Effect of geometric parameters on the acoustical performance of single inlet single outlet expansion chamber muffler

Nag, Sarthak; Gupta, Arpan; Dhar, Atul

doi:10.1109/iceeot.2016.7755147

Cited by 7 publications

(5 citation statements)

References 6 publications

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“…The three-point method is also the fastest method and is easy to use; whereas, the quadruple method is not so straightforward to deal with (Bilawchuk, Fyfe, 2003;Dube et al, 2018). The acoustic performance of the expansion chamber depends on the cross-sectional area; so that, the transmission loss parameter decreases if the diameter of the expansion chamber increases (Cao et al, 2017;Łapka, 2014;Nag et al, 2017;Zhang et al, 2009). In the low-frequency range, the transmission loss values are equal to the results obtained from the plane wave theory.…”

Section: Introductionmentioning

confidence: 86%

Archives of Acoustics

Rasoulimoghadam

Kheradmand

2019

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In the present work, an approach to obtain a design method for the size of the plenum chamber cross-section of a marine gas turbine air supply system has been investigated. Flow in ducts makes noise which is very high in the turbine inlet part because of the large amount of flow. Therefore, this phenomenon should be considered in the design process. A suitable approach to design the duct is proposed (considering acoustic and aerodynamic performance at the same time). In this method, an air supply channel system of the marine gas turbine has been categorized into three sections according to the requirements of the aerodynamic and acoustic; inlet, plenum chamber, and outlet channels with circular cross-sections. The geometrical dimensions of inlet and outlet channels have been determined using the plane waves theory about a channel, in which the effects of flow is ignored. Space limitations of battleships at the dominant frequency have been considered. Then, the optimized size of the mid-channel section, in terms of both aerodynamic and acoustic requirements, using numerical methods and regarding the effects of flow has been calculated. Various 3D turbulent flows inside the plenum chamber have been considered, in which large eddy simulation turbulence model is utilized. Ffowcs, Williams and Hawkings models are used for the sound propagation process based on the Lighthill integral equation. The validity of the simulation has been checked by comparing results (sound pressure level) with experimental data obtained from a chamber. The comparison revealed the acceptable errors for a variety of frequencies. The results disclosed that the performance of channel system aerodynamic decreased when the fraction of plenum chamber cross-section to inlet/outlet channel cross-section increased. With an increase in the cross-section size at first Acoustic performance is improved and then worsen. Six different cases of marine gas turbine air supply system configurations have been presented, in which the limitation of the battleship space is considered. Examining and comparing the acoustic performance of different cases of the air supply channel system, it was found that the amount of sound pressure level, around the air supply channel system, and the high-pressure sound area can move along the air supply channel system. Additionally, deviations from plane waves considering the effects of flow have been inspected in all cases. The reason for this deviation is the effects of the airflow through the channel system and quadrupole sources in the production of sound in the channel system, which causes higher modes.

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Section: Introductionmentioning

confidence: 86%

Archives of Acoustics

Rasoulimoghadam

Kheradmand

2019

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“…The perforated pipe strongly affects the attenuation performance of the resonator [23]. Limited by finite volume for the engine nacelle and maintaining constant external muffler dimension requires little or no change in the length of the chambers [24]， [25]. The perforated and insertion pipes are the main muffler units that affect muffler performances.…”

Section: B Orthogonal Test Designmentioning

confidence: 99%

Local Structural Optimization Method Based on Orthogonal Analysis for a Resistant Muffler

Zhou

Xue

et al. 2021

IEEE Access

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A resistant muffler is the most direct and effective means of reducing exhaust noise from earthmoving equipment. Different types of construction machinery require different mufflers. Current muffler design is mostly experience-based, and there are blind spots in the design process. The optimization scheme must constantly be revised to achieve satisfactory noise reduction. The use of a large number of optimization schemes are wasteful in terms of both cost and time. Therefore, an effective and time-saving design method for muffler optimization is needed. An optimization approach, known as the "local structural optimization method for a resistant muffler", based on orthogonal analysis is proposed in this study to optimize the design of a resistant muffler with a complex structure. The results of an orthogonal analysis for a simulation of the muffler structure show that the muffler acoustic and aerodynamic performances are affected by the inlet pipe, outlet pipe, insertion pipe, cross-flow perforated pipe and other local structures, and the results are employed to determine the influence law for the transmission loss (TL) and the exhaust back pressure, considering the local structural parameters of the muffler. The method is applied to optimize the design of a muffler suitable for an excavator and verified by performing an installation test. The experimental results show that the improved designs reduces the exhaust noise by 5 dB and the exhaust back pressure by 0.6 kPa. The improved designs exhibit higher aerodynamic and acoustic performances than a muffler prototype, showing that the proposed method is accurate, effective and reliable. The proposed method considerably simplifies the design process and saves time and cost. This method provides theoretical guidance and an optimization process for the design of a muffler for construction machinery. INDEX TERMS resistant muffler with complex structure, orthogonal test, simulation analysis, optimization design.

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“…where W i and W o are inlet and outlet power, respectively. The TL is calculated in each step of the muffler design including any physical change in the proposed muffler that affected the acoustical performance of the mufflers [14][15][16][17][18]. There is wide research discussing these parameters and investigating muffler performance by TL.…”

Section: Introductionmentioning

confidence: 99%

“…It was shown in that study that the overall TL of the cylindrical muffler would increase with the increment of the absorptive layer [15]. In another study, Nag et al (2016) analyzed the diameter for a single inlet single outlet expansion chamber and showed that increasing diameter caused improvement in TL [16]. Further, Amuaku et al (2019) focused on chamber perforations and inlet and outlet diameter variations on TL for an elliptical shape muffler and conclude that perforation has a more significant impact on performance [17].…”

Section: Introductionmentioning

confidence: 99%

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Organized Computational Measurement to Design a High-Performance Muffler

Saadabadi,

Samimi,

Hosseinlaghab

2023

Metrology

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Engine noise, as a source of sound pollution for humans and the environment, can be reduced by designing a high-performance muffler. This study presents a novel, organized design process of that muffler for the KTM390 engine as a case study. The acoustic simulation analysis is performed in COMSOL software and aerodynamic analysis is performed in ANSYS Fluent. The features of the muffler considered in this designing process are the overall length of the muffler, the presence of baffles and related parameters (baffle distance, baffle hole diameter, and baffle hole offset), and the effects of extended tubes. In order to evaluate the acoustic performance of the muffler, an objective function has been defined and measured on two frequency ranges, 75–300 Hz and 300–1500 Hz. For evaluating the aerodynamic performance of that, the amount of backpressure is analyzed to achieve a maximum of 3.3 kilopascals for this muffler. The selection of the appropriate parameters includes comparing the resulting transmission loss curves and quantitative evaluation of objective functions (for transmission loss) and backpressure. This organized design process (i.e., tree diagram) leads to an increase in the efficiency of designing mufflers (for example, 41.2% improvement on backpressure).

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Effect of geometric parameters on the acoustical performance of single inlet single outlet expansion chamber muffler

Cited by 7 publications

References 6 publications

Archives of Acoustics

Archives of Acoustics

Local Structural Optimization Method Based on Orthogonal Analysis for a Resistant Muffler

Organized Computational Measurement to Design a High-Performance Muffler

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