Active control of noise has been an emerging technology for the past two decades. Active noise control (ANC) is an attractive means to achieve large amounts of noise reduction in a small package, particularly at low frequencies, where passive noise control may be impractical. While the concept of ANC has long been established, the technological means for implementing ANC have only recently beco...

In these review paper different types of mufflers and design of exhaust system belonging engine has been studied. The object of this study is decide muffler design which one reduces a large amount of noise level and back pressure of engine. In designing, there is different parameter which has to taken in to the consideration. These parameters affect the muffler efficiency.

This pape,r describes a flow-visualizatio n technique that was employed to qualitatively evaluate the gas flow pattern inside a small, low side, hermetically sealed, re ciprocating refrigeration compressor. The applicable compressor des igns are those in which the suction gas from the evaporator is dumped into the compressor shell, and is then drawn through a muffler into the suction plenum of ...

Design of muffler system strongly influences engine efficiency and noise level. Hence, comprehension of flow characteristics inside muffler system is very important. In this study, numerical study of three-dimensional steady and unsteady compressible flow inside muffler system attached to 4-cylinder engine was performed to identify the flow characteristics. To obtain the boundary conditions for...

In recent years there has been a growing focus on reducing the suction noise from hermetic household compressors. One approach is to reduce the transmitted sound power through the suction muffler at particular frequencies. In order to better control the acoustic performance of the muffler, a large variety of muffler designs have emerged. Most notably is the appearance of mufflers with two or mo...

This paper shows the details of comparison of noise attenuation level by convergent and divergent cylindrical duct with space constraints by using Transmission loss parameter. Reactive muffler is noise reduction element on exhaust system. Two basic term is used for noise attenuation first is transmission loss (TL) and other is insertion loss (IL). The main aim of this paper is to use of TMM, FE...

Mufflers are widely used for exhaust noise attenuation in vehicles and machinery. Recent advances in modeling procedures for accurate performance prediction have led to the development of modeling methods for practical muffler components in commercial design. Muffler designers need simple and fast modeling tools, especially in the preliminary design evaluation stages. Finite Element and Boundar...

To understand the mechanisms of neuronal Zn2+ homeostasis better, experimental data obtained from cultured cortical neurons were used to inform a series of increasingly complex computational models. Total metals (inductively coupled plasma-mass spectrometry), resting metallothionein, (65)Zn2+ uptake and release, and intracellular free Zn2+ levels using ZnAF-2F were determined before and after n...

The anechoic assumption has long been used for the modeling of long exit pipes or ducts of acoustic elements [1, 2, 3, 4, 5, 6, 7]. Especially in compressor discharge line modeling, the exhaust pipe from the compressor manifold leading all the way to the condenser is usually assumed to be anechoic since it is very long. Also, experimental efforts have been made by investigators using different ...

Perforated mufflers are widely used in automotive intake and exhaust systems and need to be properly designed. However, multi-objective optimization in practical perforated muffler designs usually involves finite element or boundary element models, which demand a higher computation time for evolutionary algorithms. In this paper, an approximate model for transmission loss (TL) predictions is es...