Wyniki wyszukiwania - BazTech

1

Modeling of the two-dimensional flow caused by sea conditions and wind stresses on the example of Dead Vistula

Zima P.

Polish Maritime Research

|

2018

|

S 1

166--171

EN

The article presents the results of two-dimensional modeling of flows caused by the sea conditions and wind stresses on the example of Dead Vistula. Based on the available bathymetric data, a numerical model of the river section was created, which was supplemented with data on the position of the water table depending on hydrometeorological conditions. To describe the flow field in steady conditions, a simplified model of two-dimensional flow in the form of the bi-harmonic Helmholtz equation for the current function has been adopted, taking into account additional impacts caused by wind stresses on the water surface. Then the current function was converted into the velocity vector components. This equation, supplemented with appropriate boundary conditions, has been solved numerically using the finite difference method. On the basis of the available literature, 4 variants of hydrometeorological conditions were adopted, depending on the direction and strength of wind and sea conditions. The obtained results were compared with the results of published measurements taken on the studied section of the river. These calculations were the basis for the implementation of a two-dimensional model of the spread of pollutants in the studied section of the Dead Vistula.

2

Jak opomiarować kolektor grawitacyjny?

Zima P., Budziszewski S., Mission E., Zarychta G.

Wodociągi - Kanalizacja

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2017

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nr 5

84--87

3

Investigations on water circulation in animal sea-water basins – on the example of seals’ breeding pools

Zima P.

Polish Maritime Research

|

2017

|

S 1

224--229

EN

This paper presents general comments concerning investigations on water circulation in animal breeding pools containing sea water. As an example are given results of computer simulation of water circulation in seals’ breeding pools situated in Marine Station at Hel, belonging to Oceanographic Institute , Gdansk University. A mathematical model of three main pools was prepared with taking into account their inflow and outflow water supply points. Next, the object indication ( tracer) tests were done with the use of mathematical modelling as well as in-situ measurements. For description of flow field in steady conditions a simplified model of 2D flow in the form of Helmholtz biharmonic equation of stream function , recalculated then into velocity vector components, was used. The equation , supplemented with appropriate boundary conditions , was solved numerically by using the finite differences method. The spreading of a substance dissolved in water (tracer) was analyzed by solving 2D equation of transient advecting - dispersing transport. To solve it the finite volumes method was applied. The applied model was verified by conducting the indication tests with the use of the rhodamine WT as a tracer. The obtained results made it possible to reconstruct water circulation within the seals’ pools and identify stagnation zones in which water circulation may be made difficult.

4

Badania rozmycia dna w strefie fundamentów podpór mostowych

Kiliańczyk M., Mikołajewski P., Zima P.

Mosty

|

2017

|

nr 3/4

52--53

PL

W ostatnich latach zaczęto zauważać konieczność prowadzenia inspekcji podpor mostowych w strefie podwodnej, a technologia tych pomiarów znacznie się rozwinęła. W zależności od potrzeb i rodzaju obiektów przeprowadza się pomiary sonarowe, batymetryczne, a także inspekcje ścianek przy pomocy kamery akustycznej. Dzięki tym przeglądom zarządcy mostów mogą lepiej nadzorować eksploatowane obiekty, zmniejszyć koszty ich utrzymania, a także mieć stały pogląd na sytuację, jaka kształtuje się w obrębie filarów.

EN

The necessity of underwater bridge support inspections has been noticed in recent years, while the technology of such monitoring has been developed significantly. Sonar and bathymetric measurements are carried out, as well as inspections of walls using an acoustic camera, depending on the needs and the structure type. Due to these inspections bridge supervisors can better monitor structures maintained by them, lower the maintenance costs and be aware of the state of the supports.

5

A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern

Prybytak D., Zima P.

Archives of Hydro-Engineering and Environmental Mechanics

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2017

|

Vol. 64, nr 3-4

141--154

EN

The paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the open-source code library OpenFOAM was applied. The results of numerical solutions were compared with the results of measurements carried out on a test stand in a hydraulic laboratory. The measurements were taken with an ADV probe (Acoustic Doppler Velocimeter). Finally, differences between the results obtained from the mathematical models and the results of laboratory measurements were analysed.

6

Whirling System of Water Exchange in Breeding Pools

Matej K., Pawliczka I., Sawicki J. M., Wielgat P., Zima P.

Archives of Hydro-Engineering and Environmental Mechanics

|

2016

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Vol. 63, nr 4

253--263

EN

To create proper living conditions for sea mammals kept in closed systems, one has to make sure that the characteristics of breeding pools, such as their shape, dimensions, the facing of the walls and bottom, as well as the quality and motion of water, resemble as closely as possible the natural environment of the animals. An appropriate system of water exchange plays a very important role here. A complete exchange of water is time-consuming, expensive and troublesome, so it can be performed only periodically and should be supported by a supplementary continuous exchange. This operation improves water quality and can create a proper velocity field in breeding pools. The breeding pools investigated in the present study are located in a sealarium in Hel (Poland), which belongs to the Institute of Oceanography of the Gdansk University. Tracer measurements, carried out in these reservoirs made it possible to evaluate the intensity of continuous water exchange. It was found that this intensity was insufficient (as evidenced by large dead zones in the pools and short detention time), and therefore alterations to the existing system were proposed (i.e. a tangential position of the inlet and a centrally situated outlet). On the basis of a simplified model of circulative water flow, it was shown that the altered hydraulic system can considerably improve the situation.

7

Hydropower potential of the lower Vistula

Szydłowski M., Gąsiorowski D., Szymkiewicz R., Zima P., Hakiel J.

Acta Energetica

|

2015

|

nr 1

18--32

EN

This paper presents an estimate analysis of the hydropower potential of the lower Vistula River from Warsaw to Gdańsk Bay. The calculations were made for a hydraulic model of the lower Vistula which takes into account potential development of barrages in a cascade system. Results obtained from the model simulations and from hydrological calculations were used to estimate the power of hydropower plants and the average annual energy output from the entire cascade system. The results of calculations indicate significant energy benefits resulting from the development of a cascade of hydropower plants in the lower Vistula. This study does not discuss the cascade project’s economic viability or other aspects of its development (inland waterways, flood control, etc.).

PL

W artykule przedstawiono szacunkową analizę potencjału hydroenergetycznego dolnej Wisły na odcinku od Warszawy do Zatoki Gdańskiej. Obliczenia wykonano, przyjmując model hydrauliczny dolnej Wisły, w którym uwzględniono potencjalną zabudowę stopniami wodnymi pracującymi w układzie kaskady zwartej. Uzyskane wyniki symulacji z modelu wraz z przeprowadzonymi obliczeniami hydrologicznymi posłużyły do oszacowania mocy elektrowni wodnych oraz średniej rocznej produkcji energii całego układu kaskady. Otrzymane wyniki obliczeń wskazują na znaczące korzyści energetyczne wynikające z budowy kaskady elektrowni wodnych na dolnej Wiśle. W pracy nie podjęto ekonomicznej kwestii opłacalności wykonania analizowanej kaskady, jak również innych aspektów istnienia kaskady (żegluga śródlądowa, ochrona przeciwpowodziowa i inne).

8

Model cyrkulacji wody w zbiorniku hodowlanym na przykładzie basenów hodowlanych dla fok

Wielgat P., Zima P., Sawicki J., Pawliczka I.

Inżynieria Morska i Geotechnika

|

2014

|

nr 5

342--437

PL

Wyniki symulacji komputerowych cyrkulacji wody w basenach hodowlanych zlokalizowanych w fokarium Stacji Morskiej Instytutu Oceanografii Uniwersytetu Gdańskiego w Helu. Model matematyczny trzech głównych basenów z uwzględnieniem ich zasilania i odpływu wody. Uproszczony model dwuwymiarowego przepływu. Pomiary in situ rozkładu prędkości w charakterystycznych punktach obiektu. Odtworzenie cyrkulacji wody w basenach fokarium oraz identyfikacja stref zastoiskowych, w których cyrkulacja wody jest utrudniona.

EN

The results of computer simulations of water circulation in the breeding polls located in seal facility in the Hel Marine Station of the Institute of Oceanography at the University of Gdańsk. The mathematical model of the three major pools with respect to their inlets and outlets of water. The simplified model of two-dimensional flow. Measurements of the velocity distribution in the characteristic points of the object taken in situ. The reconstruction of water circulation in seal facility pools and identification of isolated still water body zones where water circulation is impeded.

9

Analiza hydraulicznych skutków kaskadyzacji dolnej Wisły

Szydłowski M., Gąsiorowski D., Hakiel J., Zima P., Szymkiewicz R.

Inżynieria Morska i Geotechnika

|

2014

|

nr 5

420--432

PL

Wstępna ocena wpływu potencjalnej budowy kaskady stopni piętrzących na dolnej Wiśle na warunki przepływu. Numeryczny model hydrauliczny rzeki z uwzględnieniem koncepcji kaskadyzacji dolnej Wisły (KDW). Przedstawienie i interpretacja wstępnych wyników obliczeń hydraulicznych w aspekcie wpływu KDW na bezpieczeństwo publiczne w zakresie ochrony przeciwpowodziowej, a także w odniesieniu do kwestii utworzenia drogi wodnej klasy międzynarodowej Va i produkcji energii elektrycznej.

EN

A preliminary assessment of the impact of the potential construction of dams on the flow conditions in the Vistula river. The numerical model of the river including the concept of the lower Vistula cascade (LVC). The preliminary results and interpretation of hydraulic calculations with regard to the impact of the LVC on the public safety for flood protection. The LVC implications for a creation of the international waterway of the Va class as well as for the electricity production.

10

Numerical Simulations and Tracer Studies as a Tool to Support Water Circulation Modeling in Breeding Reservoirs

Zima P.

Archives of Hydro-Engineering and Environmental Mechanics

|

2014

|

Vol. 61, nr 3-4

217–-229

EN

The article presents a proposal of a method for computer-aided design and analysis of breeding reservoirs in zoos and aquariums. The method applied involves the use of computer simulations of water circulation in breeding pools. A mathematical model of a pool was developed, and a tracer study was carried out. A simplified model of two-dimensional flow in the form of a biharmonic equation for the stream function (converted into components of the velocity vector) was adopted to describe the flow field. This equation, supplemented by appropriate boundary conditions, was solved numerically by the finite difference method. Next, a tracer migration equation was solved, which was a two-dimensional advection-dispersion equation describing the unsteady transport of a non-active, permanent solute. In order to obtain a proper solution, a tracer study (with rhodamine WT as a tracer) was conducted in situ. The results of these measurements were compared with numerical solutions obtained. The results of numerical simulations made it possible to reconstruct water circulation in the breading pool and to identify still water zones, where water circulation was impeded.

11

Numeryczna analiza wpływu budowy podpory mostu na rzece Wiśle na przepływ i rozmycie dna koryta rzeki

Szydłowski M., Zima P.

Inżynieria i Budownictwo

|

2013

|

R. 69, nr 10

553--558

PL

Opisano podejście do obliczeń hydraulicznych oparte na analizie dwuwymiarowego ruchu wody. Jako przykład przedstawiono analizę hydrodynamiki przepływu w rejonie budowanego mostu na Wiśle koło Kwidzyna. Na jej podstawie oszacowano intensywność ruchu rumowiska w rejonie podpory mostu. Omówiono także klasyczne podejście do oszacowania lokalnych rozmyć dna koryta.

EN

In this paper the two-dimensional hydrodynamic model was presented and used for the flow simulation. The hydraulic analysis for the bridge on the Vistula river near the Kwidzyn is presented as a case study example. The results were used for the identification of debris transport and river bed deformation process. The paper also presents standard approach to the calculation of local scour.

12

Numerical simulation of catastrophic flood: the case study of hypothetical failure of the Bielkowo hydro-power plant reservoir

Szydłowski M., Szpakowski W., Zima P.

Acta Geophysica

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2013

|

Vol. 61, no. 5

1229--1245

EN

The numerical modeling of flood wave propagation following the hypothetical breaks of the embankments of the Bielkowo hydro-power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland has been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating the reach and area of the inundation, related to the embankments failures, digital terrain model, and mathematical model of flood wave propagation are necessary. For the numerical simulations of flood, the mathematical model of free surface, two-dimensional unsteady water flow was applied. Four locations of potential breaks of the reservoir embankments were considered. The computed flood zones were presented on the flood hazard maps. The maps have been used by the local authorities and the dam owner to manage the flood risk related to hydro-power plants operations on the Radunia River. This type of research has been done for the first time for the water plant managed by the ENERGA Elektrownie Straszyn.

13

Simulation of Residence Time Distribution and Mixing in Reactors with Recirculation using 2D Approach

Zima P.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2011

|

Vol. 15, No 3-4

297-315

EN

In this paper, we propose a 2D approach in order to create a mathematical model for the determination of the residence time distribution for a flow reactor with recirculation. Apart from characterizing the functional residence time distribution, this model can help improve the operation of the reactor at the design stage. The mathematical model was validated by comparison with experiments carried out in a hydraulic laboratory.

14

Zastosowanie schematu McCormacka do wyznaczenia parametrów fali obniżenia w kanale dopływowym do przepompowni ścieków

Szydłowski M., Machalińska J., Zima P.

Gaz, Woda i Technika Sanitarna

|

2011

|

Nr 2

53-58

PL

Charakterystyka fali obniżenia. Model przepływu nieustalonego. Ogólna charakterystyka układu odprowadzania ścieków do Zatoki Puckiej. Krzywa spiętrzenia w kanale dopływowym i opis pracy pompowni. Obliczenia hydrauliczne fali obniżenia.

EN

Characteristics of wave reduction. Unsteady model flow. General characteristics of sewage system collection to the Pucka Bay. The curve of piling up in the inlet channel and the wordescription of the pumping station. Hydraulic calculations of wave reduction.

15

Obliczenia hydrauliczne głębokowodnego kolektora kanalizacyjnego na przykładzie wylotu ścieków z Oczyszczalni Dębogórze do Zatoki Puckiej

Szydłowski M., Zima P.

Inżynieria Morska i Geotechnika

|

2010

|

nr 2

170-177

PL

Metoda oraz przykładowe wyniki obliczeń hydraulicznych wykonanych dla projektowanego głębokowodnego kolektora w Mechelinkach odprowadzającego ścieki oczyszczone z Oczyszczalni Ścieków Dębogórze do Zatoki Puckiej. Ekspertyzę przeprowadził Wydział Inżynierii Lądowej i Środowiska PG. Pozwoliła ona na ocenę poprawności doboru układu pompowego projektowanej przepompowni ścieków.

EN

A method and exemplary results of hydraulic calculations for designed deepwater interceptor in Mechelinki which discharges purified sewages from Dębogórze Waste Water Treatment Plant to the Puck Bay. The experise has been performed by staff of Civil and Environmental Engineering Faculty. The results served for the evaluation of the pumping system for designed sewage pumping station.

16

Analiza przepływu kawitacyjnego w pompach

Sedlar M., Zima P., Pozdisek T.

Pompy, Pompownie

|

2009

|

nr 2 (133)

40-43

PL

Prezentacja pracy badawczej o charakterze poznawczym i użytkowym. Cenny przyczynek do oceny stanu rozwoju kawitacji w palisadach łopatkowych oraz przewidywania konsekwencji w postaci załamania charakterystyki i wyznaczania wartości NPSH3.

EN

Presentation of research work offering cognitive and utilisable values. A valuable contribution to the assessment of condition of cavity development in blade cascades and forecasting of consequences of characteristics collapse and NPSH3 value.

17

Two-dimensional vertical analysis of dam-break flow

Zima P.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2007

|

Vol. 11, No 4

315-328

EN

The paper concerns mathematical modeling of free surface open-channel water flow. Two-dimensional vertical Reynolds-averaged Navier-Stokes equations were used to simulate the flow. They were solved with the SIMPLE algorithm of the finite difference method using the Marker and Cell technique to trace free surface movement. The dam-break flow (water column collapse) problem on a horizontal and frictionless bottom was investigated as a test case. The mechanics of dam-break flow for wet and dry bed conditions was analyzed on the basis of numerical simulations. The obtained results are shown for varying head of water in the downstream channel. The possibility of using the shallow-water equations and the RANS model to simulate rapidly varied flows is discussed.

18

The CFD modeling in bioreactor tracer studies

Zima P.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2007

|

Vol. 11, No 4

439-447

EN

This paper presents the effects of dispersion on predicting longitudinal tracer concentration profiles in an activated sludge bioreactor located at the Wschód Waste-Water Treatment Plant in Gdansk. The aim of this study has been to use the one-dimensional advection-dispersion equation to simulate a non-active substance flow (based on the measured tracer concentration). The simulation results were compared with those obtained in the traditional tanks-in-series approach, commonly used in designing biological reactors. The dispersion coefficient was calculated from a statistical formula based on differences in the tracer concentration distributions at two sampling points. The study has shown that the numerical simulation using the one-dimensional tracer migration equation yields better results than the tanks-in-series model in predicting longitudinal tracer concentration profiles. This paper is an in-troduction to the study of reactive substances in activated sludge bioreactors.

19

Two-dimensional vertical Reynolds-Averaged Navier-Stokes equations versus one-dimensional Saint-Venant model for rapidly varied open channel water flow modelling

Szydłowski M., Zima P.

Archives of Hydro-Engineering and Environmental Mechanics

|

2006

|

Vol. 53, nr 4

295-309

EN

The paper concerns mathematical modelling of free surface open channel water flow. In order to simulate the flow two models are used -- two-dimensional vertical Reynolds-Averaged Navier-Stokes equations and one-dimensional Saint-Venant equations. The former is solved with SIPMLE algorithm of finite difference method using Marker and Cell technique to trace a free surface movement. The latter is solved using the finite volume method. The dam-break (water column collapse) problem on horizontal bottom is investigated as a test case. The calculated results are compared with each other. The numerical simulations are examined against laboratory experiment presented by Koshizuka et al (1995). The possibility of using the described models to simulate rapidly varied flow is discussed.

20

Próba oceny możliwości lokalizacji zrzutu ścieków oczyszczonych z oczyszczalni w Kościerzynie do rzeki Wierzycy w świetle regulacji prawnych dotyczących wprowadzania ścieków do jezior i ich dopływów

Szydłowski M., Zima P.

Gaz, Woda i Technika Sanitarna

|

2005

|

Nr 1

9-14

EN

Hydrological characteristics of Wierzyca catchment area. Analysis of characteristic flows. Theoretical basis for calculating pollution transport in the river. Hydrometrie measurements. Variant calculation of pollution migration time in different hydrological conditions.