Wyniki wyszukiwania dla: HYDRAULIC SYSTEMS
-
Simulations of freshwater lens recharge and salt/freshwater interfaces using the HYDRUS and SWI2 packages for MODFLOW
PublikacjaThe paper presents an evaluation of the combined use of the HYDRUS and SWI2 packages for MODFLOW as a potential tool for modeling recharge in coastal aquife rs subject to saltwater intrusion. The HYDRUS package for MODFLOW solves numerically the one-dimensional form of the Richards equation describing water flow in variably- saturated media. The code computes groundwater recharge to or...
-
Wielkogabarytowe hydrodynamiczne łożyska wzdłużne
PublikacjaW monografii przedstawiono problemy konstrukcyjne i badawcze hydrodynamicznych łożysk wzdłużnych o dużych średnicach. Łożyska takie stanowią istotne i niezwykle odpowiedzialne podzespoły hydrogeneratorów elektrowni wodnych. Z uwagi na rozmiary (średnice przekraczają niekiedy 5 metrów) i złożoność zjawisk łożyska te wymagają specjalnej postaci konstrukcyjnej, a ich dokładna analiza obliczeniowa przysparza wiele problemów. Dodatkowo...
-
Evaluation and start-up of an electro-Fenton-sequencing batch reactor for dairy wastewater treatment
PublikacjaThis study examined the performance of an integrated wastewater (WW) treatment system, namely an electro-Fenton (EF)-sequencing batch reactor (SBR), for dairy industry WW. The EF process was used as the first stage of the SBR. It degrades bio-refractory compounds via advanced oxidation processes, thereby resulting in the formation of simple biodegradable intermediates. Several factors, including the hydraulic retention time (HRT),...
-
An application for a new type of pneumatic engine concept
PublikacjaHeavy trucks are often equipped with loading and unloading systems like dock levellers with swing lip or telescopic lip. Most of these devices require hydro-electrical energy supply systems (eg. the pump that presses the working substance to the actuators must be propelled by electric engine.) The space taken by pump with electric engine can be reduced on condition that a new type of pneumatic drive will be considered. It is possible...
-
New insights into modeling two-step nitrification in activated sludge systems – The effects of initial biomass concentrations, comammox and heterotrophic activities
PublikacjaIn this study, the conventional two-step nitrification model was extended with complete ammonia oxidation (comammox) and heterotrophic denitrification on soluble microbial products. The data for model calibration/validation were collected at four long-term washout experiments when the solid retention time (SRT) and hydraulic retention time (HRT) were progressively reduced from 4 d to 1 d, with mixed liquor suspended solids (MLSS)...
-
Przygotowanie, realizacja i ocena pomiarów terenowych do identyfikacji oporności hydraulicznej sieci wodociągowej
PublikacjaW procesie tworzenia komputerowego modelu przepływów (KMP) jednym z wiodących zadań jest przygotowanie i realizacja pomiarów terenowych w celu identyfikacji oporności hydraulicznej czynnej sieci wodociągowej. Motywacją autora do przedstawienia zasad postępowania w tym zakresie jest narastająca niefrasobliwość twórców KMP, którzy w nieuprawniony sposób używają paramodeli do rozwiązywania problemów inżynierskich. W pracy zdefiniowano...
-
Estimating the uncertainty of discharge coefficient predicted for oblique side weir using Monte Carlo method
PublikacjaSide weir is a hydraulic structure, which is used in irrigation systems to divert some water from main to side channel. It is installed at the entrance of the side channel to control and measure passing water into the side channel. Many studies provided side weir water surface profile and coefficient of discharge to measure water discharge diverted into the side channel. These studies dealt with different side weir shapes (rectangular,...
-
Assessment of the impact of jet impingement technique on the energy efficiency of air-cooled BIPV/T roof tile
PublikacjaThe paper concerns a numerical analysis of cooling of the hybrid photovoltaic (PV) modules dedicated to Building-Integrated Photovoltaic/Thermal (BIPV/T) systems. Attention was focused on the photovoltaic roof tiles, using a jet impingement technique, in which the intensification of heat transfer is ensured by streams of air hitting the heat exchange partition. A series of numerical simulations were carried out to assess an influence...
-
Stormwater and snowmelt runoff storage control and flash flood hazard forecasting in the urbanized coastal basin.
PublikacjaCity of Gdańsk is located in a coastal region where changing climatic conditions increase the frequency of extreme weather events. Developing urbanization affects the hydrology of natural basins by simplification of the drainage system and reduction of infiltration and base flow. Consequently greater runoff rates flow into storm water collection systems, reservoirs and surrounding water bodies. Not only infrastructures of urban...
-
Stormwater runoff in the urbanized coastal basin of Gdańsk Urbanized basin of Gdańsk
PublikacjaAnthropopressure strongly affects the primal water cycle. Alternation of the natural basins imposes changes of drainage patterns, reduction of bioretention, infiltration and base flow. As a result the overland flow predominates and greater runoff rates flow into storm water collection systems and reservoirs. Moreover changing climatic conditions increase the frequency of rapid extreme weather events. Infrastructures of urban areas...
-
Whirling system of water exchangein breeding pools
PublikacjaTo secure the proper conditions of life for sea mammals existing in closed systems one has to maintain the character of the breeding basins (i.e. shape, dimensions, facing of walls and bottom, quality and motion of water) as natural as possible. An appropriate system of water exchange plays a very important role here. A full renewal of water is time-consuming, expensive and troublesome, so can be made only periodically, and should...
-
Przykłady realizacji i interpretacji wyników sondażowych pomiarów terenowych w czynnych systemach wodociągowych
PublikacjaW pracy przedstawiono przebieg realizacji i rezultaty sondażowych pomiarów terenowych w trzech układach dystrybucji wody o zróżnicowanym przewymiarowaniu sieci wodociągowej. Pomiary przeprowadzono w dążeniu do identyfikacji właściwości (cech) strukturalnych i funkcjonalnych układów po wieloletniej ich eksploatacji. Ustalenia te determinują opracowanie programu realizacji pomiarów dla potrzeb tarowania komputerowego modelu przepływu...
-
Przykłady realizacji i interpretacji wyników sondażowych pomiarów terenowych w czynnych systemach dystrybucji wody
PublikacjaW pracy przedstawiono przebieg realizacji i rezultaty sondażowych pomiarów terenowych w trzech układach dystrybucji wody o zróżnicowanym przewymiarowaniu sieci wodociągowej. Pomiary przeprowadzono w dążeniu do identyfikacji właściwości (cech) strukturalnych i funkcjonalnych układów po wieloletniej ich eksploatacji. Ustalenia te determinują opracowanie programu realizacji pomiarów dla potrzeb tarowania komputerowego modelu przepływu...
-
O problemie kolmatacji geowłóknin stosowanych w drenażach
PublikacjaSystemy drenażowe występujące przy obiektach drogowych są niezwykle istotnym elementem tych budowli. Jednym z materiałów, które obecnie powszechnie stosowane są w systemach drenażowych są geowłókniny. Ich zadaniem jest zabezpieczenie odwadnianego gruntu przed procesem sufozji, jak również ochrona drenażu przed zamuleniem przy jednoczesnym zachowaniu wodoprzepuszczalności. Typową trwałość drenażu, w zależności od rozwiązań, szacować...
-
POLDER AND CITY: SUSTAINING WATER LANDSCAPES ON AN URBAN EDGE
PublikacjaThe question investigated in this paper is how to maintain the environmental quality of the polder landscape encompassing the city in the condition of urban pressure on this landscape. On the basis of theoretical approaches, historical surveys and introductory study models new ideas are tested on the case study of Gdansk, a city located in the Vistula River delta in northern Poland. Research shows that the city was created as a...
-
Zintegrowane sterowanie systemami zaopatrzenia w wodę pitną
PublikacjaOptymalne ekonomicznie zaspokojenie w miastach bieżącego zapotrzebowania na wodę pitną tak, aby spełnione były wymagania jakości dostaw oraz jakości samej wody jest złożonym zadaniem. Zarówno aspekty aplikacyjne jak i teoretyczne tego problemu są przedmiotem intensywnych prac prowadzanych w sektorach naukowych i przemysłowych na całym świecie. Prace te finansowane są przez przemysł, komitety naukowe oraz Programy Ramowe Unii Europejskiej....
-
Ocena stanu technicznego konstrukcji pras filtracyjnych w Grupowej Oczyszczalni Ścieków „DĘBOGÓRZE” w Gdyni
PublikacjaPodstawowym celem pracy była rzeczowa ocena z punktu widzenia technicznego stanu trzech pras filtracyjnych, usytuowanych w budynku, położonym w Oczyszczalni Ścieków ‘DEBOGÓRZE w Gdyni. Zakres prac obejmował szczegółowa ocenę trzech układów w każdej prasie a mianowicie: - hydraulicznego, - sterowania i automatyki, - mechanicznego – związanego ze sprawdzeniem stanu konstrukcji nośnej i obudów.. Opis i analiza stanu poszczególnych...
-
Synthesis and characterization of biopolyols through biomass liquefaction of wood shavings and their application in the preparation of polyurethane wood composites
PublikacjaThe sustainability of production systems in wood processing, wood industry, and wooden waste disposal is an important issue for European industry and society. Proper development of products based on renewable wood resources gives an opportunity to provide materials with long-term environmental, social, and economic sustainability. This study aims to establish a new way of forestry and agricultural waste materials utilization by...
-
Charakterystyka eksploatacyjna pomp ciepła zainstalowanych w oczyszczalni ścieków
PublikacjaW artykule przedstawiono charakterystykę eksploatacyjną sprężarkowych pomp ciepła zainstalowanych w oczyszczalni komunalnej i wykorzystujących ścieki oczyszczone jako dolne źródło ciepła. Zastosowanie ścieków oczyszczonych jest uzasadnione ich dostępnością oraz stosunkowo wysoką temperaturą (10-25°C). Prawidłowa eksploatacja układu wymaga zastosowania pośredniego obiegu parowacza oraz regularnych zabiegów czyszczenia wymiennika...
-
Hydraulics and Pneumatics
Kursy OnlineThe lecture covers the theoretical basics of hydraulic and pneumatic drive, simple systems encountered in practice and the elements included in these systems. Examples of applications of both types of drive in mechanical engineering are also presented, as well as their advantages and disadvantages compared to other types of drive.
-
Treatment of landfill leachate by constructed wetlands: three case studies
PublikacjaThe performance of three CW systems treating landfill leachate, two located in northern Poland (Szadółki near Gdańsk and Gatka near Miastko) and one in southern Sweden (Örebro), is discussed. The CWs differ in size, hydraulic regime, type of hydrophytic plants and type of leachate pre-treatment before discharging to the CW. The CW in Szadółki consists of two parallel beds with sub-surface, horizontal flow of leachate (HSSF) planted...
-
Synergistic effects of hybrid advanced oxidation processes (AOPs) based on hydrodynamic cavitation phenomenon – A review
PublikacjaHigh-performance water treatment systems based on cavitational processes have received an increasing interest of scientific community in the past few decades. Numerous studies indicated the advantageous application of hydrodynamic cavitation as an alternative, reagent-free treatment method of various pollutants in water. Both approaches were proved as an effective method to achieve mineralization of many organic contaminants as...
-
Research of hydraulic axial piston pump at low ambient temperatures
Dane BadawczePresented data include the results of measurements of oil temperature at the inlet and outlet of the hydraulic pump (theoretical displacement is equal to 16 cm3/rev) , temperature of the heated pump and oil pressure at the inlet and outlet of the pump.
-
A new method and equipment for the detection of presence and estimation of the content of the petroleum-based fraction in lubricating oils, especially those emitted to the atmosphere
PublikacjaLubricating oil, used in cutting equipment, works in the so-called open lubrication system and is entirely emitted to the environment. When such an oil contains even a small portion of the crude oil-derived fraction, which is still very common, the oil is a serious environmental pollution. In addition, the oil mist poses a serious threat to the health of employees. Current legal regulations require users of saws and harvesters...
-
Developments in unsteady pipe flow friction modelling
PublikacjaW pracy omówiono wpływ błędów numerycznych na jakość rozwiązania równań uderzenia hydraulicznego. Wykazano rolę dyfuzji numerycznej i jej wpływ na dokładność rozwiązania w porównaniu z członem tarcia.
-
Volumetric and torque efficiency of pumps during start-up in low ambient temperatures
PublikacjaThe volumetric, torque and total efficiency of hydraulic pumps change during start-up in low ambient temperatures, as well as in thermal shock conditions, un-til they reach the set conditions. The time to reach steady-state conditions de-pends on many parameters: ambient temperature, flow rate, fluid temperature, design of hydraulic units. The author carried out tests of hydraulic pumps in the Hydraulics Laboratory of the Faculty...
-
Wpływ strat mechanicznych w siłowniku teleskopowym zespołu zagęszczającego w pojeździe do usuwania odpadów z pojemników na skuteczność prasowania odpadów
PublikacjaHydraulic telescopic cylinders are used to power the moving wall of rear loader garbage trucks equipped with the traditional "sweep and slide" system. As the garbage compression force is directly dependent on the resistance force of the moving wall, losses in the hydraulic telescopic cylinder influence the compaction process. Taking them into account in the control system may improve the operation of the compaction...
-
Research of hydrotronic variable displacement radial piston pump with electro -pneumatic control
PublikacjaThe paper presents the developed new electro-pneumatic control (pneumotronic) system for hydraulic fixed-displacement radial piston pump. Hydraulic fixed-displacement radial piston pump equipped with the proposed control system changes into hydrotronic variable-displacement radial piston pump. Pump flow rate control is realized by means of programmable logic controller, electro-pneumatic valves, pneumatic cylinders and a sensor.
-
The Methodology for Determining the Theoretical Based on the Characteristics of Effective Absorbency Versus Pressure Drop in the Motor
PublikacjaThis article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in...
-
New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
PublikacjaThis paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity...
-
Hydraulics and Pneumatics
Kursy OnlineZapoznanie ze zjawiskami fizycznymi, podstawami projektowania i eksploatacji hydraulicznych i pneumatycznych układów napędu i sterowania Acquainting with physical phenomena, the basics of design and operation of hydraulic and pneumatic drive and control systems
-
Shallow Water Equations as a Mathematical Model of Whitewater Course Hydrodynamics
PublikacjaPredicting the positions of local hydraulic phenomena, as well as accurately esti-mating the depth and velocity of the water flow are necessary to correctly config-ure a whitewater canoeing course. Currently, a laboratory and full 3D CFD model-ing are typically used in the design process to meet these needs. The article points to another possibility which can be useful at the preliminary stage of the design. The authors show that...
-
Methodology of experimental research on efficiency of hydro-mechanical automatic gearbox
PublikacjaThe article shortly describes the design and principle of operation of the hydromechanical gearbox and presents the methodology and design of test stands used for testing hydromechanical proto-type gearbox developed at Technical University of Gdansk. The article presents an approach according to which, in order to obtain reliable measurement data, it is necessary to separate the tests of the hydraulic and mechanical parts of the...
-
Analizy ilości i jakości odpływu wód deszczowych i roztopowych z kontrolowanej zlewni zurbanizowanej
PublikacjaIstotnym problemem Gdańska staje się bezpieczeństwo ekologiczne związane ze spływami miejskimi odprowadzanymi bezpośrednio do wód powierzchniowych, często akwenów użyteczności publicznej. W latach 2011÷2013, Katedra Hydrotechniki Wydziału Inżynierii Lądowej i Środowiska Politechniki Gdańskiej, we współpracy z Wojewódzkim Funduszem Ochrony Środowiska i Gospodarki Wodnej w Gdańsku oraz Gdańskimi Melioracjami, podjęła się wdrożenia...
-
Experimental Study of the Influence of Small Upward Seepage on Open-Channel Flow Turbulence
Publikacja -
Discussion of “Development of an Accurate Time integration Technique for the Assessment of Q-Based versus h-Based Formulations of the Diffusion Wave Equation for Flow Routing” by K. Hasanvand, M.R. Hashemi and M.J. Abedini
PublikacjaThe discusser read the original with great interest. It seems, however, that some aspects of the original paper need additional comments. The authors of the original paper discuss the accuracy of a numerical solution of the diffusion wave equation formulated with respect to different state variables. The analysis focuses on nonlinear equations in the form of a single transport equation with the discharge Q (volumetric flow rate)...
-
Reservoir Influence on Pressure Wave Propagation in Steel Pipes
PublikacjaThe relation between the length of steel pipe and the pressure wave period in the system, reservoir-pipe-valve, is discussed. Experiments carried out for the short steel pipes showed that in such a system, the pressure wave celerity estimated using the measured wave cycles systematically increases with the increase of the pipe length. The observed differences can exceed even 90 m=s. As the pressure wave traveling in the pipe with...
-
Wave damping and smoothing in the unsteady pipe flow
Publikacjalaboratoryjne eksperymenty wykonane dla rur polietylenowych o różnej długości wykazały obecność takich zjawisk jak zmienna prędkość propagującej fali ciśnienia oraz jej intensywne tłumienie i wygładzanie. w artykule zaproponowano modyfikacje standardowych równań przepływu nieustalonego. polega ona na wprowadzeniu zmiennej prędkości fali oraz dyssypacji energii na jej czole opisanej członem dyfuzyjnym. do rozwiązania równań zaproponowano...
-
Residence time distribution in rapid multiphase reactors
PublikacjaResidence time distribution (RTD) provides information about average hydraulic residence time and the distribution of material in the reactor. A method for determining RTD for reactors with very short hydraulic residence times is deconvolution based on extraction of real RTD by the analysis of a non-ideal input signal. The mean residence time and dispersion were determined for the spinning fluids reactor (SFR). For the first time...
-
Safety of erection and repair of steel tanks with geometric imperfections using heavylift jack-up system
PublikacjaSafety analysis is performed of cylindrical vertical steel tanks during erection using heavylift jack up system. During an assembly or repair process a set of hydraulic supports is used. It allows to use the in-place lifting of heavy steel constructions on the required height. Wind can strongly influence stability of the lifted tank. Any geometric imperfections can reduce the critical or limit load. In the work failures of the...
-
Influence of the particle size of carbonate-siliceous rock on the efficiency of phosphorous removal from domestic wastewater
PublikacjatThe aim of the study was to determine the influence of the particle size of carbonate–silica rock (opoka)used in rock filters on the efficiency of phosphorus removal from domestic wastewater. The investigationswere carried out in a laboratory using a model consisting of three vertical flow filters with carbonate–silicarock of different particle sizes (G1= 1–2 mm; G2= 2–5 mm; G3= 5–10 mm). The tested rock was subjectedto decarbonising...
-
Evaluation of the efficiency of the duty cycle of refuse collection vehicle based on real-world data
PublikacjaIn this paper a method of the efficiency evaluation of the duty cycle of Refuse Collection Vehicle is presented. Using real world data, two representative duty cycles were analysed. Total cycle efficiency was calculated, as well as the efficiency of particular cycle phases. Then, energy needed to collect and compact the waste and energy from fuel were compared. Measured and calculated values were shown on the diagrams illustrating...
-
Nowe możliwości generowania zarysów satelitowych mechanizmów roboczych
PublikacjaPlanetary hydraulic gear motors have been well known since 70's . first motors were constructed for maritime industry by hydroster from gdansk. the evolution of this type of motors led to an increase of nominal pressure and durability. nowadays the industry needs reliable and efficient motor able to work with alternative hydraulic fluids like water, emulsion and vegetable oil. therefore a new type of motors are being developed...
-
Examples of numerical simulations of two-dimensional unsaturated flow with VS2DI code using different interblock conductivity averaging schemes
PublikacjaFlow in unsaturated porous media is commonly described by the Richards equation. This equation is strongly nonlinear due to interrelationships between water pressure head (negative in unsaturated conditions), water content and hydraulic conductivity. The accuracy of numerical solution of the Richards equation often depends on the method used to estimate average hydraulic conductivity between neighboring nodes or cells of the numerical...
-
MATCHED FILTER APPROACH FOR MICROSEISMIC SIGNAL PROCESSING OF REAL DATA FROM EAST POMERANIA SHALE GAS
PublikacjaThe microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing (HF)process. An array of several hundred geophones is placed on the surface to record little ground tremors induced by fracturing process. Filtration and summation of signals from geophones is essential to identify and locate fracturing events from underground. Authors propose a method of matched filtering, that is usually...
-
Fatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C)
Dane BadawczeFatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C)
-
Fatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C, field cores)
Dane BadawczeDataset presents data of fatigue life determined for cold recycled mixture – cement bitumen treated material mixture with following binding agents: 3% cement and 5.5% emulsion (C3E5.5). Mixture was designed according to Polish requirements for the base course of pavement. Mixture contains 60% of RAP material. Specimen size: f=100 mm, h=48,4 - 70,9 mm.
-
Simulation of Residence Time Distribution and Mixing in Reactors with Recirculation Using 2D Approach
PublikacjaIn 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.
-
MICROSEISMIC EVENT DETECTION USING DIFFERENT ALGORITHMS ON REAL DATA FROM PATCH ARRAY GEOPHONE GRID FROM EASTERN POMERANIA FRACTURING JOB
PublikacjaThe microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. Hydraulic fracturing is a method of reservoir stimulation used especially for unconventional gas recovery. A matrix of several thousand geophones is placed on the surface of earth to record every little tremor of ground induced by fracturing process. Afterwards, the signal is analysed and the place of tremor occurrence...
-
DISTRIBUTION OF FLOWS IN A CHANNEL NETWORK UNDER STEADY FLOW CONDITIONS
PublikacjaThe article presents an algorithm for calculating the distribution of flow in a junction of open channel network under steady flow conditions. The article presents a simplified calculation algorithm used to estimate the distribution of flow in a network of channels under steady flow conditions. The presented algorithm is based on the continuity equation and a simplified energy equation. To describe the relationship between the...