Nauki Techniczne

Archives of Acoustics

Zawartość

Archives of Acoustics | 2023 | vol. 48 | No 4

Abstrakt

Using the tunderwater corner reflector (CR) to simulate the acoustic scattering characteristics of the military target is a new technology to counter active sonar detection. Existing underwater CRs only have the ability to interfere with the acoustic field, but have limitations in acoustic wave modulation. Therefore, acoustic metasurfaces applied on CRs to enhance the ability of acoustic wave modulation has a great application prospect. A fast prediction method based on the Kirchhoff approximation (KA) and the ray tracing theory is proposed to calculate the acoustic scattering characteristics of CR with acoustic metasurfaces in grooves array type. The accuracy of the method is verified by the finite element method (FEM) simulation. The modulation effect of CR with grooves array in different gradient combinations on the structural scattering acoustic field is analyzed. The research shows that the CR with different combinations of the acoustic metasurface has an obvious modulation effect on the amplitude of the acoustic waves and the deflection of acoustic field. In particular, the grooves array in combination with positive and negative gradients has an obvious deflection impact on the scattering acoustic field.
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Autorzy i Afiliacje

Jiaman Du
1
Zilong Peng
1
Lili Ge
1
Shijin Lyu
1 2
Fulin Zhou
3
Yan Liu
4
ORCID: ORCID

  1. School of Energy and Power Engineering Jiangsu University of Science and Technology, Zhenjiang, China
  2. National Key Laboratory on Ship Vibration and Noise, China Ship Science Research Center, Wuxi, China
  3. School of Naval Architecture, Ocean and Civi Engineering, Shanghai Jiao Tong University, Shanghai, China
  4. Shanghai Research Institute of Materials, Shanghai, China

Abstrakt

In this article, the authors present the geometry and measurements of the properties of an acoustic metamaterial with a structure composed of multiple concentric rings. CAD models of the structure were developed and subsequently used in numerical studies, which included the study of resonant frequencies using the Lanczos method and an analysis of sound pressure level distribution under plane wave excitation using the finite element method. Subsequently, experimental tests were carried out on models with the same geometry produced with three different materials (PLA, PET-G, and FLEX) using a fused deposition modeling 3D printing technique. These tests included: determining insertion loss for a single model based on tests using the measurement window of a reverberation chamber and determining transmission loss through tests in a semi-anechoic chamber. Sound wave resonance was obtained for frequencies ranging from 1700 to 6000 Hz. Notably, the experimental studies were carried out for the same structure for which numerical tests were conducted. The physical models of a metamaterial were manufactured using three different readily available 3D printing materials. The results of laboratory tests confirm that the created acoustic metamaterial consisting of multi-ring structures reduces noise in medium and high frequencies.
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Autorzy i Afiliacje

Grzegorz Szczepański
1
ORCID: ORCID
Marlena Podleśna
1
ORCID: ORCID
Leszek Morzyński
1
ORCID: ORCID
Anna Włudarczyk
1

  1. Central Institute For Labour Protection – National Research Institute, Warsaw, Poland

Abstrakt

This study used experimental measurements and the finite-element method (FEM) simulations to investigate transient underwater radiated noise induced by the impulse excitation of water surrounding a watertight steel-structured circular cylindrical shell submerged in the 176 × 8 × 4 m towing tank. The excitation was caused by dropping an iron block onto a structural bracket in the shell to generate structural vibration. The experimental results were found to be consistent with the FEM results, with the difference between the experimental and simulated sound pressure levels being less than 3 dB. Moreover, it was determined that the structural vibration also generated airborne noise in the cylindrical shell, but this contributed much less than the impulse excitation to the induction of underwater radiated noise. Finally, analysis of the sound field of the underwater noise radiation showed that it was influenced by the wall thickness of the watertight steel cylindrical shell and that of the reinforced bracket seat structure. In particular, the structural reinforcement position proved to be the diffusion breakpoint of the underwater sound radiation. This demonstrates that compared with the studied structure, a thicker and more complex reinforced structure will transmit less or incomplete sound radiation into water.
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Autorzy i Afiliacje

Chen-I Wu
1
Gee-Pinn Too
1
Bo-Hsien Wu
1

  1. Department of Systems and Naval Mechatronic Engineering, National Cheng Kung University, Tainan, Taiwan

Abstrakt

This article presents a comparison of test results from two models of anti-vibration systems (I and II) made employing MJF 3D printing technology and two different materials. The research included laboratory tests and numerical simulations, assuming a linear nature of the mechanical properties for the materials and models of structures. The aim of this research was to assess the consistency between laboratory test and numerical simulation results. In addition, evaluation of the suitability of using MJF technology to produce antivibration systems was conducted. During the laboratory tests, the response of the two models of structures to vibrations generated by an exciter was recorded using a high-speed camera. Subsequent image analysis was performed using the MOVIAS Neo software. The obtained values of vibration displacements and resonant frequencies were used to validate the numerical model created in the Simcenter Femap software. Relative differences between the values of resonant frequencies obtained experimentally and through simulations were determined. In the case of the structural model I, creating its numerical model without considering the nonlinearity of mechanical parameters was found to be unjustified. The comparison of the displacements determined during numerical simulations showed relative differences of less than 16% for both models in relation to the laboratory test results. This comparison result indicates a satisfactory accuracy in simulating this parameter. An assessment of the quality and accuracy of MJF technology-produced prints, led to the conclusion that due to the formation of internal stresses during the print creation, the use of “soft” materials in this technology is problematic.
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Autorzy i Afiliacje

Piotr Kowalski
1
ORCID: ORCID
Adrian Alikowski
1
ORCID: ORCID

  1. Central Institute for Labour Protection – National Research InstituteWarsaw, Poland

Abstrakt

In this paper, we propose a multi-layer micro-perforated panel structure based on a curled space for broadband sound absorption at low frequencies, which increases the number of perforated panel layers in a limited space using a curled space. The absorption coefficients of the structure under plane wave conditions were calculated using the transfer matrix method and the finite element method. It is demonstrated that the multilayer micro-perforated panel structure can ensure high absorption (consistently over 90%) in the frequency range of 400~5000 Hz. The sound absorption mechanism of the multi-layer micro-perforated panel structure is investigated by using the acoustic impedance along with the reflection coefficient of the complex frequency surface. In addition, we also discuss the effects of the micro-perforated panel parameters on the structural sound absorption coefficient. The results show that the proposed multi-layer micro-perforated panel structure provides an excellent solution for sound absorption in a limited space.
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Autorzy i Afiliacje

Jiaming Chu
1
Xiao Liang
1 2
Zhen Yang
1
Haofeng Liang
1
Tao Chen
1
Liang Su
1
Zhuo Zhou
3

  1. School of Mechanical Engineering, Xiangtan University, Xiangtan, China
  2. Foshan Green Intelligent Manufacturing Research Institute of Xiangtan University, Foshan, Guangdong, China
  3. School of Mechanical Engineering and State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shanxi, China

Abstrakt

Water is widely used in the mining industry, particularly in mineral enrichment processes. In the process of magnetic separation or flotation of crushed ore, a concentrate (an enriched product), and tailings (a product with a low content of a useful component) are obtained. One of the main tasks of enrichment processes is the efficient use of water resources. This is achieved by reclaiming and subsequent reusing water contained in ore beneficiation products by extracting it in industrial thickeners. Optimizing this process makes it possible to reduce water usage in the mining industry, reduce costs of mineral enrichment processes, and address extremely urgent environmental protection problems. To evaluate the process of sedimentation of the solid phase in the pulp within the thickener, measurements of parameters of longitudinal ultrasonic oscillations and Lamb waves that have traveled a fixed distance in the pulp and along the measuring surface in contact with it are used. The proposed approach allows for the consideration of pulp density, particle size of the solid phase in the ore material and the dynamics of changes in these parameters in the thickener at the initial stage of the sedimentation process. Based on the obtained values, adjustments can be made to the characteristics of its initial product, leading to reduced water usage and minimized loss of a useful component.
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Autorzy i Afiliacje

Vladimir Morkun
1
Natalia Morkun
1
Vitaliy Tron
1
Oleksandra Serdiuk
1
Alona Haponenko
1

  1. Kryvyi Rih National University, Kryvyi Rih, Ukraine

Autorzy i Afiliacje

Piotr Karwat
1

  1. Department of Ultrasound, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland

Autorzy i Afiliacje

Agnieszka Ozga
1
Jacek Wierzbicki
1
Dominik Mleczko
1

  1. Faculty of Mechanical Engineering and Robotics, Department of Mechanics and Vibroacoustics, AGH University of Krakow, Kraków, Poland

Abstrakt

In order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability to interpret voice commands with adequate mean opinion score (MOS) grades. This paper describes a quality evaluation study of a two-way speech transmission system via bandwidth over power line – power line communication (BPL-PLC) technology in an operating underground mine. We investigate how different features of the available wired medium can affect end-user quality. The results of the described study include: two types of coupling (capacitive and inductive), two transmission modes (mode 1 and 11), and four language sets of speech samples (American English, British English, German, and Polish) encoded at three different bit rates (8, 16, and 24 kbps). Our findings can aid both researchers working on low-bit rate coding and compression, signal processing and speech perception, as well as professionals active in the mining and oil industry.
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Autorzy i Afiliacje

Przemysław Falkowski-Gilski
1
Grzegorz Debita
2

  1. Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
  2. General Tadeusz Kosciuszko Military University of Land Forces, Wrocław, Poland

Abstrakt

Fouling is inevitable on the surfaces of industrial equipment, especially on heat-exchanging surfaces in contact with fluids, which causes water pollution and destroys the ecological environment. In this paper, a novel fouling-removal methodology for plate structure based on cavitation by multi-frequency ultrasonic guided waves is proposed, which can remove fouling on stainless steel plates. A numerical simulation method has been developed to study the acoustic pressure distribution on a steel plate. According to the simulation results, the distribution of sound pressure on the plate under triple-frequency excitation is denser and more prone to cavitation than in single-frequency cases and dual-frequency cases, which improves fouling removal rate. The stainless steel plate is immersed in water for the descaling experiment, and the results show that the fouling removal rates of three water-loaded stainless steel plates under different single-frequency excitation seem unsatisfactory. However, the multi-frequency excitation improves the descaling performance and the removal rate of fouling reaches 80%. This new method can be applied to the surface descaling of large equipment plates, which is of great significance for purifying water quality and protecting the ecological environment.
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Autorzy i Afiliacje

Mingkun Huang
1
Shuo Jin
Gaoqian Nie
1
Xiaopeng Wang
1
Quanpeng Zhang
1
Yang An
1 2
Zhigang Qu
1 2
Wuliang Yin
3

  1. College of Electronic Information and Automation, Tianjin University of Science and Technology, Tianjin, China
  2. Advanced Structural Integrity International Joint Research Centre, Tianjin University of Science and Technology, Tianjin, China
  3. School of Electrical and Electronic Engineering, University of Manchester, Manchester, United Kingdom

Abstrakt

On September 25–29, 2023, the LXIX Open Seminar on Acoustics OSA2023 was held in Karpacz. The conference was organized by the Wroclaw Branch of the Polish Acoustical Society (PTA). Simultaneously with the OSA2023 conference two accompanying events were held: Signal Processing Symposium SPSympo23 and 5th Polish-German Structured Conference on Acoustics PGSCA2023. 240 specialists from Poland and abroad took part in the OSA2023, SPSympo23, and PGSCA23 conferences delivering 96 papers and 6 plenary presentations.
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Instrukcja dla autorów

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Articles for publication in Archives of Acoustics should be submitted via the journal website: https://acoustics.ippt.pan.pl.

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Author guidelines and submission requirements are available here: https://acoustics.ippt.pan.pl/index.php/aa/author-guidelines.

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