Optimal Design of Side-Inlet/Side-Outlet Expansion Mufflers with Open-Ended Perforated Tubes Using Simulated Annealing

2011 ◽  
Vol 27 (4) ◽  
pp. 533-544 ◽  
Author(s):  
M.-C. Chiu ◽  
Y.-C. Chang
Keyword(s):  
Pure Tone ◽  
Recent Literature ◽  
Transmission Loss ◽  
Research Work ◽  
Broadband Noise ◽  
System Matrix ◽  
New Techniques ◽  
Acoustic Performance ◽  
Simulated Algorithm ◽  
Pole System

ABSTRACTResearch on new techniques of multi-chamber mufflers equipped with a side inlet and internal nonperforated intruding tubes has been discussed in recent literature; however, the research work of multichamber mufflers in conjunction with side inlet and open-ended perforated intruding tubes which may efficiently increase the acoustical performance has been neglected. Therefore, the main purpose of this paper is to optimize the best design shape of multi-chamber side mufflers with open-ended perforated intruding tubes within a limited space.In this paper, the four-pole system matrix in evaluating the acoustic performance is also deduced in conjunction with a simulated algorithm (SA). Results reveal that the maximum sound transmission loss (STL) is precisely located at the desired target tone. In addition, the acoustical performance of mufflers conjugated with perforated intruding tubes is superior to those equipped with non-perforated tubes. Additionally, the noise reduction ability for a three-chamber side muffler with a non-perforated intruding tube and a two-chamber side muffler with perforated intruding tubes are equivalent. Moreover, mufflers with more chambers will increase the acoustic performance for both pure tone and broadband noise.

The Optimal Design of Multi-Chamber Side Mufflers Equipped with Perforated Cross-Flow Tubes and Intruding Tubes using Simulated Annealing

2011 ◽  
Vol 27 (3) ◽  
pp. 321-335 ◽  
Author(s):  
Y.-C. Chang ◽  
M.-C. Chiu
Keyword(s):  
Optimal Design ◽  
Transmission Loss ◽  
Research Work ◽  
Cross Flow ◽  
Wave Theory ◽  
Broadband Noise ◽  
System Matrix ◽  
Acoustic Performance ◽  
Accuracy Check ◽  
The Mathematical Model

ABSTRACTResearch on new techniques of side-inlet/outlet mufflers equipped with internal non-perforated intruding tubes has been discussed in recent literature; however, the research work of multi-chamber sideinlet/outlet mufflers in conjunction with cross-flow tubes and open-ended perforated intruding tubes which may efficiently increase the acoustical performance is rare. Therefore, the main purpose of this paper is not only to analyze the sound transmission loss (STL) of three kinds of side-inlet/outlet mufflers (a three-chamber muffler with cross-flow tubes, a five-chamber muffler with cross-flow tubes and a nonperforated tube, and a five-chamber muffler with cross-flow tubes and a perforated tube) but also to optimize their best design shape within a limited space.In this paper, both the generalized decoupling technique and plane wave theory in solving the coupled acoustical problem are used. A four-pole system matrix in evaluating the acoustic performance is also deduced in conjunction with a simulated algorithm (SA). A numerical case in finding the optimal STL of mufflers, which is constrained within a basement with a side-inlet/outlet, at targeted tones has been introduced. Before the optimization is carried out, an accuracy check of the mathematical model is performed. Results reveal that the maximal STL is precisely located at the desired target tone. Moreover, it has been seen that mufflers with more chambers will increase the acoustic performance for both pure tone and broadband noise. Additionally, the acoustical performance of mufflers conjugated with perforated intruding tubes is superior to those equipped with non-perforated tubes.Consequently, the approach used for seeking the optimal design of the STL proposed in this study is indeed easy and quite effective.

Optimal Design of Multichamber Mufflers Hybridized With Perforated Intruding Inlets and Resonating Tubes Using Simulated Annealing

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Min-Chie Chiu
Keyword(s):  
Simulated Annealing ◽  
Optimal Design ◽  
Transmission Loss ◽  
Narrow Band ◽  
Broadband Noise ◽  
Optimal Result ◽  
New Techniques ◽  
Successful Approach ◽  
Pure Tones ◽  
The Mathematical Model

Recently, research on new techniques for single-chamber mufflers equipped with perforated resonating tubes has been addressed. However, the acoustical performance of mufflers having a narrow-band sound transmission loss (STL) is insufficient in reducing a broadband venting noise. To improve the acoustical efficiency, a hybrid muffler with chambers composed of perforated intruding inlets is presented. Here, we will not only analyze the STL of three kinds of mufflers (A: a one-chamber muffler hybridized with a perforated resonating tube; B: a two-chamber muffler hybridized with a perforated intruding tube and a resonating tube; and C: a three-chamber muffler hybridized with two perforated intruding tubes and a resonating tube), but also optimize the best design shape within a space-constrained situation. In this paper, both the numerical decoupling technique and simulated annealing (SA) for solving the coupled acoustical problem of perforated tubes are used. A numerical case for eliminating a broadband air compressor noise is also introduced. To verify the reliability of SA optimization, optimal noise abatements for the pure tones (400 Hz and 800 Hz) are exemplified. Before the SA operation can be carried out, the accuracy of the mathematical model is checked using the experimental data. Results indicate that the maximal STL is precisely located at the desired target tones. The optimal result of case studies for eliminating broadband noise also reveals that the overall noise reduction with respect to the mufflers can be reduced from 131.6 dB(A) to 102.1 dB(A), 89.5 dB(A), and 82.1 dB(A). As can be seen, the acoustical performance will increase when the diameters (at the inlet tubes as well as perforated holes) decrease. Moreover, it is obvious that the acoustical performance will be improved when the chambers equipped with perforated intruding inlets are increased. Consequently, a successful approach used for the optimal design of the multichamber mufflers equipped with perforated intruding tubes and a resonating tube within a space-constrained condition has been demonstrated.

Acoustic performance and flow analysis of a multi-chamber perforated resonator for the intake system of a turbocharged engine

2016 ◽  
Vol 231 (1) ◽  
pp. 120-129 ◽  
Author(s):  
Rong Guo ◽  
Wen-bo Tang ◽  
Wei-wei Zhu
Keyword(s):  
Pressure Drop ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Transmission Loss ◽  
Noise Spectrum ◽  
Broadband Noise ◽  
Test Facility ◽  
Acoustic Performance ◽  
Intake System

A multi-chamber perforated resonator is a type of silencer which can attenuate broadband noise. In order to address the noise issues originating from the intake system of a turbocharged engine, measurement tests are carried out to characterize the range and the amplitudes of the noise frequencies. A transfer matrix method and a non-linear least-squares optimization algorithm are combined in order to design the multi-chamber perforated resonator. A transmission loss test facility is designed on the basis of the two-load method so as to validate the acoustic performance of the resonator. Despite the difference between the amplitude of the transmission loss from the tests and the amplitude of the transmission loss obtained by the transfer matrix method, the shapes of the two curves have the same trend, and the measured transmission loss can meet the design target in the frequency range of interest. From the comparison between the intake noise spectrum with the resonator and the intake noise spectrum without the resonator, it can be seen that this resonator can efficiently attenuate the broadband intake noise of the engine. Also, a computational fluid dynamics flow simulation analysis of the intake system with the resonator is made so that its flow characteristics can be studied. The simulation results show that the air pressure drop of this resonator is slightly higher than that of the straight pipes but is still relatively low. It is also noted that the diameter and the curvature of the pipes have a great influence on the air velocity as well as on the pressure drop.

Shape Optimization of Mufflers Composed of Multiple Rectangular Fin-Shaped Chambers Using Differential Evolution Method

2015 ◽  
Vol 40 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Min-Chie Chiu ◽  
Ying-Chun Chang ◽  
Ho-Chih Cheng ◽  
Wei-Ting Tai
Keyword(s):  
Differential Evolution ◽  
Pure Tone ◽  
Wave Theory ◽  
Broadband Noise ◽  
Acoustic Performance ◽  
Constrained Problem ◽  
Numerical Assessment ◽  
Successful Approach ◽  
Pure Tones ◽  
The Mathematical Model

Abstract There has been considerable research done on multi-chamber mufflers used in the elimination of industrial venting noise. However, most research has been restricted to lower frequencies using the plane wave theory. This has led to underestimating acoustical performances at higher frequencies. Additionally, because of the space-constrained problem in most plants, the need for optimization of a compact muffler seems obvious. Therefore, a muffler composed of multiple rectangular fin-shaped chambers is proposed. Based on the eigenfunction theory, a four-pole matrix used to evaluate the acoustic performance of mufflers will be deduced. A numerical case for eliminating pure tones using a three-fin-chamber muffler will also be examined. To delineate the best acoustical performance of a space-constrained muffler, a numerical assessment using the Differential Evolution (DE) method is adopted. Before the DE operation for pure tone elimination can be carried out, the accuracy of the mathematical model must be checked using experimental data. The results reveal that the broadband noise has been efficiently reduced using the three-fin-chamber muffler. Consequently, a successful approach in eliminating a pure tone using optimally shaped three-fin-chamber mufflers and a differential evolution method within a constrained space has been demonstrated.

Genetic Algorithm Optimization on a Venting System With Three-Chamber Hybrid Mufflers Within a Constrained Back Pressure and Space

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Min-Chie Chiu
Keyword(s):  
Genetic Algorithm ◽  
Pressure Drop ◽  
Transmission Loss ◽  
Wave Theory ◽  
Broadband Noise ◽  
Back Pressure ◽  
System Matrix ◽  
Algorithm Optimization ◽  
Relief Valve ◽  
Noise Abatement

Recently, research on new techniques for dissipative mufflers in dealing with the higher frequencies has been addressed. However, the shape optimization of hybrid mufflers in reducing broadband noise within a constrained space as well as a pressure-drop limit which are both concerned with the necessity of operation and system venting in practical engineering work was rarely tackled. Therefore, this study will not only analyze the sound transmission loss (STL) of a space-constrained multichamber hybrid muffler but also optimize the best design shape under a specified pressure drop. In this paper, the generalized decoupling technique and plane wave theory used to solve the coupled acoustical problem of perforated mufflers with/without sound absorbing material are presented. The four-pole system matrix used to evaluate acoustic performance is also introduced in conjunction with a genetic algorithm (GA). A numerical case for eliminating a broadband venting noise emitted from a pressure relief valve using four kinds of hybrid mufflers is also introduced. To verify the reliability of the GA optimization, optimal noise abatement for a pure tone (1000 Hz) is exemplified. Before the GA operation can be carried out, the accuracy of the mathematical models need to be checked using the experimental data. The optimal result in eliminating broadband noise reveals that the overall noise reductions with respect to various mufflers under a maximal allowable pressure drop of 100 Pa can achieve 62.6, 54.8, 32.3 and 87.8 dB. Consequently, the approach used for the optimal design of the multichamber hybrid mufflers under space and back pressure constrained conditions is indeed easy and quite effective.

scholarly journals Numerical assessment of two-chamber mufflers hybridized with multiple parallel perforated plug tubes using simulated annealing method

2017 ◽  
Vol 36 (1) ◽  
pp. 3-26 ◽  
Author(s):  
Min-Chie Chiu
Keyword(s):  
Simulated Annealing ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Global Optimum ◽  
Broadband Noise ◽  
Optimization Process ◽  
Sound Transmission Loss ◽  
System Matrix ◽  
Simulated Annealing Method ◽  
Annealing Method

Enormous effort has been applied to research on mufflers hybridized with a single perforated plug tube; nonetheless, mufflers conjugated with multiple parallel perforated plug tubes that disperse venting fluid and reduce secondary noise have been overlooked. To this end, an analysis of the sound transmission loss of two-chamber mufflers with multiple parallel perforated plug tubes that are optimally designed to perform within a limited space will be presented. Here, using a decoupled numerical method, a four-pole system matrix for evaluating acoustic performance (sound transmission loss) is derived. During the optimization process, a simulated annealing method, which is a robust scheme utilized to search for the global optimum by imitating a physical annealing process, is used. Prior to dealing with a broadband noise, the sound transmission loss’s maximization relative to a one-tone noise (200 Hz) is produced to check the simulated annealing method’s reliability. The mathematical model is also confirmed for accuracy. To understand the acoustical effects brought about by the various tubes (perforated tubes, internally extended non-perforated tubes, and non-perforated tubes), mufflers with internally extended non-perforated tubes and non-perforated tubes have been evaluated. The optimization of three kinds of two-chamber mufflers hybridized with one, two, and four perforated plug tubes have also been compared. The results are revealing: the acoustical performance of mufflers conjugated with more perforated plug tubes decreases as a result of the decrement of the acoustical function for acoustical elements (II) and (III). Accordingly, in order to design a better muffler, an advanced presetting of the maximum (allowable) flowing velocity is necessary before an appropriate number of perforated plug tubes can be chosen for the optimization process.

NUMERICAL ASSESSMENT OF REVERSE-FLOW MUFFLERS USING A SIMULATED ANNEALING METHOD

2010 ◽  
Vol 34 (1) ◽  
pp. 17-35 ◽  
Author(s):  
Min-Chie Chiu
Keyword(s):  
Simulated Annealing ◽  
Transmission Loss ◽  
Reverse Flow ◽  
Global Optimum ◽  
Broadband Noise ◽  
System Matrix ◽  
Limited Space ◽  
Numerical Assessment ◽  
Accuracy Check ◽  
The Mathematical Model

Because of the necessity of maintenance and operation in industries in which the equipment layout is occasionally tight, the space for a muffler is constrained. An interest in maximizing the acoustical performance of mufflers within a limited space is of paramount importance. As mufflers hybridized with reverse-flow ducts may visibly increase acoustical performance, the main purpose of this paper is to numerically analyze and maximize their acoustical performance within a limited space. In this paper, a four-pole system matrix for evaluating the acoustic performance —sound transmission loss (STL)— is derived by using a decoupled numerical method. Moreover, simulated annealing (SA), a robust scheme used to search for the global optimum by imitating the metal annealing process, has been used during the optimization process. Before dealing with a broadband noise, the STL’s maximization with respect to a one-tone noise (300 Hz) is introduced for a reliability check on the SA method. Moreover, an accuracy check of the mathematical model is performed. Results reveal that the STL of a muffler with reverse-flow perforated ducts can be maximized at the desired frequency for pure tone elimination; moreover, the noise reduction for a broadband noise can reach 97.5 dB. Consequently, the approach used for the optimal design of the mufflers is simple and effective.

Numerical Assessment of Optimal One-Chamber Perforated Mufflers by Using GA Method

2008 ◽  
Vol 594 ◽  
pp. 368-376 ◽  
Author(s):  
Min Chie Chiu ◽  
Ying Chun Chang ◽  
Long Jyi Yeh
Keyword(s):  
Transmission Loss ◽  
Research Work ◽  
Sound Transmission ◽  
Wave Theory ◽  
Sound Transmission Loss ◽  
System Matrix ◽  
Numerical Assessment ◽  
Machine Room ◽  
The One ◽  
Constrained Conditions

Research on new techniques of perforated silencers has been addressed; however, the research work in shape optimization for a volume-constrained silencer requested upon the demands of operation and maintenance inside a constrained machine room is rare. Therefore, the main purpose of this paper is not only to analyze the sound transmission loss of a one-chamber perforated muffler but also to optimize the best design shape under space-constrained conditions. In this paper, both the generalized decoupling technique and plane wave theory are used. The four-pole system matrix used to evaluate acoustic performance is also deduced in conjunction with a genetic algorithm (GA); moreover, numerical cases of sound elimination with respect to pure tones (150, 550, 950 Hz) are fully discussed. Before GA operation can be carried out, the accuracy of the mathematical model has to be checked using Crocker’s experimental data. The results reveal that the maximum value of sound transmission loss (STL) can be optimally and precisely achieved at the desired frequencies. Consequently, the approach used for the optimal design of the one-chamber perforated mufflers is indeed easy and quite effective.

scholarly journals Experimental Study of Advanced Helmholtz Resonator Liners with Increased Acoustic Performance by Utilising Material Damping Effects

2018 ◽  
Vol 8 (10) ◽  
pp. 1923
Author(s):  
Martin Dannemann ◽  
Michael Kucher ◽  
Eckart Kunze ◽  
Niels Modler ◽  
Karsten Knobloch ◽  
...  
Keyword(s):  
Polymer Films ◽  
Helmholtz Resonator ◽  
Broadband Noise ◽  
Acoustic Energy ◽  
Acoustic Damping ◽  
Acoustic Performance ◽  
Acoustic Liners ◽  
Flexible Polymer ◽  
Noise Absorption ◽  
Aero Engines

In aero engines, noise absorption is realised by acoustic liners, e.g., Helmholtz resonator (HR) liners, which often absorb sound only in a narrow frequency range. Due to developments of new engine generations, an improvement of overall acoustic damping performance and in particular more broadband noise absorption is required. In this paper, a new approach to increase the bandwidth of noise absorption for HR liners is presented. By replacing rigid cell walls in the liner’s honeycomb core structure by flexible polymer films, additional acoustic energy is dissipated. A manufacturing technology for square honeycomb cores with partially flexible walls is described. Samples with different flexible wall materials were fabricated and tested. The acoustic measurements show more broadband sound absorption compared to a reference liner with rigid walls due to acoustic-structural interaction. Manufacturing-related parameters are found to have a strong influence on the resulting vibration behaviour of the polymer films, and therefore on the acoustic performance. For future use, detailed investigations to ensure the liner segments compliance with technical, environmental, and life-cycle requirements are needed. However, the results of this study show the potential of this novel liner concept for noise reduction in future aero-engines.

scholarly journals Low Loss Transmission Circular Polarizer for KU Band Application

2018 ◽  
Vol 1 (1) ◽  
pp. 28-33
Author(s):  
Farman Ali Mangi
Keyword(s):  
Circular Polarization ◽  
Transmission Loss ◽  
Low Loss ◽  
New Techniques ◽  
Resonant Frequencies ◽  
Circular Polarizer ◽  
Left Handed ◽  
Distinct Frequency ◽  
The Right ◽  
Ku Band

Low loss transmission circular polarizer is proposed for Ku band applications. The designed structure consists of two closely cross metallic strips which are based on FSS for 15.25 GHz and 15.28 GHz applications. The right hand circular polarization (RHCP) and left handed circular polarization (LHCP) are obtained at 15.25 GHz and at 15.28 GHz. The transmission loss through polarizer is important issue for high frequency applications. Due to transmission loss, new techniques are required to reduce the transmission loss of transmitted wave and achieve perfect circular polarization. Meanwhile, low loss transmission has been achieved by using dual layer of strips to obtain perfect circular polarization at certain mentioned resonant frequencies. Theoretically, it is found that the outgoing waves through polarizer are perfect circular polarization at the distinct frequency ranges.

Sign in / Sign up

Export Citation Format

Share Document