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1
Rola suchego zbiornika przeciwpowodziowego Szalejów Górny na rzece Bystrzyca Dusznicka ze szczególnym uwzględnieniem jego zdolności do redukcji fali wezbraniowej
Połomski Maksymilian
Gospodarka Wodna
|
2022
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Nr 6
24--30
EN
Role of the Szalejów Górny flood control dry reservoir on the Bystrzyca Dusznicka River with particular regard to its ability to reduce flood waves
2
Content available Extended elliptic mild slope equation incorporating the nonlinear shoaling effect
Xiao Q. L., Li Ch. H., Fu X. Y., Wang M. J.
Polish Maritime Research
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2016
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S 1
44--51
EN
The transformation during wave propagation is significantly important for the calculations of hydraulic and coastal engineering, as well as the sediment transport. The exact wave height deformation calculation on the coasts is essential to near-shore hydrodynamics research and the structure design of coastal engineering. According to the wave shoaling results gained from the elliptical cosine wave theory, the nonlinear wave dispersion relation is adopted to develop the expression of the corresponding nonlinear wave shoaling coefficient. Based on the extended elliptic mild slope equation, an efficient wave numerical model is presented in this paper for predicting wave deformation across the complex topography and the surf zone, incorporating the nonlinear wave dispersion relation, the nonlinear wave shoaling coefficient and other energy dissipation factors. Especially, the phenomenon of wave recovery and second breaking could be shown by the present model. The classical Berkhoff single elliptic topography wave tests, the sinusoidal varying topography experiment, and complex composite slopes wave flume experiments are applied to verify the accuracy of the calculation of wave heights. Compared with experimental data, good agreements are found upon single elliptical topography and one-dimensional beach profiles, including uniform slope and step-type profiles. The results indicate that the newly-developed nonlinear wave shoaling coefficient improves the calculated accuracy of wave transformation in the surf zone efficiently, and the wave breaking is the key factor affecting the wave characteristics and need to be considered in the nearshore wave simulations.
3
Content available Interpretacja niezgodności spawalniczych w złączu T-joint z podkładką podczas badań ultradźwiękowych
Górecki M., Jordan M.
Budownictwo i Architektura
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2016
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Vol. 15, nr 4
127--137
PL
Jedną z najczęściej stosowanych metod oceny poprawności wykonania złączy spawanych jest nieniszcząca metoda wykorzystująca fale ultradźwiękowe. Praktyka pokazuje, że pomimo wymagań stawianych personelowi wykonującemu badania, w wielu przypadkach niezgodności w spoinach czołowych w połączeniach typu T-joint z podkładką stalową są błędnie interpretowane, a w konsekwencji prowadzą do zbędnej i kosztownej naprawy złączy. W pracy zaprezentowano wyniki badań przeprowadzonych na próbkach kontrolnych, w których w rzeczywistości nie występują niezgodności spawalnicze, ale powstające wskazania na ekranie defektoskopu mogą świadczyć o występowaniu niezgodności w postaci wady pozornej.
EN
One of the most common methods for assessing the welded joints is a nondestructive method using ultrasonic waves. Despite the requirements posed to personnel engaged in research, practice shows that in many cases the incompatibilities in the butt welds in T-joint connections with backing strip are misinterpreted and consequently carry out to unnecessary and costly joints repair. The paper presents the results of tests carried out on samples without incompatibilities, for which the indications of defectoscope suggest the occurrence of apparent defect.
4
Content available Wave transformation in a multi-bar surf zone: case study of Lubiatowo (Poland)
Lan Y. J., Hsu T. W., Ostrowski R., Szmytkiewicz M.
Archives of Hydro-Engineering and Environmental Mechanics
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2016
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Vol. 63, nr 1
19--34
EN
The paper presents results of field and theoretical investigations of wave transformation in the surf zone near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly induced by breaking. The main field data comprise wave heights and cross-shore bathymetric profiles. Wave transformation is modelled theoretically by two approaches, namely the IBW PAN phase-averaged wave transformation model and the approach based on the hydraulic jump model, developed by Hsu & Lai (2009) for hydrological situations encountered under the actual conditions of two field campaigns – in 1987 and 1996. Discrepancies between the measured data and the model results are discussed. In general, the model results are in good agreement with the in-situ observations. The comparison of the field data with the computational results concerns a part of the surf zone between about 5 m water depth and the first nearshore stable bar, where the depth amounts to ca. 1.2 m.
5
Content available Wave-Induced Sediment Motion Beyond the Surf Zone: Case Study of Lubiatowo (Poland)
Cerkowniak G. R., Ostrowski R., Stella M.
Archives of Hydro-Engineering and Environmental Mechanics
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2015
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Vol. 62, nr 1-2
27--39
EN
The paper presents results of field and theoretical investigations of a natural sandy shore located near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly by breaking. The main field data comprise offshore wave parameters and three cross-shore bathymetric profiles. Waveinduced nearbed velocities and bed shear stresses are theoretically modelled for weak, moderate, strong and extreme storm conditions to determine sediment motion regimes at various locations on the seaward boundary of the surf zone. The paper contains a discussion on the depth of closure concept, according to which the offshore range of sea bottom changes can be determined by the extreme seasonal deep-water wave parameters.
6
Content available A new form of Boussinesq equations for long waves in water of non-uniform depth
Szmidt J., Hedzielski B.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2012
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Vol. 60, nr 3
631-643
EN
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.
7
Content available remote On the transformation of long gravity waves on a sloping beach
Szmidt J. K., Hedzielski B.
Oceanologia
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2010
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No. 52 (3)
363--389
EN
The transformation of long water waves arriving at a sloping beach is investigated. An approximate theory is presented for plane periodic waves propagating in water of non-uniform depth. The theoretical description of the phenomenon, based on certain kinematic assumptions, is formulated in the material variables, and the solution is constructed by applying the Hamilton variational principle. In order to assess the accuracy of the formulation and to learn more about long wave transformation, experimental measurements were carried out in a laboratory flume. In the experiments, a water wave, generated by a piston-type wave maker placed at one end of the flume, propagated towards a rigid inclined ramp installed at the other end of the flume. The wave transformation along the direction of its propagation was recorded by a set of wave gauges installed along the flume. The wave run-up on the sloping beach was measured with a special conductivity gauge placed alongside the ramp. Comparison of the theoretical results with experimental data indicates that the proposed theoretical formulation provides a good description of the main features of wave transformation behaviour over a sloping beach, except in the vicinity of the shore point, where some discrepancies occur.
8
Content available Diagnozowanie łożysk tocznych z zastosowaniem paczkowej transformacji falkowej
Wysogląd B.
Diagnostyka
|
2004
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Vol. 30, T. 2
195--198
PL
W artykule przedstawiono przykłady zastosowań paczkowej transformacji falkowej do identy-fikacji niesprawności łożysk tocznych. Paczkową transformację falkową wykorzystano do wielo-pasmowej filtracji sygnałów drgań rejestrowanych na obudowie łożyska. Doboru ortogonalnych baz falkowych, zastosowanych do analizy sygnałów, dokonano w oparciu o kryterium wykorzy-stujące ocenę intensywności impulsów wywołanych uszkodzeniem łożyska.
EN
In this paper, the examples of an application of the wavelet packed transform for the evaluation of vibration signals of rolling element bearings for fault detection are described. The wavelet packed transform was applied to multiple band-pass filtering of the signal. The orthogonal base to a given signal, which contains information about shocks produced by bearing faults, has been matched.
9
Content available Two-dimensional modelling of wave motion in shallow-water areas
Kapiński J.
Archives of Hydro-Engineering and Environmental Mechanics
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2004
|
Vol. 51, nr 1
3-24
EN
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.
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