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Tytuł:
Hydraulic transients analysis in pipe networks by the method of characteristics (MOC)
Autorzy:
Wichowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/240954.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
hydraulic transients
method of characteristics
single pipe
experimental measurement
pipe networks
numerical simulations
Opis:
The paper presents results of an experimental and theoretical study of the hydraulic transients in straight pipes and numerical simulations of unsteady flow in pipe networks. A mathematical model consists of a set of partial differential equations of hyperbolic type, which have been transformed by the method of characteristics into ordinary differential equations which are solved by the predictor-corrector method. Experimental tests have been performed, in order to examine the hydraulic transients phenomenon, in a single straight steel pipe. The experiments were carried out in the hydraulic laboratory of the Institute of Water Supply and Water Engineering, Environmental Engineering Faculty, Warsaw University of Technology. The numerical results show that the presented one dimensional model for a single pipe correctly describes the phenomenon since there is a good agreement with experimental maximum and minimum oscillations. In the paper, selected exemplary equations in a difference form for the pipe networks are also presented. One calculation example is given relating to the complex water-pipe network consisting of 17 loops, 48 pipelines and 33 nodes, supplied by two independent sources. Water-hammer throughout the whole pipeline network was caused by closing the gate valve at mid-point of one selected pipe. The results of the numerical calculations are presented in graphic form with respect to the final cross-sections of pipes.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2006, 53, 3; 267-291
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multicriteria Evaluation of Pipe Organ Construction Projects
Autorzy:
Trzaskalik-Wyrwa, Małgorzata
Wyrwa, Ireneusz
Powiązania:
https://bibliotekanauki.pl/articles/578550.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Konstrukcja organów piszczałkowych
Projekt dźwiękowy organów piszczałkowych
Wielokryterialny problem decyzyjny
Pipe organ construction
Pipe organ sound project
Multicriteria decision problem
Opis:
The construction of a pipe organ is a heterogeneous problem. Each interior, for which the instrument is planned, has its individual architectural and acoustic characteristics. The design of the instrument must be matched to the interior and therefore it will be individual and usually unique. Each investor commissioning a pipe organ also has his/her individual taste, preferences, and budget. These most important factors make the construction of a pipe organ a sum of the various relationships and a result of the willingness to compromise between objective factors and preferences of people. This paper presents the issue as a multiobjective task, in which we consider various criteria, such as size, volume, palette of timbres, etc., and show how the various options are presented to the investor. Will the best designers' solution be accepted by the investor and his/her budget? We should handle the various criteria so as to satisfy the investor without compromising the quality of the instrument.
Źródło:
Multiple Criteria Decision Making; 2014, 9; 140-150
2084-1531
Pojawia się w:
Multiple Criteria Decision Making
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Burnishing treatment of the faying surface of the pipe flange
Autorzy:
Starosta, W.
Powiązania:
https://bibliotekanauki.pl/articles/246629.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
burnishing
pipe flange
flange face
roughness
multiple regression
Opis:
On ships for connecting pipes in seawater installations, fire and other installations and for joining pipes to fittings or receivers, flange-type couplings are often used. It is important to ensure tightness between pipe flanges (ASME). If the system pressure does not exceed 1.6 MPa, “open” flange packing using flat gasket rings is used. Rubber, textolite, polyvinyl chloride or metals and alloys with good plastic properties (e.g. aluminum, copper, Monel alloy, Armco iron) can be used as a sealant material (depending on pressure in installation). The tightness of the joint determines the quality (geometric structure) of the surface of the flange at the contact point with the gasket. Reduced roughness ensures even distribution of surface mounting pressures on flange joint gasket. This article deals with the assessment of the use of burnishing as a finishing treatment for flange faces and the selection of rolling parameters. Samples used for the tests were made of S235J2 carbon steel. Burnishing treatment was done with the SKUV20 tool. The working element of the tool was in the shape of a roller. Burning was performed using the following parameters: the burnishing force (Fn) – 600 N, 800 N and 1000 N; Feed rate (f): 0.08 mm/rev, 0.13 mm/rev, 0.24 mm/rev; the speed of burnishing (vn) – for a diameter of 55 mm – was 45 m/min, 65 m/min, 78 m/min. The research was carried out on the basis of trivalent plan Hartley. As the output variables (dependent variables), the roughness reduction index (KRa) and the (Su) were adopted. Based on the multiple regression analysis, it was found that the greatest impact on reducing roughness and surface hardening of burnished material has burnishing force. The dependence between dependent variables and Fn is proportional. The effect of the burnishing speed (vn) on the values of KRA and Su parameters is statistically insignificant. Machining of the active surface of the pipe flanges should be carried out with a burnishing force of 1 kN, a feed rate of 0.08 mm/rev and a burnishing speed of 45 m/min.
Źródło:
Journal of KONES; 2017, 24, 4; 297-303
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydraulic analysis of leakage from submarine pipe network
Autorzy:
Li, J. H.
Fan, Y. T.
Powiązania:
https://bibliotekanauki.pl/articles/258776.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
submarine pipe network
leakage
transient flow
Opis:
The leakage from submarine pipe network is investigated by a numerical model in this paper. A whole event including of the steady flow before the leakage, the transient flow during the leakage and the steady flow after the leakage is considered in the model. The numerical results of the discharge and the head compare with the theoretical solution under the condition of steady flow. Good agreement is obtained. The numerical results of the discharge and the head show that the discharge and the head in each pipe changes suddenly after the leakage occurring. The abrupt trend of the discharge in each pipe is not same completely. Some change upwards, while others downwards. However, the abrupt trend of the head is always downward. The effects of leakage discharge on the transient flow are also investigated. It is founded that the larger the leakage discharge, the more obvious the abrupt trend of the discharge and the head before or after the leakage is.
Źródło:
Polish Maritime Research; 2015, S 1; 48-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural optimization on the design of an automobile engine intake pipe
Autorzy:
Xie, Jianxin
Liu, Zimeng
Powiązania:
https://bibliotekanauki.pl/articles/2104764.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
engine
intake pipe
Fluent
optimization design
Opis:
The engine intake pipe is an important part of the engine. A reasonable layout of the intake pipe can prolong service life of the engine and improve engine power. The optimization of design of the intake pipe has a great impact on the overall performance of the engine. The design of the intake pipe based on experience is subjective and unilateral, and the design cycle and experimental period are long. Ansys Fluent software is used to simulate the design, which can more intuitively reflect the air flow condition of the intake pipe and enable selection of the best layout. First of all, a three-dimensional model of the intake pipe is simulated and the airflow characteristics are studied and analyzed. The streamline diagram and velocity contour under various conditions are obtained. Then, compared with the simulation results, the position of the intake pipe is optimized. Finally, the optimized intake pipe is simulated and verified. According to the experimental results, the intake performance of the optimized intake pipe is greatly improved.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 449--461
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of Baffle Factor for Straight Pipe Flow
Autorzy:
Artichowicz, W.
Łuczkiewicz, A.
Sawicki, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/240988.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
disinfection chamber
baffle factor
pipe flow
Opis:
The baffle factor is a parameter widely used to describe flow system characteristics. This indicator is very important in designing disinfection devices. For example, it is used to convert the plug flowtime to the actual fluid residence time in the flowsystem of interest. Its accurate determination is a complex problem requiring tracer experiments or computational fluid dynamics simulations. Therefore, in practice, it is often taken from tables provided in the literature. The literature sources, however, state that the baffle factor for a flow in a straight pipe is equal to unity, which implies the identity between the pipe flow model and the plug flow model. This assumption is doubtful. The aim of the present work is to verify the baffle factor values assumed for the pipe flow. The merit of this study is the analytical derivation of the expression describing the baffle factor value with respect to flow characteristics. To this purpose, the analytical solution of a one-dimensional advection-diffusion equation with a Heaviside initial condition was used. It was demonstrated that the aforementioned assumption is wrong, as the baffle factor for a straight pipe is significantly less than unity.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2018, 65, 1; 31-39
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metodyka i przykłady prognozowania kosztów naprawy przewodów wodociągowych.
Methods for Predicting the Costs of Water-Pipe Network Repair.
Autorzy:
Hotloś, H.
Powiązania:
https://bibliotekanauki.pl/articles/237736.pdf
Data publikacji:
2006
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
sieć wodociągowa
rurociągi
uszkodzenie
naprawa
koszt
water-pipe network
water distribution system
pipe failure
repair cost
Opis:
Podstawą do prognozowania kosztów naprawy sieci wodociągowej jest znajomość jednostkowych kosztów naprawy różnych rodzajów uszkodzeń przewodów i armatury oraz znajomość liczby i intensywności ich uszkodzeń. Koszty naprawy można prognozować tam, gdzie jest prowadzona systematyczna i wieloletnia rejestracja oraz analiza tych parametrów, z uwzględnieniem m.in. rodzaju i wielkości elementów sieci oraz rodzaju ich uszkodzeń. Omówiona w pracy metodyka polega na określeniu zmian wartości intensywności uszkodzeń ( ) w stałych warunkach eksploatacji sieci oraz jednostkowych kosztów naprawy uszkodzeń (Kn) w czasie eksploatacji. Umożliwia to określenie wartości wskaźnika ( ) kosztów naprawy uszkodzeń, w przeliczeniu na jednostkę długości przewodów w jednostce czasu ( Kn) oraz całkowitych rocznych kosztów naprawy uszkodzeń z wyprzedzeniem 2-4 lata. W zależności od potrzeb, koszty naprawy można prognozować w odniesieniu do określonych odcinków przewodów, części lub całej sieci wodociągowej. Przykładowe obliczenia prognozowanych kosztów naprawy uszkodzeń przedstawiono dla sieci wodociągowej we Wrocławiu i w Oleśnicy. Znajomość i możliwość prognozowania kosztów naprawy przewodów wodociągowych może być przydatna w praktyce m.in. do planowania (z kilkuletnim wyprzedzeniem) środków finansowych na naprawę sieci oraz do podejmowania optymalnych decyzji w zakresie eksploatacji i modernizacji sieci wodociągowej z uwzględnieniem rachunku ekonomicznego.
Predictions of the repair costs for water-pipe networks require the knowledge of two major parameters: (1) the unit repair costs for a variety of pipe and plumbing fixture damage, and (2) the failure rate. Repair costs can be reliably predicted only if these parameters have been recorded and analyzed systematically for many years, and if the records include information about the type and size of the network elements, as well as about the kind of damage. The methods presented in this paper consist in determining the variations in the value of failure rate ( ) under in-service conditions, and in the value of unit costs of damage repair (Kn) during service. With such data, it is possible to determine the value of the damage repair cost index ( ) per pipe unit length in unit time ( Kn) and the total annual cost of damage repair 2 to 4 years ahead. If the need arises, the repair cost can be predicted for a specified section of the pipeline, as well as for a certain part or the whole of the water-pipe network. Examples of relevant calculations for the prediction of damage repair cost are presented for the water-pipe networks of two Polish municipalities (Wrocław and Oleśnica). Knowing how to reliably predict the pipeline repair costs is of crucial practical importance to the planning of expenditure (several years in advance) on the repair of water-pipe networks and to an optimal decision-making about the operation and modernization of the network, with the inclusion of economic calculations.
Źródło:
Ochrona Środowiska; 2006, R. 28, nr 1, 1; 49-54
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ modernizacji pompowni na parametry eksploatacyjne sieci wodociągowej
Retrofit of the pumping station and improvement in the serviceability of the water-pipe network
Autorzy:
Hotloś, H.
Powiązania:
https://bibliotekanauki.pl/articles/237620.pdf
Data publikacji:
2002
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
sieć wodociągowa
pompownia
uszkodzenia sieci
water-pipe network
pumping station
pipe failure
Opis:
Modernizacja pompowni wodociągowej, polegająca na zastosowaniu płynnej regulacji pomp powoduje m.in. stabilizację ciśnienia w sieci wodociągowej. Prowadzi to do ograniczenia awaryjności sieci wodociągowej i kosztów napraw uszkodzeń przewodów oraz do zmniejszenia strat wody. W pracy omówiono wymierne efekty wpływu modernizacji pompowni na parametry eksploatacyjne sieci, w oparciu o wieloletnie (przed i po modernizacji) badania sieci wodociągowej w Brzegu i Kłodzku. W analizie uszkadzalności i kosztów napraw uwzględniono materiał rur, rodzaj uszkodzeń i okres budowy przewodów wodociągowych. Stwierdzono, że po modernizacji pompowni maksymalne ciśnienie w sieci wodociągowej Brzegu zmniejszyło się średnio o 10%, w sieci Kłodzka o 15%, a dobowe wahania ciśnienia w Brzegu zmniejszyły się nawet o 25%. Spowodowało to ograniczenie uszkadzalności sieci wodociągowej w Brzegu o 30%, a w Kłodzku o 40%. Koszty napraw uszkodzeń przewodów w obu miastach obniżyły się o około 40%. Zmniejszeniu uległy także straty na skutek przecieków.
The retrofit of the pumping station has a number of benefits. A major one is the possibility to stabilize the pressure head in the water-pipe network, thus contributing to a noticeable reduction in the rate of pipe failure, in the cost of pipe repair and in the volume of water loss. The benefits from the retrofit of the pump house were examined by analyzing the service parameters of the water-pipe networks in two municipalities (Brzeg and Kłodzko) for many years before and after retrofit. The analyses of failure rate and repair costs involved pipe material, type of damage and period of pipeline construction. Following retrofit, the maximum pressure head in the network was reduced by 10% and 15% on average in Brzeg and Kłodzko, respectively, and daily pressure variations in the water-pipe network of Brzeg were decreased even by 25%. As a result, the rate of failure dropped by 30% and 40% in Brzeg and Kłodzko, respectively, the cost of pipe repair decreased by about 40% in both the municipalities, and there was also a reduction in water losses due to leakage.
Źródło:
Ochrona Środowiska; 2002, 4; 27-31
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Organy dawnego kościoła ewangelickiego w Strzelcach Opolskich
The pipe organ from the former protestant church in Strzelce Opolskie
Autorzy:
Poźniak, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/570435.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Opolski. Diecezjalny Instytut Muzyki Kościelnej. Katedra Muzykologii Uniwersytetu Opolskiego
Tematy:
organy piszczałkowe
historia organów na Śląsku
archiwalia
pipe organs
history of the pipe organs in Silesia Region
archives
Opis:
the literature connected with the history of organ building there are many articles describing the history of organ instruments that are contemporary non-existent e.g. those that did not survive the turbulent times of the Second World War and its political and economic consequences in the whole of Europe. The area of the very rich organ building history is Silesia where three cultures: Polish, German and Czech have coexisted for ages. There is no doubt that the true image of the organ building history in Silesia can only be achieved by a meticulous search, presentation and analysis of old documents. Obviously, it would be ideal if all the described instruments still existed. It is worth noticing that reconstructing the organ building history in Silesia on the basis of archive material describing the history of the non-existent instruments is a very desirable action with a high classification and research benefits. This article presents an organ that was enriching the musical and liturgical life of the evangelical community in Strzelce Opolskie before the Second World War. There are only few parts from the original instrument that are preserved in the attic of the church. Thanks to the book of documents about the organ that can be found in the National Archives Office in Opole, we can not only reconstruct the history of this instrument but also obtain important information in the context of the whole organ building history in Silesia. Strzelce Opolskie is a small town near Opole. The old evangelical church is situated in the centre of the town near the Town Hall. In 1982 this church was given to St. Lawrence Roman-Catholic parish. In the following three years the parish priest Jerzy Stellman refurbished the church, adapting it to the liturgy of the Roman-Catholic Church. The church (presently Corpus Christi Church) was built in 1825–1826 according to the project of Ernest Samuel Friebl. There is not much information left about the church organ from the times when it was built. At best, it was an instrument of dubious quality. This fact and the later history of the organ is described in the archive documents in the National Archives Office in Opole. The first document from that set is from 13th November 1925, the last archive document is a correspondence dated in July 1929 and it mentions obtaining 2000 RM in order to refund works undertaken on the occasion of the 100th anniversary of the church. The current presentation of the history of the non-existent organ from the evangelical church in Strzelce Opolskie obviously does not exhaust the whole topic. It does not resolve the doubts who was the author of the instrument and it does not provide other important data from its history. It only describes a few years in the second half of the 20th century when the 100th anniversary of the church and evangelical community took place. There is no doubt that the instrument in its dubious state survived till the Second World War. After the end of the war the evangelical community became a diaspora that had to finally give up maintenance of their own church. The church and organ were deteriorating. After Catholics took over the church, the instrument was dismantled and only a few parts were left in the attic of the church. That is how its history ends. The part of that history presented in this work helps to complete data about activity of such organ companies as Sauer or Berschdorf. Especially, a lot of information is given to describe the organ master workshop of Gustav Heinze from Żary.
Źródło:
Folia Organologica. International yearbook of organ and organ music; 2018, 1; 29-45
2657-6082
2719-3284
Pojawia się w:
Folia Organologica. International yearbook of organ and organ music
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for simulating transients of turbulent pipe flow
Autorzy:
Zarzycki, Z.
Kudźma, S.
Urbanowicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/280935.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
unsteady pipe flow
transients
waterhammer
efficient numerical simulation
Opis:
The paper presents the problem of modelling and simulation of transients during turbulent fluid flow in hydraulic pipes. The instantaneous wall shear stress on a pipe wall is presented in the form of integral convolution of a weighting function and local acceleration of the liquid. This weighting function depends on the dimensionless time and Reynolds number. Its original, very complicated mathematical structure is approximated to a simpler form which is useful for practical engineering calculations. The paper presents an efficient way to solve the integral convolution based on the method given by Trikha (1975) for laminar flow. An application of an improved method with the use of the Method of Characteristic for the case of unsteady flow (water hammer) is presented. This method is characterised by high efficiency compared to traditional numerical schemes.
Artykuł przedstawia zagadnienie modelowania i symulacji przebiegów przejściowych podczas turbulentnego przepływu cieczy w przewodach ciśnieniowych. Chwilowe naprężenie styczne na ściance przewodu przedstawiono w postaci całki splotowej z funkcji wagi i przyspieszenia cieczy. Funkcja wagi dla naprężenia stycznego na ściance przewodu zależy od czasu bezwymiarowego i liczby Reynoldsa. Ma ona zawiłą postać matematyczną, dlatego aproksymowano ją do prostszej postaci, przydatnej do praktycznych obliczeń inżynierskich. Przedstawiono efektywny sposób rozwiązania całki splotowej, opierając się na metodzie podanej przez Trikha (1975) dla przepływu laminarnego. Podano zastosowanie ulepszonej metody symulacji naprężenia stycznego do metody charakterystyk podczas uderzenia hydraulicznego. Charakteryzuje się ona dużą efektywnością w stosunku do metody tradycyjnej.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 1; 135-158
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of ram-press pipe bending process using elasto-plastic fem model
Autorzy:
Sidun, J.
Łukaszewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/386877.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
pipe bending
FEM analysis
finite element method
Opis:
In this paper selected aspects of numerical modelling of bending pipes process are described. Elasto-plastic material model was used in COMSOL FEM environment. The results of numerical analyses of two kinds of steel were presented. The correctness of the proposed model was verified based on comparison shapes of deformed pipe profile obtained at the ending step of bending both from numerical simulations and experiment.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 1; 47-52
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Intensity Distribution Around Organ Pipe
Autorzy:
Odya, P.
Kotus, J.
Szczodrak, M.
Kostek, B.
Powiązania:
https://bibliotekanauki.pl/articles/177568.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
organ pipe
acoustic vector sensor
sound intensity
Cartesian robot
Opis:
The aim of the paper was to compare acoustic field around the open and stopped organ pipes. The wooden organ pipe was located in the anechoic chamber and activated with a constant air flow, produced by an external air-compressor. Thus, a long-term steady state response was possible to obtain. Multichannel acoustic vector sensor was used to measure the sound intensity distribution of radiated acoustic energy. Measurements have been carried out on a defined fixed grid of points. A specialized Cartesian robot allowed for a precise positioning of the acoustic probe. The resulted data were processed in order to obtain and visualize the sound intensity distribution around the pipe, taking into account the type of the organ pipe, frequency of the generated sound, the sound pressure level and the direction of acoustic energy propagation. For the open pipe, an additional sound source was identified at the top of the pipe. In this case, the streamlines in front of the pipe are propagated horizontally and in a greater distance than in a case of the stopped pipe, moreover they are directed downwards. For the stopped pipe, the streamlines of the acoustic flow were directed upwards. The results for both pipe types were compared and discussed in the paper.
Źródło:
Archives of Acoustics; 2017, 42, 1; 13-22
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved lumping friction model for liquid pipe flow
Autorzy:
Urbanowicz, K.
Zarzycki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/280074.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
transient pipe flow
frequency-dependent friction
effective numerical solution
water hammer
cavitation
Opis:
Normally, during one-dimensional pipe flow, the friction terms are calculated with the use of a numerical method (for example MOC – method of characteristics) at every computational node along the pipe and at every time step. This procedure tends to increase the computational effort greatly. A considerable increase in computational speed can be archived by calculating the frequency-dependent friction at the end of the pipe only. To avoid possible problems (no damping at closed walls, underestimate damping on high impedance components) the frequency-dependent friction term is calculated from the flow waves. The lumping friction model in this work is based on a modificated Schohl convolution integral solution. In addition, the work examined the impact of using of simplified effective weighting function on the obtained results of numerical simulations. The modified method in conjunction with the use of simplified weighting function allow determination of real-time estimate of the basic parameters representing the fluid flow in complex hydraulic systems, water supply, etc.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 2; 295-305
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The choice of motor : transmission installation for the pipe layer
Autorzy:
Shevchyuk, V. P.
Shekhovtsov, V. V.
Krivosheev, N. V.
Powiązania:
https://bibliotekanauki.pl/articles/241544.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
motor – transmission installation
pipe layer
Opis:
The results of research, which applied character, for an industrial complex, will allow resolving topical and important issues of increase of efficiency of operation of park of special equipment in the course of a production activity, at stages of a project and preparatory work are given in article. In previous articles [1, 2, 3, 4, 5] proposed mathematical model of determination of productivity of the machine -tractor unit (MTU) with industrial function is presented in article during the pipelaying works. The mathematical model coordinates all key technical parameters of the pipelayer and the parameters defining service conditions in uniform dependence. The method of "minimization of duration of a running cycle of the machine" is put in mathematical model, as duration of a running cycle is one of generalizing indicators of technical and operational efficiency of MTU. In other words, productivity of the pipelayer is in inverse relationship with a duration of a running cycle, the less time is spent for pipeline laying, the productivity and efficiency of construction is higher. Various ways of laying of the pipeline define boundary conditions, which form some private models.
Źródło:
Journal of KONES; 2015, 22, 1; 285-288
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiphase flow mixture in 180[degrees] pipe bends
Autorzy:
Pietrzak, M.
Witczak, S.
Powiązania:
https://bibliotekanauki.pl/articles/185343.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hydrodynamics
gas-liquid flow
pipe bends
hydrodynamika
przepływ gazu i cieczy
kolanko
Opis:
This paper presents the results of research regarding measurements of the values of pressure drops during horizontal flow of gas-liquid and gas-liquid-liquid mixture through 180o pipe bends. The conducted insightful analysis and assessment during multi-phase flow in pipe bends has enabled to develop a new method for determination of their values. This new method for determining pressure drops ensures higher precision of calculation in comparison to other methods presented in literature and can be applied for calculation of these parameters during multi-phase flows in pipe bends with various geometries.
Źródło:
Chemical and Process Engineering; 2013, 34, 2; 227-239
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MENSURA INSTRUMENTI ORGANICI – CZYLI JAK STROJONO ORGANY W X W
MENSURA INSTRUMENTI ORGANICI – HOW THE PIPE ORGAN WERE TUNED IN THE X CENTURY
Autorzy:
Dyka, Lucjan
Powiązania:
https://bibliotekanauki.pl/articles/947233.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Polskich Muzyków Kościelnych
Tematy:
organy
piszczałka
strój naturalny
stosunek liczbowy
harmonia
interwał
pipe organ
pipe
natural tuning
ratio
harmony
interval
Opis:
The paper is intended to interpret the anonymous Latin Treaty entitled Mensura instrumenti organici written in the X century. The text is very concise and takes the form of a simple instruction intended for a potential constructor of pipe organs. Tuning pipes (of the same circuit) is performed exclusively by means of two ratios – epitritos (4:3) and epogdoos (9:8). The exact calculation confirms that this method proved to be reliable and results in well-tuned pipes using natural Pythagorean tuning in three octave range. Numerous mathematical calculations and the figures of pipes measurements are presented in the paper. The issues of terminology are explained in detail and Greek and Latin texts necessary for the proper interpretation of the treaty are also presented.
Źródło:
Musica Ecclesiastica; 2017, 12; 37-53
2353-6985
Pojawia się w:
Musica Ecclesiastica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient cavitating pipe flow: Computation models and methods
Autorzy:
Urbanowicz, K.
Zarzycki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1943252.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
column separation
bubby flow
numerical simulation
cavitation
transient turbulent pipe flow
unsteady friction
Opis:
The paper presents four key mathematical models of a transient cavitating pipe flow, i.e. the column separation model (CSM), the gas cavitation model (CSMG), Adamkowski’s model (CSMA) and the bubbly cavitation model (BCM). All models investigated in the paper take into account unsteady frictional loss models. The equations describing all models have been solved using the method of characteristics at first and the finite differences method then. The results of numerical simulations have been compared with the results obtained in the experiments. Transients which have taken into account the unsteady wall shear stress fit well with the results of experiments in comparison with the quasi-steady wall shear stress model.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 3-4; 159-172
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Available pipe connectors versus their geometrical correctness
Łączniki dostępne w porównaniu do poprawych geometrycznie
Autorzy:
Tytkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/119130.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
pipe connectors
constructing
expansion
złącza do rur
budowa
rozwój
Opis:
The paper discusses different constructional solutions of pipe connectors, indicating various level of background of designers who have designed them. Construction of connectors made of plate (ruled surface) and plastics have been presented.
W pracy przedstawiono różne rozwiązania konstrukcyjne łączników, wskazujące na zróżnicowane przygotowanie konstruktorów, którzy je projektowali. Przedstawiono konstrukcje łączników z blachy (powierzchnie rozwijalne) i z tworzyw sztucznych.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2013, 25; 67-72
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of visco-elasticity on pressure wave velocity in polyethylene MDPE pipe
Autorzy:
Mitosek, M.
Chorzelski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241508.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water hammer
pressure wave velocity
viscoelasticity
polyethylene MDPE pipe
Opis:
Many of the pipe materials, like polyethylene (MDPE, HDPE) or polypro-pylene (PP), turn out to be visco-elastic. The materials in particular, prove to have strongly time-dependent strain properties. As the propa-gation velocity of pressure waves primarily depends on the fluid bulk modulus and the elasticity of the pipe wall, the above material property has considered the influence in unsteady pipe flow (e.g. in water ham-mer). The pressure velocity in visco-elastic pipes depends on the pres-sure oscillation frequency. The applicability of the method of MOC char-acteristics is limited in the sense that purely elastic strain behaviour has to be assumed. In order to take into account the special properties of visco-elastic pipes, the parameters of the Kelvin-Voigt elements, as well as a complex Young's modulus (dynamic modulus of elasticity) are used to described the pressure velocity. The use of the complex wave velocity seems to be especially useful. However, the velocity should be meas-ured during unsteady water flow. The experiments carried out show that pressure disturbance velocity in MDPE pipe strongly depends on the length of the pipe-line. The velocity increases noticeably when the length of the pipe decreases.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 2; 127-140
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Organy — instrument, który „oddycha”
A pipe organ — an instrument that breathes
Autorzy:
Poźniak, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/585161.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Opolski. Redakcja Wydawnictw Wydziału Teologicznego
Tematy:
organy
aerofon
kalikant
budownictwo organowe
pipe organs
aerophones
blower – pumper
organ building
Opis:
Artykuł omawia organy jako instrument z rodziny aerofonów. Punktem wyjścia do przeprowadzenia analiz jest niewielka tabliczka informująca kalikanta o należytym wykonywaniu pracy, która znajduje się na chórze muzycznym kościoła parafialnego pw. Najświętszego Serca Pana Jezusa w Roszkowie (pow. Racibórz). Tego rodzaju instrukcje były typowe dla organów pochodzących z warsztatu organmistrzowskiego Schlag & Söhne. W artykule omówiona jest funkcja kalikanta. Artykuł stawia tezę o konieczności przywrócenia organom ich „aerofoniczności”. Przedłożone zostały trzy postulaty końcowe: 1) Należy wyposażać nowo budowane organy w mechanizmy do kalikowania — uzupełnieniem zaś tego rodzaju urządzeń powinny być „dzwonki na kalikanta” oraz instrukcje „uwrażliwiające” na to, że organy „oddychają”. 2) Wykonawcy muzyki organowej powinni być w czasie swojej edukacji artystycznej uczeni obsługi mechanizmów do kalikowania oraz gry na instrumencie kalikowanym. 3) Nagrania dokonywane na instrumentach zabytkowych, mających czynny mechanizm do kalikowania, choćby tylko w niewielkiej części powinny zostać zarejestrowane z użyciem tegoż.
The article discusses organs as an instrument of the family of aerophones. The starting point for the analyzes is a small plaque indicating an organ blower about satisfactory work performance, which is placed on the music choir of the parish church of Sacred Heart of Jesus in Roszków (near Racibórz). This kind of instructions was typical for organs from the workshop of the master organ-builder Schlag & Söhne. The article discoursed the function of a organ blower. It formulates the thesis about the need to restore the organs as an aerophone. Three final proposals were submitted: 1) The newly built organs for the artistic education should be equipped in mechanisms to organs blow. 2) Contractors of organ music should be taught manning mechanisms to organs blow and playing the blowing instrument in the course of their artistic education. 3) Recordings made on antique instruments which have active mechanism to organs blow should be recorded at least to some extent.
Źródło:
Liturgia Sacra. Liturgia - Musica - Ars; 2016, 22, 48; 541-549
1234-4214
Pojawia się w:
Liturgia Sacra. Liturgia - Musica - Ars
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for simulating frictional losses in laminar transient liquid pipe flow
Autorzy:
Urbanowicz, K.
Zarzycki, Z.
Kudźma, S.
Powiązania:
https://bibliotekanauki.pl/articles/1943217.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska
Tematy:
unsteady pipe flow
unsteady friction
weighting function
Opis:
This paper is devoted to the problem of energy dissipation and it concerns unsteady friction modeling of the liquid flow in hydraulic lines. One dimensional (1D) quasi-steady model of energy dissipation is in common use. It means that the loss of energy is estimated by the Darcy-Weisbach formulae. Such an approximation is close to reality only for slow changes of the velocity field in the pipe cross-section. In case of fast changes, like fast transients, e.g. water hammer, it fails. In this work the wall shear stress (defined as an effect of unsteady fluid friction) is presented as a sum of quasi-steady and unsteady components. The unsteady component of the wall shear stress is modeled as an convolution of the local fluid acceleration and a weighting function w(t). The weighting function, in general, makes an allowance for a relation of the historic velocity changes and the unsteady component of the wall shear stress. Primitive weighting functions have usually very complicated structures, and what is more, they make it impossible to perform an efficient simulation of dynamical runs. In this paper, a new weighting function is presented as a sum of exponential components in order to enable efficient calculation of the unsteady component wall shear stress. A few examples of the new effective method of unsteady wall shear stress simulations, in case of the water hammer, are presented. The results of the calculations are compared with experiments known in literature and satisfying results are obtained.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2010, 14, 3; 175-188
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Choice of Initial Conditions and of Solution in the Problem of Efficiency Increase of Pipes Calibration on a Mandrel
Autorzy:
Salikhyanov, D.
Bogatov, A.
Dyja, H.
Powiązania:
https://bibliotekanauki.pl/articles/352003.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot-rolled pipe
pipe calibration on a mandrel
pipe precision index
extrafocal deformation
finite element simulation
FEM
Opis:
This research work is devoted to the theoretical study of the pipe calibration on a mandrel. The aim of the study is to improve the precision of the calibrated pipes. As the paper shows, it is advisable to apply different methods of research depending on the purpose of the study of metal forming processes: mathematical, computer or physical simulation. Analytical review of existing mathematical models of the pipes calibration on a mandrel showed that the set of assumptions adopted in the mathematical modeling does not allow assessing the precision of the pipes during calibration. Therefore, finite-element method simulation package was used for this research. Research method and pipes precision index were developed on the basis of the computer simulation using Deform-3D package. The investigations have allowed us to get the dependence of the pipe precision on technological factors and to identify the root cause of reduced efficiency calibration – extrafocal deformation.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 739-742
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza numeryczna rury o przekroju gardzielowym ułożonej w gruncie
Autorzy:
Kliszczewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/365450.pdf
Data publikacji:
2017
Wydawca:
Nowoczesne Budownictwo Inżynieryjne
Tematy:
rura żelbetowa
zastosowanie
konstrukcje rurowe
otoczenie gruntowe
reinforced concrete pipe
application
pipe constructions
ground setting
Opis:
Żelbetowe rury o przekroju gardzielowym znajdują szerokie zastosowanie jako elementy odwodnienia lotnisk, przepusty komunikacyjne oraz przejścia dla małych ssaków i płazów. Rury te, ułożone w gruncie, nieraz na stosunkowo małych głębokościach, poddawane są działaniu intensywnych obciążeń. Do obliczania takich konstrukcji rurowych stosowane są metody analityczne, w których otoczenie gruntowe reprezentowane jest przez układ pionowego i poziomego parcia. Współcześnie stosowane są także metody numeryczne, które umożliwiają zarówno wariantową analizę wytrzymałościową rur o dowolnym, w tym niekołowym przekroju, jak i badanie zjawisk zachodzących w gruntowym otoczeniu tych rur.
Źródło:
Nowoczesne Budownictwo Inżynieryjne; 2017, 3; 90-93
1734-6681
Pojawia się w:
Nowoczesne Budownictwo Inżynieryjne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Światłowodowe sieci telekomunikacyjne w kopalniach
Light pipe telecommunications networks in mines
Autorzy:
Wojaczek, A.
Miśkiewicz, K.
Timler, M.
Powiązania:
https://bibliotekanauki.pl/articles/187468.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
światłowodowe sieci telekomunikacyjne
kopalnie
light pipe telecommunications lines
mines
Opis:
W artykule omówiono sieci telekomunikacyjne światłowodowe, eksploatowane w zakładach górniczych. Scharakteryzowano typowe konfiguracje i możliwe wykorzystanie tych sieci w kopalniach. Zwrócono uwagę na coraz większą rolę sieci optotelekomunikacyjnych w systemach teletransmisyjnych. Przedstawiono możliwe do wykorzystania sposoby transmisji danych w kopalniach z wykorzystaniem sieci światłowodowych. Zaprezentowano wybrane dane dotyczące sieci światłowodowych eksploatowanych w kopalniach JSW SA.
The article presents to light pipe telecommunications lines used in mines. Typical configurations of these networks were presented along with the possibilities to use them in mines. Special attention was paid to the increasing role of opto-telecommunications networks in wire transmission systems. The authors discussed possible ways of data transmission in mines with the use of light pipe networks. Finally, the article features the selected data concerning light pipe networks in the mines of the JSW S.A. mining company.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2011, R. 49, nr 10, 10; 24-31
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problem of placing the organ pipes on the windchest
Autorzy:
Węgrzyn, Damian
Wrzeciono, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/128020.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
pipe organ
windchest
organ pipe distance
organy piszczałkowe
wiatrownica
odległość między piszczałkami organowymi
Opis:
This paper presents research showing the problem occurring in the construction of a pipe organ, related to the placement of the organ pipes on the windchest. The close location of the organ pipes to each other influences the parameters of the sound generated by the pipes. It causes an intonation problem, namely the detuning of the organ pipes if they are located too close to each other on the windchest. The presented measurements show the influence of a distance between pipes of various types on basic sound parameters, such as frequency or volume level. The research carried out shows that in extreme cases the detuning reaches a temperate halftone. This has undoubtedly an impact on the tuning of organ pipes, especially in the case of a table organ or pipe organ built in a small space. In the future, the outcomes of the presented research can be applied in the windchest design.
Źródło:
Vibrations in Physical Systems; 2019, 30, 1; 1-8
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 465

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