Self-sustained aero-acoustic pulsations in gas transport systems: Experimental study of the influence of closed side branches
Self-sustained aero-acoustic pulsations in gas transport systems: Experimental study of the influence of closed side branches
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DOI：
10.1016/0022-460x(91)90893-o
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发表时间：
1991-11
影响因子：
4.7
通讯作者：
J. Bruggeman;A. Hirschberg;M. V. Dongen;A. Wijnands;J. Gorter
中科院分区：
文献类型：
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作者：
J. Bruggeman;A. Hirschberg;M. V. Dongen;A. Wijnands;J. Gorter
本文提出了一种在封闭支管中产生低频自持脉动的气动声源的理论模型。该理论成功地解释了在单侧分支实验中共振的声学和流体动力学条件。它还预测了脉动幅度的数量级以及由于摩擦和辐射引起的损失的影响。当连接处的边缘为圆形时，在双侧分支设置中观察到高脉动水平，其声速为主流的数量级。当在双侧分支设置中，第二T形接头的圆形上游边缘被尖锐边缘代替时，脉动幅度减小五倍。这种效应可以用涡流声理论来解释，这就引出了扰流器的设计。各种“扰流器”已经在缩尺模型和全尺寸实验中进行了测试。其中一些可将脉动水平降低40 dB。
A theoretical model is proposed for the aero-acoustic sources responsible for low-frequency self-sustained pulsations in pipes with closed side branches. The theory successfully explains the acoustic and hydrodynamic conditions for resonance in experiments with a single side branch. It also predicts the order of magnitude of the pulsation amplitude and the effect of losses due to friction and radiation. A high pulsation level, with acoustic velocities of the order of magnitude of the main flow, is observed in a double side branch set-up when the edges at the junctions are rounded. When in the double side branch set-up the rounded upstream edge of the second T-joint is replaced by a sharp edge, the pulsation amplitude is reduced by a factor of five. This effect, which can be explained with the theory of vortex sound, leads us to the design of spoilers. Various “spoilers” have been tested in scale model and full scale experiments. Some of these reduce the pulsation level by 40 dB.