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...

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...

The discharge muffler of the rotary compressor is used to reduce the discharge noise produced by pressure pulsations. In order to obtain the transmission loss of discharge muffler, four microphone experimental devices used to measure the transmission loss of the muffler is established. The device is based on the transfer function method on the assumption that there is only plane wave in the tub...

The optimization approach of maximal STL (sound transmission loss) and muffler dimension under space constraints within a building or machine room is fully addressed throughout the graphic analyses as well as the computer-aided numerical assessments in this paper. The primary set of design data is derived by the computer graphic analysis on sensitivity, and the successive algorithm of iteration...

The aim of this paper is to present the numerical resolution of suction muffler configurations (by means of a tridimensional, unstructured, parallel and object oriented CFD&HT TermoFluids code (Lehmkuhl, et al. 2007) specially adapted to low Mach models (Lopez et al. 2012), coupled with the numerical resolution of the whole compressor domain (by means of a modular, unstructured and object orien...

The acoustic behavior of perforated dissipative circular mufflers with empty extended inlet/outlet is investigated in detail by means of a two-dimensional (2D) axisymmetric analytical approach that matches the acoustic pressure and velocity across the geometrical discontinuities, and the finite element method (FEM). The complex characteristic impedance, wavenumber, and perforation impedance are...