Nauki Techniczne

Archives of Acoustics

Zawartość

Archives of Acoustics | 2022 | vol. 47 | No 1

Abstrakt

This review article is concerned with metamaterials, i.e. specifically engineered structures with special properties for interaction with sounds. The research on and practical design of these materials have gained momentum in the last decade, when 3D printing techniques provided the possibility to fabricate such geometrically complex structures. We briefly describe the history of research on AMMs and group them into active and passive metamaterials. For each of these groups of AMMs, we discuss the most notable construction achievements and outline the main applications. We conclude this review with a discussion of possible directions for further research and main applications of AMMs such as noise attenuation, acoustic lens, and the cloaking phenomenon.
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Autorzy i Afiliacje

Bartłomiej Sztyler
1
Paweł Strumiłło
1

  1. Institute of Electronics, Lodz University of Technology, Poland

Abstrakt

This research deals with the development of an optimization system to minimize employee noise exposure in the work environment. It is known from the literature that continuous exposure to high noise levels can cause heart overload, stress, fatigue, and increase accident numbers at a production line. Thus, it is necessary to develop acoustic solutions at an industrial level that could minimize failures and accident occurrences. The rules that regulate occupational noise exposures allow an assessment of the degrees of exposure and subsequent corrections of working conditions. It is observed that the exposure is necessary for further evaluation and correction. Therefore, this research proposes to simulate occupational noise exposure conditions through mathematical models implemented in C++, using the GUROBI linear optimization package and to act previously to minimize ONIHL (Occupational Noise-Induced Hearing Loss). One of this work results is based on Doses Values, TWA (Time Weighted Average) and Distances Covered, using these three factors simultaneously through the optimization, it obtains a route that minimizes exposure and avoids ONIHL. Although there is a need for balanced doses between employees, to this end, the Designation Problem was implemented. Thus, with the routes obtained by optimization, an efficient allocation task was made for the maintenance crew, resulting in minimized and balanced doses. This model was applied to a real industrial plant that will not be identified, only methodology and results obtained will be presented.
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Autorzy i Afiliacje

Déborah Reis
1
João Miranda
1
Jorge Reis
1
Marcus Duarte
1

  1. Department of Mechanics, Faculty of Mechanical Engineering, UFU Universidade Federal de Uberlândia, Uberlândia, Brazil

Abstrakt

We theoretically propose a method to achieve an optimum absorbing material through a modulus-near-zero (MNZ) metamaterial immersed in air or water with a change in slit width part. The destructive interference has paved the way to achieve perfect absorption (PA). Depending upon theoretical analysis, an acoustic metamaterial (AMMs) that supports resonance with a monopole (140 Hz) is developed to construct a low-frequency sound-absorbing technology. The dissipative loss effect can be by attentively controlling onto slit width to achieve perfect absorption. When there are thin slit width and visco-thermal losses in the structure, it is observed that they lead to high absorption. We use finite element simulations via COMSOL Multiphysics software to theoretical measurement in impedance tube and show the influence of structural parameters in both mediums. The results are of extraordinary correspondence at low frequency to achieve optimum perfect absorption (99%). That might support AMMs to actual engineering-related applications in the process of mitigating noise, slow sound trapping, notch filtering, energy conversion, and time reversal technology.
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Autorzy i Afiliacje

Fatma Nafaa Gaafer
1

  1. Department of Science, College of Basic Education, Wasit University, Iraq

Abstrakt

The study aims to estimate metal foam microstructure parameters for the maximum sound absorption coefficient (SAC) in the specified frequency band to obtain optimum metal foam fabrication. Lu’s theory model is utilised to calculate the SAC of metallic foams that refers to three morphological parameters: porosity, pore size, and pore opening. After Lu model validation, particle swarm optimisation (PSO) is used to optimise the parameters. The optimum values are obtained at frequencies 250 to 8000 Hz, porosity of 50 to 95%, a pore size of 0.1 to 4.5 mm, and pore opening of 0.07 to 0.98 mm. The results revealed that at frequencies above 1000 Hz, the absorption efficiency increases due to changes in the porosity, pore size, and pore opening values rather than the thickness. However, for frequencies below 2000 Hz, increasing the absorption efficiency is strongly correlated with an increase in foam thickness. The PSO is successfully used to find optimum absorption conditions, the reference for absorbent fabrication, on a frequency band 250 to 8000 Hz. The outcomes will provide an efficient tool and guideline for optimum estimation of acoustic absorbents.
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Autorzy i Afiliacje

Rohollah Fallah Madvari
1
Mohsen Niknam Sharak
2
Mahsa Jahandideh Tehrani
3
Milad Abbasi
4

  1. Occupational Health Research Center, Department of Occupational Health Engineering, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
  2. Department of Mechanical Engineering, University of Birjand, Birjand, Iran
  3. Australian Rivers Institute, Griffith University, Queensland, Australia
  4. Social Determinants of Health Research Center, Saveh University of Medical Sciences, Saveh, Iran

Abstrakt

Buzz, squeak and rattle (BSR) noise has become apparent in vehicles due to the significant reductions in engine noise and road noise. The BSR often occurs in driving condition with many interference signals. Thus, the automatic BSR detection remains a challenge for vehicle engineers. In this paper, a rattle signal denoising and enhancing method is proposed to extract the rattle components from in-vehicle background noise. The proposed method combines the advantages of wavelet packet decomposition and mathematical morphology filter. The critical frequency band and the information entropy are introduced to improve the wavelet packet threshold denoising method. A rattle component enhancing method based on multi-scale compound morphological filter is proposed, and the kurtosis values are introduced to determine the best parameters of the filter. To examine the feasibility of the proposed algorithm, synthetic brake caliper rattle signals with various SNR ratios are prepared to verify the algorithm. In the validation analysis, the proposed method can well remove the disturbance background noise in the signal and extract the rattle components with well SNR ratios. It is believed that the algorithm discussed in this paper can be further applied to facilitate the detection of the vehicle rattle noise in industry.
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Autorzy i Afiliacje

Linyuan Liang
1 2
Shuming Chen
1 2
Peiran Li
1

  1. State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401122, China
  2. State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130022, China

Abstrakt

As the virtual reality (VR) market is growing at a fast pace, numerous users and producers are emerging with the hope to navigate VR towards mainstream adoption. Although most solutions focus on providing highresolution and high-quality videos, the acoustics in VR is as important as visual cues for maintaining consistency with the natural world. We therefore investigate one of the most important audio solutions for VR applications: ambisonics. Several VR producers such as Google, HTC, and Facebook support the ambisonic audio format. Binaural ambisonics builds a virtual loudspeaker array over a VR headset, providing immersive sound. The configuration of the virtual loudspeaker influences the listening perception, as has been widely discussed in the literature. However, few studies have investigated the influence of the orientation of the virtual loudspeaker array. That is, the same loudspeaker arrays with different orientations can produce different spatial effects. This paper introduces a VR audio technique with optimal design and proposes a dual-mode audio solution. Both an objective measurement and a subjective listening test show that the proposed solution effectively enhances spatial audio quality.
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Autorzy i Afiliacje

Shu-Nung Yao
1

  1. Department of Electrical Engineering, National Taipei University, No. 151, University Rd., Sanxia Dist., New Taipei City 237303, Taiwan

Abstrakt

This study investigates listeners’ perceptual responses in audio-visual interactions concerning binaural spatial audio. Audio stimuli are coupled with or without visual cues to the listeners. The subjective test participants are tasked to indicate the direction of the incoming sound while listening to the audio stimulus via loudspeakers or headphones with the head-related transfer function (HRTF) plugin. First, the methodology assumptions and the experimental setup are described to the participants. Then, the results are presented and analysed using statistical methods. The results indicate that the headphone trials showed much higher perceptual ambiguity for the listeners than when the sound is delivered via loudspeakers. The influence of the visual modality dominates the audio-visual evaluation when loudspeaker playback is employed. Moreover, when the visual stimulus is present, the headphone playback pattern of behavior is not always in response to the loudspeaker playback.
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Autorzy i Afiliacje

Bartłomiej Mróz
1 2
Bożena Kostek
2

  1. Multimedia Systems Department, Gdansk, Poland
  2. Audio Acoustics Laboratory, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland

Abstrakt

Based on the ray acoustic model, a new relationship between the radiation force and the acoustic power is studied for a rectangular weakly focusing transducer. The effect of pressure reflection coefficient on this model is discussed. For a totally absorbing target, an approximate closed-form expression is also derived and the performance of this model is compared with that of the far-field integration model. The numerical results show that the agreement is excellent with these two models, which can be both used for correction of measured results, but the formula based on the ray acoustic model can be applied more widely in practice because of its simpler expression. The experimental results show further the effectiveness of the relationship between radiation force and acoustic power for rectangular weakly focusing transducer based on the ray acoustic model. The results presented in this paper are important for application of ultrasound transducers in therapy.
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Autorzy i Afiliacje

Lili Yu
1
Shuchang Qiao
1
Wende Shou
2 3
Junhua Li
4

  1. Merchant Marine College, Shanghai Maritime University, Shanghai 201306, China
  2. School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
  3. Shanghai Institute of Ultrasound in Medicine, Shanghai 200233, China
  4. College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China

Abstrakt

Several modelling techniques are currently available to analyse the efficiency of inter-digital transducers (IDTs) fabricated on piezoelectric substrates for producing surface acoustic wave (SAW) devices. Impulse response method, equivalent circuit method, coupling of modes, transmission matrix method, and numerical techniques are some of the popular ones for this. Numerical techniques permit modelling to be carried out with any number of finger electrode pairs with required boundary conditions on any material of interest. In this work, we describe numerical modelling of SAW devices using ANSYS to analyse the effect of mass loading, a major secondary effect of IDTs on the performance of SAW devices. The electrode thickness of the IDT influences the resonance frequency of the SAW delay line. The analysis has been carried out for different electrode materials, aluminium, copper, and gold, for different substrate materials, barium titanate (BaTiO3), X-Y lithium niobate (LiNbO3), lithium tantalate (LiTaO3), and the naturally available quartz. The results are presented and discussed.
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Autorzy i Afiliacje

Sheeja P. George
1 2
ORCID: ORCID
Johney Issac
2
Jacob Philip
3

  1. Department of Electronics, College of Engineering, Chengannur, Kerala, India
  2. Department of Instrumentation, CUSAT, Kochi, Kerala, India
  3. Amaljyothi College of Engineering, Kanjirappally, Kottayam, Kerala, India

Abstrakt

Vibro-acoustic response of an isotropic beam under the action of variable axial loads (VALs), is presented in the study. Effects of six different types of VALs and three types of end conditions on buckling, free vibration and sound radiation characteristics are investigated. Static buckling and free vibration behaviours using shear and normal deformable theorem and Ritz method. However, the forced vibration response is evaluated using modal superposition method and the acoustic radiation characteristics are obtained using Rayleigh integral. The nature of variation of VALs and end conditions are influencing buckling and free vibration characteristics remarkably. Results indicate that the acoustic response is highly sensitive to the nature of VAL and intensity of the VAL. In general, sound power at resonance decreases when the magnitude of VAL is increased.
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Autorzy i Afiliacje

Somi Naidu Balireddy
1
Jeyaraj Pitchaimani
1
Lenin Babu Mailan Chinnapandi
2
V.S.N. Reddi Chintapalli
3

  1. National Institute of Technology Karnataka Surathkal, Mangalore 575 025, India
  2. Vellore Institute of Technology Chennai, Tamilnadu 600 127, India
  3. Aditya Engineering College, Surampalem, Andhra Pradesh, India

Abstrakt

Hydroacoustic projectors are useful for generating low frequency sounds in water. Existing works on hydroacoustic projectors require two significant enhancements, especially for designers. First, we need to understand the influence of important projector design parameters on its performance. Such insights can be very useful in developing a compact and efficient projector. Second, there is a need for an integrated model of the projector based on easily available and user-friendly numerical tools which do not require development of complex customised mathematical analogs of projector components. The present work addresses both such needs. Towards these goals, an experimentally validated, easy-to-build projector model was developed and used to conduct design sensitivity studies. We show that reductions in pipe compliance and air content in oil, and an increase in orifice discharge coefficient can yield remarkable improvements in projector’s SPL. We also show that reductions in pipe length and cylinder diameter cause moderate improvements in performance in mass and stiffness controlled regions, respectively. In contrast, the projector performance is insensitive to changes in pistonic mass, cylinder length, and diaphragm stiffness. Finally, we report that while pipe compliance and air content in oil can sharply alter system resonance, the effects of changes in pipe length and pistonic mass on it are moderate in nature.
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Autorzy i Afiliacje

Vattaparambil Sreedharan Sreejith
1
Nachiketa Tiwari
1

  1. Dhwani Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh 208016, India

Abstrakt

Amplitude modulation increases the annoyance caused by wind turbine noise. One gets the improved annoyance when a penalty is added to the measured or calculated time-average sound level. The amplitude modulated wind turbine noise consists of pulses. Each of them could be characterized by the short timeaverage sound level and the modulation depth. The latter determines the pulse penalty. This paper shows how to calculate the improved annoyance of amplitude modulated wind turbine noise, when the short time-average sound level and the penalty for each pulse are known. A special case of identical pulses is discussed. The proposed methodology needs to be tested by research.
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Autorzy i Afiliacje

Rufin Makarewicz
1

  1. Chair of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland

Instrukcja dla autorów

Author Guidelines
• Manuscripts intended for publication in Archives of Acoustics should be submitted in pdf format by an on-line procedure.
• Manuscript should be original, and should not be submitted either previously or simultaneously elsewhere, neither in whole, nor in part.
• Submitted papers must be written in good English and proofread by a native speaker.
• Basically, the papers should not exceed 40 000 typographic signs.
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• Detailed information see Article Requirements.
• Manuscript should be accompanied by a cover letter containing the information:
o why the paper is submitted to ARCHIVES OF ACOUSTICS,
o suggestion on the field of acoustics related to the topic of the submitted paper,
o the statement that the manuscript is original, the submission has not been previously published, nor was sent to another journal for consideration,
o 3–5 names of suggested reviewers together with their affiliations, full postal and e-mail addresses; at least 3 suggested reviewers should be affiliated with other scientific institutions than the affiliations of the authors,
o author’s suggestion to classification of the paper as the research paper, review paper or technical note.

Article Requirements
1. At submission time only a PDF file is required. After acceptance, authors must submit all source material (see information about Figures). Authors can use their preferred manuscript-preparation software. The journal itself is produced in LaTeX, so accepted articles will be converted to LaTeX at production time.
2. The title of the paper should be as short as possible.
3. Full names and surnames should be given.
4. The full postal address of each affiliation, including the country name should be provided. Affiliations should contain the full postal address, as well as an e-mail address of one author designated as corresponding author.
5. The text should be preceded by a concise abstract (less than 200 words).
6. Keywords should be given.
7. The formulae to be numbered are those referred to in the paper, as well as the final formulae.
8. All notations should be written very distinctly.
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Items appearing in the reference list should be complete, including surname and the initials of the first name of the author, the full title of the paper/book in English followed by the information on the original paper language. In case of a book, the publisher's name, the place and year of publication should be given. In case of a periodical, the full title of the periodical, consecutive volume number, current issue number, pages, and year of publication should be given. All references in the bibliography should be cited in the text, and arranged in alphabetical order by authors' last name.
For more information on references see http://acoustics.ippt.gov.pl/public/Instructions.pdf.
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