篇名 | An Experimental Study on Laminar-turbulent Transition in a Pulsating Pipe Flow |
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卷期 | 43:1 |
作者 | Lo, Hong-sen 、 Miau, Jiun-jih |
頁次 | 017-025 |
關鍵字 | Laminar-turbulent transition 、 Pulsating pipe flow 、 HHT analysis 、 MEMS sensors 、 EI |
出刊日期 | 201103 |
Experiments were made to study the process of laminar-turbulent transition in the developing region of a pulsating pipe flow. Particular
interest was placed upon the initial growth of velocity fluctuations near the pipe wall. Shown by the hot-wire velocity signals measured and the output signals of the MEMS thermal film sensors flushed with the wall surface, the initial disturbances appeared intermittently like a packet of waves in every cycle of pulsation. The characteristics of the disturbances were further analyzed with the Hilbert-Huang Transformation (HHT), from which the characteristic frequency could be identified quantitatively. The results obtained provide valuable information relevant to understanding the initial laminar-turbulent transition in a pulsating pipe flow.