The acoustic impedance of a circular orifice in grazing mean flow: comparison with theory.
The acoustic impedance of a circular orifice in grazing mean flow: comparison with theory.
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DOI：
10.1121/1.1621865
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发表时间：
2003-12
期刊：
影响因子：
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通讯作者：
K. Peat;J. Ih;Seong-Hyun Lee
中科院分区：
文献类型：
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作者：
K. Peat;J. Ih;Seong-Hyun Lee
众所周知，掠平均流的存在会影响孔径的声阻抗，但这种影响的详细性质和理解仍然是未知的。在本文中，从最近的理论分析的问题的结果进行了比较，一组新的实验结果。目的有两个。首先，实验结果被用来验证理论。结果发现，该理论预测的电阻相当不错，但不是电抗。第二，尝试用理论解释实验结果，并给出一些物理解释。特别是，一些标度律被确认，它也表明，测得的负电阻值是预期的。正如之前认为的那样，它们并没有错误。这个问题的前几组实验数据因其显示的变化量而引人注目。因此，理论和新的实验结果也与那些早期的详细的结果，最接近地符合这里假设的条件，即充分发展的低马赫数的湍流管流通过圆孔。主要应用领域是在流动管道中，特别是通过排气消声器中的穿孔管的流动。
It is well known that the presence of a grazing mean flow affects the acoustic impedance of an aperture, but the detailed nature and understanding of the influence is still unknown. In this paper, results from a recent theoretical analysis of the problem are compared with a new set of experimental results. The purpose is twofold. First, the experimental results are used to validate the theory. It is found that the theory predicts the resistance quite well, but not the reactance. Second, the theory is used to try and give some physical understanding to the experimental results. In particular, some scaling laws are confirmed, and it is also shown that measured negative resistance values are to be expected. They are not erroneous, as previously thought. Former sets of experimental data for this problem are notable for the amount of variation that they display. Thus, both the theory and the new experimental results are also compared with those earlier detailed results that most closely conform to the conditions assumed here, namely fully developed turbulent pipe flow of low Mach number past circular orifices. The main field of application is in flow ducts, in particular, flow through perforated tubes in exhaust mufflers.