Application of the Galerkin-FEM and the improved four-pole parameter method to predict acoustic performance of expansion chambers

Barbieri, Renato; Barbieri, Nilson; Lima, Key Fonseca de

doi:10.1016/j.jsv.2003.11.063

Cited by 19 publications

(9 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 where the maximum size of the element is equal to 6 mm. This element size maintains two errors under control: the error of approximation or interpolation error and the numerical pollution caused by the indefiniteness of the variational form [3,4].…”

Section: Test Problemmentioning

confidence: 99%

“…Another parameter evaluated to check the quality of the finite element results is the unitary value of the reciprocity relation, AD À BC = 1 [12,4]. …”

Section: Test Problemmentioning

confidence: 99%

“…In this study, the objective function and the constraints are evaluated using the finite element method (FEM) and the quality of discrete solutions depends on the relation between the physical and geometrical parameters and the order of polynomial approximation [4][5][6]. FEMÕs choice was based on comparative results of studies performed in [14]:''The conclusions were that the FEM is better suited for this kind of application'' and '' The BEM, boundary element method, has been shown to be quite slow when compared to the FEM'' [14].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Finite element acoustic simulation based shape optimization of a muffler

Barbieri

2006

Applied Acoustics

View full text Add to dashboard Cite

Section: Test Problemmentioning

confidence: 99%

“…Another parameter evaluated to check the quality of the finite element results is the unitary value of the reciprocity relation, AD À BC = 1 [12,4]. …”

Section: Test Problemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Finite element acoustic simulation based shape optimization of a muffler

Barbieri

2006

Applied Acoustics

View full text Add to dashboard Cite

“…Numerical techniques such as finite element methods (FEM) and boundary element methods (BEM) have been proven to be more accurate at higher frequencies. Barbieri, et al 5 applied the Galerkin-FEM to obtain the four-pole parameters to predict the acoustic performance. Kirby 6 developed a fast and accurate hybrid finite element method for modelling automotive dissipative mufflers with perforated ducts and absorbing material.…”

Section: Introductionmentioning

confidence: 99%

Multi-objective Optimization of a Multi-chamber Perforated Muffler Using an Approximate Model and Genetic Algorithm

Zuo¹,

Wei²,

Wu³

2016

IJAV

View full text Add to dashboard Cite

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 established by correcting the thickness correction coefficient in the transfer matrix using the data calculated by the finite element model (FEM). The approximate model is computationally cheap and applicable for TL predictions above the plane wave cut-off frequency. A popular evolutionary algorithm, NSGA-, amalgamated with the approximate model, has been adopted to carry out the multi-objective optimization of a multi-chamber perforated muffler. The goals of optimization are to maximize TL at the target frequency range, as well as to minimize the valleys of TL and the size of the muffler. Both transmission loss and insertion loss of the optimized muffler are measured. Numerical and experimental results are in good agreement and show significant improvements of acoustic performance precisely at the target frequency range. Consequently, the combination of the approximate model and the NSGA-algorithm provides a fast, effective, and robust approach to co-axial perforated muffler optimization problems.

show abstract

“…It is known 6,7 that the Boundary Element Method (BEM) is reasonably accurate for predicting the performance of the expansion muffler with rigid duct walls. In order predict the performance of an expansion muffler with flexible duct walls in terms of TL numerically, it is necessary to consider the discretization of the muffler's structure using a coupled BEM-FEM model.…”

Section: Introductionmentioning

confidence: 99%

Prediction of the Performance of the Expansion Chamber in Air Ducts

Mak

Wang

2006

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

An expansion chamber is frequently used as an acoustics silencer for the control of duct-borne noise in ventilation systems. The flow of air and the effect of sound pressure may cause the vibration of the end plates of the expansion chamber and in turn will influence the performance (usually in terms of the transmission loss (TL)) of the expansion chamber. By combining the plate bending element and the plane stress element, BEM (for acoustics systems) and FEM (for the structure analysis) are applied to predict the performance of the expansion muffler. A method for calculating the TL for acoustics silencer using BEM-FEM coupled model is therefore presented, and an improved method based on the four-pole parameters used in the BEM is obtained. Keywords: expansion chamber, silencer, performance, transmission loss INTRODUCTIONDespite the benefits of thermal comfort provided by air-conditioning systems, there is an increasing concern about the noise produced by air duct systems. There are basically two types of noise control methods used in air duct systems, passive control and active control methods. The passive noise control method usually takes two forms. One is by means of viscous dissipative materials in the air duct system and the other one is by means of wave reflection by discontinuity of impedance, i.e. the expansion muffler. In order to simplify the study of the performance of the expansion muffler, the vibrating effects of the duct walls and the end plates of the expansion chamber were ignored in past works 1~3 . However, previous works suggested 4,5 that the sidewalls and the end plate of expansion chamber element should be considered as vibratory shell elements so that cavity and shell structure may interact with each other. The prediction of the performance of the expansion chamber in terms of Transmission Loss (TL) will be affected by the vibration of the duct walls and the end plate of the expansion chamber.It is known 6,7 that the Boundary Element Method (BEM) is reasonably accurate for predicting the performance of the expansion muffler with rigid duct walls. In order predict the performance of an expansion muffler with flexible duct walls in terms of TL numerically, it is necessary to consider the discretization of the muffler's structure using a coupled BEM-FEM model. By matching nodes of BEM and FEM, linear triangular boundary elements can be used to discretize Helmholtz's integral equation, and a triangular flat shell element can be created by combining a flat bending element and a plane stress element. The BEM and FEM based on the unite segmentation element can then be coupled.

show abstract

Application of the Galerkin-FEM and the improved four-pole parameter method to predict acoustic performance of expansion chambers

Cited by 19 publications

References 11 publications

Finite element acoustic simulation based shape optimization of a muffler

Finite element acoustic simulation based shape optimization of a muffler

Multi-objective Optimization of a Multi-chamber Perforated Muffler Using an Approximate Model and Genetic Algorithm

Prediction of the Performance of the Expansion Chamber in Air Ducts

Contact Info

Product

Resources

About