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Wyniki wyszukiwania dla: LABYRINTH SEALS
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Reduction of pressure forces in turbine labyrinth seals
PublikacjaPrzedstawiono nową metodę zmniejszani sił samowzbudnych typu aerodynamicznego. zastosowano ją do różnych typów nadbandażowych uszczelnień labiryntowych. Efektywność rdukcji sił samowzbudnych wynosiła nawet ponad 60%. Potwierdzone rezultay obliczeniami i eksperymentalnie.
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Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines
PublikacjaLabyrinth seals are essential components of steam turbine unit constructions. Two types of labyrinth seals can be named, the first of which is the seal without diagnostic steam extraction, and the second – with extraction. The distribution of flow parameters along the packing is affected remarkably by the average seal clearance. The presence of diagnostic extraction leads to the equation system which is determinable and can be...
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CFD analysis of fluid flow through the labyrinth seal
PublikacjaSteam and gas turbines are some of the fundamental means of power generation. The energy efficiency of the turbines, however, is not satisfactory. Ever since the start-up of the first turbine in the world, engineers have been striving for their increased efficiency. Multiple solutions to the problem of steam loss in an operating turbine are available. The use of seals is one of them. Empirical methods or numerical calculations...
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COMPARATIVE ANALYSIS OF THE RESULTS OF GAS FLOW IN A LABYRINTH SEAL FOR A NUMERICAL AND THEORETICAL MODEL
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ANALYSIS OF THE IMPACT OF MASS FLOW EXTRACTION ON THE CHANGE OF PARAMETERS IN A LABYRINTH SEAL USING THE STODOLA METHOD
PublikacjaLabyrinth seals are an important element of a steam turbine set design. The use of diagnostic extraction makes it possible to control the operation of a seal by providing information on the thermodynamic parameters along the length of the seal. Diagnostic extraction has a considerable impact on the change of the parameters, the amount of the extracted mass. This article describes the dependence of pressure in the clearance downstream...
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ANALYSIS OF THE IMPACT OF MASS FLOW EXTRACTION ON THE CHANGE OF PARAMETERS IN A LABYRINTH SEAL USING THE STODOLA METHOD
PublikacjaLabyrinth seals are an important element of a steam turbine set design. The use of diagnostic extraction makes it possible to control the operation of a seal by providing information on the thermodynamic parameters along the length of the seal. Diagnostic extraction has a considerable impact on the change of the parameters, the amount of the extracted mass. This article describes the dependence of pressure in the clearance downstream...
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Diagnostic Model of Crankshaft Seals
PublikacjaT he paper presents a research stand being a diagnostic model of radial lip seals used, among others, on crankshafts of piston combustion engines in order to identify the correctness of their operation. The possibility of determining the technical condition of lip seals on the basis of the proposed coefficient of correctness of operation has been described. T he basic features of seals influencing their correctness of...
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Centrifugal magnetic fluid seals
PublikacjaSeals perform an important and at times overlooked function in a lubricant system. They prevent or minimize the movement of the lubricant between two surfaces and also minimize the level of contamination in the system. Seals are divided into static and dynamic types. Static seals operate in systems where the mating surfaces do not move relative to each other. In contrast, dynamic seals operate under conditions where the mating surfaces...
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NEW DESIGNS OF MAGNETIC FLUID SEALS FOR RECIPROCATING MOTION
PublikacjaT he operating conditions of magnetic fluid seals during reciprocating motion are so different from those observed in rotating motion that the use of their conventional structures for reciprocating motion seals yields no good results. The analysis of the sealing mechanism of magnetic fluid seals in reciprocating motion shows that the operation of these seals is affected by the carry-over phenomenon and magnetic fluid...
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Anisakids of seals found on the southern coast of Baltic Sea
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublikacjaThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublikacjaThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Influence of lubricating oil improvers on performance of crankshaft seals
PublikacjaThis paper presents an original method for checking influence of lubricating oil improvers on performance of crankshaft seals of combustion piston engine. Crankshaft seals were tested with the use of a modified friction node of T-02 four- ball apparatus in laboratory conditions. The tests were conducted according to a worked-out algorithm. Their results confirmed usefulness of the method for determining „harmful” performance...
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Flows in turbine blade seals: CFD calculations versus experiment
PublikacjaPrzedstawiono wyniki numerycznej analizy przepływu w uszczelnieniu nadbandażowym stopnia turbinowego. Rezultaty obliczeń porównano z danymi doświadczalnymi. Eksperymenty przeprowadzono na modelowej turbinie powietrznej przy różnych częstościach obrotów wału i różnym obciążeniu turbiny.
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The Method of Reduction of Aerodynamic Forces Generated in Turbine Blade Seals
PublikacjaOpisano metodę zmniejszania sił wymuszających drgania aerodynamiczne poprzez zastosowanie nowego uszczelnienia nadbandażowego typu komorowego. Efektywność stosowania uszczelnienia komorowego potwierdzono obliczeniami numerycznymi i badaniami eksperymentalnymi.
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The Method of reduction of aerodynamic forces generated in turbine blade seals
PublikacjaThe distibution of pressure in the seal gaps does not only affect the so called '' leakage losses'' and the turbine stage overall efficiency but also plays an important role in the generation of aerodynamic forces which may cause self-excited rotor vibrations. The paper describes a chamber seal applied for the reduction of the aerodynamic forces created in shroud seals. This kind of turbine seal was patented and tested.
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FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS
PublikacjaThe article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions....
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Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results. Part II Results of life tests of multi-stage magnetic - fluid seal operating in water
PublikacjaThe edge criteria for magnetic-fluid seals durability research were described in previous article [24] and now the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are:...
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Labyrynths generators, their properties and practical application in computer games
Publikacjathis paper presents three basic algorithms for generation of mazes, and many of their modifications and examples showing their practical application in creating random structures that resembles those from the real world. the paper highlights the difference in the labyrinths classes generated by listed algorithms and describes a specific and highly likely to occur shapes that occur in generated mazes. particular attention was paid...
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Research into flows in turbine blade seals. Part I: Research methods
PublikacjaOpisano numeryczną i doświadczalną metodę badania przepływu w uszczelnieniu nadbandażowym stopnia turbinowego. Badania numeryczne przeprowadzono programem Fluent, a badania doświadczalne wykonano na powietrznej turbinie modelowej. Zamieszczono przykładowe wyniki.
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Research into flows in turbine blade seals. Part II: Numerical analysis
PublikacjaPrzedstawiono wyniki badań numerycznych programem Fluent przepływów w uszczelnieniu nadbandażowym stopnia turbinowego. Badania wykonano przy zastosowaniu różnych typów siatek obliczeniowych, różnych rodzajów "zszywek" oraz różnych metod obliczeniowych (Mixing Plane, Sliding Mesh, Multiple ReferenceFrame).
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On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
PublikacjaThis paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be...
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Mercury concentrations in marine biota with special focus on grey and ringed seals
PublikacjaMarine organisms are exposed and sensitive to effects of environmental contamination by heavy metals including different forms of mercury. Baltic seals as the top predators of the marine ecosystem are even more endangered due to (considerable) longevity as well as a long biological half-time of toxin elimination. The concentrations of mercury in seals from the Baltic is poorly known, thus the aim of this work is to determine and...
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Experimental research on effectiveness of the magnetic fluid seals for rotary shafts working in water
PublikacjaUszczelnianie wałów obrotowych, łożysk i innych zespołów mechanicznych, za pomocą cieczy magnetycznej, tworzącej przegrodę uszczelniającą utrzymywaną siłami pola magnetycznego jest techniką uszczelniania, stosowaną z powodzeniem w urządzeniach pracujących w środowisku gazowym przy ciśnieniu do około 1,0 MPa. Uszczelnienia te umożliwiają również skuteczne rozwiązywanie problemu szczelności przepustów stałych i ruchowych w urządzeniach...
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Influence of the steam within seals and glands of the turbine on its rotor motion stability.
PublikacjaPrzedstawiono metodę obliczania charakterystyk dynamicznych wpływu parowych uszczelnień turbin na ich dynamikę i stateczność ruchu wirników. Zarysowano model ''masowy'' uszczelnienia. Podano przykłady zastosowań.
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NEW DESIGNS OF CENTRIFUGAL MAGNETIC FLUID SEALS FOR ROTATING SHAFTS IN MARINE TECHNOLOGY
PublikacjaThe centrifugal magnetic fluid seals have important advantage over the conventional centrifugal seals. They maintain very good sealing capacity at static, medium and high speeds of shaft rotation, with the increased seal lifetime, and minimum torque and static friction. These seals are particularly useful in cases when the angular shaft velocity varies and sometimes decreases to nearly or exactly zero, such as in flywheel applications,...
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Rotordynamic characteristics of a chamber seal
PublikacjaThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal of a modernized type. The experiments were performed on a single-stage air model turbine of the impulse type. The experiments were performed on a single-stage air model turbine of the impulse type. The experimental data were compared with theoretical results obtained by means of CFD Fluent Code....
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Research into flows in turbine blade seals. Part III: Numerical calculations versus experiment
PublikacjaPrzedstawiono wyniki badań doświadczalnych przepływów w uszczelnieniu nadbandażowym stopnia turbinowego, przeprowadzonych na powietrznej turbinie modelowej. Rezultaty te porównano z wynikami badań numerycznych z zastosowaniem programu Fluent.
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Investigations On Water Circulation in Animal Sea-Water Basins – On the Example of Seals′ Breeding Pools
PublikacjaThis 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...
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Pressure Pulsations in Turbine Blade Seal
PublikacjaThe paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...
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Artists - researchers of postindustrial city area. SEAS In Gdańsk / Artyści-badacze przestrzeni poprzemysłowego miasta, SEAS w Gdańsku
PublikacjaArtykuł przedstawia gdańską odsłonę interdyscyplinarnego projektu SEAS, w ramach którego artyści na różne sposoby odkrywali urbanistyczny potencjał poprzemysłowych terenów w miastach portowych nad Bałtykiem i Adriatykiem.
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Pressure pulsations in turbine blade seal clearance
PublikacjaThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...
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Properties of a Sand and Bentonite Mixture as a Material for Spot Seals of Low Flood Embankments in the Area of Żuławy Elbląskie
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The Magnetic Fluid Seals Research Results vs. Kelvin-Helmholtz (K-H) instability and Preliminary Conclusions
PublikacjaIn the article a magnetic-fluid seals durability research and the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are: critical pressure, critical motion velocity and...
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Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results
PublikacjaThe edge criteria for magnetic-fluid seals durability research are critical for the seal'stechnological usefulness. The magnetic fluid seal technology in water is much moredifficult technological problem in comparison to gas or vacuum environment. There isalways problem with immediate contact between magnetic fluid and the environmentaluninspected liquids. In the paper are presented ways of experiments definitions carried outwith...
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Relationships and bioaccumulation of chemical elements in the Baikal seal (Phoca sibirica)
PublikacjaOznaczono stężenia w próbkach wątroby foki bajkalskiej, planktonu i zoobentosu ryb stanowiących źródło pokarmu dla fok. Badania przeprowadzono z wykorzystaniem technik ICP-MS oraz ICP-AES. Zbadano wpływ czynników wewnętrzynch i zewnętrznych (środowiskowych) na proces bioakumulacji z wykorzystaniem technik wielowymiarowych (ANOVA, analiza czynników) oraz analizy korelacyjnej. Stwierdzono istotny wpływ płci oraz wieku na proces akumulacji...
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Ring thruster - a preliminary optimisation study of ferrofluid seal and propeller
PublikacjaThe article reports the course of preliminary examination of a ferrofluid seal applied in liquid environment.A newly built research rig is described, and results of pressure tests performed for different shaft rotationsare discussed. Other studies carried out in the past only referred to the gas environment, while the presentexamination aims at finding an answer to the question whether magnetic liquids can be successfully used...
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Life tests of a rotary single-stage magnetic-fluid seal for shipbuilding applications
PublikacjaUse of the magnetic fluid seal technology in water is much more difficult technological problem in comparisonto gas or vacuum environment. Some seals constructed up to time been are designed as hybrid, two stagesealing structures with shields or mechanical seals used as protection measures to the magnetic fluid seal.Anyway, there is always problem with immediate contact between magnetic fluid and the environmentalliquid. In the...
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The oil film parameters of the wankel engine apex seal in aspects of durability of mating elements
PublikacjaThe Wankel engine is one of only few alternatives to the reciprocating engines. The advantages such as good value of maximum engine power to its mass ratio are still present and can have great sense in selected fields of application, for example General Aviation. Nevertheless the disadvantages of the Wankel engine design have never lost its importance and still pose an obstacle to wider use of the Wankel engine. One of the main...
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How much a geometrical model of a honeycomb seal can be simpli ed in the CFD calculation
PublikacjaThis paper presents the inuence of geometry simplication on the results obtained in the computational fluid dynamics simulation. The subject of simulation was part of the honeycomb seal located at the inlet to high pressure part of a steam turbine. There were three different geometrical models assumed in the calculations. First one was two-dimensional case and two others were three dimensional, one with the radius of curvature...
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The Effect of the Body Mass Indexes of Young Healthy Individuals on the Glyacemic Indexes of Traditional and Modified Vegetarian Meals
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Computational model for simulation of lifeboat motions during its launching from ship in rough seas
PublikacjaW artykule przedstawiono model obliczeniowy 3 D, opisujący ruch obiektu w 6 stopniach swobody (6DoF), do symulacji ruchu jedno- lub dwuzawiesiowej łodzi ratunkowej lub ratowniczej podczas opuszczania ze statku na wzburzonej wodzie. Jest to złożony model uwzględniający warunki morskie oraz elastyczność i własności tłumiące elementów i mechanizmów żurawika, liny oraz kadłuba łodzi. Ponadto przedstawiono przykładowe wyniki obliczeń...
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On the Application of Magnetoacoustic Emission for a Nondestructive Assessment of the Post Welding Heat Treatment of High Chromium Steel Weld Seams
PublikacjaThe paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal intensity (of order of about...
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Thermal utilization of meat and bone meals. Performance analysis in terms of drying process, pyrolysis and kinetics of volatiles combustion
PublikacjaA development of technology of thermal utilization requires a thorough knowledge of the physicochemical properties, as well as kinetics of combustion of volatiles and char. Due to waste management regulations the meat and bone meal (MBM) is regarded as biofuel constituting one of the alternatives to fossil fuels in the energy market. MBM is a heterogeneous material that may consist of several different fractions. The extensive...
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Analiza możliwości wpływania na pracę promieniowego uszczelnienia ślizgowego poprzez deformowanie jego panwi = Analysis of possibility of influence on the radial sliding seals operating by deformation of the bearing sleeve
PublikacjaW referacie przedstawiono zasadę działania promieniowych uszczelnień ślizgowych oraz ukazano istotny wpływ podstawowych parametrów konstrukcyjnych na skuteczność i jakość ich pracy. Uszczelnienia te stosowane są w instalacjach okrętowych śrub nastawnych, w turbinach wodnych typu Kaplana i maszynach górniczych do drążenia tuneli. Umożliwiają one wprowadzenie oleju pod ciśnieniem do wnętrza obracającego się wału. Zapewnienie stabilnej...
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Testing Students’ Entrepreneurial Self-Efficacy as an Early Predictor of Entrepreneurial Activities. Evidence From the SEAS Project
PublikacjaOver the last forty years, since Bandura (1977) introduced the concept of self-efficacy, there have been a constantly growing number of research publications using this concept. Its early development resulted in the creation of a new construct of entrepreneurial self-efficacy (ESE) proposed for the first time by (Chen et al. 1998). Since then, many different groups of research concerning ESE have emerged - one of them is the study...
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Tideless estuaries in brackish seas as possible freshwater‐marine transition zones for bacteria: the case study of the Vistula river estuary
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Extraction and Analysis of Bisphenols and Their Derivatives in Infant and Toddler Ready-to-feed Meals by Ultrasound-assisted Membrane Extraction Followed by LC MS/MS
PublikacjaThis research developed an ultrasound-assisted membrane extraction coupled with liquid chromatography-tandem mass spectrometry method for the determination of nineteen bisphenols and their derivatives in infant and toddler ready-to-feed meals. The calibration curves for all analytes were linear in the tested range, and the limit of detection and limit of quantitation were in the range 0.27 to 0.79 ng/g and 0.80 to 2.4 ng/g, respectively....
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The application of magnetic fluids in sealing nodes designed for operation in difficult conditions and in machines used in sea environment
PublikacjaPresented in article MF seals are being researched for sea technology purposes due to their excellent tightness and low resistance of motion. These features are most valuable for ring propellers and ship's main propeller shaft. There are more reasons why technologists payf significant attention for various MFseals applications in their difficult operating conditions. For instance, an advanced pumping systems are designed with contactless...
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The application of magnetic fluids in sealing nodes designed for operation in difficult conditions and in machines used in sea environment
PublikacjaPresented in article MF seals are being researched for sea technology purposes due to their excellenttightness and low resistance of motion. These features are most valuable for ring propellers and ship'smain propeller shaft. There are more reasons why technologists payf significant attention for various MFseals applications in their difficult operating conditions. For instance, an advanced pumping systemsare designed with contactless...