Stability experiments in the flow over a rotating disk
Stability experiments in the flow over a rotating disk
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旋转盘上流动的稳定性实验
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
M. Malik
中科院分区：
文献类型：
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作者：
S. Wilkinson;M. Malik
本文对静空气中旋转平面圆盘的过渡流动进行了实验研究。利用数字化热线数据，从空间坐标和速度波动两方面绘制了固定螺旋涡的轴，这是磁盘流的主要不稳定机制。给出了清洁磁盘和具有单个隔离粗糙度元素的磁盘的数据。数据表明，螺旋涡是在圆盘上离散的粗糙度扰动点产生的，并以波包的形式传播和生长。只有当这些波包合并并充满整个周长时，才会出现我们所熟悉的30个左右的漩涡模式。在湍流击穿之前，还观察到平稳的、二次不稳定性的出现。
An experimental study of the transitional flow over a flat disk rotating in quiescent ambient air has been conducted. Using digitized hot-wire data, the axes of the stationary spiral vortices, which are the primary instability mechanisms for the disk flow, have been mapped out in terms of both spatial coordinates and velocity fluctuations. Data are presented for a clean disk and a disk with a single, isolated roughness element. The data show that the spiral vortices are generated at discrete roughness disturbance sites on the disk and that they propagate and grow as wave packets. The familiar vortex pattern of 30 or so vortices results only when these wave packets have merged and filled the entire circumference. The appearance of stationary, secondary instabilities prior to turbulent breakdown has also been observed.