Predictive acoustic modeling applied to the control of intake/exhaust noise of internal combustion engines.

1996 ◽  
Vol 99 (4) ◽  
pp. 2460-2500
Author(s):  
Peter O. A. L. Davies
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Acoustic Modeling ◽  
Combustion Engines ◽  
Exhaust Noise

Calculation of Acoustic Efficiency of Exhaust Silencers for Automotive Internal Combustion Engines

2021 ◽  
pp. 41-47
Author(s):  
Vladimir Tupov ◽  
O. Matasova
Keyword(s):  
Acoustic Waves ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Control Point ◽  
Plane Waves ◽  
Exhaust System ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Exhaust Noise ◽  
Insertion Losses

Insertion losses as the main characteristic that mathematically describes the acoustic efficiency of a noise silencer has been considered. This characteristic shows the reduction of noise generated by its source, in particular by the internal combustion engine’s exhaust system, at the control point as a silencer use result. Has been presented a mathematical description of the insertion losses, and have been considered parameters necessary for calculating this characteristic. Has been demonstrated the analytical dependence of impedance for the sound emission by the exhaust system’s end hole from the coefficient of acoustic waves reflection by this hole. The performed analysis of the widely used formulas for calculating the coefficient of sound reflection by the end hole has showed their insufficient accuracy for project designs performing. Have been proposed calculation dependences providing high accuracy for calculations of the reflection coefficient modulus, and the attached length of the channel end hole without a flange in the entire range of the existence of plane waves in it. It has been shown that the end correction of this hole at ka = 0 is 0.6127, and not 0.6133, as it was mistakenly believed until now in world acoustics. Has been proposed a method for calculation the exhaust noise source internal impedance. This method more accurately, in comparison with the already known ones, describes the acoustic processes in the internal combustion engine’s exhaust manifold, thanks to increases the accuracy of calculation the silencer acoustic efficiency, that allows develop the silencer at the early stages of the design of an automotive internal combustion engine.

Acoustic Modelling and Measurements of Engine Mufflers

1998 ◽  
Vol 5 (1) ◽  
pp. 27-38
Author(s):  
Samir N.Y. Gerges ◽  
Márcio R. Kimura ◽  
J.L. Bento Coelho
Keyword(s):  
Internal Combustion Engines ◽  
Transmission Loss ◽  
Noise Source ◽  
Internal Combustion ◽  
Industrial Applications ◽  
Combustion Engines ◽  
Acoustic Modelling ◽  
Exhaust Noise ◽  
Ic Engines ◽  
Diesel Motors

Most buildings such as hospitals, hotels, governmental offices, data processing rooms, etc, are equipped with internal combustion engines, diesel motors and generators to supply energy in emergencies. These same IC engines are used for industrial applications, building services and transportation. Exhaust noise are the predominant noise source with most internal combustion engines and thus exhaust systems incorporating mufflers have been designed to reduce the noise. This paper describes the analysis of several configurations of mufflers and also presents comparisons between the results for the transmission loss obtained by numerical modelling (FEM), Transfer Matrix Method (TMM) and measurements.

scholarly journals Research of the acoustic efficiency of chamber cells of ICE exhaust silencers

2020 ◽  
Vol 320 ◽  
pp. 00016
Author(s):  
Olga Matasova ◽  
Vladimir Tupov
Keyword(s):  
Internal Combustion Engines ◽  
Theoretical Study ◽  
Internal Combustion ◽  
Wide Frequency Range ◽  
Combustion Engines ◽  
Cell Design ◽  
Frequency Range ◽  
Highly Efficient ◽  
Exhaust Noise

To reduce the exhaust noise of internal combustion engines, exhaust silencer containing chamber cells are widely used. Cell design largely determines its acoustic efficiency as a function of frequency. Therefore, in this work, a theoretical study of the most frequently used chamber noise-suppressing cells of various designs is carried out. Designs with high acoustic efficiency in a wide frequency range have been determined. The results of the study will allow the designer, using these structures, to synthesize highly efficient ICE exhaust silencers.

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