Analysis for effect of pores on acoustic performance of reactive muffler

2021 ◽  
pp. 095745652110307
Author(s):  
Pravin P Hujare ◽  
Vishal R Mote ◽  
Ashok R Mache ◽  
Deepak P Hujare ◽  
Sandeep S Kore
Keyword(s):  
Numerical Analysis ◽  
Transmission Loss ◽  
Combustion Engine ◽  
Exhaust System ◽  
Noise Pollution ◽  
Engine Exhaust ◽  
Target Frequency ◽  
Acoustic Performance ◽  
Outlet Pipe ◽  
Exhaust Noise

The major source of noise pollution was an internal combustion engine. Henceforth, the design of the engine exhaust system was a tough challenge for automotive industries. The mufflers have been used to moderate the exhaust noise from the engine to the neighboring atmosphere. So in domestic as well as the industrial application, it is required to reduce noise levels to prevent human hazards. The performance of muffler is measured in terms of transmission loss. The transmission loss of reactive muffler is depending on its geometry. This article describes the effects of pores at the inlet pipe and outlet pipe of the reactive muffler on its performance capacity at a target frequency. It is found that the muffler performance is dependent on the number and position of pores. The single chamber and double chamber reactive mufflers are used for the study. The numerical analysis is performed by COMSOL Multiphysics software. The numerical analysis result of the different models of the muffler is compared with experimental analysis. The purpose of the study is to investigate the effect of pores in inlet and outlet pipe to maximize the TL at the target frequency of reactive muffler.

scholarly journals Experimental Study of Pipes Shape Effect on Noise Reduction

2017 ◽  
Vol 5 (1) ◽  
pp. 71-86
Author(s):  
Muna S. Kassim ◽  
Ammar Fadhil Hussein Al-Maliki
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Noise Reduction ◽  
Power Plants ◽  
Combustion Engine ◽  
Exhaust System ◽  
Noise Pollution ◽  
Shape Effect ◽  
Pipe Length ◽  
Exhaust Noise

Internal combustion engine is a major source of noise pollution. These engines are used for various purposes such as, in power plants, automobiles, locomotives, and in various manufacturing machineries. The noise is caused by two reasons; the first reason is the pulses which created when the burst of high pressure gas suddenly enters the exhaust system, while the second reason is the friction of various parts of the engine where the exhaust noise is the most dominant. The limitation of the noise caused by the exhaust system is accomplished by the use of silencers and mufflers. The aim of this study is the reduction of the noise by changing its inlet and outlet pipe length and shape. Also the losses in noise for different length and shapes have been investigated experimentally. The results show that the corrugated pipe is preferable for noise reduction.

Attenuation analysis and acoustic pressure levels for double expansion chamber reactive muffler: Part 2

2018 ◽  
Vol 49 (6) ◽  
pp. 241-245
Author(s):  
Mahesh V Kulkarni ◽  
Ravindra B Ingle
Keyword(s):  
Acoustic Pressure ◽  
Combustion Engine ◽  
Exhaust System ◽  
Noise Pollution ◽  
Exhaust Pipe ◽  
Expansion Chamber ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Maximum Contribution ◽  
Exhaust Noise

The major source responsible for noise pollution is internal combustion engine. These engines are used for various purposes such as in automobiles, locomotives, and in various manufacturing machineries. In an engine, the exhaust noise and the noise produced due to friction of various parts of the engine share maximum contribution to noise pollution. Muffler is a device used to reduce noise within the exhaust system. It is arranged along the exhaust pipe for the purpose of noise attenuation. The paper describes the propagation of pressure wave in a double expansion chamber reactive muffler. The approach is useful in analysis of damping for propagation of harmonic pressure waves. The purpose of paper is to describe the finite element analysis of double expansion chamber reactive muffler using pressure acoustics and to validate it with experimental evaluation using two-load method.

Validation of set up for experimental analysis of reactive muffler for the determination of transmission loss: Part 1

2018 ◽  
Vol 49 (6) ◽  
pp. 237-240
Author(s):  
Mahesh V Kulkarni ◽  
Ravindra B Ingle
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Analysis ◽  
Transmission Loss ◽  
Combustion Engine ◽  
Exhaust System ◽  
Noise Pollution ◽  
Exhaust Pipe ◽  
Set Up ◽  
Element Method

The internal combustion engine is the major source responsible for noise pollution. In an engine, the exhaust noise and the noise produced due to friction of various parts of the engine share maximum contribution to noise pollution. A muffler is a device used to reduce noise within the exhaust system. It is arranged along the exhaust pipe for the purpose of noise attenuation. In this article, the set up for experimental analysis is developed to predict the acoustic performance of reactive muffler using the two-load method, and it is validated by measuring transmission loss of known reactive muffler model by using finite element method. For the model, transmission loss obtained from experimental analysis was compared with that obtained from the finite element method. From the result, it can be concluded that the setup developed for experimental analysis is reliable to determine transmission loss of exhaust muffler, for low to mid frequency range.

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.

The Design and Analysis of Closed-Coupled Exhaust Manifold

2012 ◽  
Vol 215-216 ◽  
pp. 1241-1245
Author(s):  
Rang Shu Xu ◽  
Xiang Feng Yan ◽  
Ling Niu ◽  
Zhi Wei Dong
Keyword(s):  
Combustion Engine ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Flow Distribution ◽  
Engine Exhaust ◽  
Business Software ◽  
Field Uniformity ◽  
Calculation Results ◽  
Cfd Method ◽  
Volume Method

The layout of closed-couple catalyst converter in internal combustion engine exhaust system is one of important way to reduce vehicle emission. CFD method based on finite volume method is adopted to numerical simulate flow distribution in the entrance of closed-coupled catalytic converter and applying business software of FLUENT to clarity the flow uniformity of inlet to ensure catalytic converter work efficiently and meet regulations. The flow field uniformity of entrance were studied and analyzed. Research finds that the shape of manifold has effect on dispersion of velocity in entrance and dispersion of velocity has a relatively strong correlation with pulsation flow. The flow reverse in junction deflect the air flow that flow into the entrance of closed-couple catalyst converter. Calculation results indicate that the uneven rate coefficient is 0.266 and volatility is 0.515 in the entrance of closed-couple catalyst.

The Design and Simulation of Diesel Engine Exhaust Muffler

2014 ◽  
Vol 556-562 ◽  
pp. 1075-1078 ◽  
Author(s):  
Zhi Hao Zhou ◽  
Dao Lai Chen ◽  
Ling Zhang Ji ◽  
Shou Peng Wan
Keyword(s):  
Diesel Engine ◽  
Transmission Loss ◽  
Simulation Method ◽  
Engine Exhaust ◽  
Diesel Engine Exhaust ◽  
Exhaust Noise

This paper is to use a fast and useful simulation method to verify the acoustics performance of the exhaust muffler which was designed, and find a better muffler. Based on analyzing the spectral of diesel engine exhaust noise and the muffler theory, and designed two different type of muffler. Got the transmission loss of muffler by using software. Finally, compared the two projects’ transmission loss and got the better effect.

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