Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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An Experimental Study of Radiated So from Elastic Thin Plate in a Turbulent Boundary Layer

난류 유동장 내에 놓인 탄성을 갖는 박판의 방사소음에 대한 실험적 연구

  • Published : 2001.10.01
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Abstract

The structural modes driven by the low wave-number components of smooth elastic wall pressure provide a relatively weak coupling between the flow and the wall motion. If the elastic thin plate has any resonant mode whose wave-number of resonance coincides with $\omega$/U$\sub$c/, the power will be transmitted to those modes of vibration by the flows. We examine the problem in which the elastic thin plate is subject to pressure fluctuations under turbulent boundary layer. Measurements are presented of the frequency spectra of the near- and far-field pressures and radiated sound contributed by the various wave modes of the thin elastic plate. Dispersion equation for wave motions of elastic plate is used to investigate the effect of bending waves of relatively low wave number on radiated sound. The low wave-number motion of elastic plate is observed to have much less influence on the low-frequency energy of wall pressure fluctuations than that of the rediated sound. High amplitude events of the wall pressure are observed to weakly couple with high-frequency energy of radiated sound for case of low tension applied to the plate. The sound source localization is applied to the measurement of radiated sound by using acoustic mirror system.

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References

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