Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.14103 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914042852933632 |
|---|---|
| author | Dunca, Tomáš Novotný, Filip Talíř, Marek Szalai, Balázs Ustinov, Nikita Skrbek, Ladislav Varga, Emil |
| author_facet | Dunca, Tomáš Novotný, Filip Talíř, Marek Szalai, Balázs Ustinov, Nikita Skrbek, Ladislav Varga, Emil |
| contents | We report preliminary results on spherical thermal counterflow generated by a small central heater in an open geometry, an open bath of superfluid He~II, as closed-cell experiments could have introduced artifacts such as overheating and boundary-induced flows. In order to eliminate them, we measure second sound attenuation in a plane-parallel resonator. Our results are at variance with the previous experiments in closed spherical cavity that showed plateau in the steady-state vortex line density and its inverse time decay, neither of which is observed presently. We find that in open geometry the vortex line density $L$ increases steadily with counterflow velocity $v_\mathrm{ns}$, displaying a crossover between $L \propto v_\mathrm{ns}^2$ typical for counterflow and $L \propto v_\mathrm{ns}^{3/2}$, characteristic for the quasi-classical scaling. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_14103 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Spherically symmetric counterflow turbulence in open geometry Dunca, Tomáš Novotný, Filip Talíř, Marek Szalai, Balázs Ustinov, Nikita Skrbek, Ladislav Varga, Emil Fluid Dynamics We report preliminary results on spherical thermal counterflow generated by a small central heater in an open geometry, an open bath of superfluid He~II, as closed-cell experiments could have introduced artifacts such as overheating and boundary-induced flows. In order to eliminate them, we measure second sound attenuation in a plane-parallel resonator. Our results are at variance with the previous experiments in closed spherical cavity that showed plateau in the steady-state vortex line density and its inverse time decay, neither of which is observed presently. We find that in open geometry the vortex line density $L$ increases steadily with counterflow velocity $v_\mathrm{ns}$, displaying a crossover between $L \propto v_\mathrm{ns}^2$ typical for counterflow and $L \propto v_\mathrm{ns}^{3/2}$, characteristic for the quasi-classical scaling. |
| title | Spherically symmetric counterflow turbulence in open geometry |
| topic | Fluid Dynamics |
| url | https://arxiv.org/abs/2509.14103 |