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Tytuł:
Laboratory investigations of deep-water wave transformation and stability
Autorzy:
Wilde, P.
Sobierajski, E.
Chybicki, W.
Sobczak, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/240986.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
laboratory investigations
deep-water wave transformation
deep-water wave stability
Opis:
The authors performed laboratory investigations and the analysis of the transformation of deep-water waves in the flume of the Institute of Hydro-Engineering. Special wave trains were generated by our piston-type wavemaker. Due to the transformation the wave profiles changed along the path of propagation. At first, the changes appeared at the ends of the wave train. Far from the generator they intruded into the middle interval of initially regular waves. Finally, the whole wave train consisted of a set of irregular groups. To study the instability problem the wave trains were modulated by superposition of wave groups with very small amplitudes. The number of waves in a group was a very important parameter. When the number was proper, even small amplitudes of modulation resulted in strong development of amplitudes of wave groups. In our theoretical analysis the non-linear Schroedinger equation was used. The comparison of laboratory and theoretical results proved that this equation is useful but it does not describe the phenomenon in the best way. There have been many attempts to construct a numerical procedure that describes the propagation of water waves. Very often the numerical algorithm is not stable and the results of calculation diverge from the expected behaviour. The authors believe that in many cases the instability is due to the physical loss of stability of the wave train and thus it is necessary to have a good understanding of the physics of the studied motion.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 3; 287-313
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave-induced stresses and liquefaction in seabed according to the biot-type approach
Autorzy:
Sawicki, A.
Mierczyński, J.
Powiązania:
https://bibliotekanauki.pl/articles/241059.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
seabed mechanics
water wave
liquefaction
Opis:
The problem of wave-induced stresses and liquefaction in the seabed according to the Biot-type approach is discussed. The first part of the paper deals with critical analysis of approaches presented in recent literature. It is shown that such approaches do not lead to proper description of the process of wave-induced pore-pressure generation and subsequent liquefaction of seabeds. The second part of this paper deals with the generalisation of the Biot-type approach to the case of shear modulus depending on mean effective stress.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 2; 131-145
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear Interactions between Gravity Waves in Water of Constant Depth
Autorzy:
Szmidt, K.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/241222.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
nonlinear water wave
wave interaction
material variables
potential solution
Opis:
The paper deals with interactions between water waves propagating in fluid of constant depth. In formulation of this problem, a nonlinear character of these interactions is taken into account. In particular, in order to simplify a solution to nonlinear boundary conditions at the free surface, a system of material coordinates is employed as independent variables in the description of the phenomenon. The main attention is focused on the transient solutions corresponding to fluid motion starting from rest. With respect to the initial value problem considered, we confine our attention to a finite fluid domain. For a finite elapse of time, measured from the starting point, the solution in a finite fluid area mimics a solution within an infinite domain, inherent for wave propagation problems. Because of the complicated structure of equations describing nonlinear waves, an approximate formulation is considered, which is based on a power series expansion of dependent variables with respect to a small parameter. Such a solution is assumed to be accurate in describing the main features of the phenomenon. Numerical experiments are conducted to illustrate the approximate formulation developed in this paper.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2015, 62, 1-2; 3-25
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the generation of water waves in a flume
Autorzy:
Wilde, P.
Wilde, M.
Powiązania:
https://bibliotekanauki.pl/articles/241118.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water wave
flume
wavemaker
horizontal motion
piston
Opis:
The present paper proposes a simple model for the calculation of a time series to control the horizontal motion of the piston of a wavemaker. It is assumed that the initial conditions correspond to water at rest. It is assumed that parameters of kinematics of the fluid (displacement, velocity and acceleration fields) at the initial time are equal to zero. In the first interval the amplitudes grow to an asymptote that corresponds to a regular monochromatic wave. In the second interval the waves decay. Calculated time series were fed in to the control system of our wavemaker and the measured horizontal displacements of the piston compared. The control series was supplemented by terms corresponding to the Stokes type solution by addition of terms with multiples of the basic frequency.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2001, 48, 4; 69-83
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the SPH Approximations in ModelingWaterWaves
Autorzy:
Szmidt, K.
Powiązania:
https://bibliotekanauki.pl/articles/241299.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water wave
SPH modeling
consistency
kernel correction
Opis:
This paper presents an examination of approximation aspects of the Smoothed Particle Hydrodynamics (SPH) in modeling the water wave phenomenon. Close attention is paid on consistency of the SPH formulation and its relation with a correction technique applied to improve the method accuracy. The considerations are confined to flow fields within finite domains with a free surface and fixed solid boundaries with free slip boundary conditions. In spite of a wide application of the SPH method in fluid mechanics, the appropriate modeling of the boundaries is still not clear. For solid straight line boundaries, a natural way is to use additional (virtual, ghost) particles outside the boundary and take into account mirror reflection of associated field variables. Such a method leads to good results, except for a vicinity of solid horizontal bottoms where, because of the SPH approximations in the description of pressure, a stratification of the fluid material particles may occur. In order to illustrate the last phenomenon, some numerical tests have been made. These numerical experiments show that the solid fluid bottom attracts the material particles and thus, to prevent these particles from penetration into the bottom, a mutual exchange of positions of real and ghost particles has been used in a computation procedure.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2013, 60, 1-4; 63-86
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On variational formulation in water wave mechanics
Autorzy:
Wilde, P.
Szmidt, J. K.
Powiązania:
https://bibliotekanauki.pl/articles/241323.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water wave
variational formulation
spatial and material description
Opis:
In this paper variational formulations for surface gravitational waves in inviscid incompressible fluids are investigated. The formulations are introduced with the help of the principle of virtual work. The starting point are equations of motion multiplied by a field of virtual displacements and integrated over the region occupied by the fluid. In derivations of the virtual work equation careful attention is paid to mutual relations between Eulerian and Lagrangian descriptions. The integration of the equation with respect to time leads to the expression for the Lagrangian function and then the Hamilton's principle. The case of a potential flow and spatial description provides a generalisation of the Lagrangian given by Luke (1967).
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 1; 55-74
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Difference Analysis of Surface Wave Scattering by Underwater Rectangular Obstacles
Autorzy:
Szmidt, K.
Powiązania:
https://bibliotekanauki.pl/articles/241339.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water wave
scattering of waves
finite difference method
Opis:
This paper deals with the problem of the scattering of surface water waves by underwater obstacles. The main goal of the investigations is to estimate the efficiency of such structures in protecting sea shelf zones from open sea waves. A useful measure of the protection is the ratio of the square of the amplitude of the transmitted wave to the square of the amplitude of the arriving wave. The problem is formulated in terms of the finite difference method. It is shown that the discrete approach to the problem leads to eigenvalue problems for two matrices resulting from the discrete description. As compared to analytical formulation, the discrete method may be convenient in application to unsteady problems and obstacles of complicated geometry.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 3-4; 179-198
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical analysis on experiments in transformation of deep-water-waves
Autorzy:
Wilde, P.
Powiązania:
https://bibliotekanauki.pl/articles/241349.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water wave
stability
transformation
wave groups
non-linear Schrödinger differential equation
Opis:
The aim of the paper is to discuss the usefulness of the non-linear Schrödinger differential equation in the study of transformations of progressive deep water waves. Its solution compared with a regular Stokes type wave is essentially restricted to the first order approximation of the second one. The difference is that the Schrödinger equation introduces the concepts of a carrier wave and complex amplitude. In this way the dispersion relation of the third order Stokes expansion is taken into account. The analysis starts with regular, non breaking Stokes waves with large amplitudes as measured in our laboratory. The third order approximation is considered and compared with the corresponding solution of the Schrödinger equation. Then small periodic modifications are introduced in the time series fed into the control system of the generator. The approximation by trigonometric series is applied and the simplified analysis of superposition of very small modifications is used (higher powers of modifications are neglected). The Schrödinger non-linear equation is used in this analysis. The comparison of experimental and calculated envelopes is good, but for the surface elevations in space it is not as good. The approximation by trigonometric series is also applied to study the case of larger modifications. Finally the solutions of the Schrödinger equation corresponding to perfect solitons, are compared with the experimental data for cases where the measured surface elevations look almost like periodic solitons. This gives a reasonable approximation of the real behaviour in a very short space interval. It is not easy to get a good numerical description for the wave problem discussed as the waves are physically unstable. The results of the presented research will be used to establish an effective numerical procedure, stress the approximations introduced by the application of the Schrödinger differential equation and show how the theoretical solutions should be compared with the measured data.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 3; 213-242
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of an Element-free Galerkin Method to Water Wave Propagation Problems
Autorzy:
Staroszczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/241246.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
gravity water wave
transient problem
element-free Galerkin method
Opis:
The paper is concerned with the problem of gravitational wave propagation in water of variable depth. The problem is solved numerically by applying an element-free Galerkin method. First, the proposed model is validated by comparing its predictions with experimental data for the plane flow in water of uniform depth. Then, as illustrations, results of numerical simulations performed for plane gravity waves propagating through a region with a sloping bed are presented. These results show the evolution of the free-surface elevation, displaying progressive steepening of the wave over the sloping bed, followed by its attenuation in a region of uniform depth. In addition, some of the results of the present model are compared with those obtained earlier by using the conventional finite element method.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2013, 60, 1-4; 87-105
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformation of long waves in a canal of variable section
Autorzy:
Szmidt, K.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/241144.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
long water wave
canal of variable section
enforcement of wave height
material variables
Opis:
The paper deals with long water waves propagating in a straight canal of constant depth and variable section. In the formulation of this problem, a simplified, one-dimensional model is considered that is based on the assumption of a “columnar” fluid motion. To this end, a system of material coordinates is employed as independent variables in the description of this phe- nomenon. The main attention is focused on transient solutions corresponding to a fluid motion starting from rest. With respect to the initial value problem considered, we confine our attention to a finite domain fluid motion induced by a piston-type generator placed at the beginning of the canal. For a finite elapse of time, measured from the starting point, the solution in the finite fluid area mimics a solution within an infinite domain, inherent for wave propagation problems. The main goal of our investigations is to describe the evolution of the free surface (the wave height) at the smallest section of the canal. Numerical examples are provided to illustrate the model formulation developed in this paper. The accuracy of this approximate description is assessed by comparing its results with data obtained in hydraulic experiments performed in a laboratory flume.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2016, 63, 1; 3-18
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Lagrangian Finite Element Analysis of Gravity Waves in Water of Variable Depth
Autorzy:
Staroszczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/241185.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
gravity water wave
variable water depth
transient problem
Lagrangian formulation
finite element method
Opis:
The paper is concerned with the problem of gravitational wave propagation in water of variable depth. The problem is formulated in the Lagrangian description, and the ensuing equations are solved numerically by a finite element method. In computations a convecting mesh that follows the material fluid particles is used. As illustrations, results of numerical simulations carried out for plane gravity waves propagating over bottoms of simple geometry are presented. For parameters typical of a laboratory flume, the transformation of a transient wave, generated by a single movement of a piston-like wave maker, is investigated. The results show the evolution of the free-surface elevation, displaying steepening of the wave over sloping beds and its gradual attenuation in regions of uniform depth.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2009, 56, 1-2; 43-61
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Water Flows around a Circular Cylinder with the SPH Method
Autorzy:
Szmidt, T.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/241295.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
transient water wave
SPH modeling
boundary conditions
approximation of shear forces
Opis:
The paper describes the SPH modeling of a plane problem of fluid flow around a rigid circular cylinder. In the model considered, the cylinder is placed in a rectangular fluid domain at a certain distance from a horizontal plane boundary, and it is subjected to fluid flow forces. The fluid motion is induced by a piston type generator. The generator - fluid system starts to move from rest at a certain moment of time. The work aims at a discrete description of the fluid flow around the cylinder and, at the same time, calculation of the pressure distribution along the circumference of the cylinder and the resultant of the pressure on the cylinder. In order to solve the initial value problem considered, a new SPH formulation of boundary conditions on the cylinder surface is proposed which match the physical condition for the fluid velocity at this boundary. For a viscous fluid, an approximate description of the stress tensor is formulated which allows to reduce the differentiation of field functions to the first order in calculating the shear forces in the SPH approach.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 1-2; 39-60
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Initial boundary value problems for vortex motion of an ideal fluid in bounded domains
Autorzy:
Szmidt, K.
Powiązania:
https://bibliotekanauki.pl/articles/241010.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
vortex motion
incompressible perfect fluid
bounded domains
boundary value problems
water wave
Opis:
The paper deals with the problem of vortex motion of an incompressible perfect fluid in bounded domains. The research is confined to chosen cases of steady velocity fields within rectangular, circular and elliptic regions with rigid boundaries. The solution to the initial-value problem of the fluid flow for the assumed velocity fields is the primary object of this paper. It is demonstrated that individual particles of the fluid have their own periods of motion and thus, one should be careful in describing such problems by means of discrete methods, especially in the Lagrangian variables. The problem discussed has its origin in numerical analysis of water waves by means of the finite difference or the finite element method.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2001, 48, 1; 19-33
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Incompressible SPH Model for Simulating Violent Free-Surface Fluid Flows
Autorzy:
Staroszczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/241132.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
gravity water wave
free surface
incompressible flow
Lagrangian description
smoothed particle hydrodynamics
Opis:
In this paper the problem of transient gravitational wave propagation in a viscous incompressible fluid is considered, with a focus on flows with fast-moving free surfaces. The governing equations of the problem are solved by the smoothed particle hydrodynamics method (SPH). In order to impose the incompressibility constraint on the fluid motion, the so-called projection method is applied in which the discrete SPH equations are integrated in time by using a fractional-step technique. Numerical performance of the proposed model has been assessed by comparing its results with experimental data and with results obtained by a standard (weakly compressible) version of the SPH approach. For this purpose, a plane dam-break flow problem is simulated, in order to investigate the formation and propagation of a wave generated by a sudden collapse of a water column initially contained in a rectangular tank, as well as the impact of such a wave on a rigid vertical wall. The results of simulations show the evolution of the free surface of water, the variation of velocity and pressure fields in the fluid, and the time history of pressures exerted by an impacting wave on a wall.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 1-2; 61-83
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear ship wake waves as a model of rogue waves and a source of danger to the coastal environment: a review
Autorzy:
Soomere, T.
Powiązania:
https://bibliotekanauki.pl/articles/48354.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Sopot
nonlinear ship
wave
extreme wave
shallow water wave
conference
Baltic Sea
marine ecosystem
coastal environment
ship traffic
speed ship
coastal area
Opis:
A substantial part of the energy of wake waves from high-speed ships sailing in shallow water is concentrated in nonlinear components which at times have a solitonic nature. Recent results of investigations into solitonic wave interactions within the framework of the Kadomtsev-Petviashvili equation and their implications for rogue wave theory are reviewed. A surface elevation four times as high as the counterparts occurs if the properties of the interacting waves are specifically balanced. The slope of the water surface may increase eightfold. The resulting structure may persist for a long time. Nonlinear wake components may exert a considerable influence on the marine ecosystem in coastal areas.
Źródło:
Oceanologia; 2006, 48, S
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A finite element method for extended KdV equations
Autorzy:
Karczewska, A.
Rozmej, P.
Szczeciński, M.
Boguniewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/330630.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
shallow water wave problem
nonlinear equations
second order KdV equations
finite element method
Petrov–Galerkin method
Opis:
The finite element method (FEM) is applied to obtain numerical solutions to a recently derived nonlinear equation for the shallow water wave problem. A weak formulation and the Petrov–Galerkin method are used. It is shown that the FEM gives a reasonable description of the wave dynamics of soliton waves governed by extended KdV equations. Some new results for several cases of bottom shapes are presented. The numerical scheme presented here is suitable for taking into account stochastic effects, which will be discussed in a subsequent paper.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 3; 555-567
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
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:
Water wave scattering by an infinite step in the presence of an ice-cover
Autorzy:
Ray, S.
De, S.
Mandal, B. N.
Powiązania:
https://bibliotekanauki.pl/articles/265982.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
fala wodna
pokrywa lodowa
aproksymacja Galerkina
water wave scattering
ice cover
infinite step
integral equation
Galerkin approximation
reflection and transmission coefficients
Opis:
The classical problem of water wave scattering by an infinite step in deep water with a free surface is extended here with an ice-cover modelled as a thin uniform elastic plate. The step exists between regions of finie and infinite depths and waves are incident either from the infinite or from the finite depth water region. Each problem is reduced to an integral equation involving the horizontal component of velocity across the cut above the step. The integral equation is solved numerically using the Galerkin approximation in terms of simple polynomial multiplied by an appropriate weight function whose form is dictated by the behaviour of the fluid velocity near the edge of the step. The reflection and transmission coefficients are obtained approximately and their numerical estimates are seen to satisfy the energy identity. These are also depicted graphically against thenon-dimensional frequency parameter for various ice-cover parameters in a number of figures. In the absencje of ice-cover, the results for the free surface are recovered.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 4; 157-168
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of nonlinear standing waves underneath a deck
Autorzy:
Majewski, D.
Sulisz, W.
Powiązania:
https://bibliotekanauki.pl/articles/1849771.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
uderzenie falii
impuls ciśnienia
budowla brzegowa
budowla morska
fala wodna
metoda elementów brzegowych
model numeryczny
wave impact
impact pressure
coastal structure
offshore structure
water wave
boundary element method
numerical model
Opis:
A theoretical approach was applied to investigate the impact of nonlinear standing waves underneath a horizontal deck. A solution was achieved by applying a boundary element method. The model was applied to predict impact pressure underneath a deck. The results show that the wave impact is a very complex momentary process. The influence of initial boundary conditions, wave parameters and deck clearance on impact pressure are analysed. The analysis shows that purely sinusoidal waves of very small amplitude may cause an impact pressure several orders of magnitude higher than a pressure arising from typical applications of a linear wave theory. The analysis shows that all these non-intuitive outcomes arise from the complexity of a wave impact process and its enormous sensitivity to initial conditions what indicates serious difficulties in a reliable prediction of a wave impact for complex wave fields or other structures. Laboratory experiments were conducted to validate theoretical results.
Zbadano proces uderzenia nieliniowych, stojących fal wodnych w spód poziomego pokładu. Wykorzystano podejście teoretyczne, którego rozwiązanie opiera się na Metodzie Elementów Brzegowych. Za pomocą modelu wyznaczono ciśnienia generowane uderzeniem fal wodnych. Wyniki wskazują na to, że proces jest bardzo złożony i ma charakter impulsowy. Analizowano wpływ początkowych warunków brzegowych, parametrów fali oraz wysokości zawieszenia pokładu nad powierzchnią spokoju na generowane ciśnienia. Wyniki pokazują, że nawet fale sinusoidalne, o małej amplitudzie mogą wywołać ciśnienia kilkukrotnie większe niż ciśnienia wynikające z typowych zastosowań teorii liniowej falowania. Pokazują również, że często nieintuicyjne wnioski wynikają ze złożoności procesu uderzenia fali i jego dużej czułości na początkowe warunki brzegowe. Wskazuje to na poważne trudności w wiarygodnym modelowaniu procesu uderzenia dla złożonych pól falowych oraz skomplikowanych układów geometrycznych budowli. Przeprowadzono również pomiary laboratoryjne w celu uzyskania danych do walidacji modelu numerycznego. Opracowany model zapewnia wyniki z dokładnością umożliwiającą zastosowanie go w zadaniach inżynierskich.
Źródło:
Archives of Civil Engineering; 2020, 66, 4; 79-96
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the geometry of ocean surface waves
Autorzy:
Massel, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/48766.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
air-sea interaction
atmosphere-ocean interaction
deep water
dynamic factor
geometry
irregular wave
marine environment
ocean surface
regular wave
shallow water
surface wave
water motion
wave breaking
wave slope
Opis:
The factors influencing the atmosphere-ocean transfer of mass and momentum, as well as incipient wave breaking and the amount of energy dissipated due to breaking, are discussed in detail. In particular, the influence of directional spreading on the statistics of surface wave slopes and the area of the wind- roughened ocean surface is demonstrated. Theoretical analysis and comparison with the available experimental data show that unimodal directional spreading is not able to reproduce the observed ratio of the cross-wind/up-wind mean square slopes. Better agreement is achieved when bimodal directional spreading, consisting of two wrapped-Gaussian distributions, is applied. The bimodal form suggested by Ewans (1998) is used in the paper. Moreover, the formulae developed here show that the increase in the area due to surface waves is rather small for both regular and irregular waves.
Źródło:
Oceanologia; 2011, 53, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new form of Boussinesq equations for long waves in water of non-uniform depth
Autorzy:
Szmidt, J.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/201637.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
long wave
Boussinesq equation
wave transformation
variable water depth
Opis:
The paper describes the non-linear transformation of long waves in shallow water of variable depth. Governing equations of the problem are derived under the assumption that the non-viscous fluid is incompressible and the fluid flow is a rotation free. A new form of Boussinesq-type equations is derived employing a power series expansion of the fluid velocity components with respect to the water depth. These non-linear partial differential equations correspond to the conservation of mass and momentum. In order to find the dispersion characteristic of the description, a linear approximation of these equations is derived. A second order approximation of the governing equations is applied to study a time dependent transformation of waves in a rectangular basin of water of variable depth. Such a case corresponds to a spatially periodic problem of sea waves approaching a near-shore zone. In order to overcome difficulties in integrating these equations, the finite difference method is applied to transform them into a set of non-linear ordinary differential equations with respect to the time variable. This final set of these equations is integrated numerically by employing the fourth order Runge - Kutta method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 3; 631-643
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Groundwater flow due to a nonlinear wave set-up on a permeable beach
Autorzy:
Przyborska, A.
Powiązania:
https://bibliotekanauki.pl/articles/47606.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
pore pressure
groundwater circulation
nonlinear wave
water flow
beach sand
shallow water
wave dynamics
coastal zone
Źródło:
Oceanologia; 2014, 56, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Addendum to “Stokes transport in layers in the water column based on long-term wind statistics: assessment using long-term wave statistics”
Autorzy:
Myrhaug, D.
Wang, H.
Holmedal, L.E.
Powiązania:
https://bibliotekanauki.pl/articles/47811.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
surface gravity wave
water transport velocity
Stokes transport
water column
wind statistics
long-term wave statisticsstatistic
Źródło:
Oceanologia; 2019, 61, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Explosive Formation and Spreading of Water-Spray Cloud - Experimental Development and Model Analyses
Autorzy:
Stefański, K.
Lewandowski, D.
Dygdała, R. S.
Kaczorowski, M.
Ingwer-Żabowska, M.
Śmigielski, G.
Papliński, A.
Powiązania:
https://bibliotekanauki.pl/articles/358806.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
explosion
water aerosol production
shock wave parameters
Opis:
The paper presents results of experimental investigations and model analysis concerning the expansion of explosively produced water-spray cloud. The regular shape of water-spray cloud produced by a charge placed in a bag flled with water is attained. Effective dispersion of bags containing 600 up to 1500 litres of water is attained. The rise and deceleration of external zone of water-spray cloud is described analytically. The parameters of pressure feld evolving around the explosively formed spray cloud were registered.
Źródło:
Central European Journal of Energetic Materials; 2009, 6, 3-4; 291-302
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Boussinesq-type Equations for Long Waves in Water of Variable Depth
Autorzy:
Szmidt, K.
Powiązania:
https://bibliotekanauki.pl/articles/241151.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
long waves
wave propagation
variable water depth
Opis:
The paper deals with the problem of the transformation of long gravitational waves propagating in water of variable depth. The main attention of the paper is focused on the derivation of equations describing this phenomenon. These equations are derived under the assumption that the non-viscous fluid is incompressible and rotation free, and that the fluid velocity components may be expressed in the form of the power series expansions with respect to the water depth. This procedure makes it possible to transform the original two-dimensional problem into a one-dimensional one, in which all unknown variables depend on time and a horizontal coordinate. The partial differential equations derived correspond to the conservation of mass and momentum. The solution of these equations is constructed by the finite difference method and an approximate discrete integration in the time domain. In order to estimate the accuracy of this formulation, theoretical results obtained for a specific problem were compared with experimental measurements carried out in a laboratory flume. The comparison shows that the proposed theoretical formulation is an accurate description of long waves propagating in water of variable depth.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2011, 58, 1-4; 3-21
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy-saving technologies with the use of water treated in magnetic fields
Ehnergosberegajushhie tekhnologii s ispolzovaniem vody, obrabotannojj v magnitnykh poljakh
Autorzy:
Zhuravska, N.
Malkin, E.
Powiązania:
https://bibliotekanauki.pl/articles/791998.pdf
Data publikacji:
2016
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
water structure
magnetic field
magnetized water
wave motion
water processing
energy saving
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2016, 16, 4
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of mangrove forest structures on wave attenuation in coastal Vietnam
Autorzy:
Bao, T.Q.
Powiązania:
https://bibliotekanauki.pl/articles/48094.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
brackish water
coastal region
forest structure
mangrove forest
marine environment
river mouth
saline water
storm
terrestrial environment
Vietnam
water quality
wave
wave attenuation
Opis:
This paper analyses wave attenuation in coastal mangrove forests in Vietnam. Data from 32 mangrove plots of six species located in 2 coastal regions are used for this study. In each plot, mangrove forest structures and wave height at different cross-shore distances are measured. Wave height closely relates to cross- shore distances. 92 exponential regression equations are highly significant with R2 >0.95 and P val. <0.001. Wave height reduction depends on initial wave height, cross-shore distances, and mangrove forest structures. This relationship is used to define minimum mangrove band width for coastal protection from waves in Vietnam.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shallow-water wave energy dissipation in a multi-bar coastal zone
Autorzy:
Pruszak, Z.
Szmytkiewicz, P.
Ostrowski, R.
Skaja, M.
Szmytkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/47959.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal region
energy dissipation
surf zone
Baltic Sea
wave parameter
wave motion
wave transformation
shallow water
coastal zone
offshore wave
Opis:
The paper presents the results of studies of wave transformation on a multi-bar cross-shore profile of the southern Baltic Sea. The field investigations of wave motion were carried out using an offshore wave buoy and string wave gauges at the IBW PAN Coastal Research Station, Lubiatowo (Poland). These experimental results were used to validate statistical relationships between characteristic wave parameters in the coastal region and to assess wave energy dissipation in the surf zone. Asimple model for calculating the residual nearshore wave energy is proposed and tested versus the data collected in situ.
Źródło:
Oceanologia; 2008, 50, 1; 43-58
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship seakeeping in UKC determination – a further study on wave force transfer functions
Autorzy:
Artyszuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/359064.pdf
Data publikacji:
2012
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
ship seakeeping
ocean wave
shallow water
motion dynamics
Opis:
Modeling of ship motions in waves concentrates in most applications on the response amplitude operator (RAO). This mathematically not demanding method of analysis is very attractive, but loses some essential information in certain situations. The objective of present contribution is to establish and investigate preliminary foundations for a seakeeping model as optimal for under keel clearance (UKC) estimation. A special attention was devoted to transients of motions, stationary harmonic motions, coupling between degrees of freedom, and the wave force transfer functions – all in the aspect of shallow water environment.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2012, 32 (104) z. 2; 5-15
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Viscoelastic model of waterhammer in single pipeline - problems and questions
Autorzy:
Weinerowska-Bords, K.
Powiązania:
https://bibliotekanauki.pl/articles/241156.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water hammer
viscoelasticity
wave speed
relaxation time
creep compliance
Opis:
In the paper, viscoelastic model of waterhammer in a single polymer pipeline is analysed. The theoretical background of viscoelastic behaviour of the structure is shown and the mathematical model of waterhammer in a polymer pipeline is presented. The main problems connected with applying the model are discussed. The main emphasis is on the question of parameter estimation. Important aspects of wave speed calibration are presented. Estimation of a second group of parameters - retardation time and creep compliance values - was analysed. Problems and questions connected with the number of parameters, methods of estimation, potential non-uniqueness of the solution and accuracy of obtained calculations were discussed.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2006, 53, 4; 331-351
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of visco-elasticity on pressure wave velocity in polyethylene MDPE pipe
Autorzy:
Mitosek, M.
Chorzelski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241508.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
water hammer
pressure wave velocity
viscoelasticity
polyethylene MDPE pipe
Opis:
Many of the pipe materials, like polyethylene (MDPE, HDPE) or polypro-pylene (PP), turn out to be visco-elastic. The materials in particular, prove to have strongly time-dependent strain properties. As the propa-gation velocity of pressure waves primarily depends on the fluid bulk modulus and the elasticity of the pipe wall, the above material property has considered the influence in unsteady pipe flow (e.g. in water ham-mer). The pressure velocity in visco-elastic pipes depends on the pres-sure oscillation frequency. The applicability of the method of MOC char-acteristics is limited in the sense that purely elastic strain behaviour has to be assumed. In order to take into account the special properties of visco-elastic pipes, the parameters of the Kelvin-Voigt elements, as well as a complex Young's modulus (dynamic modulus of elasticity) are used to described the pressure velocity. The use of the complex wave velocity seems to be especially useful. However, the velocity should be meas-ured during unsteady water flow. The experiments carried out show that pressure disturbance velocity in MDPE pipe strongly depends on the length of the pipe-line. The velocity increases noticeably when the length of the pipe decreases.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 2; 127-140
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modern Methods of Irrigation Water Purification by a Mesh-Filter Using Influence of Low Frequency Vibration
Autorzy:
Bilokon, S.
Turbal, Y.
Kunanets, N.
Pasichnyk, V.
Powiązania:
https://bibliotekanauki.pl/articles/410930.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
irrigation water
low-frequency vibration
standing wave
floating impurities
Opis:
The article is devoted to the analysis of different methods of irrigation water purification from suspended particles. There have been considered the problems of irrigation water purification by using the low-frequency vibration technology and the effects arising from the influence of vibration on the water with different floating impurities. Vibration parameters that allow obtaining the effect of standing wave was substantiated. Also in the article have been disclosed the influence of low-frequency vibration on the quality of water purification depending on the types of pollution and their granulometric composition. Obtained the hydraulic characteristics of the mesh such as the effect of vibration on the pressure loss.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2019, 8, 2; 21-26
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D Modeling of Wave Propagation in Shallow Water by the Method of Characteristics
Autorzy:
Khalilabadi, Mohammad Reza
Powiązania:
https://bibliotekanauki.pl/articles/31340098.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
wave propagation
shallow water
MOC method
waveguide
transmission loss
Opis:
In this paper, a 2D numerical modeling of sound wave propagation in a shallow water medium that acts as a waveguide, are presented. This modeling is based on the method of characteristic which is not constrained by the Courant–Friedrichs–Lewy (CFL) condition. Using this method, the Euler time-dependent equations have been solved under adiabatic conditions inside of a shallow water waveguide which is consists of one homogeneous environment of water over a rigid bed. In this work, the stability and precision of the method of characteristics (MOC) technique for sound wave propagation in a waveguide were illustrated when it was applied with the semi-Lagrange method. The results show a significant advantage of the method of characteristics over the finite difference time domain (FDTD) method.
Źródło:
Archives of Acoustics; 2022, 47, 3; 407-412
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Periodic variability of currents induced by topographically trapped waves in the coastal zone in the Gulf of Finland
Autorzy:
Talpsepp, L.
Powiązania:
https://bibliotekanauki.pl/articles/48759.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
trapped wave
Sopot
current
water exchange
Finland Gulf
topographical wave
Pakri Bay
conference
Baltic Sea
Estonia
Opis:
The aim of this paper is to examine the water exchange regime between the bays of northern Estonia (Pakri Bay, Ihasalu Bay and Muuga Bay) and the open part of the Gulf of Finland. To this end, the current measurements and CTD-castings performed at the border of the bays and the open part of the Gulf of Finland in summer 1994, 1995–96 and 1997 are analysed. All the current measurements displayed one feature in common: the existence of periodic variability with a current amplitude of between 5 and 25 cm s−1 and a variability period of 3–4 days (68 hours in Pakri Bay, 72 hours in Muuga Bay and 78 hours in Ihasalu Bay). The amplitudes of this variability differed during different time periods of the experiment and in different parts of the southern Gulf of Finland. The hypothesis was propounded that this variability is the result of bottom-trapped waves, as had been found in many other regions of the Baltic Sea (Aitsam & Talpsepp 1982, Talpsepp 1983). To interpret the results of the measurements, a model of bottom-trapped waves for this region was used. This was the short-wave version of Huthnance’s (1978) numerical model of coastal-trapped waves, according to which the wave parameters for the experimental regions were calculated. Comparison of the model and the measurements implies that coastal-trapped waves do exist off the southern coast of the Gulf of Finland.
Źródło:
Oceanologia; 2006, 48, S
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformation of statistical and spectral wave periods crossing a smooth low-crested structure
Autorzy:
Carevic, D.
Loncar, G.
Prsic, M.
Powiązania:
https://bibliotekanauki.pl/articles/48874.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
transformation
wave parameter
statistical method
spectral method
breakwater
empirical model
irregular wave
nonlinear interaction
water depth
Opis:
We carried out experimental studies of a smooth submerged breakwater in a wave channel in order to study such a structure impacts on the changes of statistically and spectrally defined representative wave periods as waves cross it. We discuss the impact of relative submersion, i.e. the relationship between the breakwater crown submersion and the incoming significant wave length Rc/Ls−i, on the representative wave periods. The mean periods, estimated using statistical and spectral methods, were compared in front of and behind the breakwater: the two periods turned out to be identical. Based on the measurements of the spectral mean wave periods in front of and behind the breakwater, an empirical model is derived for estimating the reduction in mean spectral period for submerged and emerged smooth breakwaters.
Źródło:
Oceanologia; 2012, 54, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stokes transport in layers in the water column based on long-term wind statistics
Autorzy:
Myrhaug, D.
Wang, H.
Holmedal, L.R.
Powiązania:
https://bibliotekanauki.pl/articles/48704.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
surface gravity wave
water column
water transport velocity
wind
Stokes transport
North Sea
North Atlantic
Źródło:
Oceanologia; 2018, 60, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Attenuation of wave-induced groundwater pressure in shallow water. Part 1
Autorzy:
Massel, S.R.
Przyborska, A.
Przyborski, M.
Powiązania:
https://bibliotekanauki.pl/articles/49074.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
fluctuation
oceanic water
attenuation
filtration
groundwater pressure
sandy beach
beach ecosystem
surface wave
shallow water
Opis:
A coastal aquifer has a dynamic seaward boundary at the beach face where physical and ecological processes are influenced by oceanic water level fluctuations. Many basic groundwater concepts and the role of the impact of groundwater seepage on beach ecosystems are still poorly understood. Studies are needed to improve our understanding of the relationships between surface and subsurface flow processes on beaches. This is particularly helpful in clarifying the interaction of the physical processes, biodiversity and productivity of sandy beaches, sediment transport and coastal structure stability and modern beach nourishment techniques. As the estimation of infiltration into beach sand is very difficult to carry out under real sea conditions, a control led large-scale laboratory experiment was carried out in the LargeWave Channel in Hannover (Germany) as part of a project supported by the European Community (contract HPRI-CT-2001-00157). First part of the paper describes the technology applied in the experiment and reports some preliminary results.
Źródło:
Oceanologia; 2004, 46, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-dimensional modelling of wave motion in shallow-water areas
Autorzy:
Kapiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/241315.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
swash zone
shallow water
wave transformation
Lagrangian approach
two-dimensional model
Opis:
A new mathematical model for prediction of a two-dimensional wave motion in shallow water is presented herein. It can be applied to investigate shoaling, diffraction, refraction, breaking, bottom friction and wave run-up on a beach, as well as mass transport and orbital motion. The model also includes an oblique wave approach to the shore and irregular bottom topography. Such engineering constructions as seawalls, breakwaters and groins are simulated numerically. Simple results of computations, shown in graphic form, indicate possible practical applications of the model.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 1; 3-24
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Attenuation of wave-induced groundwater pressure in shallow water. Part 2. Theory
Autorzy:
Massel, S.R.
Przyborska, A.
Przyborski, M.
Powiązania:
https://bibliotekanauki.pl/articles/48824.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
water pressure
filtration
mathematical modelling
groundwater pressure
sandy beach
surface wave
Źródło:
Oceanologia; 2005, 47, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Circulation of groundwater due to wave set-up on a permeable beach
Autorzy:
Massel, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/48887.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
groundwater circulation
water flow
filtration
surface wave
sandy beach
mathematical modelling
Opis:
Sandy beaches are highly exploited but very dynamic and fragile environments. Driven by waves, the water flow through the beach body is able to transport oxygen, and hence help to maintain biological activity in the porous media. The paper presents a theoretical attempt to predict the groundwater circulation due to wave set-up. Two systems of circulations have been discovered, related to two different gradients of the set-up height. For the offshore gradient, the horizontal excess pressure gradient induces flow in the offshore direction. However, closer to the shore, the pressure gradient is reversed and the resulting flow moves shorewards.
Źródło:
Oceanologia; 2001, 43, 3; 279-290
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of pore media distribution on the elastic parameters of rocks in Miocene sediments (Carpathian Foredeep, Poland, B deposit)
Autorzy:
Bała, M.
Powiązania:
https://bibliotekanauki.pl/articles/184347.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
P-wave velocity
S-wave velocity
theoretical Kuster– Toksöz model
Biot-Gassmann model
water saturation
gas saturation
porosity
Opis:
This paper presents the results of modelling compressional and shear wave velocities and elastic moduli, as well as Poisson’s coefficient changes in sandstone-shale rocks, based on the distribution of media reservoir (water, gas) in the pore space. Modelling was performed using the Estymacja-TP computer program and theoretical Kuster–Toksöz and Biot–Gassmann relationships. Phase distribution of saturating pores (ellipsoidal shapes) in several ways was assumed. Calculations were made of elastic parameters in the deposits of the autochthonous Miocene Sarmatian in the borehole B-4. Using a method similar to the so-called “fluid substitution” velocity of compressional and shear waves, elastic moduli, Poisson’s ratio and bulk density, under various conditions of water and gas saturation, were calculated. The assumed change in water saturation ranged from Sw = 0% to 100%.
Źródło:
Geology, Geophysics and Environment; 2015, 41, 2; 155-167
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling flow in the porous bottom of the Barents Sea shelf
Autorzy:
Massel, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/48663.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
porous medium
surface wave
tide
Barents Sea
shelf
organic carbon
water transport
water flow
meteorological condition
Źródło:
Oceanologia; 2013, 55, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kaliski węzeł wodny
Kalisz water loop
Autorzy:
Małecki, Z. J.
Wira, J.
Powiązania:
https://bibliotekanauki.pl/articles/407612.pdf
Data publikacji:
2011
Wydawca:
Instytut Badawczo-Rozwojowy Inżynierii Lądowej i Wodnej Euroexbud
Tematy:
węzeł wodny
rzeka
kanał
fala powodziowa
water loop
river
canal
flood wave
Opis:
Kaliski Węzeł Wodny (KWW) tworzy rzeka Prosna ze swym głównym nurtem przepływającym przez centrum Kalisza wraz z dopływami: prawostronnymi – Pokrzywnicą i Swędrnią; lewostronnymi – Piwonką i Krępicą oraz kanałami: Rypinkowskim i Bernardyńskim. Topniejący śnieg i intensywne deszcze zasilające w wodę rzeki, wpływają na krótkotrwałe wysokie stany wody w ciekach. Zasoby wód powierzchniowych w południowej i południowo – wschodniej Wielkopolsce ocenia się jako najniższe w kraju. Podstawowym zadaniem Kaliskiego Węzła Wodnego ( w tym budowli wodnych) jest złagodzenie (spłaszczenie) fal powodziowych a szczególnie w okresie wystąpienia tzw. wody stuletniej o przepływie 219 m3/s.
Kalisz Water Loop (KWL) is formed by the Prosna river with its main stream flowing through the centre of Kalisz and its tributaries; right-hand side: the Pokrzywnica and the Swędrnia, left-hand side: the Piwonka and the Krępica and canals: the Rypinkowski and the Bernardyński. Melting snow and intense rainfall supplying water to the river cause short-term high water levels in water courses. Resources of surface waters in the southern and south-eastern Wielkopolska are estimated as the lowest in Poland. The basic function of the Kalisz Water Loop (including water structures) is to mitigate (flatten) flood waves, particularly when the so-called century water of 219 m3/s flow occurs.
Źródło:
Zeszyty Naukowe. Inżynieria Lądowa i Wodna w Kształtowaniu Środowiska; 2011, 4; 101-115
2082-6702
Pojawia się w:
Zeszyty Naukowe. Inżynieria Lądowa i Wodna w Kształtowaniu Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rayleigh Waves Transformation in Liquefying Water-saturated Sands
Autorzy:
Staroszczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/241359.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
Rayleigh surface wave
water-saturated sand
excess pore pressure generation
soil liquefaction
Opis:
The behaviour of a water-saturated sand deposit subjected to dynamic loads induced by the propagation of Rayleigh surface waves is analysed. Cyclic shearing of the saturated sand matrix due to ground motions results in the development of excess pore pressures in the soil and its subsequent liquefaction. The phenomena of pore pressure generation and soil liquefaction are investigated within the framework of a compaction theory for saturated granular media. The results of calculations, carried out by a finite-element method, illustrate the evolution of pore pressures and the development of liquefaction zones in the soil, and show the variation of surface wave parameters with the progressive degradation of the strength of the subsoil.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2016, 63, 2-3; 173-190
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Currents and waves in the Northern Gulf of Riga: measurement and long-term hindcast
Autorzy:
Suursaar, U.
Kullas, T.
Aps, R.
Powiązania:
https://bibliotekanauki.pl/articles/47862.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
hydrodynamic modelling
water exchange
wave
Riga Gulf
Baltic Sea
long-term hindcast
wave measurement
wind force
wind condition
atmospheric circulation
Opis:
Based on measurements of waves and currents obtained for a period of 302 days with a bottom-mounted RDCP (Recording Doppler Current Profiler) at two differently exposed locations, a model for significant wave height was calibrated separately for those locations; in addition, the Gulf of Riga-Vainameri 2D model was validated, and the hydrodynamic conditions were studied. Using wind forcing data from the Kihnu meteorological station, a set of current, water exchange and wave hindcasts were obtained for the period 1966–2011. Current patterns in the Gulf and in the straits were wind-dependent with characteristic wind switch directions. The Matsi coast was prone to upwelling in persistent northerly wind conditions. During the hindcast period, currents increased along the Koiguste coast and in the Suur Strait, waves decreased noticeably off Koiguste but fluctuated without a clear linear trend near Matsi. The spatially contrasting results for differently exposed coasts were related to the corresponding variations in local wind conditions and to changes in atmospheric circulation patterns over northern Europe.
Źródło:
Oceanologia; 2012, 54, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Report on the development of the Vistula River plume in the coastal waters of the Gulf of Gdańsk during the May 2010 flood
Autorzy:
Zajaczkowski, M.
Darecki, M.
Szczucinski, W.
Powiązania:
https://bibliotekanauki.pl/articles/47599.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Vistula River
river plume
flood
flood wave
Gdansk Gulf
coastal water
hydrological condition
water discharge
suspended matter
concentration
Opis:
The hydrological conditions, suspended matter concentrations and vertical par- ticulate matter flux were measured as the River Vistula flood wave (maximum discharge) was flowing into the southern part of the Gulf of Gdańsk on 26 May 2010. Extending offshore for several tens of kilometres, the river plume was well stratified, with the upper layer flowing away from the shore and the near-bottom water coastwards.
Źródło:
Oceanologia; 2010, 52, 2; 311-317
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Flood Wave Propagation with Wet-dry Front by One-dimensional Diffusive Wave Equation
Autorzy:
Gąsiorowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/241192.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
diffusive wave equation
shallow water equations
overland flow
floodplain inundation
finite element method
Opis:
A full dynamic model in the form of the shallow water equations (SWE) is often useful for reproducing the unsteady flow in open channels, as well as over a floodplain. However, most of the numerical algorithms applied to the solution of the SWE fail when flood wave propagation over an initially dry area is simulated. The main problems are related to the very small or negative values of water depths occurring in the vicinity of a moving wet-dry front, which lead to instability in numerical solutions. To overcome these difficulties, a simplified model in the form of a non-linear diffusive wave equation (DWE) can be used. The diffusive wave approach requires numerical algorithms that are much simpler, and consequently, the computational process is more effective than in the case of the SWE. In this paper, the numerical solution of the one-dimensional DWE based on the modified finite element method is verified in terms of accuracy. The resulting solutions of the DWE are compared with the corresponding benchmark solution of the one-dimensional SWE obtained by means of the finite volume methods. The results of numerical experiments show that the algorithm applied is capable of reproducing the reference solution with satisfactory accuracy even for a rapidly varied wave over a dry bottom.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 111--125
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave-induced stresses and pore pressures near a mudline
Autorzy:
Sawicki, A.
Staroszczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/48728.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
water pressure
wave-induced stress
elasto-plasticity
earth pressure coefficient
soil permeability
pore water saturation
yield condition
seabed mechanics
Opis:
Conventional methods for the determination of water-wave induced stresses in seabeds composed of granular soils are based on Biot-type models, in which the soil skeleton is treated as an elastic medium. Such methods predict effective stresses in the soil that are unacceptable from the physical point of view, as they permit tensile stresses to occur near the upper surface of the seabed. Therefore, in this paper the granular soil is assumed to behave as an elastic-ideally plastic material, with the Coulomb-Mohr yield criterion adopted to bound admissible stress states in the seabed. The governing equations are solved numerically by a finite difference method. The results of simulations, carried out for the case of time-harmonic water waves, illustrate the depth distributions of the excess pore pressures and the effective stresses in the seabed, and show the shapes of zones of soil in the plastic state. In particular, the effects on the seabed behaviour of such parameters as the degree of pore water saturation, the soil permeability, and the earth pressure coefficient, are illustrated.
Źródło:
Oceanologia; 2008, 50, 4; 539-555
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 75

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