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Wyświetlanie 1-13 z 13
Tytuł:
Analiza techniczno-ekonomiczna zastosowania zbiorników grawitacyjno-podciśnieniowych
Application of the vacuum-driven tanks - technical and economical analysis
Autorzy:
Mrowiec, M.
Kochańska, O.
Szeląg, B.
Powiązania:
https://bibliotekanauki.pl/articles/297443.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
zbiorniki retencyjne
ścieki opadowe
kanalizacja deszczowa
storage tanks
drainage systems
hydrodynamic models
Opis:
W artykule przedstawiono problematykę działania zbiorników grawitacyjno-podciśnieniowych w systemach odprowadzania ścieków opadowych z obszarów zurbanizowanych. Głównym celem była ocena działania tego typu zbiorników dla hydrogramów generowanych na podstawie opadów rzeczywistych w odróżnieniu od przyjmowanych w dotychczasowych publikacjach opadów obliczeniowych. Przeprowadzone zostały badania symulacyjne z zastosowaniem modelu hydrodynamicznego zlewni zurbanizowanej, wykonanego przy użyciu programu SWMM5. Model ten uwzględniał specyfikę hydraulicznego działania zbiornika grawitacyjno-podciśnieniowego typu Parkus. Na podstawie danych pluwiometrycznych z okresu 2009-2012, zarejestrowanych na deszczomierzu zlokalizowanym w Częstochowie, dokonano analizy funkcjonowania zbiornika grawitacyjno-podciśnieniowego. Rozpatrzonych zostało pięć różnych wariantów udziału objętości napełnianej podciśnieniowo w całkowitej objętości retencyjnej (od 25 do 75% udziału) dla zmiennych wartości jednostkowego natężenia odpływu ze zbiornika (od 4 do 16 dm3/s⋅ha). Na podstawie przeprowadzonych symulacji możliwe było określenie częstotliwości włączania urządzeń do wytwarzania podciśnienia, jak też objętości ścieków, retencjonowanej średniorocznie w warunkach podciśnieniowych. Otrzymane wyniki umożliwiły wskazanie warunków, w jakich zastosowanie podciśnienia do retencjonowania ścieków opadowych jest technicznie i ekonomicznie uzasadnione.
As a result of urbanization, stormwater runoff flow rates and volumes are significantly increased due to increasing impervious land cover and the decreased availability of depression storage. Storage reservoirs are the basic devices to efficiently control the flow-rates in drainage systems during wet weather. Presented in the paper conception of vacuum-driven detention tanks allows to increase the storage capacity by usage of space above the free surface water elevation at the inlet channel. Partial vacuum storage makes it possible to gain cost savings by reduction of both the horizontal area of the detention tank and necessary depth of foundations. In order to determine the effectiveness of their operation a hydrodynamic model was developed using SWMM5 software. Continuous simulations covered a period of four years (rainfall data were recorded on raingage in Czestochowa during the years 2010-2012) and took into account the variable share of the vacuum retention in the total volume: from 25 to 75%. The result of the simulation makes it possible to estimate the cost-effectiveness of vacuum application in comparison to traditional constructions of storage tanks. The results indicated that it is reasonable to use such constructions even if the retention of nearly 50% of total volume is under vacuum conditions.
Źródło:
Inżynieria i Ochrona Środowiska; 2014, 17, 1; 31-40
1505-3695
2391-7253
Pojawia się w:
Inżynieria i Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling the impact of surface currents in a harbor using graph theory
Autorzy:
Kasyk, L.
Kowalewski, M.
Pyrchla, J.
Kijewska, M.
Leyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/135565.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
hydrodynamic models
graph theory
geographic information system (GIS)
electronic navigational chart (ENC)
accident
Opis:
Ensuring security in a harbor requires research into its infrastructure using spatial environmental data. This paper presents a methodology that defines the design of a graph for modeling the interactions between surface currents and moving objects. Combining this graph with port charts that integrate electronic navigation charts with coastal orthophotographs allows us to perform a multidimensional analysis. In addition, the complete information about navigation and harbor infrastructure allows us to predict the effects of currents on objects that are moving in the dock. The capabilities of this application were tested in the Gdynia harbor and the defined graph is based on sea currents generated by the numerical hydrodynamic model M3D.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 46 (118); 189-196
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dokładność hydrodynamicznych modeli Bałtyku a bezpieczeństwo w polskim rejonie odpowiedzialności SAR
Accuracy of hydrodynamic models of the Baltic Sea and safety in the Polish SAR responsibilty area
Autorzy:
Pyrchla, J.
Kowalewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/130432.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
poszukiwania
ratownictwo
modele hydrodynamiczne
dane geoinformatyczne
modelowanie matematyczne
search
rescue
hydrodynamic models
geoinformatical data
mathematical modelling
Opis:
Zgodnie z międzynarodowymi dokumentami planistycznymi dotyczącymi ratownictwa morskiego w Polskim rejonie odpowiedzialności SAR należy wyznaczać obszar poszukiwania w oparciu o środowiskowe dane geinformatyczne. Referat przedstawia modele hydrodynamiczne jako główne źródło tych danych w rejonie Bałtyku Południowego. Koncentruje się wokół problemów związanych z wyznaczeniem dokładności danych z hydrodynamicznych modeli Bałtyku. Przedstawiono wyniki badań nad tym zagadnieniem wykonanych w ramach projektu nr 0 T00A 01328 finansowanego przez Ministerstwo Nauki i Szkolnictwa Wyższego. Zaprezentowano analizę błędów modeli hydrodynamicznych jako funkcję zależną od czasu symulacji. Przedstawiono praktyczne wykorzystanie rezultatów badań podczas planowania akcji ratowniczych w polskim rejonie SAR.
According to international planning documents concerning lifeboat service in Polish SAR responsibility area, a rescue area must be established in accordance with geoinformatical data. This article presents hydrodynamic models as the main source of those data in the South Baltic Region. It focuses on problems related to establishing the accuracy of data from hydrodynamic models of the Baltic Sea. The paper presents results of research concerning the issue, conducted within project no. 0T00A 01328, funded by the Ministry of Science and Higher Education. Also the error analysis of hydrodynamic models was presented as a function dependent on the simulation time. Practical applications of research results while planning rescue operations in Polish region of SAR were illustrated.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2009, 19; 373-385
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A graphical model to determine the influence of surface currents on small objects immersed in water
Autorzy:
Kijewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/135216.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
estimating survivor location
search survivor movement
object searching
search planning
trajectory prediction
search and rescue
graph theory
hydrodynamic models
Opis:
This paper proposes a model of the interactions between surface currents and small, moving objects. These objects are immersed in water so that the part extending above the water is no larger than a human head. These interactions are defined as the weighted-directed graph. The basis for determining the edge weights are the directions of the surface currents. The speeds of these currents are used to calculate the time of moving objects. According to the modelling method of the surface-current influence on small objects, presented in this paper, it is possible to implement an application supporting search-and-rescue-operation planning. This method can be used to locate small objects, such as survivors, when planning search-and-rescue operations. Thus, the routes of these objects moving together with surface-water masses can be predicted using this method.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 47 (119); 170-175
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation in reduced scale hydraulic models of the mooring system of ships docked under the effect of the passage of other vessels (passing ship)
Autorzy:
Esferra, R.
Bernardino, J.C.M
Bezerra, R.
Pion, L.M.
Powiązania:
https://bibliotekanauki.pl/articles/2063985.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
passing Ship
hydraulic models
mooring system
passing ship phenomenon
ship's mooring
hydrodynamic interaction effect
hydrodynamic forces
reduced scale models
Opis:
Vessels moored at port terminals may be subject to excessive strain on mooring lines, induced by other ships passing in their vicinity. This phenomenon is called hydrodynamic interaction, and well known in the international literature as Passing Ship. It occurs due to the displacement of the mass of water between the two vessels, which, consequently, induces hydrodynamic stresses on the two ships. Within this context, scale models are a powerful tool for hydrodynamics studies, being able of reproduce the complex water flow phenomena that take place around passing and moored ship. This paper presents a scale model technique to study the Passing Ship phenomenon and its application on a case study developed for the Santos Port. The study was based on the analysis of the results of simulations performed on a 1:170 scale model to compare the effect of various navigations conditions on the mooring lines of a docked ship.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2021, 15, 3; 845--852
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Difference melt model
Autorzy:
Kazhikenova, Saule Sh.
Shaltakov, Sagyndyk N.
Nussupbekov, Bekbolat R.
Powiązania:
https://bibliotekanauki.pl/articles/1845514.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Navier-Stokes equations
hydrodynamic
approximations
mathematical models
melt
Opis:
The basic objective of the research is to construct a difference model of the melt motion. The existence of a solution to the problem is proven in the paper. It is also proven the convergence of the difference problem solution to the original problem solution of the melt motion. The Rothe method is implemented to study the Navier-Stokes equations, which provides the study of the boundary value problems correctness for a viscous incompressible flow both numerically and analytically.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 607-627
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Difference melt model
Autorzy:
Kazhikenova, Saule Sh.
Shaltakov, Sagyndyk N.
Nussupbekov, Bekbolat R.
Powiązania:
https://bibliotekanauki.pl/articles/1845525.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Navier-Stokes equations
hydrodynamic
approximations
mathematical models
melt
Opis:
The basic objective of the research is to construct a difference model of the melt motion. The existence of a solution to the problem is proven in the paper. It is also proven the convergence of the difference problem solution to the original problem solution of the melt motion. The Rothe method is implemented to study the Navier-Stokes equations, which provides the study of the boundary value problems correctness for a viscous incompressible flow both numerically and analytically.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 607-627
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Supporting marine environment research by modeling
Autorzy:
Jakacki, Jaromir
Przyborska, Anna
Darecki, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/1955263.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska
Tematy:
Modeling-Baltic Sea
coupled models
regional models
hydrodynamic modeling
eBalticGrid system
SatBaltic system
Opis:
The Centre of Informatics – Tri-City Academic Supercomputer and Network (CI TASK) was founded over twenty-five years ago, in 1994. It was a very important initiative undertaken as a result of rapid development of computer technology and one of its main goals was to integrate the computer resources of scientific communities in the Tri-City. CI TASKstarted to provide computing resources and the first steps in the world of high-performance computing must have been proved to be a significant challenge. The scientific community of the Institute of Oceanology has been cooperating with that computing centre since the very beginning.Currently, CI TASKprovides the widest set of tools and hardware that can be used for ocean modeling purposes. The main goal of this work is expression of appreciation and gratitude for the people who have contributed to the developing of this institution and helped in the work using their tools.CI TASK has been helpful in a great number of past and present tasks, however, in this paper we would like to present only three results of our work – a coupled ice-ocean model of the Baltic Sea, assessment of contamination for potential leak age from chemical munition dumped after the Second World War, and the currently operating SatBaltic system.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2018, 22, 4; 351--363
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The unique solvability of stationary and non-stationary incompressible melt models in the case of their linearization
Autorzy:
Kazhikenova, Saule Sh.
Powiązania:
https://bibliotekanauki.pl/articles/1409389.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Navier-Stockes equations
hydrodynamic
approximations
mathematical models
incompressible melt
Opis:
The article presents ε-approximation of hydrodynamics equations’ stationary model along with the proof of a theorem about existence of a hydrodynamics equations’ strongly generalized solution. It was proved by a theorem on the existence of uniqueness of the hydrodynamics equations’ temperature model’s solution, taking into account energy dissipation. There was implemented the Galerkin method to study the Navier-Stokes equations, which provides the study of the boundary value problems correctness for an incompressible viscous flow both numerically and analytically. Approximations of stationary and non-stationary models of the hydrodynamics equations were constructed by a system of Cauchy-Kovalevsky equations with a small parameter ε. There was developed an algorithm for numerical modelling of the Navier-Stokes equations by the finite difference method.
Źródło:
Archives of Control Sciences; 2021, 31, 2; 307-332
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction and analysis of new mathematical models of the operation of ship propellers in different maneuvering modes
Autorzy:
Kryvyi, O.
Miyusov, M. V.
Kryvyi, M.
Powiązania:
https://bibliotekanauki.pl/articles/24201453.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
ship propellers
curvilinear motion
mathematical models
hydrodynamic forces
hydrodynamic moments
wake fraction
thrust-deduction factor
drift angle
Opis:
The influence of the curvilinear movement of the ship on the operation of the propeller was studied. It is shown that even at small values of the drift angle and the angular velocity of the vessel, the transverse component of the force on the propeller and the moment are non-zero and cannot be neglected. The existing and proposed new effective mathematical models of the longitudinal and transverse components of force and moment caused by the operation of the ship's propeller are analyzed. Simple expressions for the coefficients of the propeller thrust and the moment on the propeller shaft, the wake fraction, the thrust-deduction factor, and the flow straightening factor on the propeller at any drift angles and angular velocity are obtained. Numerical analysis of the obtained dimensionless components of forces and moments caused by the operation of the propeller is carried out, and their adequacy is shown. It is shown how the specified parameters change for all possible values of the drift angle and angular velocity. For a few commercial vessels of various types, technical characteristics and calculated dynamic parameters are given for the construction of mathematical models of propeller operation during curvilinear movement of the vessel.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 1; 95--102
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The robot joint lubrication with ultra-thin hyperelastic superficial layers
Autorzy:
Wierzcholski, K.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/243815.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
robot joint lubrication
various curvilinear hyperactive thin
soft layer shapes
basic hydrodynamic equations
physical models
humanoid robot
Opis:
The surface of humanoid robots is more or less deformable metal and plastic replica of human body. An advanced humanoid robot has human like behaviour – it can talk, run, jump or climb stairs in a very similar way a human does. Hence follows that operation of construction of the robots artificial joints to be similar for biological joints activities. This fact requires applying proper as well corresponding soft solid materials, and specific lubricants. To the interesting phenomena belong the fact, that as well the surfaces of an articular cartilage human joint as the soft surfaces of the robot joints, coated with ultra-thin hyperelastic multi-layers, plays an important role in the surface active lubrication, relative small friction forces and wear during the human limb or robot body activities in the movement. The presence of the ultra-thin hyperelastic layers consisting the soft bearing materials including hyperelastic nano-particles during the robot bearing lubrication enables to indicate numerous positive effects among other the decreases the friction coefficient values. Therefore, the results obtained in this paper may be applicable during the joint-endo-prosthesis or artificial joint design in new humanoid robots, where instead cartilage and synovial fluid are applied new soft materials with active hyperelastic micro- and nano- particles. In this paper is shortly presented the mathematical model of hydrodynamic lubrication of thin boundary layer describing the robot joint. Mathematical model in 3D for lubricant consists of three equations of motion, continuity equation, conservation of energy equation and Young-Kelvin-Laplace equation describing the thin layer interfacial energy.
Źródło:
Journal of KONES; 2016, 23, 3; 555-562
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical research of the chip removal process in milling of the closed profile slots
Autorzy:
Gnytko, O.
Kuznetsova, A.
Powiązania:
https://bibliotekanauki.pl/articles/2201130.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
closed slots
milling
chip removal
mathematical models
pneumatic hydrodynamic force
zamknięte szczeliny
frezowanie
usuwanie wiórów
modele matematyczne
pneumatyczna siła hydrodynamiczna
Opis:
Purpose: The chip removal from the cutting zone of closed slots (T-shaped, "dovetail", etc.) is relevant since the repeated cutting of the chip with the blades of the tool teeth leads to a decrease in the resource of the cutting tool and processing accuracy. However, theoretical studies of the processes of filling, accumulation, and movement of the chip have not been considered. The purpose of the research is to develop the theoretical foundations of the chip filling and removing processes from profile slots using pneumatic hydrodynamic action of pressure jets of cooling liquid. Design/methodology/approach: Several stages of the analysed process are considered, namely the separation and filling of the space between the cutter teeth with the chip, filling the machined slot with the chip, removing the chip element from the space between the cutter teeth, moving the chip element along the machined slot, moving the chip array along the machined slot, pneumatic hydrodynamic impact. Findings: The complex of mathematical models have been developed to describe the functioning of the chip removal system during the milling of the closed profile slots in this research. The set of the developed models makes it possible to determine the required values of the design and operating parameters of devices that ensure the chip removal from the cutting zone as a result of the use of inertial forces and the application of additional compulsory forces. Research limitations/implications: Theoretical studies were applied for T-shaped slots for milling cutters with diameters from 12.5 mm to 95 mm made of high-speed steel and carbide inserts during steels and cast irons processing. The use of pneumatic hydrodynamic action is limited by the diameters of the nozzle hole from 0.5 mm to 3 mm. Practical implications: The practical significance of the research lies in the ability to control the process of timely chip removal from the cutting zone and to prevent the repeated ingress of the chip under the milling cutter blade. This is achieved by a set of mathematical models that simulate the chip removal process. Research can be applied in production in slots milling, using a liquid not only to cool the cutting zone but also to remove the chip in a timely manner. Originality/value: Theoretical studies previously not carried out for closed profile slots are presented in the research.
Źródło:
Archives of Materials Science and Engineering; 2022, 113, 2; 69--76
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of the data on the surface currents and wind parameters generated by numerical models on the Szczecin Lagoon area
Autorzy:
Kijewska, M.
Pleskacz, K.
Kasyk, L.
Powiązania:
https://bibliotekanauki.pl/articles/117323.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Szczecin Lagoon
surface current
wind parameters
hydrodynamic model
weather forecast
numerical models
Geographic Information System (GIS)
High Frequency Surface Wave Radar (HFSWR)
Opis:
This study focuses on the investigation of available surface currents and wind parameters for employing them in order to predict the survivor movement in the Szczecin Lagoon waters. For this purpose, the surface currents and wind parameters were generated by selected numerical models and the wind parameters were also measured with the telemetry devices. In this paper, the PM3D hydrodynamic model and the NEMS, ECMWF, GFS weather forecast models have been investigated. The measurements of the wind parameters, recorded at the Brama Torowa I and Trzebież stations, were also analyzed. As part of the research, an expert method was used to evaluate the surface currents parameters. In turn, the method based on comparing the forecasted wind parameters with the measured wind parameters was applied in order to assess uncertainties of these parameters. The comparative analyses of the data on the surface currents and wind parameters have been done and probabilistic models for uncertainties of these forecasted parameters have been formulated. Additionally, relations between the surface currents speeds and the wind speeds, in the case when their directions were consistent, have been also discovered.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2018, 12, 4; 729-737
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-13 z 13

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