Intermittent Switching Between Potential Flow and Turbulence in Superfluid Helium at mK Temperatures
Intermittent Switching Between Potential Flow and Turbulence in Superfluid Helium at mK Temperatures
复制标题
mK 温度下超流氦中势流和湍流之间的间歇切换
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
W. Schoepe
中科院分区：
文献类型：
--
作者：
M. Niemetz;H. Kerscher;W. Schoepe
在温度低至25 mK时，研究了振荡微球周围的超流体流动。在0.5 K以下，发现稳定的层流低于临界速度，而大驱动器的湍流则被中间范围的驱动力分开，其中流动不稳定，在层流和湍流阶段之间间歇性切换。我们记录了这种切换现象的时间序列，并对切换概率进行了统计分析。湍流相的平均寿命随着驱动的增大而增大，并在一个临界值处变为无限大。在临界速度以上的层流相的稳定性受到自然本底放射性或宇宙射线的限制。
Superfluid flow around an oscillating microsphere is investigated at temperatures down to 25 mK. Stable laminar flow below a critical velocity and turbulence at large drives are found to be separated below 0.5 K by an intermediate range of driving forces where the flow is unstable, intermittently switching between laminar and turbulent phases. We have recorded time series of this switching phenomenon and have made a statistical analysis of the switching probability. The mean lifetime of the turbulent phases grows with increasing drive and becomes infinite at a critical value. Stability of the laminar phases above the critical velocity is limited by natural background radioactivity or cosmic rays.