Autor: Miszczak, A. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Determination of variable pseudo-viscosity coefficients for oils with the Rivlin - Ericksen properties
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247350.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: pseudo-viscosity coefficients
apparent viscosity
Rivlin-Ericksen equation
viscosity curves
Opis:: Modern oils, that lubricate the sliding friction pairs, contain more and more additives. These additives change the oil properties to the non-Newtonian. Furthermore, the friction and wear products and also the products of combustion in internal combustion engines, result in a change of the oil properties, from Newtonian to the non-Newtonian. Frequently, researchers suggest to use so-called „smart fluids”, for example, the ferro-oils as lubricants of sliding friction pairs exposed to strong magnetic fields or the absence of gravity. The ferro-oils are also characterized by the non-Newtonian properties. The viscosity characteristics of these oils are described rather well by the Rivlin-Ericksen constitutive equation. The Rivlin-Ericksen constitutive equation contains the coefficients, which are difficult to estimate or determine experimentally. One of the possibilities to determine these coefficients is the method proposed by Prof. K. Wierzcholski [12]. This method requires the experimental results of dynamic viscosity changes as a function of shear rate. The measurements of dynamic viscosity should be conducted for the widest possible range of shear rates. Then, using the viscosity curves and nonlinear system of equations, the auxiliary coefficients are determined. These coefficients generate the equations that describe the variable pseudo-viscosity coefficients. Not all oils have an intensive exponential character of viscosity changes in dependence on shear rate. In these cases it is possible to determine the constant coefficients of pseudo-viscosity [1, 3, 7, 8]. This paper presents the examples of determination of the variable pseudo-viscosity coefficients for the selected lubricating oils and ferro-oils.
Źródło:: Journal of KONES; 2013, 20, 1; 201-208
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Analysis of the influence of the changes in the value of dynamic viscosity coefficient in the direction of oil film thickness on the journal bearing load carrying capacity
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/243539.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: slide journal bearing
load carrying capacity
friction force
friction coefficient
numerical calculation
Opis:: This article presents the results of numerical calculations of the hydrodynamic pressure distribution, load carrying capacity, friction force and friction coefficient of the slide journal bearing, if the assumed model of hydrodynamic lubrication takes into account the dependence of oil viscosity values on its temperature in all three directions of the adopted coordinate system, in particular, also across the thickness of the lubricant layer. This research considered the slide journal bearing lubricated with the Newtonian oil. The flow of oil was modelled as laminar and stationary. The bearing bushing had a full angle of wrap and its surfaces were smooth. In order to obtain hydrodynamic pressure distributions, the Reynolds type equation was numerically solved by application of the finite difference method (FDM). The numerical procedures for this research were prepared with the Mathcad 15 software. When adopting the classic models and simplifications for the hydrodynamic lubrication and a thin boundary layer, it is assumed, that the hydrodynamic pressure of lubricating oil does not depend on the position measured across the height of the lubrication gap. On the other hand, it is known, that the dynamic viscosity strongly depends on the temperature, which is a function of all three spatial variables. The aim of this work is to include, in the hydrodynamic lubrication model, the changes of viscosity in the direction of oil film thickness, and to investigate how it will affect the hydrodynamic pressure distribution and load carrying capacity of the journal bearing.
Źródło:: Journal of KONES; 2018, 25, 3; 355-362
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Analysis of the load carrying capacities and the friction force in the gap of the slide journal bearing lubricated with a non-Newtonian oil described by a power-law model
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/244543.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: numerical calculation
load carrying capacities
friction forces
non-Newtonian oil
power law model
Opis:: In this paper, the author presents the results of numerical calculations of load carrying capacities and friction forces in the gap of the slide journal bearing lubricated with an oil on the non-Newtonian's properties. In the studies, the power-law model has been assumed to describe the relationship between the stress tensors and shear rate tensors. The analytical and numerical calculations have been performed for the plain bearing, non-porous with a full wrap angle. It has been assumed isothermal, laminar and steady flow of lubricant in the gap of a slide bearing. Numerical calculations have been performed for the Gumbel’s boundary conditions and dimensionless lengths of the bearings like L=b/R =2;1.5;1; ½ and ¼. The flow-rate index and coefficient of consistency have been adopted based on the results of experimental studies of changes of dynamic viscosity in terms of a shear rate. It has been assumed that the apparent viscosity depends only on the shear rate. Dynamic viscosity of the engine oil, used in a gasoline engine with a capacity of 1800 cm3, has been tested on the Haake Mars III rheometer. The analytical solutions presented in the paper were based on more general derivations carried out by Professor K. Wierzcholski in his article: ‘Non-linear hydrodynamic lubrication in conjugated fields’ (publication in printing). In this paper, the key quantities such as components of vector of the velocity, hydrodynamic pressure and temperature were presented in the form of convergent power series. The values of load carrying capacities and friction forces were determined and compared for the event where the oil has properties of Newtonian and non-Newtonian. Calculations have been made for the dimensionless quantities.
Źródło:: Journal of KONES; 2016, 23, 3; 327-335
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Structure analysis of the surface of plunger and barrel assembly in the injection pump pumping section
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/246030.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: atomic force microscope
surface topography
roughness
plunger
barrel
injector pump
pumping section
Opis:: Precision surfaces in a diesel engine’s fuel system are used in the two components. First one is the pumping section in the injection pump. The second ones are injectors. In this paper authors present results of the topography measurements of the surface of plunger and barrel assembly in the injection pump pumping section. The measurements were performed using the atomic force microscopy (AFM) NT-206. The measured surface topographies were shown in the form of two and three-dimensional views of selected areas of the investigated surfaces. There are also presented the profiles of the selected area cross-sections as well as roughness height distribution and cumulative height distribution of roughness. Additionally, the basic parameters describing the surface roughness, such as: a roughness average Ra, a root mean square value Rq of roughness, a skewness Ssk (Rsk) and kurtosis Sku (Rku), are also specified. The samples (plungers and barrels), which have been measured, come from the injection pump pumping section as a new ones and after estimated period of operation time. The lateral precision surfaces have been measured. The atomic force microscope NT-206 allows to perform scanning of the measured surface with maximum are dimensions of 32 μm x 32 μm and maximal roughness height of ± 1 m. Scanned surfaces was divided into 256x256 measuring points and the measurements were performed in the static (contact) mode. After surface scanning on the atomic force microscope, the data was calculated in the SurfaceXplorer® 1.311 or Gwyddion 2.35 software. In this paper, only selected surfaces from the several dozen performed scans are shown. The obtained results allow to determinate the degree and type of wear of tested surfaces at the micro-level.
Źródło:: Journal of KONES; 2014, 21, 3; 227-234
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Analysis of surface topography of slide journal bearings and micro - bearings
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247394.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: surface topography
atomic force microscope
static contact mode
height distributions of surface roughness
Opis:: In this paper, the author presents the results of measurements of the slide journal bearings and micro-bearings sleeves and journal surfaces. The study was performed with the atomic force microscope (AFM) NT-206. The results of measurements of surface topography are presented in the form of a 2D and 3D map of surface topography and also in the form of profiles for selected cross-sections of examined surfaces. Additionally, the height distributions of surface roughness are presented. The Atomic Force Micsroscope NT-206 allows investigating the surface of sample with maximum scanning area 32μm x 32μm and with the maximum value of roughness ±1μm. The measurements can be carried out in three modes: static (contact) mode, dynamic (non-contact) mode, dynamic intermittent mode. The author used the contact mode. The application of this mode of operation, in the case of samples with a hard surface, for example, the journal of a bearing, enables to obtain a good mapping of the measured surface. The presented in this paper results of surface topography measurements, include the calculated values of the Ra and Rq parameters and also the maximum value of the distance between the lowest and the highest surface inequality. The obtained results allow evaluating the amount and type of wear of researched elements in the micro-scale and they also are useful in the design of such surface layers of co-operating components, in order to obtain optimum tribological properties. When considering the impact of the surface roughness on the change of height of bearing gap, and consequently the change of flow and operating parameters, the information about average distribution of roughness value is required. With such measurements, it is possible to obtain these data. In the presented research the micro-bearings from personal computers hard drives, as well as classic bearings and sleeves, were investigated.
Źródło:: Journal of KONES; 2013, 20, 4; 285-292
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Operating parameters of slide micro – bearings with consideration of oil temperature changes and micro - grooves on sleeve surface
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247490.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: HDD micro-bearings
micro-grooved surfaces
oil viscosity changes in gap height
hydrodynamic pressure
friction forces
load carrying capacity
Opis:: In this paper author presents results of numerical calculations of hydrodynamic pressure distribution in bearing gap, load-carrying capacity, friction force and friction coefficient of slide micro-bearing considering the influence of lubricating oil temperature changes and also taking into account the influence of micro-grooves, which occur on sleeve internal surface. The micro-grooves on that surface are in longitudinal direction. The equation, which describes a bearing gap with micro-grooves on sleeve surface, was adopted from prof. K Wierzcholski's investigations. In very thin gap height of cylindrical micro-bearings, large gradients of temperature can be observed. This causes significant changes of oil dynamic viscosity in the gap height direction. According to this, oil flow velocity, friction forces, and a hydrodynamic pressure during the micro-bearing operation are changing. Up to now the influence of temperature on oil viscosity changes and due to this, on hydrodynamic pressure and on load carrying capacity in cylindrical micro-bearing gap in numerical way were not considered yet. The numerical calculations were performed with the use of Mathcad 14. The finite differences method and own computational procedures were implemented. The calculations were begun by solving the Reynolds' equation, assuming, that the dynamic viscosity is constant. After calculating the hydrodynamic pressure distribution, the temperature distribution in lubricating oil was determined. The obtained function of temperature was used to describe the viscosity changes with temperature. Next step involved determining the hydrodynamic pressure distribution taking into account the viscosity dependence on temperature, and then new distribution of temperature and again new values of viscosity were calculated. Calculations were repeated until assumed convergence and accuracy were reached. The friction force depends on pressure gradient and rotational motion of bearing journal. Part of friction force, which resulting from the pressure gradient, is determined for the area, where the oil film occurs, i.e. from omega p to omega k. Part of friction force, which is related to journal motion, is determined for full wrap angle, i.e. from 0 to 2 pi. The results were presented in the form of graphs, for eccentricity ratio gamma from 0.1 to 0.9, for dimensionless length of the bearing L1=1/4. In numerical calculations were used the theoretical considerations and solutions presented in papers of K. Wierzcholski and A. Miszczak.
Źródło:: Journal of KONES; 2012, 19, 2; 329-336
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Surface topography of operated slide journal micro - bearings used in HDD
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/242978.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: atomic force microscope
surface topography
microgrooves
herringbone grooves
micro bearing in HDD
Opis:: In this paper author present results of measurements of slide journal micro-bearings surface topography measured with an atomic force microscope (AFM). The results of measurements of surface topography were presented in the form of surface topography maps, three-dimensional graphs and some examples of selected cross-sections of investigated surface in the form of profile graphs. Measurements of surface topography were made for journals and sleeves of slide journal micro-bearings from personal computers' hard disc drives, with the Atomic Force Microscope NT-206 produced in MTM in Minsk, Republic of Belarus. In this research author used two identical sets of micro-bearings from 2.5" HDD Samsung HM160HI 5400rpm and 3.5" HDD Seagate Barracuda 7200.10 ST380815AS 7200 rpm hard disc drives. First set of those four microbearings worked for a year at rated RPM continuously (i.e. 24 hours a day). Second set of the same micro-bearings also worked for a year at rated RPM, but in intermittent mode (i.e. 15 minutes on, 15 minutes off). The values of profile roughness parameters Ra and Rq and the distance between maximum peak height and maximum valley depth are presented as well. The application SurfaceXplorer registered trademark was used for processing and visualization of the data obtained from AFM NT-206, which besides from generating 2D, 3D and profile diagrams, was used to calculate and draw graph of height distribution. Surface topography of investigated bearings sleeves was also measured using Hommeltester T8000-R60 profilometer. Those measurements give information about micro-grooves dimensions and location. On the surfaces of studied micro-bearings, some micro-grooves can be found in form of herringbone, with depth about 1.5..m and width 150..m. Received information about micro-grooves geometry will allow developing proper theory of hydrodynamic lubrication for micro-bearings with micro-grooves.
Źródło:: Journal of KONES; 2012, 19, 4; 449-456
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Distribution of hydrodynamic pressure in the interspace of lateral sliding bearings lubricated by ferrofluid with different concentrations of magnetic particles
Autorzy:: Frycz, M.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245424.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic pressure distributions
capacity
ferrofluid
magnetic field
numeric calculation
Opis:: This paper presents the numerical results of hydrodynamic pressure distributions and capacity in the gap of ferrofluid-lubricated slide bearing with different concentrations of magnetic particles. Ferrofluid is a colloidal mixture of dispersing agent (base) and diffused (magnetic particles). The most common distracted factors are Fe3O4, Ge2O2 or NiO. Scattering factor is mostly water, mineral oil, synthetic oil. In addition, the magnetic particles are coated with a surfactant in the form of long chains of molecules or electrostatic coating. Reynolds-type equation has been derived from the equations of momentum and continuity equation for laminar, steady and isothermal flow. Viscoelastic model Rivlin-Ericksen type of lubricant has been adopted. It has been adopted also that the dynamic viscosity depends generally on the magnetic field. The equations of momentum, continuity and Maxwell's equation with a constitutive equation were made dimensionless, and then them small units of higher order have been omitted (units of the order of the relative radial clearance: i//=0.001). Such estimated system of equations of motion was divided into two subsystems by the small parameter method. The basic system of differential equations which consider the effect of the magnetic field has been received and the additional system which takes into account influences of non-Newtonian properties as well. Integrating the appropriate momentum equations and imposing boundary conditions the velocity vector components and the Reynolds-type equation have been obtained. While computer simulations of the magnetic field were assumed that the longitudinal component of magnetic induction vector does not change with the length of the bearing. Reynolds-type equation by which the hydrodynamic pressure distributions can be determined has been solved numerically using Mathcad and ourselves calculation procedures. The paper presents results of numerical calculations of hydrodynamic pressure distribution and lift force for the simulated values of the magnetic field and ferrofluid's dynamic viscosity and for different relative eccentricities and dimensionless length of the bearing. The results presented in the paper are the solutions of a basic system.
Źródło:: Journal of KONES; 2011, 18, 3; 83-89
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: A new problem of hydrodynamic lubrication with temperature and viscosity variations in gap height direction
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245652.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: liquid viscosity changes in thin gap height direction
temperature
adhesion or capillary forces variations in thin gap height direction new analytical solutions
Opis:: Numerous Authors of scientific papers occurring in hydrodynamic theory of slide bearing lubrication, up to now almost always had neglected the oil dynamic viscosity variations caused by temperature, adhesion forces, capillary forces, or hydrogen ion concentration across the film thickness by virtue of the statement of the constant temperature as well constant adhesion as capillary forces in the thin bearing gap height direction. In addition, simultaneously by virtue of boundary layer simplifications for energy equation and by virtue of new measurements performed in micro and nano- level follows that oil temperature gradients and its values differences and adhesion or capillary gradients of forces in bearing gap height directions are not negligible small. The contemporary hydrodynamic theory of lubrication for non-isothermal lubricant flow is unfortunately based on the assumption of constant viscosity values across the film thickness, despite abovementioned self-evident contradiction between the fact of constant viscosity and simultaneously temperature variations in gap height direction. Such problem was up to now not sufficient critical examined and explained in practical and theoretical sense. After Authors, knowledge by virtue of above problem the most scientific papers in the domain of non-isothermal and lamellar hydrodynamic slide bearing or biobearing lubrication were up to now not sufficient correctly solved. It denotes that the main hydrodynamic lubrication solutions presenting for example hydrodynamic pressure by the modified Reynolds equation and temperature by the energy conservation equation are not sufficiently correctly obtained and next not correctly solved. Therefore are assumed simultaneously the temperature T and oil dynamic viscosity variations in length, width and bearing gap- height directions. From this assumption follows, that the energy equation must be solved simultaneously with the equations of motion i.e. consequently with pressure equation where viscosity depends on temperature and temperature depends on the coordinate in gap height direction.
Źródło:: Journal of KONES; 2016, 23, 2; 423-430
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Adhesion and capilarity in micro-bearing lubrication
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/245795.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: adsorption
adhesion
capillary forces
micro-bearing lubrication
Opis:: Present paper shows the some main phenomena which have important influence on the micro-bearing operating parameters. To above mentioned phenomena belong: adhesion forces, adsorption forces, capillary forces, elastic and hyperelastic deformations of cooperating micro-bearing surfaces, Van-der Waals electrostatic forces on the micro-bearing surfaces. Because the height of super thin micro-bearing gap is very small often smaller than l micrometer, hence the adhesion forces and capillary forces arising in micro-bearing gap, provoke the oil dynamic viscosity changes. This fact leads to the hydrodynamic pressure and bearing carrying capacity changes. The performed research play off the main role of mechanical micro-deformations of cooperating micro-bearing surfaces on non-Newtonian oil dynamic viscosity and here are indicated the influence of capillary force on adhesion forces in micro-scale. The micro-deformations of the micro-bearing gap height are effecting the changes of oil flow velocity in the gap, this fact leads to the share rate changes and therefore we obtain changes of apparent viscosity of the non-Newtonian oil.
Źródło:: Journal of KONES; 2009, 16, 3; 489-495
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Magnetic field impact on the temperature and pressure distribution in slide journal bearing
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/246908.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: slide journal bearing
magnetic induction field
non-Newtonian lubricant
conjugated fields
new general method
load carrying capacity
pressure decrements
pressure increments
Opis:: The topic of the presented article aims to demonstrate a new principle of hydrodynamic lubrication in mechanical, non-isothermal and electro-magnetic fields. In this article is presented hydrodynamic slide journal bearing in electromagnetic field. The aim of this article is a new general analytical and numerical solution determined the influence of the electro-magnetic field on the temperature distribution in the internal surfaces of the slide-bearing sleeve and pressure distribution in bearing gap. To the research methods and materials used in this article realization belong: the Mathcad 15 Professional Program and new semi-analytical methods applied for theory of hydrodynamic lubrication extended to the curvilinear orthogonal surface and coordinates. Particular solutions are introduced to the cylindrical coordinates. To the obtained results of lubrication of movable sleeve surface belong the increments of the bearing load carrying capacity during the presence and absence magnetic induction field in the case if non-Newtonian lubricant features and constant temperature are taken into account. Simultaneously are observed the increments of the bearing load carrying capacity during the presence magnetic field and Newtonian lubricant. Temperature increments (decrements) without and with magnetic field lead to the hydrodynamic pressure decrements (increments). Moreover are assumed simultaneously the temperature T and oil dynamic viscosity variations in length, width and bearing gapheight directions. From this assumption follows, that the energy equation must be solved simultaneously with the equations of motion i.e. consequently with pressure equation where viscosity depends on temperature and temperature depends on the coordinate in gap height direction.
Źródło:: Journal of KONES; 2017, 24, 2; 279-286
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: The friction force and friction coefficient in the journal sliding bearing ferrofluid lubricated with different concentrations of magnetic particles
Autorzy:: Frycz, M.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247265.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydrodynamic pressure
capacity
friction force
friction coefficient
ferrofluid
numeric calculation
Opis:: There is an important operational parameter in the case of sliding bearings are friction forces and coefficient of friction. It depends on how much proportions of heat in the gap of the oil film from the value of the friction force. Ferrofluid lubricated sliding bearings have specific structure and are suitable only for use in specific cases. We may use them in the absence of gravity, vacuum, or in case of strong magnetic fields or radioactive. Maintenance of lubricant in the oil-gap as well as the viscosity change occurs through controlling of the external magnetic field. Change of the value of viscosity and mass forces (magnetic forces) in the equation of momentum depends on the concentration of magnetic particles and the intensity of external magnetic field. The aim of this paper is to present the influence of concentration of magnetic particles on the friction force value and coefficient of friction. The numerical calculations of friction forces and friction coefficient have been performed before setting the hydrodynamic pressure and a lift force from the Reynolds-type equation. Reynolds-type equation has been derived from basic equations, ie equations of momentum and equations of stream's continuity. There have been also used Maxwell's equations for the ferrofluid in the case of stationary magnetic field's existence. It has been assumed stationary and laminar flow of lubricant liquid and the isothermal model for lubrication of slide bearings. As the constitutive equation has been used Rivlin-Ericksen one. The cylindrical journal bearing of finite length with the smooth sleeve of whole angle of a belt has been taken into consideration. In a thin layer of oil film has been assumed constancy of the oil density with temperature changes and the independence of the oil's thermal conductivity coefficient from thermal changes. The viscosity of the oil depends mainly on the magnetic field.
Źródło:: Journal of KONES; 2011, 18, 4; 113-120
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Friction forces on the lubricated surfaces in micro and nano scale
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/241987.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: AFM
experimental data
dynamic friction forces
Opis:: The present paper determines static and dynamic friction forces and friction coefficients using atomic force microscope during the hydrodynamic viscoelastic liquid flow in the thin boundary layer around the cells of two cooperating bodies. Atomic force microscope is necessary in performed experimental investigations and measurements of friction forces. Therefore, proper parameters of microscope are described and illustrated in specific enlargement. The use of microscope of atomic forces AFM for complex technical investigations to a large extent has facilitated carrying-out the measurements of tissue surface features and control of its growing process in human joint and deforming process in micro-bearing alloy. During conventional nano-scale measurements of surface topography, the AFM microscope makes it possible to simultaneously map local lateral forces and oscillatory phases of translations, which may be interpreted as a representation of local friction forces and local adhesive forces as well as values of elasticity modules. One of the important advantages of the AFM microscope application in the area of investigations with the use of bio-reactors is the possibility of carrying out measurements directly in liquid, namely that surrounds the cells or micro-bearing gaps
Źródło:: Journal of KONES; 2008, 15, 4; 597-602
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: The project of memory and genetic code simulations for joint lubrication
Autorzy:: Wierzcholski, K.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/241989.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: Curvilinear bone heads
capacity memory simulations
genetic code of biological liquids
Opis:: This paper presents the optimization, simulation and practical application of operating parameters(load carrying capacity, friction forces, friction coefficient, wear) for hydrodynamic intelligent articular and artificial bio-bearing joints with curvilinear nano-shaped surfaces. One of the reason of such bone head and endoprosthese profile is that this profile contributes to the variation (an increase or decrease) the memory joint capacity. Such properties are very important and required in human joints. A general theory of materials with memory is the theory developed by Noll and Koleman. The simple solid body and liquid theory presented in this paper is based on the assumption that stress is defined by a whole deformation history. The changes of bio-bearing superficial surfaces presented in this paper are described by the process of changes of mass of a body system defined by non-Newtonian synovial liquid properties and its genetic (congenital) factors, which depends on epigenetic (environmental) factors (temperature, mechanical stress and strain, internal and external physical fields, etc.). Scientific problems considered in the paper are mainly focused on comparisons and practical applications of tribological processes, which occur during fluid flow around cells lubrication on the nano-surfaces in nano-bearings, as well as surfaces of bio-bearings.
Źródło:: Journal of KONES; 2008, 15, 4; 591-596
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Acoustic emission as friction force indicator after test stands experiments
Autorzy:: Ziegler, B.
Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/242687.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: non-destructive testing
acoustic emission
plain bearing
friction force
Opis:: This paper describes the use of acoustic emission measurement as an indicator of friction force into hydrodynamic journal bearings. The parameters load, speed, friction force, oil-temperature as well as the displacement of the sleeve are mainly measured in mutual dependence in journal plain bearing test stands. The friction force can not be measured directly, it must be calculated from the reaction force of the sleeve. Many different constructions are in use with the aim to load the bearing with a minimized influence of friction force measurement. Because of the huge influence to the friction force it is desirable to have parameters that are corresponding with it and are independent of the bearing load. We investigate the applicability of the acoustic emission analysis to indicate the friction force at an existing plain bearing test stand. The adoption of the acoustic emission measurement system (the diversion of the waves from the sleeve, the wave propagation through the AE transducer, the measurement chain and the damping of the mechanical and electrical disturbance) onto the test stand is described.
Źródło:: Journal of KONES; 2007, 14, 4; 579-586
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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