Proceedings of the KSME Conference (대한기계학회:학술대회논문집)
- 2003.04a
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- Pages.2066-2070
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- 2003
An Experimental Study on the Impulse Noise Emitted from the Exit of a Perforated Pipe
다공관 출구로부터 방사된 충격성 소음에 관한 실험적 연구
Abstract
This experimental study describes the propagation characteristics and suppression of the impulse noise emitted from the exit of a perforated pipe attached to the open end of a simple shock tube. The experiment is performed through the systematic change of the shock wave Mach number and the geometrical parameters such as the porosity, hole diameter and length of the perforated pipe. The experimental results for the near and far sound field are presented and explained in comparison with those for a straight pipe. The results obtained show that for the near sound field the impulse noise strongly propagates toward to the pipe axis, but for the far sound field the impulse noise uniformly propagates toward to the all directions, indicating that the directivity pattern is almost same regardless of the pipe type. Moreover, the noise reduction performance of perforated pipe depends upon the condition of sound field. For the near sound field the perforated pipe has a little performance to suppress the impulse noise, but for the far sound field the perforated pipe has little performance to suppress the impulse noise.
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