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Photogrammetric Development Of The Threshold Water At The Dam On The Vistula River In Wloclawek From Unmanned Aerial Vehicles (Uav)
PublikacjaBarrage in Wloclawek (Poland) was designed by Hydroprojekt and built in the years of 1962 - 1970 as the first stage of the planned Lower Vist ula Cascade. Cascade design assumed the construction of 8 dams in Wyszogr o d, Plock, Wloclawek, Nieszawa (Ciechocinek as an option), Solec Kujawski, Chelmno, Opalen and Tczew. Nieszawa dam was supposed to ensure the maintenance of an adequate free surface...
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Environmental aspects of shale gas recovery in Baltic Basin
PublikacjaFactors limiting shale gas exploration and exploitation in Pomorskie Voivodeship are presented. In particular, ground and surface water availability and land/community impact is discussed. Production from unconventional reservoirs requires proper well completion through hydraulic fracturing, hence voluminous streams of water are needed – in total 8000 to 20000 m3 per 1000 m of borehole length. 17 major groundwater basins were characterized....
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Modeling and experimental investigation of the hydraulic jump in liquid film formed by an impinging two-phase air-water jet
PublikacjaPrzedstawiono model analityczny układu hydraulicznego powstałego na skutek uderzenia strugi dwufazowej wody i powietrza. Obliczenia porównano z badaniami eksperymentalnymi przeprowadzonymi na własnym stanowisku badawczym. Uzyskano zadowalającą zgodność.
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Applicability of arrays of microjets heat transfer correlations to design compact heat exchangers
PublikacjaThe article presents experimental studies on a compact heat exchanger with heat transfer intensification by means of impinging microjets. The pursuit to provide high performance of heat exchangers is a response to the demand both in economics and in the universal tendency to miniaturization of industrial equipment. This paper presents the design and tests of a prototype, microjet heat exchanger. The modular design of the heat exchanger...
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Influence of type of material on performance of hydraulic components in thermal shock conditions
PublikacjaDuring the start-up of a hydraulic system in low ambient temperatures an incorrect operation may occur. The principles and conditions of safely operating hydraulic driven machines and devices are essential to designers and operators. For this reason the author of this article has conducted a series of tests on hydraulic components and systems in thermal shock conditions (cooled-down components were supplied with hot working medium)....
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Apparent Molar Volumes and Isentropic Compressibilities of Tetraalkylammonium Bromides in Aqueous Propane-1,2-diol. An Attempt to Design Hydraulic Liquids
PublikacjaApparent molar volumes and apparent molar compressibilities for tetramethylammonium, tetraethylammonium, tetrapropylammonium, and tetrabutylammonium bromides in water, propane-1,2-diol, and water−propane-1,2-diol mixtures (mass fraction: 0.25, 0.50, and 0.75) have been determined from solution density measurements at T = 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K and sound velocity measurements at T = 298.15 K...
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Losses and power balance in hydraulic satellite motor supplied with oil and HFA-E emulsion
PublikacjaMineral oil and HFA-E emulsion are liquids which differ in viscosity, density and lubricant properties. Therefore, supplying hydraulic satellite motor with these liquids, differences between quantity of hydraulic, volumetric and mechanical losses are observed. These losses influence efficiency of conversion of hydraulic energy into mechanical energy and thereby power balance of motor. The research of satellite motor has been conducted...
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Hydraulic fracturing process in rocks – small-scale simulations with a novel fully coupled DEM/CFD-based thermo-hydro-mechanical approach
PublikacjaW artykule przedstawiono dwuwymiarową (2D) symulację numeryczną szczelinowania hydraulicznego w małej skali przeprowadzoną w próbkach skał posiadających pojedynczą szczelinę wtryskową. Wykorzystano unikalny model termo-hydro-mechaniczny (THM) w skali porów oparty na DEM/CFD do symulacji dwufazowego laminarnego przepływu płynu (wody i gazu) z przenoszeniem ciepła w nienasyconych materiałach porowatych o niskiej porowatości. Korzystając...
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CZYNNIKI DECYDUJĄCE O PRZYDATNOŚCI KOMPUTEROWEGO MODELU PRZEPŁYWÓW W SIECI WODOCIĄGOWEJ
PublikacjaW pracy poddano analizie wielozadaniowy proces tworzenia komputerowego modelu przepływów. W efekcie zidentyfikowano szereg czynników ograniczających obszar stosowania modelu w praktyce inżynierskiej. W zakresie pozyskiwania danych strukturalnych i operacyjnych wskazano potencjalne źródła błędów, które przyczyniają się do zmniejszenia dokładności odwzorowania stanu rzeczywistego. Specjalną rangę nadano specyfikacji czynników związanych...
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Power balance in hydraulic satellite motors supplied with oil and HFA-E emulsion
PublikacjaMineral oil and HFA-E emulsion are liquids which differ in viscosity, density and lubricant properties. Therefore, supplying hydraulic satellite motors with these liquids, differences between quantity of hydraulic, volumetric and mechanical losses are observed. These losses influence efficiency of conversion of hydraulic energy into mechanical energy and thereby power balance of motors.
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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...
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PRELIMINARY RESULTS FROM APPLICATION PHOSLOCK® TO REMOVE PHOSPHORUS COMPOUNDS FROM WASTEWATER
PublikacjaThe aim of the study is to assess the removal effectiveness of phosphorus compoundsby using lanthanum-modified bentonite. This material was produced by the Australian company Phoslock® Water Solutions Pty Ltd. According to the company, Phoslock® has substantial capacity to bound phosphate anions. The investigation was carried out in steady conditions in laboratory model with beakers. The results of the study are related to the...
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On the durability of the hydraulic satellite motor working mechanism in overload condition
PublikacjaThe paper presents the newest construction of the hydraulic satellite pump/motor. In this study, the fracture of the hydraulic satellite motor working mechanism is investigated. Factors influencing the durability of satellite working mechanism have been described. The durability of the hydraulic satellite motor working mechanism at a load, corresponding to a pressure of 15 MPa supplied with refined rapeseed oil is very low. Analyses...
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The influence of pressure drop on the working volume of a hydraulic motor
PublikacjaReliability and maintenance analysis of hydraulic positive machines basicly focused on the processes of their wear and failure. But in order to correctly assess the mechanical and volumetric efficiency of a hydraulic motor, both at the stage of development research or at the stage of control tests during its exploitation, the working volume of this motor must be correctly determined. Therefore this paper proposes a new method of...
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Control of the bridge span vibration with high coefficient passive damper. Theoretical consideration and application
PublikacjaThe research was carried out due to the problem of vibration on the lively pedestrian drawbridge across the Motlawa River in the city of Gdansk. In the design stage, the main span of the footbridge showed unfavorable dynamic properties, which may create a comfort problem for pedestrians. The first vertical bending eigenfrequency was recognized as 1.64 Hz. The original design of the footbridge was equipped with a driving cylinder...
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Design and experimental investigations of a cylindrical microjet heat exchanger for waste heat recovery systems
PublikacjaCompact heat exchangers have more and more applications in many areas, including the HVAC, food and petrochemical industry. This paper describes the development of heat exchanger technology for waste heat recovery (WHR) from a range of processes. Case-study testing shows that the proposed heat exchanger can successfully enhance heat transfer and recover waste heat in a range of applications making them economically, environmentally and...
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Investigation method and mathematical model of pressure losses in hydraulic rotary motor
PublikacjaTis paper presents a way of determining the coefcient k of the pressure losses Δp (fow drag) in internal ducts 8 Mp of SWSB-63 hydraulic motor. Te coefcient is determined at a fow rate equal to the theoretical capacity Q of the Pt pump feeding the motor , the losses are related to the nominal pressure p in the hydraulic system. Te investigations n followed a model of energy performance of hydraulic rotary motor, proposed by...
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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.
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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublikacjaThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART V) METHODS ENSURING CORRECT START-UP OF HYDRAULIC COMPONENTS OF SHIP’S ONBOARD DEVICES IN LOW AMBIENT TEMPERATURES
PublikacjaA large number of hydraulic devices and systems are started in low ambient temperatures. A good example of such a device is the hoisting winch on the ship. Starting hydraulic drive units in thermal shock conditions (rapid supply of hot oil to the cold unit) may lead to incorrect operation of the actuating system, for instance, due to the loss of clearance between cooperating elements. The article presents methods to prevent the...
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DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
PublikacjaHydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital...
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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...
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Safety assessment of a concrete viaduct damaged by vehicle impact and an evaluation of the repair
PublikacjaDamage to lower parts of viaducts caused by impact from under-passing high vehicles is relatively frequent. One such incident, in which a viaduct was damaged by the impact from a truck with an improperly assembled hydraulic crane, is considered in this work. The analysis is based on a detailed object damage evaluation, 3D laser scanning, and numerical simulations. The aim of the study is to accurately model the vehicle impact into...
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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...
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Hydraulic equations for vortex separators dimensioning
PublikacjaThe paper presents a set of hydraulic expressions developed to design vortex separators. These devices are used for gravitational removal of suspensions from wastewater. Measurements and theoretical considerations allowed the authors to formulate a mathematically simple velocity field model. Than, equations describing particle motion in the separator were derived. Finally, a technical procedure for hydraulic design of vortex separators...
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Review and evaluation of cold recycling with bitumen emulsion and cement for rehabilitation of old pavements
PublikacjaThe article presents Polish experience with cold recycling of asphalt pavements with theusage of bituminous emulsion and cement. In the 1990s numerous roads in Polandrequired immediate reinforcement due to their significant degradation. Implementation ofthe cold recycling technology was one of the solutions to this problem. Cold recycledmixtures containebeside the recycled asphalt pavement and aggregateetwo differenttypes of binding...
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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.
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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...
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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...
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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...
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Perforating systems in shale gas recovery
PublikacjaHydraulic fracturing is common method of shale gas recovery. Due to environmental, economical and technological problems many alternative technologies have been developed. One of the most promising group of technologies is based on perforating systems. This paper describes theoretical and practical aspects of best known technologies used to create perforations. New perforating/fracturing technologies which can replace hydraulic fracturing...
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NEW CONCEPT OF HYBRID PROPULSION WITH HYDROSTATIC GEAR FOR INLAND WATER TRANSPORT
PublikacjaThe article presents the development of author’s concept of a diesel/hydraulic propulsion system for inland watercraft. Due to specific nature of vessel navigation on rivers, classical propulsion systems with shaft lines can be effectively replaced by systems with hydraulic power transmission. A solution is also presented of a hybrid design with extra electric port having the form of a pumping system driven from a battery of accumulators....
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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...
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Mathematical model defining volumetric losses of hydraulic oil compression in a variable capacity displacement pump
PublikacjaThe objective of the work is to develop the capability of evaluating the volumetric losses of hydraulic oil compression in the working chambers of high pressure variable capacity displacement pump. Volumetric losses of oil compression must be determined as functions of the same parameters, which the volumetric losses due to leakage, resulting from the quality of design solution of the pump, are evaluated as dependent on and also...
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Determination of the theoretical and actual working volume of a hydraulic motor
PublikacjaA new methodology of determination of the theoretical and actual working volume of a hydraulic motor based on the characteristics of the delivered flow rate into hydraulic motor vs. the rotational speed at a constant pressure drop in the working chambers is described in this paper. A new method of describing the delivered flow rate into a motor per one shaft revolution as a nonlinear function of the pressure drop in the motor working...
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Hydraulic valve design methodology for hydro turbine control system
PublikacjaThe control of the turbine and its equipment in a hydroelectric power plant requires the HPU (hydraulic power unit) to deliver large volumes of working fluid in a short time at specific optimum control parameters. The use of typical proportional flow control valves created by manufacturers of hydraulic components in low-pressure control systems is disadvantageous due to high pressure losses in the control chambers. This paper presents...
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Numerical Analysis of Steady Gradually Varied Flow in Open Channel Networks with Hydraulic Structures
PublikacjaIn this paper, a method for numerical analysis of steady gradually varied fl ow in channel networks with hydraulic structures is considered. For this purpose, a boundary problem for the system of ordinary differential equations consisting of energy equation and mass conservation equations is formulated. The boundary problem is solved using fi nite difference technique which leads to the system of non-linear algebraic equations....
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Energetic model of hydraulic system of refuse collection vehicle based on simulation and experimental data
PublikacjaThis paper presents an energetic model of hydraulic system of a refuse collection vehicle. First, benefits resulting from implementation of an energetic model in the industry and operation of a Refuse Collection Vehicle are briefly explained. Then, components of the energy consumption in hydraulic circuits of compactor and lifting device are described and combined into a comprehensive model that can be evaluated using basic measurement...
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Removal of nitrogen from wastewater: Unsolved problems and possible solutions with partial denitrification/anammox systems
PublikacjaAbstract Nitrate (NO3−) is more stable than ammonia (NH4+) and nitrite (NO2−) among the majority of emerging pollutants in wastewater that can harm the ecosystem by depleting oxygen and water quality, thereby posing environmental and human health risks. Despite anaerobic ammonium oxidation (anammox) being a common method for nitrogen (N) removal from wastewater, it leaves behind residual NO3− of around 11 %. Maintaining the stability...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublikacjaDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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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...
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Method of sum of power losses as a way for determining the ki coefficients of energy losses in hydraulic motor
PublikacjaThis paper shows application of the method of sum of power losses to determining energy losses which occur in hydraulic rotary motor in situation when not all laboratory data are at one’s disposal or when no use is made of data contained in catalogue charts. The method makes it possible to determine the coefficients ,ki , of energy losses occurring in the motor. The method of sum of power losses is based on the approach proposed...
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COMPUTER ANALYSIS OF HYDRAULIC CONDITIONS IN A SANITARY CHAMBER
PublikacjaThis paper presents analysis of hydraulic conditions of sewage flow down the slipway (ramp) in the collecting sanitary chamber connecting 3 collectors on the inlet: ⌀600, ⌀800 and ⌀1400 and one on the outlet ⌀1600 mm, with a maximum difference of elevation 5 m. The mathematical model has been made and hydraulic calculations were carried out in steady flow conditions. Then wastewater surface elevation, energy grade line elevation,...
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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...
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Design of a test bench for determining the general characteristics of an internal combustion engine using a hydraulic power take-off system
PublikacjaThe paper presents a design of an engine test bench, which is used to determine the general characteristics of a truck engine using a power take-off (PTO). PTO drives a hydraulic system that generates a load on the engine at various points in its operation in the power range specified by the hydraulic system. The design allows for stationary and mobile tests with the test bench mounted on the truck, without any modification of...
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Insights into the flow characteristics during hydraulic fracturing
PublikacjaThis paper presents a numerical model to study fracture propagation during water-based hydraulic fracturing. To address the computational challenges associated with the numerical model, the proposed approach employs a set of overlapping spheres arranged in a monolayer to construct a porous specimen containing pre-existing cracks. The fluid-filled cracks represent various stages of initiation and propagation of fluid-driven fracture....
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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...
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Influence of operating pressure on the durability of a satellite hydraulic motor supplied by rapeseed oil
PublikacjaThis article describes the results of a durability test of a hydraulic satellite motor supplied by rapeseed oil. The tests were carried out on a test stand in a power recuperation system. The tests of the motor were carried out at a constant shaft speed for three fixed pressure drops in the motor. This made it possible to demonstrate the influence of the motor operating pressure on the durability of the satellite mechanism. The...
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Effect of Simultaneous Valve Closures in Hydraulic Piping Systems
PublikacjaThe paper investigates wave interference (between pressure waves) occurring in simple hydraulic systems. Water hammer was induced by simultaneous closure of three valves located at the reservoirs of a “Y” type hydraulic system. Numerical simulations were carried out with the help of the freeware computer package Allievi enabling the reader to replicate results in a direct manner. The influence of the following quantities has been...
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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...