This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Study on the Relation Between Pulsating Flow and the Noise
Annotation ability available
Sector:
Language:
English
Abstract
Behavior of pressure waves in exhaust pipes of a reciprocating internal combustion engine influences greatly the noise generated at the end of pipe.
To find the relation between the flow pattern throughout the exhaust pipe and exhaust noise, a pulsating flow through a pipe with and without a nozzle, the area ratio of the nozzle to the pipe being 0.25, was experimentally examined. The pulsating flow was generated by the rotary valve.
The pressure histories at each station along the pipe and the noise generated at the end of the pipe were measured against the different rotational speeds of the rotary valve. The pressures were differentiated with respect to time so that the intensity of the pressure waves was estimated, and wave diagram was constructed.
As a result, the relation between the increase and decrease in the intensity of the pressure wave and the rotational speed was found to be related to the arrival time of the compression waves at the rotary valve and the end of pipe. Intensity of the compression wave which is produced when the valve is about to open contributed most to the generation of the noise.
Recommended Content
Citation
Futagami, Y. and Iwamoto, J., "A Study on the Relation Between Pulsating Flow and the Noise," SAE Technical Paper 961822, 1996, https://doi.org/10.4271/961822.Also In
References
- Sekine N. et al. “Study of Silencer Characteristics in Gas Flow with Shock Wave (2nd Report, Pressure Characteristics of Silencer)” Trans. JSME(B) 61 584 36 41 1995
- Endo M. Iwamoto J. “The Influence of Wave Action on Mass Flow Rate through Pipe” SAE Paper 911724 1991
- Sekine N. et al. “Initiation and Propagations of Shock Waves in the Exhaust Pipe of an Internal Combustion Engine” Trans. JSME(B) 54 498 527 531 1987
- Takayama K. et al. “Shock Wave Development and Propagation in Automobile Exhaust Systems” SAE Paper 880082 1989
- Matsumura S. et al. “Shock Wave Formation in the Exhaust Pipe of an Internal Combustion Engine” Trans. JSME(B) 56 532 200 205 1990
- Matsumura S. et al. “Noise Induced by Shock Waves in Automobile Exhaust Systems” Jour. JSAE 47 6 30 35 1993
- Iwamoto J. “Experimental Investigation of a Rotary Valve” TDU Report 22 127 150 1974