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Tytuł:
Special optical communication filter based on Thue-Morse photonic crystal structure
Autorzy:
Alipour-Banaei, H.
Serajmohammadi, S.
Mehdizadeh, F.
Hassangholizadeh-Kashtiban, M.
Powiązania:
https://bibliotekanauki.pl/articles/173823.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal
Thue-Morse structure
optical filter
transfer matrix method
TMM
Opis:
In this paper we proposed a novel narrowband optical filter for wavelength division multiplexing applications. Due to their high transmission efficiency and very narrowband properties, we used the 5th generation Thue-Morse structure for designing our proposed filter. But novelty of our work is introducing another ID photonic crystal structure as a defect structure into the Thue-Morse structure in order to create pass band inside the photonic band gap of the Thue-Morse structure. All of the simulations and calculations have been done using the transfer matrix method. The most interesting property of this filter is that by increasing the number of the periods of the ordinary 1D photonic crystal, the number of the pass bands increases.
Źródło:
Optica Applicata; 2016, 46, 1; 145-152
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prognozirovanie processa utilizacii proizvodstvennyh othodov matricej tehnologičeskih koèfficientov na baze metoda balansa
Prediction of industrial waste disposal matrix of technological factors on the basis of the method for balance
Autorzy:
Arefyev, I.
Powiązania:
https://bibliotekanauki.pl/articles/360373.pdf
Data publikacji:
2013
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
matrix
method of balance
recycling
ecology
Opis:
Traditional methods for assessing threats were ekological but today are ineffective. It is proposed to address this problem based on the classic balance method, known as the law of conservation of matter Lomonosov– Lavoisier, according to which the total mass of the physical system is preserved for all natural and man-made processes, including the procedures for processing and disposal.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2013, 35 (107); 5-10
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of global experiences in evaluation of mining zone: Case study the Zohreh River
Zastosowanie globalnych doświadczeń w ocenie strefy wydobycia: Przypadek rzeki Zohreh
Autorzy:
Azarang, Farhang
Shafaei Bejestan, Mahmood
Jafari, Ghazal
Karami, Maryam
Powiązania:
https://bibliotekanauki.pl/articles/293030.pdf
Data publikacji:
2019
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
global experiences
sand and gravel mining
river matrix method
Zohreh River
globalne doświadczenie
metoda macierzowa
rzeka Zohreh
wydobycie piasku i żwiru
Opis:
The materials mining from rivers have a variety of negative and positive effects. Currently, one of the most important issues in river engineering is the proper management of materials mining. In this research, global experiences and international standards for managing sand and gravel mining have been applied to evaluate the mining area in the Zohreh River in Khuzestan province (Iran). One of the evaluation methods in this field is the river matrix method. In this method, which is defined on the basis of river pattern, river characteristics such as river size, site location of materials, associated channel and type of deposit are being considered. In this research, a segment of the Zohreh River between Sardasht Zeydun bridge and Mohseniyeh village in which has good potential for gravel mining was selected and evaluated for river characteristics, mining potential and application of river matrix method. The study indicates that the Zohreh River has a braided pattern in the range. The volume of sediment materials in the target area is about 10 000 m3, the length and width of the mining area are 125 and 80 m respectively, and surface extraction with a maximum depth of 1 m was recommended for extraction of materials. At the end of the research, management solutions and solutions for mining of river materials were presented using various standards.
Pozyskiwanie materiału rzecznego niesie ze sobą wiele negatywnych i pozytywnych skutków. Obecnie jednym z głównych problemów inżynierii rzecznej jest właściwe zarządzanie wydobyciem materiałów. W badaniach wykorzystano globalne doświadczenie i międzynarodowe standardy wydobycia piasku i żwiru do oceny obszaru eksploatacji w rzece Zohreh w prowincji Khuzestan (Iran). Jedną z metod oceny jest metoda macierzowa. W metodzie tej, którą definiuje się na podstawie układu rzeki, bierze się pod uwagę takie cechy rzeki, jak: wielkość, lokalizacja materiału, kanały boczne i rodzaj depozytu. Do badań wybrano odcinek rzeki Zohreh pomiędzy mostem Sardasht Zeydun a wsią Mohseniyeh, gdzie istnieją duże możliwości wydobycia żwiru. Oceniono właściwości rzeki, potencjał wydobywczy i zastosowanie metody macierzowej. Badania wykazały, że rzeka Zohreh na badanym odcinku ma układ wielokorytowy. Objętość materiału osadowego na badanym obszarze wynosi ok. 10 000 m3, długość i szerokość terenu wydobywczego to odpowiednio 125 i 80 m, a zalecana maksymalna głębokość wydobycia materiału wynosi 1 m. W podsumowaniu badań przedstawiono rozwiązania w zakresie wydobycia materiałów rzecznych z uwzględnieniem różnych standardów.
Źródło:
Journal of Water and Land Development; 2019, 41; 19-30
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behavior and failure tracking of structural elements using applied element method
Autorzy:
Badawy, Mahmoud Mohamed
Mustafa, Suzan Ali A.
Bakry, Atef Eraky
Powiązania:
https://bibliotekanauki.pl/articles/35561246.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
applied element method
AEM
numerical analysis
stiffness matrix
large deformation failure tracking
Opis:
Applied element method (AEM) is a recently displacement-based structural analysis method. It provides the benefits of both the finite element method (FEM) and the discrete element method (DEM). This method relies on those structures are segmented into rigid elements linked by normal and shear springs. In this paper a brief note of the AEM is given. Then, using the AEM, a 2D MATLAB open source program was created to analyze different structures with varied boundary conditions and to permit researchers for enhancing the method. The proposed program was verified using linear elastic analysis and large deformation static analysis. The influence of element size and the number of connecting springs between elements was studied. Finally, the proposed program was capable of tracking failed elements and their spread. In addition, the program could predict deflection values and structure deformed shape.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 3; 203-222
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MCPA decomposition method in soil matrix using ozone as an oxidant
Metoda rozkładu MCPA w matrycy glebowej z użyciem ozonu jako utleniacza
Autorzy:
Balawejder, M.
Antos, P.
Jozefczyk, R.
Pieniazek, M.
Odzimek, E.
Powiązania:
https://bibliotekanauki.pl/articles/905746.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
2-methyl-4-chlorophenoxyacetic acid
decomposition method
soil matrix
ozone
oxidant
soil contamination
Opis:
In presented research a method for remediation of MCPA contaminated soil based on the combination of fluidization process technique and ozone was utilized. Exposition of soil contaminated with MCPA at the concentration of 0,1 % w/w on the a mixture of air and ozone allowed for removal of over 90% of MCPA in form of MCPA 2-ethylhexanol-ester (MCPA 2-EHE) in laboratory conditions. The efficacy of the method was proven by GC-MS analysis of MCPA concentration profile during soil remediation procedure and by comparing of kinetic data, such as half life time, with the natural half life time of MCPA in the soil.
Źródło:
Polish Journal of Soil Science; 2014, 47, 2
0079-2985
Pojawia się w:
Polish Journal of Soil Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An application of stiffness matrix method to determining of dispersion curves for arbitrary composite materials
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/244021.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
SHM system
multi-layered composites
elastic waves
dispersion curves
stiffness matrix method
Opis:
Nowadays multi-layered composite material is very often applied in different kind of structures, like aircrafts, boats or vehicles. Parts of structures, which are made of these materials, are significantly lighter in comparison with traditional materials, like aluminum or steel alloys. On the other hand, the process of damage creation and evolution in the case of composites is much more complex. Moreover, the damages, which are characteristic for multi-layered materials (matrix cracking, fibre breakage, delaminations), are very difficult to detect at early stage of creation. Hence, there is a need to develop the advanced methods to detect them without destroying tested composite element. One of them is based on analysis of elastic wave propagation through the composite structure. Unfortunately, elastic waves possess strongly dispersive character. Thus, it is necessary to determine dispersion curves for investigated material before the tests in order to appropriate interpretation of received dynamic response of structure. In the case of arbitrary composite materials, it is rather challenging task. In the present article the relatively new, analytical method is applied, namely stiffness matrix method. The fundamental assumptions and the theoretical formulation of this method are discussed. Next numerical examples are presented, namely the dispersion curves are determined for the single orthotropic lamina and multi-layered 'quasi - isotropic' composite plate. The studied plates are made of glass fibres and epoxy resin. In the case of single lamina, the dispersion curves are determined in the parallel, perpendicular and arbitrary direction of waves propagation with respect to the fibre direction. In the case of multi-layered plates, the dispersion curves are computed for one arbitrary direction. Additionally, the phase and group velocities for fundamental modes and fixed excitation frequency are estimated in all directions of waves propagation.
Źródło:
Journal of KONES; 2016, 23, 1; 47-54
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical and numerical identification of lamb waves modes for hybrid composites
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/245066.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
structural health monitoring
elastic waves
dispersion curve
stiffness matrix method
numerical simulations
finite element method
group velocity
fale sprężyste
krzywa dyspersji
symulacje numeryczne
metoda elementów skończonych
prędkość grupowa
Opis:
The current work is devoted to the problem of analytical and numerical identification of fundamental elastic waves' modes, namely symmetric mode S0 and antisymmetric mode A0, in the case of hybrid composite. The investigated material consists of one layer made of aluminum alloy Pa38 and six layers made of glass fabric/epoxy resin. At the very beginning, the dispersion curves are determined with the use of stiffness matrix method. The calculated values of phase velocities are verified by numerical simulation. The semi – analytical finite element method is applied. Next, the numerical simulations of elastic waves propagation are performed. In the studied model, the plane state of strain is assumed. These simulations are carried out with the use of finite element method. The excitation signal is a sine wave modulated by Hanning window. The simulation is repeated for different excitation frequency. The group velocities of wave modes S0 and A0 are estimated and compared with the analytical results. The evaluation of the group velocities is based on the analysis of the appropriate components of displacement. The two different method are employed, namely: cross – correlation method and envelope extraction by Hilbert transform. Generally, the obtained results are in a good agreement. However, the method based on envelope extraction by Hilbert transform provides better correlation between analytical and numerical results. The significant discrepancy is observed in the case of symmetric mode S0 for relatively high values of frequency. It is caused by the dispersion phenomena. The analytical calculations are performed with the use of SCILAB 5.5.2 free software and the numerical simulations are carried out with the use of finite element system ANSYS 13.0.
Źródło:
Journal of KONES; 2017, 24, 1; 31-38
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of dispersion curves for composite materials with the use of stiffness matrix method
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/386825.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
structural health monitoring
layered composite materials
guided waves
dispersion curves
stiffness matrix method
Opis:
Elastic waves used in Structural Health Monitoring systems have strongly dispersive character. Therefore it is necessary to determine the appropriate dispersion curves in order to proper interpretation of a received dynamic response of an analyzed structure. The shape of dispersion curves as well as number of wave modes depends on mechanical properties of layers and frequency of an excited signal. In the current work, the relatively new approach is utilized, namely stiffness matrix method. In contrast to transfer matrix method or global matrix method, this algorithm is considered as numerically unconditionally stable and as effective as transfer matrix approach. However, it will be demonstrated that in the case of hybrid composites, where mechanical properties of particular layers differ significantly, obtaining results could be difficult. The theoretical relationships are presented for the composite plate of arbitrary stacking sequence and arbitrary direction of elastic waves propagation. As a numerical example, the dispersion curves are estimated for the lamina, which is made of carbon fibers and epoxy resin. It is assumed that elastic waves travel in the parallel, perpendicular and arbitrary direction to the fibers in lamina. Next, the dispersion curves are determined for the following laminate [0°, 90°, 0°, 90°, 0°, 90°, 0°, 90°] and hybrid [Al, 90°, 0°, 90°, 0°, 90°, 0°], where Al is the aluminum alloy PA38 and the rest of layers are made of carbon fibers and epoxy resin.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 2; 121-128
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the configuration of the fiber-metal laminates on the dispersion relations of the elastic wave modes
Autorzy:
Barski, Marek
Muc, Aleksander
Stawiarski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2146565.pdf
Data publikacji:
2020
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
FML
fiber metal laminates
GLARE
elastic wave modes
dispersion curves
stiffness matrix method
laminaty metalowo-włókniste
mody fal sprężystych
krzywa dyspersji
metoda macierzy sztywności
Opis:
The current work is devoted to the determination of dispersion curves for elastic wave modes. The studied elastic waves propagate across metal-fiber hybrid composites. In order to solve the problem, special software has been developed with the use of C++. This software works with the MS Windows operating system and the proposed solution is based on the multi-threading mechanism. It makes possible to significantly speed up the calculations. The relatively new approach is used namely the stiffness matrix method. At the very beginning, the dispersion curves are determined for the traditional composite materials of cross-ply configuration, for which the layers are made of glass fiber/epoxy resin and carbon fiber/epoxy resin. The impact of the total number of layers on the dispersion curves is investigated. Next, the influence of the thickness of the layers, which are made of aluminum alloy, on the dispersion characteristic is studied. In the second case, it is assumed that the total thickness of the composite material wall for all cases is identical.
Źródło:
Vibrations in Physical Systems; 2020, 31, 2; art. no. 2020202
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
LMI based stability criterion for uncertain neutral-type neural networks with discrete and distributed delays
Autorzy:
Baskar, P.
Padmanabhan, S.
Syed Ali, M.
Powiązania:
https://bibliotekanauki.pl/articles/2049954.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
stability analysis
neutral networks
Lyapunov method
Linear Matrix Inequality
Opis:
This paper studies the problem of robust stability analysis for uncertain neutral-type neural networks with discrete and distributed delays. By constructing an appropriate Lyapunov- Krasovskii functional, new delay-dependent criteria are obtained. We utilized the free-weighting matrices approach and bounding lemmas to estimate the derivative of the Lyapunov-Krasovskii functional. The stability criterion are established in terms of linear matrix inequalities (LMIs). Finally, a numerical example is presented to illustrate the effectiveness of the proposed method.
Źródło:
Control and Cybernetics; 2020, 49, 1; 77-97
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An influence matrix technique for multi-domain solution of the Navier-Stokes equations in a vorticity-streamfunction formulation
Zastosowanie metody macierzy wpływu w połączeniu z metodą dekompozycji obszaru obliczeniowego do rozwiązania równań Naviera-Stokesa sformułowanych w postaci wirowość-funkcja prądu
Autorzy:
Bogusławski, A.
Kubacki, S.
Powiązania:
https://bibliotekanauki.pl/articles/280218.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
spectral methods
domain decomposition method
influence matrix technique
Opis:
The paper presents new multi-domain algorithms based on the influence matrix technique applied together with the non-overlapping iterative domain decomposition method for solution of the incompressible Navier- Stokes equations in vorticity-streamfunction formulation. The spectral Chebyshev collocation method and the influence matrix algorithm are applied for solution of the Stokes problem in each subdomain resulting from time discretization of the Navier-Stokes equations, while the patching conditions (continuity of the solution and continuity of its first order derivative) at the interfaces between subdomains are satisfied using the iterative domain decomposition algorithm.
W pracy przedstawiono nowy iteracyjny algorytm dekompozycji obszaru obliczeniowego oparty na metodzie macierzy wpływu w zastosowaniu do równań Naviera- -Stokesa dla przepływu czynnika nieściśliwego w sformułowaniu wirowość-funkcja prądu. Spektralna metoda kolokacji wykorzystująca szeregi wielomianów Czebyszewa oraz metoda macierzy wpływu została zastosowana do rozwiązania zagadnienia Stokesa, będącego rezultatem dyskretyzacji równań Naviera-Stokesa w funkcji czasu, w każdym z podobszarów obszaru obliczeniowego, natomiast warunek ciągłości rozwiązania i jego pierwszej pochodnej na powierzchniach rozdziału pomiędzy podobszarami został uzyskany przy pomocy metody iteracyjnej.
Źródło:
Journal of Theoretical and Applied Mechanics; 2009, 47, 1; 17-40
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of commutation conditions on steady states in matrix converter
Autorzy:
Borkowski, D.
Sobczyk, T. J.
Powiązania:
https://bibliotekanauki.pl/articles/141341.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przekształtnik macierzowy
regulacja przepływu mocy
metoda bilansu harmonicznych
matrix converter
power flow control
harmonic balance method
Opis:
The paper investigates a significant influence of transients on steady states in a matrix converter with the one-periodic control strategy. Proposed controller can be used as an interconnection device within a power system for a power flow control. However, the presence of inductances in external systems has the significant influence on steady state of a matrix converter operation. The special current injection method has been developed to ensure a proper operation of a matrix converter. Presented analysis of steady states is carried out in a frequency domain using the harmonic balance method. Obtained numerical results, which are confirmed by a time domain analysis, prove the effectiveness of the proposed method.
Źródło:
Archives of Electrical Engineering; 2011, 60, 1; 77-83
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determining preference orders based on a majority margin matrix
Autorzy:
Bury, H.
Wagner, D.
Powiązania:
https://bibliotekanauki.pl/articles/406661.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
profile of preference orders
pairwise comparisons
outranking matrix
majority margin matrix
Debord’s method
Opis:
When determining a group ranking, the information about experts’ opinions may be sometimes incomplete. In such cases, usually only the outranking matrix L or the majority margin matrix ΔL is available. Debord [2] presented a technique for constructing the set of experts’ opinions based on the majority margin matrix. The method proposed – simple and efficient – provides a set of experts’ opinions consistent with the given majority margin matrix.
Źródło:
Operations Research and Decisions; 2013, 23, 2; 25-41
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MAP/PH/1 queueing model with working vacation and crowdsourcing
Autorzy:
Chakravarthy, Srinivas R.
Ozkar, Serife
Powiązania:
https://bibliotekanauki.pl/articles/748791.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Queueing • Crowdsourcing • Matrix-analytic method • Quasibirth- and-death process • Markovian arrival process • Phase type.
kolejkowanie • crowdsourcing(madrosc tłumu • macierzowa analiza stanów ustalonych • pseudo procesy narodzin i smierci • strumien zgłoszen Markowa.
Opis:
Odwoływanie sie do madrosci tłumu (crowdsourcing-u, okazjonalnych serwisów zewnetrznych) jest wykorzystywane w róznych dziedzinach. Znane sa przykłady ze słuzby zdrowia, informatyki, nauk o srodowisku, z biznesu oraz marketingu. Jednakze dopiero od niedawna zastosowano modele teorii kolejek na uzytek modelowania tej metody powiezania zadan. Badania te obejmuja modele kolejek typu M/m/c, MAP/pH/1 i MAP/PH/c. Motywacja dla tych modeli sa usługi, których realizacje zlecamy do pewnej grupy klientów, a nastepnie ta grupa klientów decyduje sie swiadczyc podobne usługi dla innych grup klientów. Przykładowo, jedna grupa klientów odwiedza sklepy w celu zakupu penych towarów, podczas gdy drugi typ klientów zleca zakup tych dóbr przez Internet czy telefon i oczekuje ich dostarczenia. Wówczas obsługa sklepu stacjonarnego wykorzystuje odwiedzajacych ich klientówjako kurierów do obsługi inny grupy klientów. Nie wszyscy klienci sklepie sa gotowi, a w niektórych przypadkach jest to niemozliwe, aby pełnic role posredników działajacych na rzecz sklepu stacjonarnego. Wprowadzamy zatem prawdopodobienstwo tego, ze klienci jest skłonny przyjac zlecenie obsługi innych klientów. Ninieszy artykuł zajmuje sie obsługa z mozliwoscia wakacje i urlop w pracy przy modelu obsługi  MAP/PH/1 z wykorzystaniem crowdsourcingu. Zastosowano macierzowe metody analityczne do badania systemu w stanu ustalonym. Podano przykłady numeryczne wykazujace znaczace korzysci z wprowadzenia takich wariantów w klasycznych modelachkolejkowych.
Crowdsourcing has been used in different domains such as healthcare, computer science, environmental sciences, business and marketing. However, only recently, queueing models useful in the context of crowdsourcing have been studied. These studies involve queueing models of the type M/M/c, MAP/PH/1, and MAP/PH/c. In this paper we introduce vacation and working vacation in the context of MAP/PH/1 with crowdsourcing and highlight the qualitative aspects of the model through illustrative examples.
Źródło:
Mathematica Applicanda; 2016, 44, 2
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise Elimination of a Multi-tone Broadband Noise with Hybrid Helmholtz Mufflers Using a Simulated Annealing Method
Autorzy:
Chiu, M-C.
Powiązania:
https://bibliotekanauki.pl/articles/176674.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multiple tones
hybrid
Helmholtz
four-pole transfer matrix method
SA method
Opis:
Noise control is essential in an enclosed machine room where the noise level has to comply with the occupational safety and health act. In order to overcome a pure tone noise with a high peak value that is harmful to human hearing, a traditional reactive muffler has been used. However, the traditional method for designing a reactive muffler has proven to be time-consuming and insufficient. In order to efficiently reduce the peak noise level, interest in shape optimization of a Helmholtz muffler is coming to the forefront. Helmholtz mufflers that deal with a pure tone have been adequately researched. However, the shape optimization of multi-chamber Helmholtz mufflers that deal with a broadband noise hybridized with multiple tones within a constrained space has been mostly ignored. Therefore, this study analyzes the sound transmission loss (STL) and the best optimized design for a hybrid Helmholtz muffler under a space- constrained situation. On the basis of the plane wave theory, the four-pole system matrix used to evaluate the acoustic performance of a multi-tone hybrid Helmholtz muffler is presented. Two numerical cases for eliminating one/two tone noises emitted from a machine room using six kinds of mufflers (muffler AF) is also introduced. To find the best acoustical performance of a space-constrained muffler, a numerical assessment using a simulated annealing (SA) method is adopted. Before the SA operation can be carried out, the accuracy of the mathematical model has been checked using the experimental data. Eliminating a broadband noise hybridized with a pure tone (130 Hz) in Case I reveals that muffler C composed of a one- chamber Helmholtz Resonator and a one-chamber dissipative element has a noise reduction of 54.9 (dB). Moreover, as indicated in Case II, muffler F, a two-chamber Helmholtz Resonator and a one-chamber dissipative element, has a noise reduction of 69.7 (dB). Obviously, the peak values of the pure tones in Case I and Case II are efficiently reduced after the muffler is added. Consequently, a successful approach in eliminating a broadband noise hybridized with multiple tones using optimally shaped hybrid Helmholtz mufflers and a simulated annealing method within a constrained space is demonstrated.
Źródło:
Archives of Acoustics; 2012, 37, 4; 489-498
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 78

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