Temat: hydrodynamic conical bearing - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Generalized Newtonian fluids as lubricants in the hydrodynamic conical bearings : a CFD analysis
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/242462.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic conical bearing
generalized Newtonian fluid
CFD
non-Newtonian oil
pressure distribution
dynamic viscosity
ferro-oil
Opis:: Additives, ageing or wear and impurities can cause, that relationship between shear stress and shear rate in a lubricating oil is or becomes non-linear, and due to this, a significant change in the values of operating parameters of slide hydrodynamic bearings may occur. It is important to take into account such dependence during design and simulations of slide bearings. The calculations, which consider the non-linear properties of the lubricating oil, can be carried out by adopting the generalized Newtonian fluid models. This paper shows the result of CFD simulation of slide conical bearings hydrodynamic lubrication, assuming that the lubricating oil behaves as a generalized Newtonian fluid. The hydrodynamic pressure distributions, load carrying capacities and friction torques were calculated for bearings lubricated with different types of generalized Newtonian fluids and the obtained data were compared. In the study, the following models of fluids were adopted: the Power-law fluid (Ostwald-de Waele), the Cross fluid and the Carreau fluid. The coefficients of mentioned relationships were determined by fitting the curves described by each model to the experimental data using the least squares approximation method. The calculations of hydrodynamic pressure distributions, load carrying capacities and friction torques were carried out using the commercial CFD software Ansys Fluent from the Ansys Workbench 2 platform.
Źródło:: Journal of KONES; 2016, 23, 2; 89-95
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: CFD analysis of influence of axial position of shaft on hydrodynamic lubrication of slide conical bearing
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/241575.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic lubrication
conical bearing
slide bearing
radial clearance
CFD
Opis:: During the operation of a slide bearing, the position of its shaft or sleeve varies due to many factors, such as vibrations, load changes, changes in the lubricating viscosity. The vibrations or varying load can cause, that the position of the bearing shaft, measured along its axis of rotation, changes. This is particularly important for sliding bearing with conical geometry. Due to the geometry of this kind of bearing, i.e. where the radius of this bearing (of the shaft and sleeve) has not a constant value, as in the case of a journal bearing, it is more difficult to obtain proper values and describe its hydrodynamic lubrication. This article shows the results of hydrodynamic lubrication of the slide conical bearing, for which the changes in the position of the bearing shaft in the longitudinal direction, i.e. along its axis of rotation, were taken into account. The commercial CFD software, designed for solving general for flow phenomena problems, was used in the simulations. This article shows the results of simulations, assuming that the lubricating oil behaves as a generalized Newtonian fluid. The hydrodynamic pressure distributions, load carrying capacities and friction torques were calculated for the concerned bearing. The aim of this work is to show how the operating parameters of the slide conical bearing can be influenced, by only changes of the position of the shaft along the axis of its rotation.
Źródło:: Journal of KONES; 2017, 24, 3; 37-44
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: CFD analysis of effect of misalignment plane position on hydrodynamic lubrication of slide conical bearing
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/246851.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: slide bearing
hydrodynamic lubrication
conical bearing
misalignment
CFD
pressure distribution
Opis:: The numerical calculations of the hydrodynamic lubrication of slide bearings can be carried out by modelling the oil flow for a given value of height of bearing lubrication gap. On the basis of the assumed height of the lubrication gap, the values of hydrodynamic pressures, load carrying capacities, friction forces, temperatures, can be determined. The bearing lubrication gap height can be influenced by many effects, e.g. misalignment between the shaft axis and the axis of the sleeve, vibrations, varying load, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces. This article presents the results of numerical simulations concerning the influence of the misalignment between the axis of shaft and the axis of sleeve of the sliding conical bearing on its hydrodynamic lubrication, by taking into account the position of the plane in which the misalignment occurs. In this study, there was defined an angle between the plane in which the misalignment occurs and the plane in which lies the line of centres of corresponding bearing without misalignment. In this research, to investigate the impact of the position of the plane in which the misalignment occurs, the CFD software, designed to solve general flow phenomena, was used. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal. A lubricating oil has shear properties as the Ostwald-de Waele fluid.
Źródło:: Journal of KONES; 2017, 24, 2; 65-72
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numerical analysis of influence of bearing material thermal conductivity coefficient on hydrodynamic lubrication of a conical slide bearing
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/246592.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: slide bearing
hydrodynamic lubrication
conical bearing
heat conduction
pressure distribution
Opis:: One of the main parameters affecting the hydrodynamic lubrication of slide bearings is the viscosity of lubricating oil. Many studies show, that significant changes in the viscosity of oil occur along with changes in its temperature. The influence on the temperature distribution in the lubrication gap of the slide bearing have a variety of factors, and one of them is the amount of heat exchanged between the lubricant and the environment. The temperature of the lubricating oil of operating bearing is usually higher than the ambient temperature. In addition to the convection, which occurs during the flow (heat exchange related to the oil supply and discharge system) some amount of heat is transferred to the bearing sleeve material (and also to the bearing shaft), and then it is conducted to sleeve outer surface. The amount of heat transferred through the bearing sleeve is mainly dependent on the difference of temperatures between inner and outer sleeve surfaces and also depend on the heat conduction coefficient of sleeve material. This article presents the results of modelling of the influence of amount of heat conducted through the bearing material, on the hydrodynamic lubrication of a conical slide bearing. The study concerned various values of the heat conduction coefficient of the bearing material to investigate its influence on the temperature values of lubricating oil, and thus, on its viscosity, on the distribution of hydrodynamic pressure and on the calculated values of bearing load carrying capacities and friction forces.
Źródło:: Journal of KONES; 2018, 25, 2; 89-96
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Simulations of the influence of the heat flux at the shaft surface of the conical slide bearing on its hydrodynamic lubrication and operating parameters
Autorzy:: Czaban, Adam
Miszczak, Andrzej
Powiązania:: https://bibliotekanauki.pl/articles/243495.pdf
Data publikacji:: 2019
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic lubrication
slide bearing
conical bearing
heat conduction
pressure distribution
viscosity
Opis:: The aim of this work is to investigate, how in the adopted model of hydrodynamic lubrication of a conical slide bearing, the change of the heat flux value at the bearing shaft, affects bearing operating parameters. In this research, the authors use, the known from the literature, Reynolds type equation, describing the stationary hydrodynamic lubrication process of a conical slide bearing. The analytical, solutions, that determine the components of the lubricating oil velocity vector and the equation (analytical solution of energy equation) determining the threedimensional temperature distribution in the lubrication gap, was also adopted from previous works. In order to obtain numerical solutions, the Newton’s method was used, and the derivatives in the Reynolds type equation were approximated by the finite differences. An application of the method of subsequent approximations allowed considering the influence of temperature, pressure and shearing rate on the viscosity of lubricating oil. The considerations were performed by adopting the Reynolds condition of the hydrodynamic oil film. It was tested, how the assumed value of the heat flux on the bearing shaft surface affects the values of the obtained operating parameters, i.e. the transverse and longitudinal component of the load carrying capacity, friction force and coefficient of friction.
Źródło:: Journal of KONES; 2019, 26, 4; 29-37
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: CFD analysis of the impact of a cone opening angle parameter on the hydrodynamic lubrication of the conical slide bearing
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/242697.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic lubrication
slide bearing
conical bearing
cone opening angle
CFD
pressure distribution
Opis:: The height of the oil lubrication gap is the primary quantity that determines in simulations the operating parameters of a hydrodynamic slide bearing. It is influenced by multiple effects, such as vibrations during operation, varying load, misalignment between the shaft axis and the axis of the bearing sleeve, the roughness of the journal and sleeve surfaces, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces etc. It is important to take into account such effects considering hydrodynamic lubrication simulations and design of the slide bearings. The one of the factors influencing the height of the oil lubrication gap of the conical slide bearing is the difference between the opening angle of the cone of bearing shaft and opening angle of the cone of bearing sleeve. The aim of this work is to investigate the impact of the difference between the values of these angles on the hydrodynamic lubrication of the conical slide bearing. The commercial CFD software Ansys Fluent, from the Ansys Workbench 2 platform, was used to determine the hydrodynamic pressure distributions, load carrying capacities and friction torques of the simulated bearings. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal, there is no misalignment between the axis of bearing journal and axis of bearing sleeve, the surfaces of the journal and sleeve are smooth and lubricating oil acts as a liquid described by the Ostwald-de Waele power law model.
Źródło:: Journal of KONES; 2016, 23, 3; 71-77
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: CFD analysis of non-Newtonian and non-isothermal lubrication of hydrodynamic conical bearing
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/243876.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: conical bearing
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
non-isothermal flow
pressure distribution
Opis:: In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of non-isothermal oil flow in a bearing lubrication gap and also with assumption, that oil has non- Newtonian properties. The determination of hydrodynamic pressure distribution in bearing gap was carried out by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were performed for bearings without misalignment, i.e. where the cone generating line of bearing shaft is parallel to the cone generating line of bearing sleeve. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that the flow in the bearing lubrication gap is isothermal. Some other simplifying assumptions are: a steady-state operating conditions of a bearing, incompressible flow of lubricating oil, no slip on bearing surfaces, pressure on the side surfaces of bearing gap is equal to atmospheric pressure. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:: Journal of KONES; 2014, 21, 4; 49-56
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: An analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing
Autorzy:: Koprowski, M.
Powiązania:: https://bibliotekanauki.pl/articles/260459.pdf
Data publikacji:: 2007
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:: unsymmetrical lubricating gap
conical slide bearing
numerical calculations
hydrodynamic pressure distribution
load carrying capacity
Opis:: This paper presents a computer analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing. Numerical calculations were carried out with the use of the software Matlab 7.1 and Mathematica 5.2 for example conical slide bearings of different values of cone apex angles of pin and sleeve and set values of relative eccentricity and skewing angle as well as dimensionless bearing length equal to 1.
Źródło:: Polish Maritime Research; 2007, 4; 59-63
1233-2585
Pojawia się w:: Polish Maritime Research
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: CFD analysis of hydrodynamic lubrication of slide conical bearing with consideration of the bearing shaft and sleeve surface roughness
Autorzy:: Czaban, A
Powiązania:: https://bibliotekanauki.pl/articles/246600.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: conical bearing
surface roughness
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
pressure distribution
sand-grain roughness
Opis:: In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of the effect of the bearing shaft and sleeve surface roughness. The oil flow in a bearing lubrication gap largely depend on the condition of the cooperating surfaces of a bearing. Surface irregularities are formed already at the manufacturing process and furthermore the quality of the surface may change during operation of a bearing. In this work, as a parameter describing surface condition, the Ks roughness height parameter was taken (i.e. sand-grain roughness height). The hydrodynamic pressure distribution in lubrication gaps of investigated bearings were calculated by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were conducted for bearings without misalignment. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that bearings have smooth surfaces and there is no slip on surfaces. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:: Journal of KONES; 2014, 21, 3; 35-40
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: CFD analysis of the hydrodynamic lubrication of a misaligned, slide conical bearing
Analiza CFD hydrodynamicznego smarowania stożkowego łożyska ślizgowego o nierównoległych osiach czopa i panewki
Autorzy:: Czaban, A.
Powiązania:: https://bibliotekanauki.pl/articles/188596.pdf
Data publikacji:: 2016
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: hydrodynamic lubrication
sliding bearing
conical
misaligned
CFD
non-Newtonian oil
hydrodynamiczne smarowanie
łożysko stożkowe
ślizgowe
nierównoległość osi
nienewtonowski olej
Opis:: The lateral loads carried by hydrodynamic bearings, and also their uneven distribution, introduce an additional axial misalignment between the shaft and sleeve. The machining and mounting errors also result in improper initial alignment of bearing shaft or sleeve. Furthermore, due to vibrations, misalignment of shaft fluctuates during the operation of the bearing. This has an impact on the operating parameters of the bearing, and, in extreme cases, where the maximum allowable value of the misalignment is exceeded, the bearing can be damaged. The aim of this work is to investigate the effect of misalignment on the hydrodynamic pressure distribution in the conical sliding bearing lubrication gap and on the bearing load carrying capacity and friction force values. This paper shows the result of a CFD simulation of hydrodynamic conical bearings lubrication with the assumption that the bearings are misaligned, i.e. where the rotation axis of bearing shaft is not parallel to the axis of the cone of the bearing sleeve. The commercial CFD software ANSYS Fluent was used in this research. It was assumed that the flow of lubricating oil is laminar, without slipping on bearing surfaces, and that the oil has non-Newtonian properties.
Nierównomierny rozkład sił obciążających łożysko ślizgowe, a co za tym idzie – deformacja wału powodują powstawanie nierównoległości pomiędzy osią czopa a osią panewki łożyska. Dodatkowo błędy procesu obróbki lub pomiędzy osią czopa i osią panewki. Położenie osi czopa nie jest stałe podczas pracy łożyska i zmienia się np. w związku z jego drganiami. Celem tej pracy jest zbadanie wpływu nierównoległości osi obrotu czopa w stosunku do osi panewki na rozkład ciśnienia hydrodynamicznego, wartości sił nośnych i na wartość momentu tarcia w stożkowym łożysku ślizgowym. W niniejszej pracy zaprezentowano wyniki symulacji CFD dla stożkowego łożyska ślizgowego przy założeniu, że przepływ oleju w szczelinie smarnej jest laminarny. Założono, że olej jest płynem o właściwościach nienewtonowskich, a zależność naprężeń od szybkości ścinania jest opisana relacją Ostwalda de Waele. Symulacje przeprowadzono dzięki wykorzystaniu komercyjnego oprogramowania CFD Ansys Fluent.
Źródło:: Tribologia; 2016, 268, 4; 41-53
0208-7774
Pojawia się w:: Tribologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: An Analysis of Hydrodynamic Pressure Distribution and Load Carrying Capacity of a Conical Slide Bearing Lubricated with Non-Newtonian Second Grade Flui
Analiza rozkładu ciśnienia hydrodynamicznego i siły nośnej w stożkowym łożysku ślizgowym smarowanym olejem o właściwościach nienewtonowskich drugiego rzędu
Autorzy:: Miszczak, Andrzej
Czaban, Adam
Powiązania:: https://bibliotekanauki.pl/articles/189591.pdf
Data publikacji:: 2019
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: small parameter method
Reynolds type equation
load carrying capacity
hydrodynamic pressure
Rivlin-Ericksen model
non-Newtonian oil
conical slide bearing
metoda małego parametru
równanie typu Reynoldsa
siła nośna
ciśnienie hydrodynamiczne
model Rivlina-Ericksena
olej o właściwościach nienewtonowskich
stożkowe łożysko ślizgowe
Opis:: In this paper, the authors present the equations of the hydrodynamic lubrication theory for conical slide bearings lubricated with the oil with properties described by the Rivlin-Ericksen model. It is assumed, that the considered lubricating oil shows non-Newtonian properties, i.e. it is an oil for which, apart from the classic dependence of oil viscosity on pressure, temperature and operating time, there is also a change in dynamic viscosity values caused by the changes of shear rate. The method of a small parameter was used to solve the conservation of momentum, stream continuity, and energy conservation equations. The small parameter method consists in presenting the sought functions (pressure, temperature, components of the velocity vector) in the form of a uniformly convergent series expansion in powers of a constant small parameter. These functions are substituted into the system of basic equations, and then the series are multiplied by the Cauchy method. By a comparison of the coefficients with the same powers of a small parameter, we obtain systems of partial differential equations, from which the subsequent approximations of unknowns of the sought functions are determined. The small parameter method separates the non-linear system of partial differential equations and creates several linear systems of equations. The aim of this work is to derive the equations describing and allowing the determination of the temperature distribution, hydrodynamic pressure distribution, velocity vector components, load carrying capacity, friction force and friction coefficient in the gap of conical slide bearing, lubricated with the oil of the properties described by the Rivlin-Ericksen model, taking into account its viscosity changes due to time of operation.
W artykule autorzy przedstawiają równania hydrodynamicznej teorii smarowania olejem o modelu Rivlina-Ericksena stożkowego łożyska ślizgowego. Olej ten charakteryzuje się nienewtonowskimi właściwościami, czyli jest to olej, dla którego, oprócz klasycznych zależności lepkości oleju od ciśnienia, temperatury i czasu eksploatacji, występuje dodatkowo zmiana lepkości dynamicznej od szybkości ścinania. Do rozwiązania równań zachowania pędu, ciągłości strugi i zachowania energii wykorzystano metodę małego parametru. Metoda ta polega na przedstawieniu poszukiwanych funkcji (ciśnienia, temperatury, składowych wektora prędkości) w formie jednostajnie zbieżnego szeregu potęgowego rozwiniętego względem stałego małego parametru. Funkcje te podstawia się do układu równań podstawowych, a następnie wymnaża te szeregi metodą Cauchy’ego. Porównując współczynniki przy jednakowych potęgach małego parametru, otrzymuje się układy równań różniczkowych cząstkowych, z których wyznacza się kolejne przybliżenia niewiadomych, poszukiwanych funkcji. Metoda małego parametru rozprzęga nieliniowy układ równań różniczkowych cząstkowych, tworząc kilka liniowych układów równań. Celem niniejszej pracy jest wyprowadzenie równań umożliwiających wyznaczenie rozkładu temperatury, rozkładu ciśnienia hydrodynamicznego, składowych wektora prędkości, siły nośnej, siły tarcia i współczynnika tarcia w szczelinie poprzecznego łożyska ślizgowego smarowanego olejem o modelu Rivlina-Ericksena z uwzględnieniem zmian lepkości od czasu eksploatacji oleju.
Źródło:: Tribologia; 2019, 284, 2; 83-95
0208-7774
Pojawia się w:: Tribologia
Dostawca treści:: Biblioteka Nauki

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