Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Navier-Stokes flow" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-22 z 22
    Tytuł:
    A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern
    Autorzy:
    Prybytak, D.
    Zima, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/241287.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    potential flow
    Stokes flow
    Navier-Stokes flow
    BEM
    OpenFOAM
    Opis:
    The paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the open-source code library OpenFOAM was applied. The results of numerical solutions were compared with the results of measurements carried out on a test stand in a hydraulic laboratory. The measurements were taken with an ADV probe (Acoustic Doppler Velocimeter). Finally, differences between the results obtained from the mathematical models and the results of laboratory measurements were analysed.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2017, 64, 3-4; 141-154
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the magnetization-based Lagrangian methods for 2D and 3D viscous flows. Part 2 - numerical implementation and results
    Langrangeowska metoda magnetyzacji dla dwu i trójwymiarowych ruchów płynu lepkiego. Część II - realizacja numeryczna i wyniki
    Autorzy:
    Duszyński, P.
    Olszewski, P.
    Poćwierz, M.
    Styczek, A.
    Szumbarski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/281273.pdf
    Data publikacji:
    2002
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    viscous flow
    Navier-Stokes equations
    magnetization
    stretching
    Opis:
    The numerical implementation of the Lagrangian method using particles of the magnetization field (magnetons) has been considered. A detailed description of essential elements of the algorithm has been provided. The presentation has focused on computations of stretching, where a novel integral-based rather than point wise approach has been proposed. The results of test computations, carried out for viscous flows past 2D and 3D bodies, have been presented. Difficulties with obtaining stable large-time simulations have been encountered and discussed. It has also been shown that, in contrast to flows around solid bodies, the vortex dynamics in the absence of boundaries can be successfully simulated, however, some consistent remeshing technique may by necessary to achieve appropriate resolution.
    W tej części pracy przedstawiono realizację numeryczną i opis wyników wyznaczania ruchów cieczy lepkiej uzyskanych lagrangeowską metodą cząstek magnetyzacji. Podano szczegóły wyznaczenia członu źródłowego (tzw.stretching term). Zaproponowano szczególny nowy sposób postępowania związany z tym efektem. Praca zawiera wyniki symulacji opływów dwu i trójwymiarowych oraz dyskusję napotkanych trudności. Podano też wyniki symulacji ewolucji swobodnych struktur wirowych. Modelowanie takich struktur jest prostsze wobec braku warunku brzegowego.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2002, 40, 4; 825-846
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the magnetization-based Lagrangian methods for 2D and 3D viscous flows. Part 1 - theoretical background
    Lagrangeowska metoda magnetyzacji dla dwu i trójwymiarowych ruchów płynu lepkiego. Część I - Podstawowe sformułowania
    Autorzy:
    Styczek, A.
    Szumbarski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/281483.pdf
    Data publikacji:
    2002
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    viscous flow
    Navier-Stokes equations
    magnetization
    gauge transform
    Opis:
    The paper presents the background of an alternative formulation of the Navier-Stokes equation using a variable called the magnetization. Several variants of governing equations, based on different choices of a particular gauge transform, are discussed. The remaining part of the paper is devoted to the formulation of a Lagrangian approach to 2D and 3D viscous flows. First, the carrier of the magnetization (the magneton) is defined and the corresponding induction law is derived. The instantaneous velocity field is constructed as a superposition of contributions from a large set of magnetons and a uniform stream. An essential feature of the method is a one-time-step operator splitting, consisting in the consecutive solution of three sub-problems: generation of the magnetization on solid boudaries, advection-diffusion of the magnetization and sretching.
    W artykule przedstawione jest sformułowanie problemu granicznego dla równań Naviera-Stokesa z użyciem tzw. pola magnetyzacji. Sformułowanie nie jest jednoznaczne, lecz wiąże się z przyjętą transformacją cechowania. Rozważane są różne postacie tej transformacji i dokonuje się wyboru odpowiednich wariantów. Pole magnetyzacji przedstawione jest w formie lagrangeowskiej. Wprowadza się cząstki będące źródłami tego pola i określa się związane z ich zbiorem pole prędkości. Cząstki magnetyzacji (zwane magnetonami) poruszają się w indukowanym polu prędkości, wykonują ruch losowy odpowiadający dyfuzji i podlegają przekształceniu w sposób opisany członem źródłowym (tzw. stretching). Warunek brzegowy sformułowany na opływanym ciele jest realizowany przez tworzenie w każdej chwili nowych cząstek ulokowanych w bliskim otoczeniu powierzchni ciała.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2002, 40, 2; 339-355
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Multiblock parallel computation of an incompressible 3D flow in turbomachines
    Autorzy:
    Papierski, A.
    Rabiega, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1954540.pdf
    Data publikacji:
    1999
    Wydawca:
    Politechnika Gdańska
    Tematy:
    numerical simulations
    turbomachinery
    incompressible flow
    3D Navier-Stockes solver
    Navier-Stokes solver
    parallel computing
    Opis:
    A finite volume numerical method for the prediction of a fluid flow in complex geometries such as turbomachinery channels has been parallelized using a domain decomposition approach. A mathematical formulation of a 3-D incompressible steady flow has been presented on the basis of the N-S equations in a grid-oriented co-ordinate system with contravariant velocity components. A parallelized pressure-based implicit algorithm with discretization on a staggered grid has been developed. A message exchange system with a boundary exchange, developed by the authors, has been described. Exemplary calculations have been carried out for a laminar flow through a curved duct and for an inviscid flow through a stage of the centrifugal pump. A good agreement has been obtained in both the cases. Despite considerable simplification that has been introduced in the flow through the pump stage, the computations have shown nearly the same pressure rise in the stage as the measurements. Further directions of numerical investigations of a flow through turbomachines, including in particular those devoted to pressure losses related to the rotor-stator interaction, have been mentioned.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 1; 39-52
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Two-dimensional vertical analysis of dam-break flow
    Autorzy:
    Zima, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933149.pdf
    Data publikacji:
    2007
    Wydawca:
    Politechnika Gdańska
    Tematy:
    mathematical modeling
    Reynolds-averaged Navier-Stokes equations
    rapidly varied free surface flow
    dam-break flow
    Opis:
    The paper concerns mathematical modeling of free surface open-channel water flow. Two-dimensional vertical Reynolds-averaged Navier-Stokes equations were used to simulate the flow. They were solved with the SIMPLE algorithm of the finite difference method using the Marker and Cell technique to trace free surface movement. The dam-break flow (water column collapse) problem on a horizontal and frictionless bottom was investigated as a test case. The mechanics of dam-break flow for wet and dry bed conditions was analyzed on the basis of numerical simulations. The obtained results are shown for varying head of water in the downstream channel. The possibility of using the shallow-water equations and the RANS model to simulate rapidly varied flows is discussed.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 4; 315-328
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical investigation of flow in mixed-flow pump with volute
    Autorzy:
    Sedlar, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1967635.pdf
    Data publikacji:
    2001
    Wydawca:
    Politechnika Gdańska
    Tematy:
    CFD
    computational fluid dynamics CFD
    flow separation
    cavitation
    Navier-Stokes equation
    unsteady phenomena
    mixed-flow pump
    volute
    Opis:
    The work considers the modelling of flow in a complete mixed-flow pump with volute, including tip leakage flows, using both quasi-steady and true transient models of rotor/stator interaction. The CFX-TASCflow CFD package from AEA Technology is applied to calculate flows for a wide range of flow rates from about 0.2 to 1.4 Q/sub 0pt/. Fairly detailed flow structures have been predicted based on the flow rates, especially impeller inlet recirculation and separation on the suction side of the blades for suboptimal rates of flow, as well as strong secondary flows and separation in the volute for off-design conditions. The rotor/stator interaction influence on flow phenomena both in the impeller and volute have been investigated with very interesting results, providing good insight into the dynamics of flow close to the volute tongue. Based on the computational results, pump performance curves (Q-H, Q- eta /sub h/ and Q-P, eta /sub h/ being the hydraulic efficiency) have been obtained. The data from this numerical investigation have been used to improve the inlet part of the impeller blades, especially close to the tip. The geometry modifications have resulted in reduced cavitation in the impeller as well as noise at suboptimal rates of flow.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 595-602
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A parallel adaptive code for compressible Navier-Stokes simulations
    Autorzy:
    Banaś, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1954541.pdf
    Data publikacji:
    1999
    Wydawca:
    Politechnika Gdańska
    Tematy:
    numerical simulations
    compressible flow
    Navier-Stokes solver
    finite element method
    parallel computing
    adaptive meshes
    Opis:
    The paper presents a finite element code for compressible flow simulations. The code has two important features: adaptivity to increase accuracy of computations by selectively refining a finite element mesh and efficient parallel performance due to a special implementation based on concept of patches of elements. The algorithm for approximating the compressible Navier-Stokes equations is a version of the stabilized finite element method. Three time integration strategies are implemented, explicit, linear implicit and nonlinear implicit, and the GMRES method is used to solve systems of linear equations. For parallel simulations the code uses a special algorithm for mesh partition. The performance of the code is tested for two examples of supersonic flows: one inviscid and one viscous.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 1; 17-37
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oil leaks intensity in variable-height gaps
    Natężenie przepływu przecieków oleju w szczelinach o zmiennej wysokości
    Autorzy:
    Zloto, T.
    Kowalski, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/792722.pdf
    Data publikacji:
    2013
    Wydawca:
    Komisja Motoryzacji i Energetyki Rolnictwa
    Tematy:
    variable height gap
    hydraulic machine
    Navier-Stokes equation
    hydraulic oil
    oil leakage
    flow intensity
    Źródło:
    Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2013, 13, 2
    1641-7739
    Pojawia się w:
    Teka Komisji Motoryzacji i Energetyki Rolnictwa
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Numerical Study of Combined Natural and Marangoni Convection in a Square Cavity
    Autorzy:
    Cicek, K.
    Baytas, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/116928.pdf
    Data publikacji:
    2009
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Numerical Study
    Square Cavity
    natural convection
    Marangoni Convection
    Buoyancy-Driven Flow
    Thermo Capillary Flow
    Navier-Stokes Equations
    Rayleigh Number
    Opis:
    Through the aim of this study, the effects of combined buoyancy-driven flows and thermo capillary flows, which are emerged from temperature differences, on fluid flow and heat transfer numerically investigated with differentially heated side walls in a free surface square cavity. The study has been accomplished with three milestones to achieve the right solutions. For every milestone Navier-Stokes, continuity and energy equations are discretized by using finite volume method and grids with 52 x 52 control volumes. Results are presented Pr=1, Pr=7 and Pr=100. The effect of positive and negative Marangoni number on fluid flow and heat transfer at different Rayleigh number are considered and discussed.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2009, 3, 2; 173-178
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Two-dimensional vertical Reynolds-Averaged Navier-Stokes equations versus one-dimensional Saint-Venant model for rapidly varied open channel water flow modelling
    Autorzy:
    Szydłowski, M.
    Zima, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/241158.pdf
    Data publikacji:
    2006
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    mathematical modelling
    Reynolds-averaged Navier-Stokes equations
    Saint-Venant equations
    free surface flow
    rapidly varied flow
    dam-break problem
    Opis:
    The paper concerns mathematical modelling of free surface open channel water flow. In order to simulate the flow two models are used -- two-dimensional vertical Reynolds-Averaged Navier-Stokes equations and one-dimensional Saint-Venant equations. The former is solved with SIPMLE algorithm of finite difference method using Marker and Cell technique to trace a free surface movement. The latter is solved using the finite volume method. The dam-break (water column collapse) problem on horizontal bottom is investigated as a test case. The calculated results are compared with each other. The numerical simulations are examined against laboratory experiment presented by Koshizuka et al (1995). The possibility of using the described models to simulate rapidly varied flow is discussed.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2006, 53, 4; 295-309
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Method of lines for the incompressible Navier-Stokes equations in the stream-function formulation
    Autorzy:
    Kosma, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/1965151.pdf
    Data publikacji:
    2005
    Wydawca:
    Politechnika Gdańska
    Tematy:
    Navier-Stokes equation
    stream-function formulation
    method of lines
    compact schemes
    driven cavity
    backward-facing step flow
    Opis:
    The aim of this paper is to simulate the laminar motion of viscous incompressible fluid and the transition between the laminar and the turbulent state in simply connected domains. The developed numerical algorithms are based on the solution of an initial-boundary value problem for the full incompressible Navier-Stokes equations, written in the form of a fourth-order equation for the stream function. The spatial derivatives and the boundary conditions are discretized on uniform grids by means of sixth-order compact schemes together with fourth-order finite-difference formulas, while the continuity of the time variable is preserved. The resulting system of ordinary differential equations has been integrated using the backward-differentiation predictor-corrector method. The efficiency of the numerical algorithms is demonstrated by solving two problems of viscous liquid plane flows in a square driven cavity and a backward-facing step. Calculations for the cavity flow configuration have been obtained for Reynolds numbers ranging from Re=100 to Re=30000 on uniform 50×50 and 100×100 grids. Calculations for the backward-facing step have been made for Re ≤ 3000 with channel lengths, L, within the range 10-30, on 30L×30 uniform grids. The computed stream-function contours and velocity fields have been compared with numerical results reported in the literature.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 1; 17-35
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Implementation of turbulence damping in the OpenFOAM multiphase flow solver interFoam
    Autorzy:
    Polansky, Jiri
    Schmelter, Sonja
    Powiązania:
    https://bibliotekanauki.pl/articles/2091357.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    multiphase flow
    stratified flow
    turbulence damping
    computational fluid dynamics
    OpenFOAM
    Reynolds-averaged Navier–Stokes
    Detached Eddy Simulation
    Delayed Detached Eddy Simulation
    Opis:
    In the presented work Egorov’s approach (adding a source term to the ω-equation in the k-ω model, which mimics the damping of turbulence close to a solid wall) was implemented in on the subclass of shear stress transport models. Hence, turbulence damping is available for all shear stress transport type models, including hybrid models that are based on the ω-equation. It is shown that turbulence damping improves the prediction of the axial velocity profile not only for Reynolds-averaged Navier–Stokes simulation but also for detached eddy simulation and delayed detached eddy simulation models. Furthermore, it leads to a more realistic estimation of the pressure drop and, hence, to a more correct prediction of the liquid level. In this paper, simulation results for four different turbulence models are presented and validated by comparison with experimental data. Furthermore, the influence of the magnitude of the damping factor on the pressure drop in the channel is investigated for a variety of different gas-to-liquid flow rate ratios. These investigations show that higher gas-to-liquid flow rate ratios require higher damping factors to correctly predict the pressure drop. In the end, advice is formulated on how an appropriate damping factor can be determined for a specific test case.
    Źródło:
    Archives of Thermodynamics; 2022, 43, 1; 21--43
    1231-0956
    2083-6023
    Pojawia się w:
    Archives of Thermodynamics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of CFD for analysis of the ship and propeller flow
    Autorzy:
    Bugalski, T. J.
    Szantyr, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1953974.pdf
    Data publikacji:
    1998
    Wydawca:
    Politechnika Gdańska
    Tematy:
    computational fluid dynamics CFD
    CFD
    propeller flow
    ships
    Navier-Stokes equation
    free surface
    propeller operation
    PANSHIP computer system
    Opis:
    The paper describes the computer system PANSHIP for analysis of flow around the ship hull moving with constant velocity in calm water, including the effects of free surface and propeller operation. This system calculates the potential flow using the discrete distribution of Rankine sources on the hull. Viscous flow is computed using the integral method in the bow section and Reynolds averaged Navier Stokes equation (RANS) in the stern section of the ship hull. Results of this analysis may be directly used in ship hull design and they may also serve as input for calculation of the unsteady flow phenomena accompanying propeller operation in the non-uniform velocity field generated by the hull. PANSHIP has been verified experimentally and it forms a useful tool available for ship designers and for marine hydrodynamicists.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 349-356
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Validation of a flow channel to investigate velocity profiles of friction-reducing ship coatings
    Autorzy:
    Weisheit, J.
    Schneider, V. E.
    Serr, J. M.
    Hagemeister, N.
    Oeffner, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1841545.pdf
    Data publikacji:
    2021
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    ship coatings
    flow Channel
    vessel velocity
    laser Doppler velocimeter
    computational fluid dynamics
    AIRCOAT project
    reynolds averaged navier stokes
    measurement volume
    Opis:
    Reducing friction with specialised hull coatings or air lubrication technologies has a potential reducing energy consumption and emissions in shipping. The EU project AIRCOAT combines both by developing a passive air lubrication technology inspired by nature that is implemented on a self-adhesive foil system. Besides validating the friction reduction it is of high interest to understand the underlying mechanism that causes the reduction. Therefore, a flow channel was designed, that creates a stationary turbulent flow within a square duct allowing for non-invasive measurements by laser doppler velocimetry. The high spatial resolution of the laser device makes recording velocity profiles within the boundary layer down to the viscous sublayer possible. Determination of the wall shear stress τ enables direct comparison of different friction reduction experiments. In this paper we validate the methodology by determining the velocity profile of the flat channel wall (without coatings). We further use the results to validate a CFD model in created in OpenFOAM. We find that velocities along the longitudinal axis are generally in good agreement between numerical and experimental investigations.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2021, 15, 1; 225-231
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Novel method of physical modes generation for reduced order flow control-oriented models
    Autorzy:
    Morzyński, M.
    Nowak, M.
    Stankiewicz, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/127922.pdf
    Data publikacji:
    2014
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    Navier-Stokes equation
    eigenmodes
    Reduced Order Modelling
    flow control
    równanie Naviera-Stokesa
    postać drgań własnych
    modelowanie zredukowanego rzędu
    kontrola przepływu
    Opis:
    Physical flow modes are of particular interest for Reduced Order Flow Control-Oriented Models. Computation of physical modes as the eigensolution of linearized Navier-Stokes equations is a cumbersome and difficult task, especially for large, 3D problems. Instead we propose the solution of Navier-Stokes equation in the frequency domain and investigation of the system response to local or global perturbation. The flow variables are perturbed around steady basic state and the system response is used to construct mode basis suitable for ROMs.
    Źródło:
    Vibrations in Physical Systems; 2014, 26; 189-194
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical Simulation of Nonlinear Water Wave Problems
    Autorzy:
    Lo, D. C.
    Hu, Jia-Shen
    Lin, I-Fu
    Powiązania:
    https://bibliotekanauki.pl/articles/116613.pdf
    Data publikacji:
    2008
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Weather Navigation
    Numerical Simulation
    Oceanography
    Nonlinear Water Wave Problem
    Navier-Stokes Equations
    Solitary Waves
    Free-Surface Flow Problem
    Streamfunction Vorticity Formulation
    Opis:
    The main purpose of present paper aims at the establishment of a numerical model for solving the nonlinear water wave problems. The model is based on the Navier-Stokes equations with the consideration of a free-surface through the streamfunction-vorticity formulation. The main advantage of the streamfunction-vorticity formulation is that pressure field can be eliminated from the Navier-Stokes equations. To demonstrate the model feasibility, the present studies are first concentrated on problems including the collision of two solitary waves with different amplitudes, and the overtaking collision of two solitary waves. Then, the model is also applied to a solitary wave passes over the submerged obstacle in a viscous fluid. Finally, the application of present study is also to simulate the generation of solitary waves by underwater moving object. All examples give very promising results, those applications reveal that present formulation is a very powerful approach to simulate the fully nonlinear water wave problems.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2008, 2, 2; 137-142
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mathematical modelling of the process of pipeline deformation through which gas-liquid mixtures with aggressive components are transported
    Autorzy:
    Oliynyk, A. P.
    Feshanych, L. I.
    Grygorchuk, G. V.
    Powiązania:
    https://bibliotekanauki.pl/articles/2172155.pdf
    Data publikacji:
    2022
    Wydawca:
    Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
    Tematy:
    tense state
    pipeline
    viscous fluid flow
    dynamic viscosity
    Navier-Stokes equations
    gas mixture
    rurociąg
    lepkość dynamiczna
    równania Naviera-Stokesa
    mieszanka gazowa
    Opis:
    Purpose Mathematical modelling of the process of deformation of pipeline, transporting gas-liquid mixtures with aggressive components and a comparative analysis of the value of the specified velocity depending on the dynamic viscosity of the multicomponent gas mixture is conducted. Design/methodology/approach A mathematical model of the process of leakage of the transported product due to the loss of tightness of the pipe based on the system of Navier-Stokes equations with boundary conditions with considering the geometry of the leakage zones and the value of the leakage rate is implemented. Findings Models of the process of deformation of the pipeline due to displacements of a certain set of surface points by specifying different types of functions, describing the geometry of deformed sections are constructed. The method of calculating the tensely deformed state based on the data on the movement of surface points by comparing different ways of setting functions, taking into account the actual configuration of sections and axes is improved. The change of flow characteristics in the pipeline when changing the structure of the mix, transported by studying of influence of change of dynamic viscosity is investigated; The method of calculating the rate of leakage of the mixture in case of loss of tightness due to the occurrence of critical stresses in the pipe material is improved. Research limitations/implications Building a model of the deformation process, information about the nature, duration of forces and loads affecting the pipeline is not used. The law of the pipeline movement was constructed having taken into account the deformation of the sections in three directions. The necessity to take wind loads into account, estimating the real tensely deformed state was displayed. Practical implications Using the method of calculating the tensely deformed state based on the data on the movement of surface points by comparing different ways of setting functions, taking into account the actual configuration of sections and axes. Originality/value According to the computational algorithms created on the basis of the specified models, the calculations of the tense state of the pipelines and the flow rate of the mixture depending on its composition were performed. An analysis of the results of calculations - tense intensity and flow rate depending on the dynamic viscosity of the mixture is performed. The influence on the flow parameters - the flow rate of the mixture and the force of hydraulic resistance - changes in the dynamic viscosity of the mixture is analyzed.
    Źródło:
    Journal of Achievements in Materials and Manufacturing Engineering; 2022, 111, 2; 57--63
    1734-8412
    Pojawia się w:
    Journal of Achievements in Materials and Manufacturing Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical simulation of channel flow over a skewed equilateral cavity
    Autorzy:
    Kamel, Abanoub G.
    Haraz, Eman H.
    Hanna, Sarwat N.
    Powiązania:
    https://bibliotekanauki.pl/articles/1839759.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    finite difference method
    incompressible flow
    channel flow
    lid-driven
    shear-driven
    skewed cavity
    Navier-Stokes equations
    równanie Naviera-Stokesa
    przepływ nieściśliwy
    metoda różnic skończonych
    przepływ kanałowy
    Opis:
    In this paper, an incompressible, two-dimensional (2D), time-dependent, Newtonian, laminar, and internal channel fluid flow over a skewed equilateral cavity is simulated using the finite difference method (FDM) and alternating direction implicit (ADI) technique. Navier-Stokes equations are solved numerically in stream function-vorticity formulation. The goal of tackling this problem depends on its academic significance by studying the difference between lid-driven and shear-driven cavity flows in terms of the formation of Moffatt eddies at the sharp corner, also to obtain the length and intensity ratios of these counter-rotating vortices. The value of velocity components along the centerlines of the skewed cavity was revealed at low and intermediate Reynolds numbers (Re), typically (Re = 200 and 2000) at two different skew angles of mainly 30° and 45°. Likewise, the blocked-off regions’ method is used to deal with the geometry of the skewed cavity especially the sharp corners. Furthermore, as Re increases, the main vortex approaches the skewed cavity center and the counter-rotating vortices get bigger in size and intensity, and their number increases.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 3; 29-43
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical simulation of 3D flow in axial turbomachines
    Autorzy:
    Yershov, S.
    Rusanov, A. V.
    Gardzielewicz, A.
    Lampart, P.
    Świrdyczuk, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1953978.pdf
    Data publikacji:
    1998
    Wydawca:
    Politechnika Gdańska
    Tematy:
    numerical simulation
    axial turbomachines
    3D flow
    3D viscous compressible flow
    Navier-Stokes equation
    ENO reconstruction
    computational efficiency
    computational fluid dynamics CFD
    Godunov-type upwind differencing
    Opis:
    The paper is intended to describe a method for the calculation of 3D viscous compressible (subsonic or supersonic) flow in axial turbomachines described in the form of thin-layer Reynolds-averaged Navier-Stokes equations. The method draws on Godunov-type upwind differencing and ENO reconstruction suggested by Harten (1987), so as to assure monotonicity preservation and high accuracy of computational results. The computational efficiency is achieved thanks to the implementation of a simplified H-type multi-grid approach and delta -form implicit step. Turbulent effects are simulated with the help of a modified algebraic model of Baldwin-Lomax (1978). This method was at the foundation of a computer code-a complex software package to calculate 3D flow in multi-stage turbomachines that allows us to obtain local characteristics, like temperature, pressure, density or velocity distributions, as well as global characteristics, such as flow rates, stage reaction, flow efficiency for the considered turbine/compressor stage. The paper also gives selected results of computation of a number of turbomachinery cascades, showing that these results agree reasonably well with the available experimental data.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 319-347
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dusty time fractional MHD flow of a Newtonian fluid through a cylindrical tube with a non-Darcian porous medium
    Autorzy:
    Imo-Mani-Singha, H.
    Sengupta, Sanjib
    Powiązania:
    https://bibliotekanauki.pl/articles/1839832.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    time-fractional order Navier-Stokes equation
    Laplace decomposition method
    LDM
    Magnetohydrodynamics
    MHD
    dusty flow
    non-Darcy porous medium
    ciecz newtonowska
    przepływ cieczy nienewtonowskiej
    Laplace Decomposition Method
    magnetohydrodynamika
    Opis:
    In this paper, time fractional flow of a Newtonian fluid through a uniform cylindrical tube with a non-Darcy porous medium in the presence of dust particles under the application of a uniform magnetic field along the meridian axis is discussed. The implication of time fractional order differential equations in flow problems and some benefits of fractional order differential equations are highlighted. The Laplace Decomposition Method (LDM) is used to obtain an approximate solution to the proposed problem. The impact of fractional order and integer order of the differential equations and also the effects of some important parameters on the flow system are shown in the forms of graphs and a table. The convergence test of the solution is done. It has been observed that the fractional order differential equation reveals more things like the decrease in dust particle velocity due to the increase in magnetic field for fractional order derivatives, whereas, no noticeable change in dust particle velocity due to the change in magnetic field for integer order derivatives are observed. Also, it is observed that an increase in a fractional order derivative decrease the fluid as well as the dust particle velocities. The skin friction at the walls of the tube are also highlighted.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 4; 101-114
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dusty time fractional MHD flow of a Newtonian fluid through a cylindrical tube with a non-Darcian porous medium
    Autorzy:
    Imo-Mani-Singha, H.
    Sengupta, Sanjib
    Powiązania:
    https://bibliotekanauki.pl/articles/1839728.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    time-fractional order Navier-Stokes equation
    Laplace decomposition method
    LDM
    Magnetohydrodynamics
    MHD
    dusty flow
    non-Darcy porous medium
    ciecz newtonowska
    przepływ cieczy nienewtonowskiej
    Laplace Decomposition Method
    magnetohydrodynamika
    Opis:
    In this paper, time fractional flow of a Newtonian fluid through a uniform cylindrical tube with a non-Darcy porous medium in the presence of dust particles under the application of a uniform magnetic field along the meridian axis is discussed. The implication of time fractional order differential equations in flow problems and some benefits of fractional order differential equations are highlighted. The Laplace Decomposition Method (LDM) is used to obtain an approximate solution to the proposed problem. The impact of fractional order and integer order of the differential equations and also the effects of some important parameters on the flow system are shown in the forms of graphs and a table. The convergence test of the solution is done. It has been observed that the fractional order differential equation reveals more things like the decrease in dust particle velocity due to the increase in magnetic field for fractional order derivatives, whereas, no noticeable change in dust particle velocity due to the change in magnetic field for integer order derivatives are observed. Also, it is observed that an increase in a fractional order derivative decrease the fluid as well as the dust particle velocities. The skin friction at the walls of the tube are also highlighted.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 4; 101-114
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of Waterloo MAPLE 9.5 and Wolfram MATHEMATICA 5.1 software for analytic solving of certain nonlinear partial differential equations of physics
    Zastosowanie pakietów MAPLE 9.5 oraz MATHEMATICA 5.1 do analitycznego rozwiązywania wybranych nieliniowych równań różniczkowych cząstkowych fizyki
    Autorzy:
    Stępień, Ł.T.
    Powiązania:
    https://bibliotekanauki.pl/articles/952947.pdf
    Data publikacji:
    2008
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    nieliniowe równania różniczkowe cząstkowe
    rozwiązania analityczne
    rozwiązania dokładne
    równanie Naviera-Stokesa
    równanie Monge'a-Ampere'a
    równanie stałego przepływu izentropowego
    nonlinear partial differential eguations
    analytic solutions
    exact solutions
    Navier-Stokes eguation
    Monge-Ampere eguation
    steady isentropic flow eguation
    Opis:
    In the current paper some applications of the packet MAPLE (v. 9.5) for analytic solying of certain nonline partial differential eguations have been presented. Additionally, for graphic presentation of the found solutions packet MATHEMATICA (v. 5.1) has been applied.
    W niniejszej pracy zostały przedstawione zastosowania pakietu MAPLE (wersja 9.5 do analitycznego znajdywania rozwiązań wybranych nieliniowych równań różniczkowych cząstkowych. Do prezentacji graficznej tych rozwiązań użyto pakietu MATHEMATICA (wersje 5.1).
    Źródło:
    Computer Science; 2008, 9; 147-155
    1508-2806
    2300-7036
    Pojawia się w:
    Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-22 z 22

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies