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    Wyświetlanie 1-12 z 12
    Tytuł:
    Numerical simulations of gap flow above rotating disk
    Autorzy:
    Wasilczuk, F.
    Flaszyński, P.
    Doerffer, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1938643.pdf
    Data publikacji:
    2015
    Wydawca:
    Politechnika Gdańska
    Tematy:
    computational fluid dynamics CFD
    internal flow
    flow control
    Opis:
    A rotating disk can be considered a basic configuration for the investigations of the impact of various conditions on the flow through the clearance between the shrouded turbine blade and the casing. Numerical calculations using Fine/Turbo Numeca were conducted to examine the influence of the rotational velocity and the pressure difference across the disk on the flow conditions, especially the mass flow through the clearance. The results were validated using the experimental data. Moreover, the flow field was investigated to reveal the vortices induced in the flow. The calculations showed a significant drop of the mass flow with a rise of the rotation velocity. Additionally, the vortex created upstream of the disk at higher rotation velocities was observed. The phenomenon of separation at the edge of the disk was investigated.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 89-100
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Applicability of flow simulation models to the case of radial inflow onto a rotating core
    Autorzy:
    Biernacki, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1955813.pdf
    Data publikacji:
    2001
    Wydawca:
    Politechnika Gdańska
    Tematy:
    turbulent flow
    numerical flow simulation
    flow simulation models
    steam turbines
    turbine inlet
    computational fluid dynamics CFD
    Opis:
    The paper presents the results of fluid flow simulations carried out by means of the FIDAP7.6 program (a fluid dynamics FEM package) for the case of radial inflow onto a rotating shaft. The particular geometric configuration has been chosen to resemble a generalized inlet chamber of twin low-pressure steam turbines, but with the axial outlet section extended to allow better observation of flow instabilities in that region. The calculations were carried out for the same channel geometry for both compressible and incompressible flow, using the same or slightly varying boundary conditions. Extensive variation in non-physical parameters of the model was explored, such as applying different meshes over the region, as well as utilizing different turbulence and upwinding models. The intent of this research was to evaluate the relative applicability of the various available flow models to the simulation of axisymmetric flows with steep velocity gradients, and to discover the limitations of these models. The calculations have in fact established significant differences in the behavior of the simulated flow for the different meshes and models. Some results were characterized by extensive areas of recirculating flow whereas others, for the same boundary conditions, showed no recirculation. Correct near-wall meshing as well as the choice of the upwinding scheme were established as the critical factors in this regard. There was also noticeable variation in outlet velocity profiles. An extensive zone of separation within the investigated channel as well as a standing annular vortex near the point of stagnation are flow features of some interest. These patterns of flow change in response to the changing non-physical parameters; the separation zone in particular is absent or slow to develop under some setups. The influence of inflow parameters, the initial velocity distribution and turbulent intensity in particular, on flow behavior in contact with the rotating shaft have also been an area of investigation, as these are often defined with considerable uncertainty in practical applications. It was observed that some latitude in assuming these parameters did not significantly alter the relevant flow parameters at outlet (the velocity and pressure distributions), although it did induce variation in other aspects of the flow (such as the extent of the standing vortex).
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 2; 141-154
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Computational fluid dynamics methods in turbomachinery
    Autorzy:
    Chmielniak, T. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1953985.pdf
    Data publikacji:
    1998
    Wydawca:
    Politechnika Gdańska
    Tematy:
    computational fluid dynamics CFD
    CFD
    turbomachinery
    numerical methods
    modelling
    steady flow
    unsteady flow
    multiphase flow
    multicomponent flow
    blade cooling
    Opis:
    This paper aims to present a general view of flow problems in turbomachinery and the current levels of numerical methods for solving these problems. The flow models used for modelling phenomena in blade cascades are presented. Models of turbulence are discussed. A variety of examples of turbomachinery problems, such as steady, unsteady, multiphase and multicomponent flows, and also blade cooling are described. The actual research fields of computational fluid mechanics are presented.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 205-213
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical investigation of the secondary flow development in turbine cascade
    Autorzy:
    Doerffer, P.
    Rachwalski, J.
    Magagnato, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1955810.pdf
    Data publikacji:
    2001
    Wydawca:
    Politechnika Gdańska
    Tematy:
    turbines
    computational fluid dynamics CFD
    secondary flow
    wind turbines
    Opis:
    The results represent the first attempt of the numerical analysis of 3-D secondary flows formed in the linear turbine cascade wind tunnel. Numerical simulations were carried out by means of the SPRC code. It was possible to make presented here calculations thanks to the cluster of PC's providing sufficient computational resources. In order to be able to verify the obtained results the case considered is the workshop test case (D.G.Gregory-Smith 1994 Turbomachinery Workshop Test Case No.3 116). It has been shown that the obtained results are in a very good agreement with experiment. It gave confidence in the results and several important conclusions concerning the development of streamwise vortices could be made thanks to the work carried out.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 2; 165-178
    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:
    Numerical simulation and theoretical analysis of the 3D viscous flow in centrifugal impellers
    Autorzy:
    Kang, S.
    Hirsch, Ch.
    Powiązania:
    https://bibliotekanauki.pl/articles/1967654.pdf
    Data publikacji:
    2001
    Wydawca:
    Politechnika Gdańska
    Tematy:
    centrifugal compressor
    secondary flow
    CFD
    computational fluid dynamics CFD
    tip leakage flows
    Opis:
    This paper investigates the three-dimensional viscous ow in centrifugal impellers through theoretical analysis and numerical simulations, which is a summary of the authors' recent work. A quantitative evaluation of the dierent contributions to the streamwise vorticity is performed, namely, the passage vortices along the endwalls due to the ow turning; a passage vortex generated by the Coriolis forces proportional to the local loading and mainly active in the radial parts of the impeller; blade surface vortices due to the meridional curvature. In the numerical simulation the NASA Large Scale Centrifugal Compressor (LSCC) impeller with vaneless diuser is computed at three ow rates. An advanced Navier-Stokes solver, EURANUS/TURBO is applied with an algebraic turbulence model of Badwin-Lomax and a linear k-" model for closure, for dierent meshes. An in-depth validation has been performed based on the measured data. An excellent agreement is obtained for most of the data over a wide region of the ow passage. Structures of the 3D ow in the blade passage and the tip region, and their variations with ow rate as well, are analysed based on the numerical results.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 433-458
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Transonic flows, shock wave-turbulent boundary layer interaction
    Autorzy:
    Doerffer, P.
    Kaczyński, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1953982.pdf
    Data publikacji:
    1998
    Wydawca:
    Politechnika Gdańska
    Tematy:
    transonic flows
    shock waves
    turbulent boundary layer interaction
    computational fluid dynamics CFD
    CFD
    flow configurations
    profile flow
    helicopter rotor
    hovering
    forward flight
    internal flows
    Opis:
    Shock wave-boundary layer interaction is one of the most important phenomenon in transonic flows. Due to its complexity it is difficult as well for experimental as for numerical study. The growing potential of CFD is therefore of great importance. Different aspects of shock wave-boundary layer interaction should be studied in different flow configurations. Therefore results concerning profile flow, helicopter rotor at hovering and forward flight and internal flows are presented in this paper. These are to illustrate our ability in CFD in general. Besides flow simulation the development of codes is carried out.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 271-286
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wizualizacja przepływu Couettea-Taylora dla płynu newtonowskiego : zastosowanie metody CFD
    Couette-Taylor flow visualization for Newtonian fluid : application of the CFD method
    Autorzy:
    Peryt-Stawiarska, S.
    Tomkiel, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/2070356.pdf
    Data publikacji:
    2009
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    przepływ Couette'a-Taylora
    CFD
    mechanika numeryczna płynów
    woda
    Couette-Taylor flow
    computational fluid dynamics CFD
    water
    Opis:
    W pracy przedstawiono wyniki symulacji numerycznych CFD dla przepływu Couctle'a-Taylora. Symulacje numeryczne wykonano dla jednofazowego przepływu płynu newtonowskiego (wody) przez trójwymiarową geometrię dwóch współosiowych walców. Wyniki symulacji CFD przedstawiono w postaci map i profili prędkości.
    The results of CFD simulation for the Couette-Taylor flow are presented in the paper. The 3D numerical simulations of one-phase flow of Newtonian fluid (water) were carried out. In the work the flow through two coaxial cylinders was considered. Final results were presented in a form of velocity maps and profiles.
    Źródło:
    Inżynieria i Aparatura Chemiczna; 2009, 3; 158-160
    0368-0827
    Pojawia się w:
    Inżynieria i Aparatura Chemiczna
    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:
    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:
    Performance Investigation of a Double Pipe Heat Exchanger under Different Flow Configuration by Using Experimental and Computational Technique
    Autorzy:
    Kannojiya, V.
    Gaur, R.
    Yadav, P.
    Sharma, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/139516.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    heat exchanger
    computational fluid dynamics CFD
    FLUENT code
    parallel-counter flow
    wymiennik ciepła
    obliczeniowa mechanika płynów
    kod FLUENT
    równoległy przepływ przeciwprądowy
    Opis:
    Heat exchangers are widely employed in numerous industrial applications to serve the heat recovery and cooling purpose. This work reports a performance analysis of a tube in tube heat exchanger for different flow configuration under variable operating conditions. The experimental investigation was performed on a U-shaped double pipe heat exchanger set up whereas Commercial Computational Fluid Dynamics code FLUENT along with k-ε turbulence modeling scheme was implemented for the simulation study. The flow solution was achieved by implementing k-ε turbulence modeling scheme and the simulation findings were compared with the experimental results. The experimental findings were in good agreement with the simulation results. The counter-flow configuration was found to be 29.4% more effective than the cocurrent one at low fluid flow rate. Direct relationship between heat transfer rate and flow rate is observed while effectiveness and LMTD showed inverse relationship with it. The significance of inlet temperature of hot and cold stream has been evaluated, they play crucial role in heat exchange process.
    Źródło:
    Archive of Mechanical Engineering; 2018, LXV, 1; 27-41
    0004-0738
    Pojawia się w:
    Archive of Mechanical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zastosowanie numerycznej mechaniki płynów CFD do modelowania zabezpieczania pomieszczeń stałymi urządzeniami gaśniczymi gazowymi
    Application of Computational Fluid Dynamics CFD for Modeling of Protection of Premises by Fixed Gaseous Extinguishing System
    Autorzy:
    Boroń, S.
    Kubica, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/372766.pdf
    Data publikacji:
    2016
    Wydawca:
    Centrum Naukowo-Badawcze Ochrony Przeciwpożarowej im. Józefa Tuliszkowskiego
    Tematy:
    stałe urządzenie gaśnicze gazowe
    gaz obojętny
    czyste środki gaśnicze
    czas retencji
    model przepływu gazu przez pomieszczenie
    numeryczna mechanika płynów CFD
    fixed gaseous extinguishing system
    inert gases
    clean extinguishing agents
    retention time
    model of gas flow through the room
    computational fluid dynamics CFD
    Opis:
    Cel: W artykule podjęto problem bezpieczeństwa pożarowego pomieszczeń chronionych instalacją stałych urządzeń gaśniczych gazowych. Zwiększenie precyzji i wiarygodności modelowania procesu gaszenia gazem gaśniczym można osiągnąć poprzez zastosowanie metod numerycznej mechaniki płynów CFD przy wykorzystaniu oprogramowania ANSYS FLUENT. Celem badań było opracowanie modelu numerycznego CFD wypływu gazu gaśniczego z przestrzeni chronionej i zbadanie z jego pomocą skuteczności gaśniczej określonych typów gazów. Projekt i metody: W artykule przedstawiono propozycję numerycznego modelu przepływu gazu gaśniczego przez pomieszczenie. Zawarto także opis badań eksperymentalnych i obliczeń analitycznych przeprowadzonych w celu jego walidacji. Wskazano na przykłady praktycznego wykorzystania opracowanego modelu CFD do symulacji, których wyniki mogą wspomagać projektowanie stałych urządzeń gaśniczych gazowych. Wyniki: Analiza porównawcza zebranych wyników symulacji pozwoliła wskazać model Standard k- ε jako model zapewniający największą zbieżność wyników z wynikami badań w skali rzeczywistej. Wartości czasu retencji uzyskane w drodze symulacji były bliższe wynikom rzeczywistym w porównaniu z wartościami otrzymanymi na podstawie obliczeń przeprowadzonych z wykorzystaniem modelu normowego. Wnioski: Modelowanie CFD umożliwia poddanie analizie mechanizmu przepływu gazu przez pomieszczenie z większą dokładnością niż dotychczas stosowane modele. Pozwala to na optymalizację doboru rodzaju oraz ilości gazu gaśniczego z uwagi na czas retencji. Dobór gazu gaśniczego o gęstości mieszaniny zbliżonej do gęstości powietrza daje możliwość uzyskania czasu retencji przekraczającego czas retencji otrzymany w przypadku zastosowania gazów wskazanych w obowiązujących normach. Zastosowanie modelowania CFD umożliwia prowadzenie badań przy wykorzystaniu przestrzeni wirtualnej, eliminując przy tym niebezpieczeństwo związane z prowadzeniem prac pomiarowych stanowiących zagrożenie dla ludzi oraz redukuje koszty finansowe związane z wyładowaniem gazu.
    Aim: The problem of fire safety of areas protected by fixed gaseous extinguishing system is discussed. Increasing the accuracy and reliability of the modeling of gas extinguishing process can be achieved by using methods of computational fluid dynamics CFD using ANSYS FLUENT software. The aim of the study was to develop a numerical CFD model of extinguishing gas flow of the protected space and to examine the extinguishing effectiveness of particular type of norm gases and newly proposed extinguishing gas mixtures with a density similar to the density of air, which significantly limited the phenomenon of outflow of gas from the room and allowed to get longer retention times. Project and methods: The paper proposes a numerical model of extinguishing gas flow through the room which was developed using ANSYS Fluent program, the description of experimental researches carried out in real scale and analytical calculations based on the norm model of gas flow through the room carried out to validate the created CFD model. Examples of practical use of CFD model for simulation, results of which can provide information to support the design of fixed gaseous extinguishing systems were presented. Results: On the basis of a comparative analysis of the collected simulation results model Standard k-ε was indicated as a model that provides the greatest convergence of test results in real scale. Retention times obtained by the computer simulation were closer to real scale results than the retention times obtained on the basis of calculation using the norm wide interface model. Conslusions: The use of CFD modeling allows to review the mechanism of gas flow through the room with greater accuracy than previously used models. This allows for optimal selection of the type and amount of extinguishing gas due to the retention time. Selection of extinguishing gas with the mixture density similar to air density, makes it possible to obtain a retention time exceeding the retention time of the gases specified in the applicable standards. The use of CFD modeling allows to conduct research using virtual space, eliminating the danger related to measurement process posing a threat to humans and reduce financial costs associated with the discharge of extinguishing gas.
    Źródło:
    Bezpieczeństwo i Technika Pożarnicza; 2016, 42, 2; 151-157
    1895-8443
    Pojawia się w:
    Bezpieczeństwo i Technika Pożarnicza
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-12 z 12

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