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Search results for: UNSTEADY PIPE FLOW
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STUDY ON THE EFFECTIVENESS OF THE TURBINE CONDENSER AIR EXTRACTION SYSTEM USING HYDRO EJECTORS
PublicationThe aim of the paper is to investigate the effectiveness of the 18K380 steam turbine condenser air extraction system using hydro ejectors. Motivation for the analysis is a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it is necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact...
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The flow of nitrogen into the euphotic zone of the Baltic Proper as a result of the vertical migration of phytoplankton: An analysis of the long-term observations and ecohydrodynamic model simulation
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Neoplasia detection in Macoma balthica (Bivalvia) from the Gulf of Gdansk (Baltic Sea, Poland) — comparison of flow cytometry, histology and chromosome analysis.
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3D calculations of aerodynamic forces causing self-excited vibrations of turbine rotor systems. Part I: Shroud seal flow inwestigations
PublicationOpisano numeryczną i doświadczalną metodę badania przepływu w uszczelnieniu nadbandażowym stopnia turbinowego. Badania numeryczne przeprowadzono programem Fluent, a badania doświadczalne wykonano na powietrznej turbinie modelowej. Uwzględniono niesymetryczny rozkład szczeliny nadbandażowej na skuteknie centrycznego położenia osi wirnika względem osi cylindra. Zamieszczono przykładowe wyniki.
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Electromagnetic Control and Dynamics of Generalized Burgers’ Nanoliquid Flow Containing Motile Microorganisms with Cattaneo–Christov Relations: Galerkin Finite Element Mechanism
PublicationIn our research work, we have developed a model describing the characteristics of the bio-convection and moving microorganisms in the flows of a magnetized generalized Burgers’ nanoliquid with Fourier’s and Fick’s laws in a stretchable sheet. Considerations have been made to Cattaneo–Christov mass and heat diffusion theory. According to the Cattaneo–Christov relation, the Buongiorno phenomenon for the motion of a nanoliquid in...
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Example of Using Particle Swarm Optimization Algorithm with Nelder–Mead Method for Flow Improvement in Axial Last Stage of Gas–Steam Turbine
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Analiza przepływu oleju przez rowek smarowy wzdłużnego łożyska ślizgowego = Analysis of the lubricant flow through the hydrodynamic thrust bearings groove
PublicationSmarowanie zanurzeniowe jest tradycyjnym sposobem smarowania wzdłużnych łożysk ślizgowych. Jednak rozwiązanie to wykazuje umiarkowaną skuteczność w zapewnieniu optymalnie niskich temperatur w filmie smarowym a ponadto jest przyczyną strat mocy związanych z mieszaniem oleju w obudowie łożyska, co jest szczególnie widoczne w łożyskach szybkoobrotowych. Wymagania stawiane nowym konstrukcjom łożysk ślizgowych to zwiększanie nośności...
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Hydrostatic drives as safe and energy saving machines. The drive investigation method compatible diagram of power increase opposite to the direction of power flow
PublicationProjektanci i producenci napędu hydrostatycznego nie dysponują możliwością dokładnego określania jego sprawności energetycznej zmieniającej się szeroko w polu pracy napędzanego urządzenia a więc w pełnym zakresie zmiany prędkości i obciążenia silnika hydraulicznego oraz lepkości zastosowanego czynnika roboczego. Dotyczy to zarówno określania strat i sprawności maszyn wyporowych (pompy i silnika hydraulicznego) zastosowanych w układzie...
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Response to the queries raised by Dr M.M. Awad in a letter to editor comments on “Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels”
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Modelowanie przepływu wód podziemnych w strefie brzegowej morza - możliwości prognozowania = Groundwater flow modeling in the coastline area - prediction possibilities
PublicationSpecyficzne warunki występowania wód podziemnych w strefie brzegowej morza sprawiają, że ich eksploatacja jest sprawą złożoną i powinna być weryfikowana na modelu numerycznym. Zasadniczym zagrożeniem jest ingresja słonych wód morskich, która może być wzbudzona eksploatacją. Innym czynnikiem, który może przyczynić się do ingresji wód słonych do warstwy wodonośnej może być podniesienie się poziomu morza. W pracy przedstawiono wyniki...
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Modelling of Hydraulic Fracturing in Rocks in Non-isothermal Conditions Using Coupled DEM/CFD Approach with Two-Phase Fluid Flow Model
PublicationSkała łupkowa jest materiałem silnie niejednorodnym, nieciągłym i porowatym. W warunkach nieizotermicznych ruch płynu w układzie porów i kapilar jest silnie sprzężony z przenoszeniem ciepła. Przebieg szczeliny hydraulicznej silnie zależy od stopnia nasycenia skały. Opracowano innowacyjny model termo-hydro-mechaniczny oparty na modelu DEM w celu szczegółowego śledzenia frakcji ciecz/gaz w porach i pęknięciach pod kątem ich różnej...
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Estimating the uncertainty of discharge coefficient predicted for oblique side weir using Monte Carlo method
PublicationSide 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,...
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Thermal Energy Development in Magnetohydrodynamic Flow Utilizing Titanium Dioxide, Copper Oxide and Aluminum Oxide Nanoparticles: Thermal Dispersion and Heat Generating Formularization
PublicationThe main aim of this article heat transfer in thermal engineering deals with the production, use, transformation, and transfer of thermal energy. Engineering and industrial fields including food packaging, the production of food additives, electronic cooling, microturbines, etc. heavily rely on heat transmission. Due to its intriguing potential in industries like the production of polymers, paper, crystal glass, etc., scientists...
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Levels of hemoglobin and lipid peroxidation metabolites in blood, catalase activity in erythrocytes and peak expiratory flow rate in subjects with passive exposure to tobacco smoke
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Measurement of temperature at sliding polymer surface by grindable thermocouples
PublicationThis paper is devoted to experimental study of capabilities and limitations of grindable thermocouples as applied to polymer materials sliding on metal. Chromel–alumel and chromel–copel grindable thermocouples have been developed and tested for wide ranges of contact pressure and sliding velocity. The background temperature of the sliding surface can be determined as the lower envelope of the signal from the grindable thermocouple....
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PROPELLER INVESTIGATIONS BY MEANS OF NUMERICAL SIMULATION
PublicationThe analyses of hydroacoustics are of high interest at the moment due to strong impact of hydroacoustic phenomena on marine environment; the noises, generated e.g. by marine traffic, may be harmful for sea life. The analyses presented here are focused on one of main sources of noises generated by ships, i.e. cavitating propeller. The goal of the work is the assessment of the cavitation phenomenon, carried out with the standard...
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ENHANCED EVAPORATION OF THE DROPLETS OF CONDENSATE IN THE ASYMMETRICAL SHOCK WAVE ZONE
PublicationIn the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages [4,5]. The formation and evolution of these droplets lower the performance of the wet stages of the turbines, and their effects on the efficiency are collectively known as wetness losses [4]. Nowadays, due to work of steam turbines at partial load, process of homogeneous and heterogeneous condensation still is current....
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Detailed experimental investigations on frictional pressure drop of R134a during flow boiling in 5 mm diameter channel: The influence of acceleration pressure drop component =Études expérimentales détaillées sur la chute de pression frictionnelle du R134a lors de l'ébullition en écoulement dans un canal de 5 mm de diamètre : influence de la composante d'accélération de la chute de pression
PublicationThis article presents detailed two-phase diabatic pressure drop data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg m−2 s−1. The obtained data are used as a validation of the void fraction literature models, a set of graphs shows comparisons, for a representative set of experimental conditions,...
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Some coatings of high cavitation resistance produced by CO2 laser beam. XIV International Symposium on Gas Flow, Chemical Lasers and High Power Lasers.
PublicationPrzedstawiono wyniki badań odporności kawitacyjnej stali 2H13, 45 i żelaza Armco po laserowym stopowaniu ich powierzchni różnymi kompozycjami proszków Co, Mo, Ni, Mn i Cr, Ti. Wykazano różne własności kawitacyjne otrzymanych warstw w zależności od otrzymanej mikrostruktury.
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Cardiovascular and Perceptual Responses to Resistance Training with Practical Blood Flow Restriction Induced by a Non-Elastic Band vs. Pneumatic Cuff: A Crossover Randomized Study
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Aiding (opponent) flow of hybrid copper–aluminum oxide nanofluid towards an exponentially extending (lessening) sheet with thermal radiation and heat source (sink) impact
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MHD darcy-forchheimer nanofluid flow and entropy optimization in an odd-shaped enclosure filled with a (MWCNT-Fe3O4/water) using galerkin finite element analysis
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Numeryczne modelowanie prędkości płynięcia warstw blachy bimetalowej w procesie walcowania = The numerical modelling of the layers flow velocity in bimetal plates rolling proces
PublicationW pracy przedstawiono wyniki obliczeń numerycznych dotyczących procesu asymetrycznego walcowania blach bimetalowych 18G2A+1H13.
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Analysis of magnetic field inside thin-layer ferromagnetic objects
PublicationResults of the numerical analysis of the magnetic field inside an infinitely long, thin-layer ferromagnetic pipe with and without a barrier were presented in this paper. Two wires with current symmetrically placed on two sides of the pipe are the sources of magnetic field. Numerical calculations for the quasi-steady state for chosen frequency band were carried out in the Flux 2D.
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Aleksandra Romanowska dr inż.
PeopleEmployee in the Highway and Transportation Engineering Department at the Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Poland. Her research interests include: modelling of road traffic, road safety, trip generation, transport behaviour and preferences of academic societies, planning sustainable urban mobility. In 2019 she was granted a PhD degree, under the supervision of Prof. Kazimierz Jamroz...
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Janusz Cieśliński prof. dr hab. inż.
PeopleHe was born on April 15, 1954 in Slupsk. He graduated from the Faculty of Mechanical Engineering at Gdańsk University of Technology (1978). In 1986 he received the title of Doctor, in 1997 he obtained the title of Ph.D. with habilitation, and in 2006 he received the title of Professor. He worked as head of department and vice-dean for Education at the Faculty of Mechanical Engineering for two terms (2002-2008). His research interests...
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Changes in heat flow of V2O5 nanorods under inert atmosphere
Open Research DataThe DataSet contains the DSC curves of V2O5 nanorods obtained at 650°C. The information about nanorods synthesis is described in the Journal of Nanomaterials.
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Changes in heat flow of V2O5 nanorods under oxidizing atmosphere
Open Research DataThe DataSet contains the DSC curves of V2O5 nanorods obtained at 650°C. The information about nanorods synthesis is described in the Journal of Nanomaterials.
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Przepływ wody w ośrodkach nienasyconych o podwójnej porowatości: zastosowanie metody homogenizacji. Unsaturated water flow in double porosity media: application of the homogenization theory
PublicationPrzedstawiono model matematyczny przepływu w gruncie o podwójnej porowatości wyprowadzony metodą homogenizacji. Otrzymano równanie makroskopowe z parametrami efektywnymi i członem źródłowym. Przedstawiono wyniki przykładowych obliczeń numerycznych i porównania z modelem znanym z literatury.
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Comparison of the performance of direct current atmospheric pressure glow microdischarges operated between a small sized flowing liquid cathode and miniature argon or helium flow microjets
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Numeryczna analiza trójwymiarowego przepływu w polimerowym łożysku smarowanym wodą = Numerical analysis of three dimensional flow in water lubricated bearing with polymer bearing bush
PublicationW referacie przedstawiono wyniki obliczeń łożysk smarowanych wodą w oparciu o metodę CFD - obliczeniowej mechaniki płynów. Wykazano przydatność nowoczesnych narzędzi obliczeniowych do rozwiązywania podobnych problemów.
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Application of the F-statistic of the Fisher-Snedecor distribution to analyze the significance of the effect of changes in the compression ratio of a diesel engine on the value of the specific enthalpy of the exhaust gas flow
PublicationThe paper discusses the impact of changes in the compression ratio on the operating parameters of a diesel engine, e.g. on the temperature of exhaust gases. It presents the construction of the laboratory test stand, on which experimental measurements were realized. It is characterized how the actual changes of the compression ratio were introduced to the existing engine. The program of experimental investigations taking into account...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationAbstract: The mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also on the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationThe mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods....
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Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublicationThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have 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...
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Second law analysis of a 3D magnetic buoyancy-driven flow of hybrid nanofluid inside a wavy cubical cavity partially filled with porous layer and non-Newtonian layer
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Two-dimensional vertical Reynolds-averaged naviers-stokes equations versus one-dimensional Saint-Venant model for rapidly varied open channel water flow modelling
PublicationPrzedstawiono dwa modele przepływu wody ze swobodną powierzchnią -płaski pionowy model Reynoldsa i model de Saint-Venanta.Do rozwiązania równań pierwszego modelu zastosowano schemat SIMPLE oraz wykorzystano metodę cząstek znaczonych MAC do wyznaczania swobodnej powierzchni wody. Równania Saint-Venanta rozwiązano metodą objętości skończonych. Obydwa modele zastosowano do symulacj zjawiska typu katastrofa zapory. Porównano wyniki...
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Wioletta Gorczewska-Langner dr inż.
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Review on mechanisms and efficiency of removal of microbiological contaminants in constructed wetlands
PublicationConstructed wetlands (CW) have been considered as a waste and a stormwater treatment systems for small communities or for areas with unsteady sewage flow conditions. Several investigations were undertaken for estimation suspended solids, organic matter and nutrients efficiency removal but only few focused on retention of microorganisms in constructed wetlands. In this review mechanisms of elimination of viruses, indicator bacteria...
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Application of Shape Memory Alloys in Pipeline Couplings for Shipbuilding
PublicationThe aim of the study is to analyse shape memory alloy (SMA) pipeline joints in limited space applications for all kinds of ships. Generally, the space available in various areas on ships is strictly limited and service works usually meet many obstacles. If we consider a pipeline, the flange joints always require a larger free space around the pipe than the pipe alone. A simultaneous problem can occur with the propeller shaft line...
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Modelling of FloodWave Propagation with Wet-dry Front by One-dimensional Diffusive Wave Equation
PublicationA 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...
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Cavitation resistance of OH18N9 steel alloyed with vaidus amount of TiC or Mn by means of laser beam. XIV International Symposium on Gas Flow, Chemical Lasers and High Power Lasers.
PublicationPrzedstawiono badania odporności kawitacyjnej stali OH18N9T po laserowym stopowaniu jej powierzchni węglikiem TiC oraz manganem. Wykazano, że wzbogacenie obrabianej stali manganem powoduje przemiany fazowe pod wpływem działania obciążeń kawitacyjnych, co przyczynia się do wzrostu odporności kawitacyjnej. Wzmacnianie stali węglikiem TiC powoduje natomiast zanik zdolności stali do wzmacniania odkształceniowego.
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The effect of a miniature argon flow rate on the spectral characteristics of a direct current atmospheric pressure glow micro-discharge between an argon microjet and a small sized flowing liquid cathode
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Coupling of cold vapor generation with an atmospheric pressure glow microdischarge sustained between a miniature flow helium jet and a flowing liquid cathode for the determination of mercury by optical emission spectrometry
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Pulse-Modulated Radio-Frequency Alternating-Current-Driven Atmospheric-Pressure Glow Discharge for Continuous-Flow Synthesis of Silver Nanoparticles and Evaluation of Their Cytotoxicity toward Human Melanoma Cells
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Application of gas flow headspace liquid phase micro extraction coupled with gas chromatography-mass spectrometry for determination of 4-methylimidazole in food samples employing experimental design optimization
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Comparative study of high‑pressure fluid flow in densely packed granules using a 3D CFD model in a continuous medium and a simplified 2D DEM‑CFD approach. Granular Matter
PublicationIzotermiczny ściśliwy jednofazowy przepływ cieczy przez niejednorodną masę ziarnistą składającą się z gęsto upakowanych zachodzących na siebie kul imitujących skałę pod wysokim ciśnieniem zbadano numerycznie przy użyciu dwóch różnych podejść. Pierwsze podejście zwane pełnym modelem 3D CFD stosowało metodę skończonych objętości (FVM) do rozwiązania uśrednionego równania Naviera-Stokesa zakładając model naprężeń Reynoldsa (BSL) w...
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Fluid Mechanics, L/L/E, DaPE, sem. 04, summer 21/22 (PG_00050282)
e-Learning CoursesLECTURES Introduction and basic definitions. Properties of fluids. Models of fluids. Fluids in equilibrium. Determination of hydrostatic forces. Archimedes" law. Methods of fluid flow description. General motion of fluid. Deformation of fluid element. Vortex motion of fluid. Principles of conservation of mass, momentum and energy. Balance of entropy. Navier-Stokes equation. Bernoulli equation. Similarity of flow phenomena. Potential...
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Rurka ciepła z pętlą obiegową jako urządzenie do odzysku ciepła
PublicationW pracy przedstawiono możliwości odzysku ciepła za pomocą rurki ciepła z pętlą obiegową (ang. loop heat pipe)
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Experimental and theoretical study on high-temperature creep of VT6 titanium alloy under multi-axial loading conditions
PublicationIn the framework of damage mechanics, we discuss a new mathematical model that describes the kinetics of the stress–strain state and damage accumulation during material degradation by the mechanism of long-term strength under complex multiaxial stress state. An experimental and theoretical technique is proposed for determination of material parameters and scalar constitutive functions for damaged media based on specially set experiments...