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1

Reliability aspects of the effect of application 2% and 8% ferro-oil as a lubricant in a slide journal bearing on its operating parameters

Frycz Marcin

Journal of KONBiN

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2020

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Vol. 50, iss. 1

77--93

EN

The purpose of this paper is to determine the impact of using ferro-oil with 2% or 8% concentration of the magnetic particles as the lubricant of the slide journal bearing on its operating parameters regarding the reliability aspect. There has been presented an analytical and numerical calculation model based on experimentally determined physical quantities describing the dependence of viscosity of ferro-oil on fundamental parameters in the paper. Numerical calculations were performed by solving the Reynold’s type equation using the finite difference method using Mathcad 15 and own calculation procedures.

PL

Celem niniejszej pracy jest określenie jaki wpływ na zmianę parametrów eksploatacyjnych łożyska ślizgowego w aspekcie niezawodności może mieć zastawanie jako środka smarnego ferro-oleju o 2% lub 8% stężeniu cząstek magnetycznych. W pracy został przedstawiony analityczno-numeryczny model obliczeniowy bazujący na eksperymentalnie wyznaczonych fizycznych wielkościach opisujących zależność lepkości ferro-oleju od zmian podstawowych parametrów pracy. Obliczenia numeryczne wykonano rozwiązując równania typu Reynoldsa metodą różnic skończonych przy wykorzystaniu program Mathcad 15 i własnych procedur obliczeniowych.

2

The Effect of the Concentration of Magnetic Particles on the Operating Parameters of a Slide Journal Bearing Lubricated with Ferro-Oil

Frycz Marcin

Tribologia

|

2019

|

nr 2

43--55

EN

This paper presents an analysis of changes in basic operational parameters of a slide journal bearing in an aspect of a concentration of magnetic particles in ferro-oil as a lubricant. The first part of the article presents an analytical-numerical calculation model. This model is based on experimentally determined physical parameters describing the dependence of ferro-oil viscosity on changes at basic operating parameters. Moreover, dimensionless load carrying capacity, dimensionless friction force and dimensionless coefficient of friction numerical calculations have been obtained by solving the Reynolds type equations using the finite difference method in Mathcad 15 program and the author’s own calculation procedures. The obtained results have been presented in the form of graphs taking into account the influence of the following factors: external magnetic field, corrections related to the influence of pressure changes, corrections related to the influence of temperature changes and corrections related to non-Newtonian properties of the ferro-oil. The analysis of the obtained characteristics in the paper has been carried out, observations have been made as well as conclusions have been drawn regarding the optimal concentration of magnetic particles in the ferro-oil lubricating the slide journal bearing.

PL

W niniejszej pracy została przedstawiona analiza zmian podstawowych parametrów eksploatacyjnych poprzecznego łożyska ślizgowego w aspekcie stężenia cząstek magnetycznych w ferro-oleju będącego czynnikiem smarującym. W pierwszej części pracy został zaprezentowany analityczno-numeryczny model obliczeniowy. Model ten oparty został na fizycznych wielkościach opisujących zależność lepkości ferro-oleju od zmian podstawowych parametrów pracy wyznaczonych na drodze doświadczalnej. Z kolei obliczenia numeryczne rozkładu bezwymiarowej siły nośnej, bezwymiarowej siły tarcia oraz bezwymiarowego współczynnika tarcia wykonano, rozwiązując równania typu Reynoldsa metodą różnic skończonych przy wykorzystaniu program Mathcad 15 i własnych procedur obliczeniowych. Uzyskane wyniki przedstawione zostały w postaci wykresów uwzględniających kolejno wpływ: zewnętrznego pola magnetycznego, korekty związane z wpływem zmian ciśnienia, korekty związane z wpływem zmian temperatury oraz korekty związane z właściwościami nienewtonowskimi ferro-oleju. Dokonana została analiza uzyskanych charakterystyk, zostały poczynione obserwacje oraz wyciągnięte wnioski dotyczące optymalnej zawartości cząstek magnetycznych w ferro-oleju smarującym poprzeczne łożysko ślizgowe.

3

Distributions of hydrodynamic pressure in the gap of slide journal bearing lubricated with ferro-oil

Frycz Marcin

Journal of KONES

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2019

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Vol. 26, No. 4

53--61

EN

This research work is part of a broader comprehensive issue, which is the analysis of flow and operating parameters of journal slide bearings lubricated with ferro-oil. In this article, the author presents only the main assumptions and essential transformations of the analytical and numerical model for determining the pressure distributions in the gap of a slide journal bearing lubricated with ferro-oil. It is cardinal that the rheological and magnetic values of ferro-oil parameters adopted in numerical calculations are based on the results of actual values obtained in the author’s earlier research work. There are presented the pressure distributions by abovementioned method in the article for cases of bearings lubricated with ferro-oils with different concentration of magnetic particles. The obtained results are shown in the form of a set of four complementary characteristics of the dimensionless pressure distributions. First and main of them are the calculations for classical Newtonian lubrication but they take into account the influence of the magnetic field on the distributions. The next of the presented characteristics are so-called "corrections" of pressure distribution values, taking into account as follows: effects of changes in ferro-oil viscosity related to temperature changes, impacts of ferro-oil viscosity changes related to pressure changes and the effect of non-oil properties of the lubricant. The article includes a qualitative and quantitative analysis of the obtained results as well as observations and conclusions are presented in it.

4

Researching and modeling of the dynamic viscosity of the ferro-oils with the different concentrations of magnetic particles in the aspect of pressure changes

Frycz M.

Tribologia

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2017

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nr 2

39--48

EN

In this article, the results of the experimental research of determining the dynamic viscosity of the ferro-oils with different concentration of the magnetic particles in terms of pressure change are presented. The research was conducted on the Thermo Scientific Haake Mars III rheometer in the configuration with a pressure chamber. The applied configuration allowed the author to conduct research on the change of viscosity for the selected pressure values p in range from 0 to 100 bars. The research was conducted for three selected temperature values, including t = 30°C, 60°C, and 90°C, as well as selected shear rates of 200 and 600s-1. The chosen concentration values of the magnetic particles were nCS = 1%, 2%, 4%, 6%, and 8%. The viscous characteristics gathered as a result of the research have been analysed with the aim of identifying the nature of the correlations and to create mathematical-physical models of changes in the dynamic viscosity of the ferrooils due to the change in pressure in terms of concentrations of the magnetic particles. Analysis, identification, and adaptation of the characteristics were conducted using the StatSoft STATISTICA ver. 9 software. Selected mathematical adaptations of the acquired results were submitted through the enhanced analysis. In addition, parameters of the course of functions were designated and their qualitative assessments were made.

PL

W artykule zaprezentowane zostały wyniki eksperymentalnych badań wyznaczania lepkości dynamicznej ferro-olejów o różnym stężeniu cząstek magnetycznych w aspekcie zmian ciśnienia. Badania zostały przeprowadzone na reometrze Thermo Scientific Haake Mars III w konfiguracji z tzw. komorą ciśnieniową. Zastosowana konfiguracja pozwalała na prowadzenie badań zmian lepkości dla wybranych wartości ciśnienia p z zakresu od 0 do 100 bar. Badania przeprowadzono dla trzech wybranych wartości temperatur dla t = 30°C, 60°C oraz 90°C i wybranych prędkości ścinania: 200 oraz 600 s-1. Przyjęte wartości stężenia cząstek magnetycznych wynosiły nCS = 1%, 2%, 4%, 6% i 8%. Uzyskane w wyniku badań charakterystyki lepkościowe poddane zostały analizie zmierzającej do identyfikacji charakteru zależności i wykreowanie matematyczno-fizycznych modeli zmian lepkości dynamicznej ferro-olejów od zmian ciśnienia w aspekcie stężenia cząstek magnetycznych. Analizy, identyfikacji i dopasowania charakterystyk dokonano przy wykorzystaniu oprogramowania StatSoft STATISTICA wer. 9. Pogłębionej analizie poddano wyselekcjonowane dopasowania matematyczne uzyskanych wyników doświadczalnych. Wyznaczono ponadto parametry przebiegu funkcji i dokonano ich oceny jakościowej.

5

Influence of magnetic particles concentration in ferro-oil on values of friction force and coefficient of friction of slide journal bearing

Frycz M., Miszczak A.

Journal of KONES

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2017

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Vol. 24, No. 1

143--150

EN

This article has been focused on the analysis of changes in friction force as well as coefficient of friction of slide journal bearing in terms of the concentration of magnetic particles in the lubricating ferro-oil. There has been present an analytical and numerical calculation model based on experimentally determined physical quantities describing the dependence of ferro-oil’s viscosity on fundamental parameters such as temperature, pressure or external magnetic field in the paper. Numerical calculations of the dimensionless friction force as well as the dimensionless friction coefficient were performed by solving the Reynold’s type equation using the finite difference method using Mathcad 15 and own calculation procedures. The obtained results has been presented in the form of a series of graphs that take into account: the influence of external magnetic field, corrections related to the influence of pressure changes, corrections related to the influence of temperature changes and finally corrections related to non-Newtonian ferro-oil properties. An analysis of the obtained characteristics has been made so the observations and conclusions were drawn regarding optimum magnetic particle content in the ferro-oil lubricating the sliding journal bearing.

6

The influence of temperature on coefficient of magnetic susceptibility χ of ferro-oils with different concentrations of magnetic particles

Frycz M.

Tribologia

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2016

|

nr 5

21--30

EN

In this paper, the authors presented research concerning the determination of the relation between magnetic susceptibility coefficient χ of ferro-oil and temperature changes. The tests were conducted on the ferro-oil samples of various, chosen magnetic particles concentrations: 1%, 2%, 4%, 6%, and 8%. In accordance with the conclusions resulting from Curie-Weiss equation, the values of magnetic susceptibility χ depend on the physicochemical features of considered material, including the magnitude and amount (concentration) of magnetic particles and physical properties of its environment, i.e. the kind and direction of magnetic field and also on the operating temperature, which is the main subject of conducted tests in this paper. This article presents the structure of the bench used for experimental designation of magnetic susceptibility coefficient in relation to temperature changes of tested ferro-oil. Moreover, the authors demonstrated a method enabling the determination of these values from obtained measurement data, conducted the analysis of obtained results and presented the conclusions.

PL

W niniejszym artykule zostały przedstawione badania dotyczące określenia zależności współczynnika podatności magnetycznej χ ferro-oleju od zmian temperatury. Badaniom poddane zostały próbki ferro-olejów o różnych, wybranych stężeniach cząstek magnetycznych: 1%, 2%, 4%, 6% i 8%. Zgodnie z wnioskami wynikającymi z równania Curie-Weissa wartości podatności magnetycznej χ zależą głównie od własnych cech fizykochemicznych rozpatrywanego materiału, w tym od wielkości i ilości (stężenia) cząstek magnetycznych oraz od fizycznych właściwości jego otoczenia, tj.: rodzaju i kierunku pola magnetycznego, jak również od temperatury pracy, która stanowi zasadniczy temat podjętych badań. W artykule zaprezentowana została budowa stanowiska do eksperymentalnego wyznaczenia współczynnika podatności magnetycznej w kontekście zmian temperatury badanego ferro-oleju. Ponadto zaprezentowana została metoda umożliwiająca wyznaczenie tych wartości z pozyskanych danych pomiarowych oraz dokonano analizy uzyskanych wyników zakończonej wnioskami.

7

The ferro-oils viscosity depended simultaneously on the temperature and magnetic oil particles concentration η = η(t,ϕ). Part 1

Frycz M.

Journal of KONES

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2016

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Vol. 23, No. 2

113--120

EN

The purpose of this article is to determine, identify and describe the viscosity characteristics of the ferro-oil with different concentrations of magnetic particles at context of temperature changes. These characteristics were determined for the following test conditions: atmospheric pressure, constant shear rate and absent of an external magnetic field. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 1%, 2%, 4%, 6% and 8%. Tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Penzzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant. Analysis of the results, identifying and fitting of characteristics has been made by means of software StatSoft STATISTICA ver.9.1. There has been also undertaken comparison of the accuracy of estimation of reached results by selected mathematical models as well as these results have been rated according to their compliance with theoretical assumptions. Moreover, the waveform parameters of functions have been determined and their assessed quality has been done also. The obtained characteristics going to be used by author in his future work to build mathematical models of viscosity changes of ferro-oils in the aspect of changes of parameters like temperature, pressure, shear rate and the value of the external magnetic field. The determined parameters of physical properties will be used in analytical and numerical studies of flow and operating parameters of slide journal bearings lubricated with ferro-oils.

8

The ferro-oils viscosity depended simultaneously on the temperature and magnetic oil particles concentration η = η(t,ϕ). Part 2

Frycz M.

Journal of KONES

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2016

|

Vol. 23, No. 3

127--134

EN

The purpose of this article is to determine and describe the viscosity characteristics of the ferro-oils at context of temperature changes depend on different concentrations of magnetic particles. These characteristics were determined for the following test conditions: atmospheric pressure, constant shear rate and absent of an external magnetic field. In Part I of the paper there was determined and described four mathematical-physical models of fittings of the viscosity characteristics: exponential, fourth-degree polynomial and two homographic models – second- and third-degree. In present Part II of the paper above mentioned models have been developed. That has been done their depending on parameter of concentrations of magnetic particles ϕ in ferro-oil. There have been also undertaken comparison of the accuracy of estimation of reached results by selected mathematical models as well as these results have been rated according to their compliance with theoretical assumptions. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 1%, 2%, 4%, 6% and 8%. Tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Pennzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant. Analysis of the results, identifying and fitting of characteristics has been made by means of software StatSoft STATISTICA ver. 9.1. The obtained characteristics going to be used by author in his future work to build mathematical models of viscosity changes of ferro-oils in the aspect of changes of parameters such as temperature, pressure, shear rate and the value of the external magnetic field. The determined parameters of physical properties will be used in analytical and numerical studies of flow and operating parameters of slide journal bearings lubricated with ferro-oils.

9

Generalized Newtonian fluids as lubricants in the hydrodynamic conical bearings : a CFD analysis

Czaban A.

Journal of KONES

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2016

|

Vol. 23, No. 2

89--95

EN

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.

10

Influence of pressure on ferro-oil dynamic viscosity

Frycz M., Czaban A.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2014

|

nr 83

45--52

EN

In this paper authors present the results of dynamic viscosity measurements of ferro-oil in aspect of pressure changes. The investigation concerned the ferro-oil with 1.4% concentration of magnetic nano-particles in the base oil, which satisfies SAE 15W-40 standard. The dynamic viscosity measurements were performed on the Thermo Scientific Haake Mars III rheometer and by applying the measuring system called a pressure chamber. The measurements were made at ferro-oil temperatures: 30, 60 and 90 degrees of Celsius, in the range of shear rates from 15 to 200 [1/s] and at gauge pressures: 0, 10, 40, 70 and 100 bars. The results show, that the pressure has an significant impact on the ferro-oil dynamic viscosity, because the increase in pressure of ferro-oil causes a significant increase in its viscosity value. The correctness of the results obtained using a pressure chamber at zero overpressure, was verified by comparison with the results obtained with the coneplate configuration.

PL

W pracy autorzy prezentują wyniki pomiarów lepkości dynamicznej wybranego ferrooleju w zależ- ności od ciśnienia. Badania dotyczyły ferrooleju, w którym udział cząstek ferromagnetycznych wynosił 1,4% w oleju bazowym, który to spełnia normę SAE 15W-40. Pomiary lepkości dynamicznej zostały wykonane przy wykorzystaniu reometru Haake Mars III firmy Thermo Scientific wraz z układem pomiarowym służącym do badania lepkości dynamicznej olejów przy ciśnieniu wyższym niż ciśnienie otoczenia (tzw. komora ciśnieniowa). Pomiary przeprowadzono przy temperaturach ferrooleju: 30, 60 i 90 stopni Celsjusza, w zakresie szybkości ścinania od 15 do 200 [1/s] oraz przy ciśnieniach: 0, 10, 40, 70 i 100 bar. Wyniki pokazują, że ciśnienie ma wpływ na lepkość dynamiczną oleju, ponieważ zwiększanie ciśnienia ferrooleju powoduje znaczący wzrost wartości jego lepkości. Poprawność otrzymanych wyników przy wykorzystaniu komory ciśnieniowej przy zerowym nadciśnieniu została sprawdzona poprzez porównanie z wynikami otrzymanymi na układzie płytka-stożek.

11

Eksperymentalna metoda wyznaczenia współczynników podatności magnetycznej χ ferroolejów o różnym stężeniu cząstek magnetycznych

Frycz M., Anioł P.

Tribologia

|

2014

|

nr 3

29--38

PL

W niniejszym artykule została zaprezentowana budowa stanowiska badawczego do eksperymentalnego wyznaczenia współczynników podatności magnetycznej χ ferroolejów o różnym stężeniu cząstek magnetycznych oraz została przedstawiona analiza wyników pozyskanych tą metodą. Zewnętrzne, jednorodne, stałe pole magnetyczne uzyskano za pomocą dwóch płytek stałych magnesów umieszczonych równolegle, a zmiany wartości pola zadawano poprzez możliwość kontrolowanego przemieszczania tych magnesów względem siebie. Pomiędzy magnesami umieszczona została próbka badanego oleju, a wartości natężenia pola magnetycznego pomierzono z użyciem miernika indukcji pola magnetycznego Smart Magnetic Sensor SMS 102. Badaniom poddano ferrooleje o wybranych stężeniach cząstek magnetycznych, tj.: 8%, 6%, 4% oraz 2% objętościowo.

EN

This paper presents the construction of an experimental test bench to determine the magnetic susceptibility coefficients χ of ferro oils with different concentrations of magnetic particles, and also the analysis of the results that were obtained by this method. The outer, homogeneous, constant magnetic field was obtained by means of the two plates of permanent magnets arranged in parallel, and changes the field value were carried out by the possibility of controlled movement of the magnets relative to each other. Samples of lubricants were placed between the magnets, and the magnetic field strength was measured by using the magnetic induction SMS Smart Magnetic Sensor 102. Ferro oils with selected concentrations of magnetic particles of 8%, 6%, 4%, and 2% were studied.

12

Wpływ stężenia cząstek magnetycznych w ferrooleju na wartość siły nośnej w poprzecznym łożysku ślizgowym przy uwzględnieniu zmian lepkości od pola magnetycznego, ciśnienia i temperatury

Miszczak A., Frycz M.

Logistyka

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2014

|

nr 6

7549--7558

PL

Celem pracy jest wyznaczenie wpływu stężenia cząstek magnetycznych na wartości wybranych parametrów pracy tj. ciśnienia hydrodynamicznego i siły nośnej, poprzecznego łożyska ślizgowego, smarowanego ferroolejem, przy uwzględnieniu wpływu obecności zewnętrznego pola magnetycznego, zmian ciśnienia i temperatury na zmianę lepkości. W pracy dokonano obliczeń numerycznych rozkładu ciśnienia hydrodynamicznego i siły nośnej bazujących na rozwiązaniu równań typu Reynoldsa metodą różnic skończonych. Składowe natężenia pola magnetycznego wyznaczono poprzez rozwiązanie analityczno-numeryczne równań Maxwella. Jako równanie konstytutywne zastosowano równanie Rivlina-Ericksena. Do obliczeń wykorzystano program Mathcad 15 i własne procedury obliczeniowe. W obliczeniach wykorzystane zostały rzeczywiste wartości współczynników materiałowych takich jak współczynnik podatności magnetycznej , współczynnik opisujący wpływ indukcji magnetycznej na lepkość dynamiczną B, współczynnik opisujący wpływ temperatury na lepkość dynamiczną T, które wyznaczone zostały na podstawie badań eksperymentalnych.

EN

Aim of the paper is to determine the effect of concentration of the magnetic particles on the selected parameters, ie. Hydrodynamic pressure and load carrying capacity of the sliding journal bearing lubricated with ferro-oil, taking into account the effect of the presence of an external magnetic field, pressure and temperature changes. The paper presents numerical calculations of the hydrodynamic pressure distribution as well as load carrying capacity based on the solution of Reynolds equations using the finite differences method. The components of the magnetic field strength have been determined by analytical and numerical solution of Maxwell's equations. The Rivlin-Ericksen equation has been used as the constitutive equation. The Mathcad 15 software and own computational procedures have been used for analytical calculations in the paper. In the calculations have been used the real values of the coefficients of materials such as magnetic susceptibility factor , the coefficient describing the effect of the magnetic induction on the dynamic viscosity B and the coefficient describing the effect of temperature on the dynamic viscosity T, which were determined based on experimental studies.

13

Models of viscosity characteristics η=η(b) of ferro-oil with different concentration of magnetic particles in the presence of external magnetic field

Frycz M., Czaban A.

Journal of KONES

|

2014

|

Vol. 21, No. 4

119--126

EN

The purpose of this article is to determine, identify and describe the viscosity characteristics of the ferro-oil with different concentrations of magnetic particles in the presence of an external magnetic field interaction. These characteristics are defined in the context of magnetic induction changes. These rheological tests were performed on a Physica MCR 301 rheometer. It was used a measuring system ‘plate to plate’ type which was armed with magneto-rheological research system MRD 180/1T. The tests were performed for the selected temperature of the medium i.e. 90°C, the shear rate θ changes were carried from 0 to 1000 1/s. Changes of the magnetic field intensity value were ranged from 0 to 500 mT. The selected concentrations of magnetic particles in a ferro-oil were 1%, 2%, 4%, 6% and 8% and the tested ferro-oil was product of FerroTec of Unterensingen (Germany), which is a mixture of colloidal mineral motor oil Penzzoil’s LongLife Gold's SAE 15W-40 with Fe3O4 magnetic particles and the surfactant. Analyses of the results, identify and matching characteristic were calculated using STATISTICA software. It has been proposed three categories of functions mapping the waveforms of the results obtained experimentally: the exponential function, logarithmic with basis of the normal and the polynomial function.

14

Impact of magnetic particles concentration in ferrooil on its magnetic susceptibility coefficient χ

Frycz M., Anioł A.

Journal of KONES

|

2014

|

Vol. 21, No. 4

111--117

EN

The purpose of this article is to determine the effect of the concentration of magnetic particles in ferro-oil on the value of its magnetic susceptibility coefficient χ. Determination of the flow and operating parameters of slide journal bearings lubricated with ferro-oils requires, inter alia, designation the first magnetization N and the magnetic induction B vector components, dependent on the magnetic propertis of the lubricant. The fundamental problem lies in the inability to make direct accurate measurement of magnetic induction in the lubricating gap of slide bearing and its solution is to determine it on the analytical and numerical way. A key issue for the accuracy of such solutions is to obtain reasonably accurate values of magnetic susceptibility χ. This article attempts to determine these values and estimate their relationship with the concentration of magnetic particles concentration in ferro-oil being potential lubricant above-mentioned bearings. In this paper, the authors present the characteristic of experimental test benches to determine the coefficients of the magnetic susceptibility. They present method of determining this value from obtained measurement data and analyse the impact of the magnetic particles concentration in ferro-oil on its magnetic susceptibility values. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 2%, 4%, 6% and 8% and the tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Penzzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant.

15

Effect of the magnetic particles concentration on the ferro-oil’s dynamic viscosity in presence of an external magnetic field in the aspect of temperature changes

Czaban A., Frycz M., Horak W.

Journal of KONES

|

2013

|

Vol. 20, No. 2

55--60

EN

There is presented an effect of the changes of the concentration of magnetic particles included in the ferro-oil on its dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. The authors assume that the concentration of magnetic particles in ferro-oil can significantly affects its basic physical properties as dynamic viscosity, as well as the operational properties of journal sliding bearings ferro-oil’s lubricated. The equally significant as the above mentioned properties may affect the external environmental conditions of operation, especially temperature changes. In this context, an important technique’s issue appears to determine the principles of selection of optimal concentration of above mentioned particles according to the existing environmental conditions of its operation, or the expectations laid against the operation of the devices. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate-to-plate” measurement system with an adapter to magneto-rheological studies MRD 180/1T. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for four selected temperature range of 60º, 70º, 80º and 90ºC as regards changes an external magnetic field intensity 0-700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8%.

16

Effect of the magnetic particles concentration on the ferro-oil’s dynamic viscosity in presence of an external magnetic field in the aspect of shear rate’s variations

Frycz M., Horak W.

Journal of KONES

|

2013

|

Vol. 20, No. 3

139--144

EN

The purpose of this study is to determine the effect of changes in the concentration of magnetic particles in ferrooil to change its physical properties, in particular the dynamic viscosity in a constant external magnetic field in terms of changes in shear rate and changes in the intensity of that field. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate -plate” measurement system with an adapter to magneto-rheological studies MRD 180/1T. The applied adapter enable to obtain almost homogeneous distribution of magnetic field strength. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for shear rate’s changes from 0 to 1000 1/s as regards changes an external magnetic field intensity 0–700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8% and the tested ferrofluid was product of FerroTec of Unterensingen (Germany), which is a mixture of colloidal mineral motor oil Penzzoil’s LongLife Gold's SAE 15W-40 with Fe3O4 magnetic particles and the surfactant. The paper presents, in the form of graphs, the changes of ferro-oil’s dynamic viscosity as a function of shear rate and concentration of magnetic particles in the aspect of external magnetic field’s intensity changes. The results of research were also subjected to analysis. The obtained characteristics of ferro-oil’s viscosity show clear evidence of non-Newtonian properties of the liquids. There is observed progression of these properties with increasing of magnetic particles concentration. This fact indicates the essential effect of the addition mentioned particles to the change of the ferro-oil’s viscosity characteristics.

17

Experimental values of temperature distribution in a sliding bearing sleeve lubricated with non-Newtonian oils

Miszczak A.

Polish Maritime Research

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2005

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nr 3

16-26

EN

This paper presents results of experimental investigations of temperature distributions on inner surface of a sleeve of transverse sliding bearing lubricated with non-Newtonian oils. The measurements were performed by means of Pt100 miniature sensors placed close to internal surface of the sleeve. To measure sleeve temperature distributions use was made of a test stand installed at Gdynia Maritime University. Delo 1000 Marine 30 oil, SAE 15W40 basic oil, and aferro-oil made of the SAE 15W40 basic oil were used as a lubricating medium. During measuring temperature distributions for the ferro-oil different intensity values of external magnetic field generated by electromagnets were applied.