Performance analysis of reactive silencers withconsideration of the effects of higher order acoustic modes반사형 소음기에 있어서 고차 모드 음파의 영향을 고려한 성능 해석

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 528
  • Download : 0
This dissertation presents the general method of three dimensional modeling of the fundamental reactive muffler elements such as the simple expansion chamber, the flow-reversing chamber and the resonator, for the theoretical prediction of their acoustic performances. From the solution of three-dimensional cylindrical wave equation subjected to the appropriate boundary conditions, the exact mathematical expressions of the four-pole parameters or transmission matrices are derived, and they are in turn substituted into the transmission loss equation, so that the black box approach for the whole silencing system can be realized. Firstly, the effects of higher order acoustic modes produced by the areal discontinuities of the simple expansion chamber with mean flow on the acoustic performance are studied. The chamber is modeled as a piston-driven circular rigid tube with no losses and by using the Fourier-Bessel expansion a general expression of the output pressure to the given input uniform volume velocity is obtained for a whole chamber. Quantitative estimation for the transmission loss can be performed using the derived four-pole parameters, whereas the characteristics of the chamber as a result of the interactions between the plane wave and the transverse waves can be easily investigated with respect to the relative locations of the inlet/outlet, the chamber length and the mean flow. The expression as a form of C in four-pole parameters is adopted to describe the chamber characteristics for computational convenience. Using the derived four-pole parameters, the transmission losses for both the concentric and offset inlet/outlet configurations are predicted and compared with the experimental results. The theoretical results of this study are in good agreements with the measured transmission losses. Secondly, a mathematical expression is derived for the prediction of the transmission loss of the reversing-chamber muffler with circular cross section in a similar mann...
Advisors
Lee, Byung-Ho이병호
Description
한국과학기술원 : 기계공학과,
Publisher
한국과학기술원
Issue Date
1985
Identifier
60909/325007 / 000795205
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 기계공학과, 1985.2, [ xiv, 132 p. ]

URI
http://hdl.handle.net/10203/42629
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=60909&flag=dissertation
Appears in Collection
ME-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0