An experimental study of oblique transition in plane Poiseuille flow
An experimental study of oblique transition in plane Poiseuille flow
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平面泊肃叶流斜过渡的实验研究
DOI：
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发表时间：
1998
影响因子：
3.7
通讯作者：
P. Alfredsson
中科院分区：
文献类型：
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作者：
P. Elofsson;P. Alfredsson
最近对斜波的相互作用进行了理论和数值研究，发现斜波的相互作用会导致亚临界流向线性波扰动的快速转变。过渡场景包括高低速流向条纹的形成和瞬时增长，以及随后导致崩溃的高频扰动的快速增长。本研究是首次对倾斜过渡进行广泛的实验研究。实验在平面泊肃叶流空气通道中进行，其中通过振动带产生斜波，每壁一个，并用热线风速计绘制流动的发展。实验包括低振幅和高振幅的波浪扰动；在这两种情况下都会产生条纹结构。对于低振幅情况，这些结构会衰减，而对于高振幅，流动会走向崩溃。这项研究证实并扩展了先前的理论和数值结果，表明倾斜转变可能是一种重要的转变情景。
Interactions of oblique waves have recently been investigated theoretically and numerically and found to give rise to rapid transition in flows subcritical to linear wave disturbances. The transition scenario consists of the formation and transient growth of streamwise streaks of high and low velocity and later a rapid growth of high-frequency disturbances leading to breakdown. The present study is the first extensive experimental investigation of oblique transition. The experiments were carried out in a plane Poiseuille flow air channel in which the oblique waves were generated, one at each wall, by vibrating ribbons and the development of the flow was mapped with hot-wire anemometry. The experiments consist both of low- and high-amplitude wave disturbances; in both cases streaky structures are created. For the low-amplitude case these structures decay, whereas for the high amplitude the flow goes towards breakdown. This study has confirmed and extended previous theoretical and numerical results showing that oblique transition may be an important transition scenario.