论文标题
外部随机强迫下开普勒流动的扰动动力学
Perturbations dynamics in Keplerian flow under external stochastic forcing
论文作者
论文摘要
我们研究了外部随机力下开普勒流中线性扰动的动力学。从流量结构和边界条件的细节中抽象，我们考虑了剪切盒近似中的问题。假定外力的平均值为零，即使如此，诱导的扰动也形成了稳态，该稳态将角动量转移到流动的外围。最有效的情况是基于诱导涡旋的瞬时扩增，随后发射剪切声波，其中通量的最大值线性取决于雷诺数。因此，这种机制对于天体物理流很重要，对于天体物理流动，巨大的雷诺数是典型的。同时，通过分析问题，我们发现，对于剪切盒近似近似的不可压缩流体，随机强迫并不会导致平均角动量转移。因此，流体的可压缩性在这里起着重要作用，并且不能忽略它。
We investigate the dynamics of linear perturbations in Keplerian flow under external stochastic force. To abstract from the details of flow structure and boundary conditions, we consider the problem in the shearing box approximation. An external force is assumed to have zero mean, even so, induced perturbations form a steady-state, which provides angular momentum transfer to the periphery of the flow. The most effective scenario is based on the transient amplification of induced vortices with the following emission of shearing sound wave, wherein the maximum of the flux linearly depends on Reynolds number. Thus such a mechanism is significant for astrophysical flows, for which enormous Reynolds numbers are typical. At the same time, addressing the problem analytically, we found that for incompressible fluid in the shearing box approximation stochastic forcing does not lead to average angular momentum transfer. Thus the compressibility of the fluid plays an important role here, and one cannot neglect it.
