimoto, M. Tsubota, Phys. Rev. B92, 224513(2015).
[3] S. Ikawa, M. Tsubota, Phys. Rev. B93, 184508 (2016).
79