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Wyszukujesz frazę "acoustic propagation" wg kryterium: Temat


Tytuł:
The Influential Factors and Prediction of Kuroshio Extension Front on Acoustic Propagation-Tracked
Autorzy:
Xu, Weishuai
Zhang, Lei
Wang, Hua
Powiązania:
https://bibliotekanauki.pl/articles/31339753.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Kuroshio Extension front
acoustic propagation
convergence zone prediction
Opis:
The Kuroshio Extension front (KEF) considerably influences the underwater acoustic environment; however, a knowledge gap persists regarding the acoustic predictions under the ocean front environment. This study utilized the high-resolution ocean reanalysis data (JCOPE2M, 1993–2022) to assess the impact of the KEF on the underwater acoustic environment. Oceanographic factors were extracted from the database using the Douglas-Peucker algorithm, and acoustic propagation characteristics were obtained using the Bellhop raytracing model. This study employed a backpropagation neural network to predict the acoustic propagation affected by the KEF. The depth of the acoustic channel axis and the vertical gradient of the transition layer of sound speed were identified as the fundamental factors influencing the first area of convergence, with correlations between the former and the distance of the first convergence zone ranging from 0.52 to 0.82, and that for the latter ranging from −0.42 to −0.7. The proposed method demonstrated efficacy in forecasting first convergence zone distances, predicting distances with less than 3 km error in >90% of cases and less than 1 km error in 68.61% of cases. Thus, this study provides a valuable predictive tool for studying underwater acoustic propagation in ocean front environments and informs further research.
Źródło:
Archives of Acoustics; 2024, 49, 1; 95-106
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure field in a plane layer
Autorzy:
Baranowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/331904.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic waves propagation
acoustic waves
waves generation
Opis:
The paper presents results of analytical and numerical investigations of a plane acoustic waves propagation through a plane layer surrounded by another medium. The waves generation problem is discussed. The mathematical model of the pressure propagation in the layer is proposed. Propagated through the layer changes in pressure, the reflected and transmitted waves were studied. Some results of numerical investigations are presented.
Źródło:
Hydroacoustics; 2010, 13; 9-16
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modeling of uncertainty in acoustic propagation via generalized Polynomial Chaos
Autorzy:
Dammak, Khalil
Koubaa, Sana
Elhami, Abdelkhalak
Walha, Lassaad
Haddar, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/280126.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
finite element simulation
uncertainty quantification
acoustic propagation
generalized Polynomial Chaos
Opis:
This work aims at increasing the performance prediction for acoustic propagation systems that will operate in the presence of the inevitable parameters uncertainty. In the present contribution, the finite element method is applied to solve an acoustic problem described by the Helmholz equation when the geometric and material properties present uncertainty. The influence of the uncertainty of physical parameters on the pressure field is discussed. The results using the polynomial chaos expansion method are compared with Monte Carlo simulations. It is show that uncertainty levels in the input data could result in large variability in the calculated pressure field in the domain.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 1; 3-15
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Cold Eddy on Acoustic Propagation (Case Study : Eddy in the Persian Gulf)
Autorzy:
Mahpeykar, Omid
Ashtari Larki, Amir
Akbari Nasab, Mohammad
Powiązania:
https://bibliotekanauki.pl/articles/31339990.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Persian Gulf
cold eddy
transmission loss (TL)
acoustic propagation
BELLHOP model
Opis:
It is essential for oceanographers to study the effects of marine phenomena such as currents, surface mixed layer, eddies, internal waves, and other ocean features on acoustic propagation, as most marine measurement equipment operates on this basis, like sonar. The eddy impact on acoustic transmission in the marine environment is very significant because changes in temperature and salinity disrupt the sound speed due to the presence of eddy, thus the acoustic propagation in the sea. Although cold eddies are in the Persian Gulf widely, one eddy is selected to study their impacts on acoustic propagation because they have similar properties in terms of temperature and salinity. In this research, after identifying eddies in the Persian Gulf automatically, the effect of a cold eddy on acoustic propagation was investigated at different depths using the BELLHOP model. Most eddies are cyclonic with 5–10 km of radius based on algorithm outputs. Studies on the lifespan of eddies showed that the occurrence of cyclonic eddies with a lifespan of more than three days is more than anticyclonic ones. Examination of the eddy effect on acoustic propagation showed that the transmission loss (TL) during the progress of the acoustic wave across the eddy increases with increasing the depth of the sound source. Also, the presence of cold eddy compared to the conditions it does not exist increases the transmission loss. The study of three-dimensional acoustic propagation also confirmed the obtained results in two-dimensional mode and clearly showed the role of cold eddy in increasing the TL.
Źródło:
Archives of Acoustics; 2022, 47, 3; 413-423
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical model of acoustic wave propagation in shallow water
Autorzy:
Kozaczka, E.
Grelowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/258460.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow water acoustics
propagation of acoustic waves in water layer
Opis:
The work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “deformed” by different phenomena. The acoustic field distribution in the real shallow sea is affected not only by multiple reflections, but also by stochastic changes in the free surface shape, and statistical changes in the seabed shape and impedance. The paper discusses fundamental problems of modal sound propagation in the water layer over different types of bottom sediments. The basic task in this case was to determine the acoustic pressure level as a function of distance and depth. The results of the conducted investigation can be useful in indirect determination of the type of bottom.
Źródło:
Polish Maritime Research; 2017, 2; 48-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie modeli propagacji fali akustycznej na przykładzie funkcjonowania zakładu unieszkodliwiania odpadów w Ścinawce Dolnej
Comparison of acoustic wave propagation models on the example of functioning of the disposal works in Ścinawka Dolna
Autorzy:
Szałata, Ł.
Cuske, M.
Godzwa, A.
Powiązania:
https://bibliotekanauki.pl/articles/372286.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
modelowanie hałasu
propagacja fali akustycznej
zakład unieszkodliwiania odpadów
noise modeling
acoustic wave propagation
Waste Management Plant
Opis:
Artykuł przedstawia metodykę prognozowania propagacji fali akustycznej dla Zakładu Unieszkodliwiania Odpadów w Ścinawce Dolnej. Modelowanie wykonano w dwóch różnych programach modelujących: ZewHalas oraz LEQProffesional. Przeprowadzone modelowania wskazują na to, iż pomimo zastosowania dwóch odrębnych modeli matematycznych, wyniki propagacji fali akustycznej są do siebie bardzo zbliżone.
The paper presents the methodology of acoustic wave propagation prediction for Waste Management Plant in Ścinawka Dolna. Modeling was performed in two different modeling programs: ZewHalas and LEQ Proffesional. Modeling carried out indicate that, despite the use of two different mathematical models, the results of the acoustic wave propagation are very similar.
Źródło:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski; 2014, 155 (35); 33-40
1895-7323
Pojawia się w:
Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of ship-generated noise in shallow sea
Autorzy:
Kozaczka, E.
Grelowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/259166.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow water acoustics
propagation of acoustic waves in water layer
wave modes in shallow sea
underwater noise produced by ship
Opis:
Contamination of sea environment by noise and any energy radiated to water constitutes today a problem to which more and more attention is paid, in view, a.o., of consequences of an impact of these factors onto marine fauna. European Union has introduced a directive by which EU countries are made responsible to undertake efforts aimed at reaching a good envirenmental status of European seas by 2020. A main source of underwater noise is sea transport of any kind. Propagation of underwater acoustic disturbances in the Baltic Sea highly differs from the course of the phenomenon in a deep sea. Model of spherical propagation cannot be applied to this case in view of water environment limitation by seabed and free water surface, i.e. a reduction of the problem to wave propagation in a water layer of the depth comparable with acoustic wave length. This paper is aimed at demonstration of possible assessment of range of acoustic disturbances generated by a ship sailing in shallow sea, by using a method described in the work [13]. The research was made on the basis of results of own measurements of underwater noise produced by ships in the Gdansk Bay area. An important factor which decIdes on a range of underwater disturbances is a kind of seabed sediments. In this paper there are presented results of numerical investigations based on real data dealing with noise produced by a selected floating unit (ship) for selected characteristic spectral components. The simulations were conducted for the shallow sea model of definite physical parameters such as acoustic wave propagation velocity, geometrical dimensions (water depth) and seabed acoustic parameters as well.
Źródło:
Polish Maritime Research; 2018, 2; 37-46
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Modelling of Sport and Hunting Shooting Ranges in the Aspect of Shaping Noise Emissions Into the Environment
Autorzy:
Boczkowski, Arkadiusz
Powiązania:
https://bibliotekanauki.pl/articles/2064764.pdf
Data publikacji:
2020
Wydawca:
STE GROUP
Tematy:
noise
sound propagation
acoustic modelling
shooting ranges
Opis:
The article deals with the problem of acoustic modelling of sport and hunting shooting ranges for the purposes of carrying out acoustic impact assessments on the environment. The fashion for recreational shooting and the dynamic development of shooting ranges resulted in conflict situations between the shooting range and the residents. Increasingly, the condition for allowing the shooting range to be used is to carry out an acoustic analysis to confirm the lack of noise nuisance. Therefore, it is necessary to develop guidelines for acoustic modelling of shooting ranges, taking into account their purpose and types of shooting axes. Each of the shooting axes is designed for a different type of shooting and thus has different acoustic characteristics. In the article, the author presents a method of modelling noise emissions from the shooting range on the example of one of the popular shooting competitions which is the hunting trap. First, acoustic measurements of the unit noise source related to the firing of shots by a firearms shooter were made. Then the directional characteristics of this source were determined, the shooting axis of the “hunting trap” type was modelled during a typical shooting competition and its directionality was determined. Then, on the example of a specific shooting range, the possibility of using the results to analyse the propagation of noise into the environment during typical shootings on the trap axis was presented.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2020, 3, 1; 308--319
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Creating Acoustic Maps Employing Supercomputing Cluster
Autorzy:
Czyżewski, A.
Kotus, J.
Szczodrak, M.
Powiązania:
https://bibliotekanauki.pl/articles/177400.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise pollution
acoustic noise monitoring
noise propagation model
supercomputing
acoustic maps
Opis:
The implemented online urban noise pollution monitoring system is presented with regard to its conceptual assumptions and technical realization. A concept of the noise source parameters dynamic assessment is introduced. The idea of noise modeling, based on noise emission characteristics and emission simulations, was developed and practically utilized in the system. Furthermore, the working system architecture and the data acquisition scheme are described. The method for increasing the speed of noise map calculation employing a supercomputer is explained. The practical implementation of noise maps generation and visualization system is presented, together with introduced improvements in the domain of continuous noise monitoring and acoustic maps creation. Some results of tests performed using the system prototype are shown. The main focus is put on assessing the efficiency of the acoustic maps created with the discussed system, in comparison to results obtained with traditional methods.
Źródło:
Archives of Acoustics; 2011, 36, 2; 395-418
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Intensity Imaging Methods for in-situ Wave Propagation
Autorzy:
Weyna, S.
Powiązania:
https://bibliotekanauki.pl/articles/177914.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
scientific visualization
acoustic mapping
wave propagation
sound intensity
noise control
Opis:
In the paper the author has described the visualization methods in acoustic flow fields and show how these methods may assist scientists to gain understanding of complex acoustic energy flow in real-life field. A graphical method will be presented to determine the real acoustic wave distribution in the flow field. Visualization of research results, which is unavailable by conventional acoustics metrology, may be shown in the form of intensity streamlines in space, as a shape of floating acoustic wave and intensity isosurface in three-dimensional space. In traditional acoustic metrology, the analysis of acoustic fields concerns only the distribution of pressure levels (scalar variable), however in a real acoustic field both the scalar (acoustic pressure) and vector (the acoustic particle velocity) effects are closely related. Only when the acoustic field is described by both the potential and kinetic energies, we may understand the mechanisms of propagation, diffraction and scattering of acoustic waves on obstacles, as a form of energy image. This attribute of intensity method can also validate the results of CFD/CAA numerical modeling which is very important in any industry acoustic investigations.
Źródło:
Archives of Acoustics; 2010, 35, 2; 265-273
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of seasonal acoustic properties of sea water in selected waters of the southern Baltic
Autorzy:
Grelowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/259798.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
sound propagation in sea water
acoustic climate of Baltic Sea
Opis:
Climate Research of the globe is a current task, in particular to confirm the general hypothesis of global warming associated with an increase in average temperature. The sea acoustic climate is derived from the concept of climate and refers to the conditions of propagation of acoustic waves in a particular basin. In this paper, the results of systematic measurements of temperature, salinity and velocity distributions of sound in the area of the southern Baltic will be present. The focus will be on the results of extensive measurements carried out „in situ” in particular.
Źródło:
Polish Maritime Research; 2016, 1; 25-30
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling the Geometry of an Underwater Channel for Acoustic Communication
Autorzy:
Naman, Hala A.
Abdelkareem, A. E.
Powiązania:
https://bibliotekanauki.pl/articles/2174453.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
channel impulse response
geometry channel model
multipath propagation
underwater acoustic communication
Opis:
The achievement of efficient data transmissions via underwater acoustic channels, while dealing with large data packets and real-time data fed by underwater sensors, requires a high data rate. However, diffraction, refraction, and reflection phenomena, as well as phase and amplitude variations, are common problems experienced in underwater acoustic (UWA) channels. These factors make it difficult to achieve high-speed and long-range underwater acoustic communications. Due to multipath interference caused by surface and ocean floor reflections, the process of modeling acoustic channels under the water’s surface is of key importance. This work proposes a simple geometry-based channel model for underwater communication. The impact that varying numbers of reflections, low water depth values, and distances between the transmitter and the receiver exert on channel impulse response and transmission loss is examined. The high degree of similarity between numerical simulations and actual results demonstrates that the proposed model is suitable for describing shallow underwater acoustic communication environments.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 4; 3--12
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badanie parametrów przestrzenno-czasowych zaburzeń ośrodka wywołanych lotem pocisku
Investigations of spatial-temporary parameters of projectile sound propagation
Autorzy:
Pietrasieński, J.
Żygadło, S.
Rodzik, D.
Warchulski, J.
Warchulski, M.
Powiązania:
https://bibliotekanauki.pl/articles/210172.pdf
Data publikacji:
2007
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
hałas balistyczny
fala akustyczna
badania eksperymentalne
balistyka
projectile sound propagation
acoustic wave
experimental research
Opis:
W pracy opisano zjawisko zaburzeń ośrodka wywołanych wystrzałem z lufy i przelotem pocisku z prędkością naddźwiękową. Zbudowano model i wyliczono parametry przestrzenno - czasowe zaburzeń. Przeprowadzono badania eksperymentalne. Porównano wyniki symulacji i badań eksperymentalnych.
The phenomenon of muzzle blast and supersonic projectile sound propagation is described in this paper. The model has been built and spatial-temporary parameters of these disturbances have been calculated. Experimental investigations were carried out. The results of simulation and experiments have been compared.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2007, 56, sp.1; 413-422
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of the sound propagation for a railway vehicle moving on the track
Modelowanie propagacji hałasu podczas przejazdu pojazdu kolejowego na nasypie
Autorzy:
Borwin, Marta
Komorski, Paweł
Szymański, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/33334967.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Poznański Instytut Technologiczny
Tematy:
noise
propagation
acoustic measurement
passing
railway vehicle
track
hałas
propagacja
pomiar akustyczny
przejazd
pojazd kolejowy
nasyp
Opis:
The article presents the process of modeling the phenomenon of noise propagation generated during the passage of a railway vehicle as a function of distance from the sound source and of octave frequencies. The conducted experimental studies served as the basis for the development of sound propagation models. Acoustic measurements were carried out in the area of the railway line whose track was elevated on a track foundation. Then a model was developed that most faithfully reproduces the analyzed phenomenon in real conditions.
W artykule przedstawiono proces modelowania zjawiska propagacji hałasu generowanego podczas przejazdu pojazdu kolejowego w funkcji odległości od źródła dźwięku oraz częstotliwości oktawowych. Podstawą do opracowania modeli propagacji dźwięku były zrealizowane badania eksperymentalne. Pomiary akustyczne przeprowadzono w obszarze linii kolejowej, którego tor był zlokalizowany na nasypie. Następnie opracowano model, który najwierniej odwzorowuje analizowane zjawisko w warunkach rzeczywistych.
Źródło:
Rail Vehicles/Pojazdy Szynowe; 2019, 3; 60-68
0138-0370
2719-9630
Pojawia się w:
Rail Vehicles/Pojazdy Szynowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Modelling of Sound Radiation from a T Junction of City Roads in Windy Conditions
Autorzy:
Piddubniak, O.
Piddubniak, N.
Powiązania:
https://bibliotekanauki.pl/articles/176734.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
T junction of city roads
traffic noise propagation
stationary phase method
acoustic pressure
power flow density
Opis:
The sound radiation from vehicles travelling on the city roads with T junction was considered. The wind effect on acoustic field was taken into account. The solution of this problem was found with the help of the integral Fourier transforms and stationary phase method as the superposition of solutions for the cases of vehicles moving along the straight roads and roads with right-angle bend. As an example, the numerical analysis of traffic noise characteristics was carried out for the T junction city road on one of streets in the town of Łódź (Poland).
Źródło:
Archives of Acoustics; 2016, 41, 3; 543-558
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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