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 "flow channel" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-10 z 10
    Tytuł:
    Experimental Analysis of Relations Between Coherent Turbulent Structures and Formation of Bedforms
    Autorzy:
    Termini, D.
    Sammartano, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/241077.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    open channel flow
    sediment transport
    bed forms
    flow turbulence structure
    Opis:
    The present paper describes an experimental investigation on the interactions between flow turbulence and sediment motion. During the experiments, detailed measurements of flow velocity components were carried out using an Acoustic Doppler Velocimeter (ADV). The occurrence of turbulent events (inward interaction, ejection, sweep and burst) was verified through conditioned quadrant analysis. The quantitative information on the spatial and temporal evolution of turbulent events was obtained through space-time correlations of the conditioned data. As the primary objective was to analyse how turbulent structures influence formation of bedforms, the spatial scale of turbulent event evolution has been compared with the wavelength of bed-forms (alternate bars) observed on the bed. The analysis has essentially highlighted that such spatial scale compares well with the wavelength of the bars.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2008, 55, 3-4; 125-143
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lagrangian Model for a Single Saltating Grain in the Near-Wall Region of an Open-Channel Flow
    Autorzy:
    Czernuszenko, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/241181.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    Lagrangian model
    open-channel flow
    particle-particle interaction
    Opis:
    A mathematical model for the continuous saltation of a particle near the granular bed in an open-channel flow is developed in detail. The model is based on the Lagrangian equations governing particle motion, and it takes into account the following forces: drag, lift, gravitation, virtual mass and the force responsible for particle-particle interactions. A model of particle-particle collisions is developed and used to determine the mean impulsive force acting upon a particle flowing and rebounding from the channel bed. The model can simulate the continuous saltation trajectories of a single particle in the near-bed region of turbulent flows, in which particle motion is controlled by collisions. The model has been calibrated and verified with available published data in a rather wide range of grain sizes from 0.53 mm to 15 mm. All parameters, such as lift, drag, restitution, friction coefficients and roughness height, have been set on the basis of a reanalysis of these published data.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2013, 60, 1-4; 31-50
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical Modelling of Fish Passage with Turning Pools
    Autorzy:
    Maniecki, Ł.
    Powiązania:
    https://bibliotekanauki.pl/articles/241474.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    open channel flow
    fishway
    turbulence
    numerical model
    turning pool
    Opis:
    An assessment of operating conditions in a baffled fish passage with pool dimensions of 2:2 3:0 m, and 180 horizontally turning pools, was carried out using numerical computations and a site survey of water flow velocity distribution. Velocity was measured with a PMS electromagnetic flowmeter and a hydrometric current meter in representative cross-sections of the fish passage in the pool centres and in the baffle barrier cross-section area. Numerical computations were also performed for two alternative baffle locations in the fishway. One reflected the actual conditions, and the other was an alternative arrangement designed to improve hydraulic conditions for fish migration. The numerical model used the Large Eddy Simulation (LES) method, which makes it possible to detect large vortexes. The study pays close attention to the velocity field analysis as well as the distribution and sizes of vortexes in the turning pool of the culvert. The results of numerical computations and the site survey show high consistency, and the proposed baffle placement modification significantly improves flow conditions, especially in the entry section of the passage.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2018, 65, 1; 41-66
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lax-Wendroff and McCormack Schemes for Numerical Simulation of Unsteady Gradually and Rapidly Varied Open Channel Flow
    Autorzy:
    Machalińska-Murawska, J.
    Szydłowski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/973864.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    open channel flow
    mathematical modeling
    numerical simulation
    FDM schemes
    Opis:
    Two explicit schemes of the finite difference method are presented and analyzed in the paper. The applicability of the Lax-Wendroff and McCormack schemes for modeling unsteady rapidly and gradually varied open channel flow is investigated. For simulation of the transcritical flow the original and improved McCormack scheme is used. The schemes are used for numerical solution of one dimensional Saint-Venant equations describing free surface water flow. Two numerical simulations of flow with different hydraulic characteristics were performed – the first one for the extreme flow of the dam-break type and the second one for the simplified flood wave propagation problem. The computational results are compared to each other and to arbitrary solutions.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2013, 60, 1-4; 51-62
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Experimental Analysis of Horizontal Turbulence of Flow over Flat and Deformed Beds
    Autorzy:
    Termini, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/241285.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    open-channel flow
    flow turbulence structure
    burst cycle
    bed forms
    laboratory experiments
    Opis:
    Laboratory experiments in a straight flume were carried out to examine the evolution of large-scale horizontal turbulent structures under flat-bed and deformed-bed conditions. In this paper, the horizontal turbulence of flow under these conditions is analyzed and compared. The conditioned quadrant method is applied to verify the occurrence of turbulent events. The distributions of horizontal Reynolds shear stress and turbulent kinetic energy are also presented and discussed. Results show the occurrence of an “initial” sequence of horizontal vortices whose average spatial length scales with the channel width. Under deformed-bed conditions, this spatial length does not change.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2015, 62, 3-4; 77-99
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A turbulence model for 3-d flows with anisotropic structure of turbulence
    Autorzy:
    Czernuszenko, W.
    Rylov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/241364.pdf
    Data publikacji:
    2005
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    3D flow
    mathematical model
    numerical simulation
    open channel flow
    turbulence model
    Opis:
    A new turbulence model for flows in open channels with compound cross-sections is presented. The structure of turbulence in these channels can be anisotropic. This structure is described by the turbulent stress tensor that is presented here as the sum of two tensors, namely, normal and shear stress tensors. The normal and shear turbulent stresses are expressed by the turbulence intensities and the mixing length tensor (MLT), respectively. The turbulence intensities can be learned from measurements or another suitable approaches. One such approach that allows calculating the main component of the normal stresses is presented in the paper. The components of MLT are defined based on a new concept of generic mixing length (GML). The generic mixing length is assumed to depend on both distances; from the nearest wall and from the water surface. To demonstrate how the new model works the basic hydrodynamic equations (parabolic approximation of Reynolds equations) together with the turbulence model are solved. The well-known Patankar and Spalding (1972) algorithm was used when solving these equations. A series of numerical simulations were performed for different components of MLT and different channel geometries.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 4; 303-320
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hydraulic Loss Coefficients in 1D Flows
    Autorzy:
    Sawicki, J. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/241418.pdf
    Data publikacji:
    2007
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    hydraulic loss
    closed-conduits flows
    water hammer
    open channel flow
    Opis:
    Determination of hydraulic losses is a very important problem, both from the cognitive and practical points of view. For the uniform and steady fluid streams these losses are described by the well known algebraic expressions, containing some experimental coefficients. In technical practice it is commonly assumed, that these coefficients can be applied also for more complex kinds of flow (non-uniform and even unsteady). However, the problem analysis shows that the proper level of conformity between the results of calculations and measurements can be obtained only after a considerable enlargement of the loss coefficient. Investigation of available characteristics of non-uniform and unsteady 1D velocity fields, presented in this article, leads to the conclusion that this enlargement is physically justified and in some cases it is possible to determine correction factors, which enable recalculation of "basic" coefficients into their new values, suitable for more complex models of 1D flows.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2007, 54, 2; 95-116
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparison of Average Energy Slope Estimation Formulas for One-dimensional Steady Gradually Varied Flow
    Autorzy:
    Artichowicz, W.
    Mikos-Studnicka, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/241083.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    open channel
    steady flow
    gradually varied flow
    standard step method
    energy slope
    Opis:
    To find the steady flow water surface profile, it is possible to use Bernoulli’s equation, which is a discrete form of the differential energy equation. Such an approach requires the average energy slope between cross-sections to be estimated. In the literature, many methods are proposed for estimating the average energy slope in this case, such as the arithmetic mean, resulting in the standard step method, the harmonic mean and the geometric mean. Also hydraulic averaging by means of conveyance is commonly used. In this study, water surface profiles numerically computed using different formulas for expressing the average slope were compared with exact analytical solutions of the differential energy equation. Maximum relative and mean square errors between numerical and analytical solutions were used as measures of the quality of numerical models. Experiments showed that all methods gave solutions useful for practical engineering purposes. For every method, the numerical solution was very close to the analytical one. However, from the numerical viewpoint, the differences between the methods were significant, as the errors differed up to two orders of magnitude.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 89--109
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Flow in a skewed compound open channel with trees on a flood plain
    Autorzy:
    Fukui, Y.
    Urayama, T.
    Takamizu, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/241408.pdf
    Data publikacji:
    2003
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    skewed compound open channel
    trees on the flood plain
    drag force
    secondary flow
    Opis:
    In this research, the flow in a skewed compound channel with trees on the flood plain along the skewed part is studied. Three cases are assumed. Namely, 1) there are no trees on the flood plain along the main skewed part; 2) there are many trees on the flood plain set in order; and 3) there are many trees on the flood plain in disorder. In this research, 1) changes of water level and velocity in the channel; 2) the de-velopment of secondary flow as water flows downward; 3) the drag force due to the existence of trees; and 4) the changes of the river bed level in a movable bed condition are investigated. Numerical analyses using 2-D shallow water theory are also carried out to reproduce a flow in the skewed channel. As a result, the hydraulic quantities, for example water depth and the velocity cal-culated for a case setting trees in order and close together, are available in the river planning for a situation in which some of the trees were washed downstream. Such hydraulic quantities become severe for conditions in order and close to-gether in the flood. During the experiment using sand, channel beds are deformed by piling up and digging of sands or stones in various cases.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 1; 3-19
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Impact of Energy Slope Averaging Methods on Numerical Solution of 1D Steady Gradually Varied Flow
    Autorzy:
    Artichowicz, W.
    Prybytak, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/240952.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    standard step method
    numerical integration
    initial-value problem
    ordinary differential equation
    open channel
    steady gradually varied flow
    energy slope
    Opis:
    In this paper, energy slope averaging in the one-dimensional steady gradually varied flow model is considered. For this purpose, different methods of averaging the energy slope between cross-sections are used. The most popular are arithmetic, geometric, harmonic and hydraulic means. However, from the formal viewpoint, the application of different averaging formulas results in different numerical integration formulas. This study examines the basic properties of numerical methods resulting from different types of averaging.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2015, 62, 3-4; 101-119
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-10 z 10

      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