论文标题
磁性球形枪口流动的回流流量不稳定性的实验研究
Experimental investigation of the return flow instability in magnetic spherical Couette flow
论文作者
论文摘要
我们以Gainsn为工作流体进行磁性球形COUETTE（MSC）流动实验，以及内部与外球体半径$ r _ {\ rm i}/r _ {\ rm i}/r _ {\ rm o} = 0.5 $，reynolds $ reynolds $ { ha} \在[27.5,40] $中。在\ {2、3、4 \} $中旋转不同的方位角波数$ m \ in \ {2、3、4 \} $在实验中在某些范围内表现出$ {\ rm ha} $的某些范围，这取决于$ {\ rm ha} $的值是固定的还是与不同的初始值固定的。这些观察结果证明了旋转波的多稳定性，我们将其归因于代表MSC流量状态的动力系统，当$ {\ rm ha} $变化时，倾向于沿分叉图的同一解分支移动。在固定和变化的$ {\ rm ha} $的实验中，旋转波的旋转频率与非线性稳定性分析的结果一致。简短的数值研究表明，流动中发展的旋转波的方位角波数的差异也取决于最初激发的方位模式。
We conduct magnetic spherical Couette (MSC) flow experiments in the return flow instability regime with GaInSn as the working fluid, and the ratio of the inner to the outer sphere radii $r_{\rm i}/r_{\rm o} = 0.5$, the Reynolds number ${\rm Re} = 1000$, and the Hartmann number ${\rm Ha} \in [27.5,40]$. Rotating waves with different azimuthal wavenumbers $m \in \{2, 3, 4\}$ manifest in certain ranges of ${\rm Ha}$ in the experiments, depending on whether the values of ${\rm Ha}$ were fixed or varied from different initial values. These observations demonstrate the multistability of rotating waves, which we attribute to the dynamical system representing the state of the MSC flow tending to move along the same solution branch of the bifurcation diagram when ${\rm Ha}$ is varied. In experiments with both fixed and varying ${\rm Ha}$, the rotation frequencies of the rotating waves are consistent with the results of nonlinear stability analysis. A brief numerical investigation shows that differences in the azimuthal wavenumbers of the rotating waves that develop in the flow also depend on the azimuthal modes that are initially excited.
