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Wyświetlanie 1-15 z 19
Tytuł:
New designs of centrifugal magnetic fluid seals for rotating shafts in marine technology
Autorzy:
Matuszewski, Leszek
Powiązania:
https://bibliotekanauki.pl/articles/260045.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
magnetic fluids
ferrofluids
lubricants
magnetic seals
static seals
rotational seals
Opis:
The 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, ship propeller main shafts, etc. Unique properties of the magnetic fluid give rare opportunities for application in marine design, where perfect sealing together with reliable lubrication are required. The paper presents a typical design and operation principle of a centrifugal magnetic fluid shaft seal, along with new design solutions. Not only in ocean technology and underwater robotics. Some cases of application of centrifugal magnetic fluid seals in modern sealing technology are included.
Źródło:
Polish Maritime Research; 2019, 2; 33-46
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Remarks on aerodynamic forces in seals of turbine stages
Autorzy:
Stępień, R.
Kosowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/259359.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
rotor dynamics
self-excited vibrations
aerodynamic forces
blade seals
turbine shrouds
Opis:
This paper presents results of numerical examination of flow through over-shroud seals of turbine stages. Various labyrinth seals of different configurations and number of sealing teeth were considered. It was demonstrated that results of investigations of isolated seals cannot be directly used for analyzing turbine stage operation. Such approach may lead to relatively large errors in determining value of aerodynamic force and direction of its action.
Źródło:
Polish Maritime Research; 2009, S 1; 58-63
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines
Autorzy:
Kaszowski, P.
Dzida, M.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/259462.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
Fanno curve
diagnostic extraction
Opis:
Labyrinth 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 inversed to calculate the average seal clearance Si. Analysing the obtained results leads to the conclusion that the information about this parameter provides opportunities to monitor the current state of the packing in real time. The applied calculation procedure bases on the de Saint - Venant equation. The article also includes a brief description of both types of seals.
Źródło:
Polish Maritime Research; 2013, 4; 34-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on effectiveness of the magnetic fluid seals for rotary shafts working in water
Autorzy:
Szydło, Z.
Matuszewski, L.
Powiązania:
https://bibliotekanauki.pl/articles/260453.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propulsion systems operating in water
magnetic fluids
tightness
seals
Opis:
This paper presents course of research on ferro-fluidal seals used in water. The tests were carried out for a hydrophobic magnetic fluid and specially selected profiles of sealing lips at various linear velocities in sealing unit. Though the tests were preliminary their results showed that the research on application of magnetic fluids to seals working in liquid environment should be continued. From the point of view of development of ring drives the most important advantage of ferro-fluidal seals is their smallest drag as compared with seals of other types.
Źródło:
Polish Maritime Research; 2007, 4; 53-58
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
Autorzy:
Włodarski, W.
Kosowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/259389.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
rotor dynamics
self-excited vibrations
aerodynamic forces
blade seals
turbine shrouds
Opis:
This 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 expected in the case of application of the simplification consisting in neglecting inertia coefficients, proposed in the literature. It was simultaneously demonstrated that seals can be also met of weak damping qualities, for which to neglect damping coeffcients is allowable.
Źródło:
Polish Maritime Research; 2009, S 1; 71-74
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostic model of crankshaft seals
Autorzy:
Bzura, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/260475.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine gas turbine
inlet air fogging
applicability
Opis:
The 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. The basic features of seals influencing their correctness of operation were also described, along with examples of determining the durability limits of lip seals. A modified version of the friction node of the T-02 four-ball apparatus is presented. It allows to check the correctness of sealing lips operation as well as to test the compatibility between the steel shaft, sealing lip and sealed lubricating oil. It was shown that the test results confirmed the usefulness of the hypothesis that the quality of oil affects the durability of sealing lips and their coefficient of correctness. Additionally, attention was paid to the possibility of analyzing the pumping effect affecting the transition of the seal-shaft system from the state of partial suitability S2 to the state of full suitability S1 or to the state of unfitness S3 , and because the change in the state of such a system is random, it requires a probabilistic analysis.
Źródło:
Polish Maritime Research; 2019, 3; 39-46
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure of magnetic fluid seals operating in water: preliminary conclusions
Autorzy:
Matuszewski, L.
Powiązania:
https://bibliotekanauki.pl/articles/259844.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
seal
magnetic fluid
Opis:
The article analyses properties of magnetic fluid seals installed in rotary sealing nodes 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 exposed to longterm utility water loads, at different water pressures and shaft revolutions. The basic seal durability criterion was the number of revolutions made by the sealing node shaft until the appearance of water tightness loss (leakage). It was found that the main factor leading to the wear of the seal is the relative speed of the magnetic fluid with respect to that of the utility water, and this process is heavily affected by the pressure acting on the seal. The reported test results are presented in the form of diagrams showing the seal durability (time until water tightness loss) as a function of rotational speed. The curves shown in the diagrams are regular, with two different rotational speed ranges: the highspeed range, when the tightness loss is relatively fast, and the low-speed range, with a clear tendency to prolong the seal lifetime. These diagrams were given the name of durability curves of the MF seal operating in water. The results of the performed tests suggest formal similarity between the experimental data distribution concerning tightness loss processes occurring in magnetic fluid seals operating in water environment and metal fatigue processes. The article proposes a preliminary simplified durability model to describe the examined phenomenon.
Źródło:
Polish Maritime Research; 2017, 2; 113-120
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of lubricating oil improvers on performance of crankshaft seals
Autorzy:
Bzura, P.
Powiązania:
https://bibliotekanauki.pl/articles/260544.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
performance
scientific hypothesis
sealing systems
Opis:
This 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 fourball 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 of sealing systems, which makes it possible to assess operational usability of lubricating oil improvers. On the basis of an analysis of the results a scientific hypothesis saying that lubricating oil quality affects correctness of performance of crankshaft seals of combustion piston engine, was formulated. The hypothesis was verified by means of induction inference and statistical method with taking into account Fisher statistics.
Źródło:
Polish Maritime Research; 2018, S 1; 172-177
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ring thruster – a preliminary optimisation study of ferrofluid seal and propeller
Autorzy:
Szydło, Z.
Matuszewski, L.
Powiązania:
https://bibliotekanauki.pl/articles/963466.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ferrofluid seals
underwater propulsion
Opis:
The 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 rotations are discussed. Other studies carried out in the past only referred to the gas environment, while the present examination aims at finding an answer to the question whether magnetic liquids can be successfully used in underwater applications. The obtained answer is positive, but further, more comprehensive investigations of the problem are necessary.
Źródło:
Polish Maritime Research; 2007, S 1; 71-74
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of diagnosing labyrinth seals in fluid-flow machines
Autorzy:
Krzyślak, P.
Winowiecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/259824.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth sealings
steam turbines
sealing diagnostics
Opis:
Steam turbines constitute fluid flow machines which are used for driving engines of power plants, merchant and naval ships. They are commonly applied in power industry to driving electric generators. One of the impotant elements which affect efficiency of steam turbines used in power industry and for ship propulsion is state of labyrinth sealings whose aim is to minimize losses associated with steam leakage within turbine casing. Until now to assess state of labyrinth sealings has been only possible after stopping the turbine and its dismantling in order to determine values of clearances in the sealings. This paper presents a method which makes it possible to assess state of labyrinth sealings without the necessity of stopping and dismantling the machine. This is the method which allows to assess on-line state of machine sealings during its operation.
Źródło:
Polish Maritime Research; 2008, 3; 38-41
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An electric ring thruster as auxiliary manoeuvring propulsion system for watercraft - construction analysis
Autorzy:
Matuszewski, L.
Falkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/963464.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
electric motor
steering
magnetism
ferrofluid seals
Opis:
The reported project aimed at examining properties and purposefulness of use of modern electromagnetic bearings for a screw propeller in a prototype version of a synchronous ring motor with rare earths magnets. Bearings of this type generate electromagnetic forces which keep the rotor in a state of levitation. The rotating machine with magnetic bearings can work in any environment which reveals diamagnetic properties (air, vacuum, water, liquid gases, etc.). However, a basic quality of the magnetic bearings is elimination of cooling installation and lubrication, which is necessary for proper operation of rotating machines with rolling and slide bearings, undergoing wear with time. Therefore the lifetime of the machine supported on magnetic bearings is incomparable with others. Also torque losses on this bearing are the smallest, compared to all known types of bearings. Ring thrusters can be used as the main drive for relatively small sea-going and inland vessels, and as manoeuvring drive for ships of arbitrary size, especially for AES (All Electric Ship) type vessels. This type of propeller is extremely useful for any types of abyssal vessels, autonomous and remotely controlled, and on submarines. It can also be used as effective generator of electric current for charging batteries in towing trains, barges for instance. The project consisted of three research tasks: 1. Designing, manufacturing and examination of a magnetic bearing on-line controlled by a digital controller, 2. Manufacturing a model of a ring thruster and examination of characteristics of a propeller mounted in the ring, 3. Examining the ferrofluid seal. A concept of the new thruster is a consequence of investigations carried out in Poland upon propellers and magnetic bearings in years 2001-2005.
Źródło:
Polish Maritime Research; 2007, S 1; 62-66
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and optimization design of offshore drilling seal
Autorzy:
Zhang, Y.
Zhang, X.
Chang, X.
Wu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/260627.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
offshore drilling
design optimization
seals
finite element analysis
MATLAB
Opis:
Three-cone bit is the key equipment in the exploration of the oil in offshore drilling and exploration, the bearing system and the seal system are the critical components for the bit. Especially in the offshore drilling environment, the seal design need to be carefully considered. A multi-objective optimization design including orthogonal design method and F-test with finite element analysis for a three-cone bit seal is proposed. Firstly, the calculation method of optimization targets are given, including the minimization of maximum contact pressure and leakage rate analyzed by ANSYS and MATLAB respectively, to maximize seal life and reliability. Then, an orthogonal experiment approach is used to investigate the effects of the eleven parameters on the seal performance, and the influence degrees of the seal factors on the optimization targets have been confirmed by F-test, and the reasonable factors can be determined by the trend of the targets. Finally, in order to validate the analysis results, a new seal was designed and tested on a seal tester compared to the previous seal. In this test, the seal maximum interface temperature that reflects the position of maximum contact pressure can be obtained by using three high precision thermocouples. Both the experiment results and the numerical analyses proved that the maximum contact pressure and leakage rate of the improved seal have been reduced compared to the previous.
Źródło:
Polish Maritime Research; 2017, S 3; 72-78
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza krytyczna metod obliczania uszczelnień labiryntowych w maszynach cieplnych wirnikowych
Autorzy:
Kaszowski, Paweł
Dzida, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2073538.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
fanno curve
zasada de Saint-Venanta
maszyny przepływowe
metody obliczeniowe
Opis:
Uszczelnienia labiryntowe są ważnym elementem budowy maszyn cieplnych wirnikowych. Istnieje wiele metod obliczeniowych, pozwalających określić parametry termodynamicznych gazu na długości dławnicy labiryntowej. W niniejszej pracy przedstawiona zostanie krytyczna analiza metod obliczania uszczelnień labiryntowych dostępnych w literaturze oraz przykładowe wyniki obliczeń wykonanych metodą wyznaczania linii Fanno i zasady De Saint–Venanta.
Źródło:
Journal of Polish CIMEEAC; 2019, 14, 1; 97--110
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New designs of magnetic fluid seals for reciprocating motion
Autorzy:
Matuszewski, Leszek
Bela, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2033241.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
magnetic fluid seal
reciprocating motion
critical pressure
sealing mechanism
failure reason of the seal
new seal designs
Opis:
The 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 film deformation in the sealing gap, which depends on the velocity of the reciprocating motion. The reduced amount of magnetic fluid in the sealing gap caused by the reciprocating motion of the shaft is the main reason for seal failures. The paper presents a short characterisation of magnetic fluid sealing technology, the principle of sealing, the operation of the magnetic fluid and the seal failure mechanism in linear motion of the shaft. Moreover, some new structural designs of hybrid seals, being combinations of typical hydraulic seals with magnetic fluid seals for reciprocating motion, and some examples of magnetic fluid sealing structures for hydraulic cylinders and piston compressors which havepractical application values are presented.
Źródło:
Polish Maritime Research; 2021, 4; 151-159
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on water circulation in animal sea-water basins – on the example of seals’ breeding pools
Autorzy:
Zima, P.
Powiązania:
https://bibliotekanauki.pl/articles/259209.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
circulation of water in animal breeding pool
water flow through the pools
computer simulation
Opis:
This paper presents general comments concerning investigations on water circulation in animal breeding pools containing sea water. As an example are given results of computer simulation of water circulation in seals’ breeding pools situated in Marine Station at Hel, belonging to Oceanographic Institute , Gdansk University. A mathematical model of three main pools was prepared with taking into account their inflow and outflow water supply points. Next, the object indication ( tracer) tests were done with the use of mathematical modelling as well as in-situ measurements. For description of flow field in steady conditions a simplified model of 2D flow in the form of Helmholtz biharmonic equation of stream function , recalculated then into velocity vector components, was used. The equation , supplemented with appropriate boundary conditions , was solved numerically by using the finite differences method. The spreading of a substance dissolved in water (tracer) was analyzed by solving 2D equation of transient advecting - dispersing transport. To solve it the finite volumes method was applied. The applied model was verified by conducting the indication tests with the use of the rhodamine WT as a tracer. The obtained results made it possible to reconstruct water circulation within the seals’ pools and identify stagnation zones in which water circulation may be made difficult.
Źródło:
Polish Maritime Research; 2017, S 1; 224-229
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 19

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