Self-sustained radial oscillating flows between parallel disks
Self-sustained radial oscillating flows between parallel disks
复制标题
平行盘之间的自持径向振荡流
DOI：
10.1017/s0022112085001586
复制
发表时间：
1985
影响因子：
3.7
通讯作者：
Wen‐Jei Yang
中科院分区：
文献类型：
--
作者：
S. Mochizuki;Wen‐Jei Yang
本文采用染料喷射、氢气泡产生和石蜡雾三种流动显示方法研究了定常流入平行圆盘间的径向流动。三种不同的流动模式，观察到在1.5和50之间的Re范围内。(1)无边界层分离和再附着的定常流动，Re <Rec。（2）在Rec [les ] Re < Ret范围内，一种向下游衰减的自控流动振荡。(3)当Re [ges ] Ret. Rec和Ret分别为临界雷诺数和过渡雷诺数。振荡流是由周期性地和交替地从两个盘分离的涡旋（即分离环形气泡）组成的涡街引起的。非定常涡量输运方程的差分解与某些实验观测结果大体一致。研究结果表明，平行圆盘径向流动中剪切层的分离和再附着是非定常现象，涡的成核、生长、迁移和衰减过程是自维持的。
The flow-visualization methods of dye injection, hydrogen-bubble generation and paraffin mist are employed to investigate radial flow between parallel circular disks with a steady influx. Three distinct flow patterns are observed in the range of Re between 1.5 and 50. (1) Steady flow without boundary-layer separation and re-attachment, for Re < Rec. (2) A self-controlled flow oscillation which decays further downstream, in the range of Rec [les ] Re < Ret. (3) A self-sustained flow fluctuation which develops into a laminar-turbulent transition with a reverse transition further downstream, when Re [ges ] Ret. Rec and Ret are the critical and transition Reynolds number, respectively. The oscillating flows are caused by a vortex street consisting of vortices (i.e. separating annular bubbles) that separate periodically and alternately from both disks. Finite-difference solutions of the unsteady vorticity transport equation broadly agree with certain experimental observations. The study concludes that the separation and reattachment of shear layers in the radial flow through parallel disks are unsteady phenomena and the sequence of nucleation, growth, migration and decay of the vortices is self-sustained.