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Study of Mechanism of Silencer Drainage Noise

Article of Honda R&D Technical Review Vol.22 No.2


Noise occurring at the exhaust outlet during idling and originating in condensate water accumulating in the silencer reduces the commercial appeal of vehicles. Visualization tests reproducing a silencer and predictive calculations based on a one-dimensional model were conducted in order to elucidate the mechanism of occurrence of this noise and study measures to prevent it. The results showed that pulsative pressure from the engine and the internal resonance of the exhaust pipes were factors in drainage noise, and the noise occurred when water films that had been generated and blocked the outlet pipe in areas in which the particle velocity was highest migrated downstream and broke up.
In addition, in order to prevent drainage noise, increasing the pressure differential before and after the formation of the water film, DP, is an effective measure in increasing drainage performance during idling.


(1) Japan Society of Mechanical Engineers ed.,: Handbook of Gas-Liquid Two-Phase Flow Technology, Second Edition, Corona Publishing, p. 604 (2006)
(2) Shimizu, F.: Analysis of Gas/Liquid Two-Phase Flow in a Siphon Tube, 18th Symposium on Computational Fluid Dynamics, C7-4 (2004)
(3) Tatsuno, M.: Formation of Liquid Fountains in a Kundt's Tube, Reports of Research Institute for Applied Mechanics Kyushu University, Vol. 128, p. 31-36 (2005)
(4) Matsuo, K.: Compressible Fluid Dynamics, Rikogakusha Publishing, p. 29-31
(5) Nisikawa, N., Hiraoka, K.: Ryutai Rikigaku, Baihukan Publishing, p. 105 (1998) (in Japanese)

Author (organization or company)

Osamu MATSUDA(Automobile R&D Center)、Michihiro TOKUNAGA(Automobile R&D Center)

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