scholarly journals Computational Model for Radial Plain Bearing with Non-Circular Bearing Surface Profile and Fusible Coating on Shaft Surface

2021 ◽  
Vol 2096 (1) ◽  
pp. 012023
Author(s):  
M A Mukutadze ◽  
M V Novakovich ◽  
N S Zadorozhnaya
Keyword(s):  
Bearing Capacity ◽  
Mechanical Energy ◽  
Surface Profile ◽  
Energy Dissipation Rate ◽  
Flow Equation ◽  
Zero Approximation ◽  
Plain Bearing ◽  
Bearing Surface ◽  
First Approximation ◽  
Friction Parameters

Abstract The paper presents a study based upon: a Newtonian fluid flow equation (“thin layer”), a continuity equation, and an equation of the molten-profile radius for a shaft coated with a fusible metal alloy; considering a mechanical energy dissipation rate formula, the authors produced an asymptotic and accurate automodel solution for the zero approximation (melting ignored) and first approximation (adjusted for melting) of a radial plain bearing featuring a fusible metal coating and a bearing profile adapted to the specific friction parameters. The paper further presents analytical dependencies describing the molten surface radius, velocity and pressure fields for zero and first approximation. Besides, it determines the key operating parameters of the frictional couple, the bearing capacity, and the friction. It also shows how the parameters arising from the melting of the surface affect the bearing capacity and friction where the bearing surface profile is adapted to the specific conditions of friction.

scholarly journals Mathematical Model of Micropolar Lubricant Considering Viscosity-Pressure Dependence

2021 ◽  
Vol 2096 (1) ◽  
pp. 012104
Author(s):  
A V Morozova ◽  
N S Zadorozhnaya ◽  
M A Mukutadze ◽  
V I Kirishchieva
Keyword(s):  
Bearing Capacity ◽  
Friction Force ◽  
Pressure Dependence ◽  
Friction Pair ◽  
Mechanical Energy ◽  
Surface Profile ◽  
Energy Dissipation Rate ◽  
Flow Equation ◽  
Metal Coating ◽  
The Impact

Abstract In the study, based on the micropolar fluid flow equation for a “thin layer”, the continuity equation, the equation describing the profile of the molten contour of the guide coated with a low-melting metal alloy, and the equation for the mechanical energy dissipation rate, asymptotic and exact self-similar solution has been found for the zero (without considering the melting) and first (considering the melting) approximation of wedge-shaped support with the slider support profile adapted to the friction conditions and the low-melting metal coating of the guide surface. The research has taken into account the pressure dependence of the lubricant rheological properties and the melt having micropolar properties in the laminar flow regime. Analytical dependencies have been obtained for the molten surface profile of the low-melting metal coating of the guide and the field of velocities and pressure for the zero and first approximations. Also, the basic performance characteristics of the friction pair under consideration have been determined: the bearing capacity and the friction force. The impact of parameters determined by the coating melt, adapted to the support profile friction conditions, and the parameter characterizing the pressure dependence of the lubricant viscosity on the bearing capacity and friction force has been estimated.

scholarly journals Mathematical model of wedge-shaped plain bearing considering the dependence of viscosity on pressure

2021 ◽  
Vol 2131 (2) ◽  
pp. 022039
Author(s):  
A Mukutadze ◽  
V Prikhodko ◽  
I Dolgiy
Keyword(s):  
Bearing Capacity ◽  
Rheological Properties ◽  
Friction Force ◽  
Friction Pair ◽  
Flow Equation ◽  
Plain Bearing ◽  
New Approach ◽  
Self Similar Solution ◽  
The Given ◽  
Standard Support

Abstract This paper outlines a new approach for finding an asymptotic and exact self-similar solution for the zero and first (without taking into account the melt and considering the melt, respectively) approximation of the wedge-shaped plain bearing with a non-standard support profile of the slide and the low-melting metal coating of the surface. The given approach is based on the flow equation of a ferromagnetic fluid for a «thin layer», the continuity equation, as well as the equation describing the profile of the guide’s molten contour. The proposed method takes into account the dependence of the rheological properties of the lubricant and the melt that have ferromagnetic properties in the laminar flow on pressure. We have succeeded in obtaining accurate analytical dependences for the field of velocities and pressure at zero and first approximations and the ones for the profile of the guide’s molten surface. Besides, we have managed to determine the key performance properties for the slide–guide friction pair, including load-bearing capacity and friction force. Finally, we could assess how the bearing capacity and friction force are influenced by parameters caused by the coating melt adapted to the conditions of the support profile friction and a parameter that characterize the rheological properties of the lubricant.

Energy dissipation rate in a baffled vessel with pitched blade turbine impeller

1991 ◽  
Vol 56 (9) ◽  
pp. 1856-1867 ◽  
Author(s):  
Zdzisław Jaworski ◽  
Ivan Fořt
Keyword(s):  
Energy Dissipation ◽  
Cross Sections ◽  
Mechanical Energy ◽  
Vessel Diameter ◽  
Energy Dissipation Rate ◽  
Mean Velocity ◽  
Agitated Vessel ◽  
Radial Profiles ◽  
Pitched Blade Turbine ◽  
Turbine Impeller

Mechanical energy dissipation was investigated in a cylindrical, flat bottomed vessel with four radial baffles and the pitched blade turbine impeller of varied size. This study was based upon the experimental data on the hydrodynamics of the turbulent flow of water in an agitated vessel. They were gained by means of the three-holes Pitot tube technique for three impeller-to-vessel diameter ratio d/D = 1/3, 1/4 and 1/5. The experimental results obtained for two levels below and two levels above the impeller were used in the present study. Radial profiles of the mean velocity components, static and total pressures were presented for one of the levels. Local contribution to the axial transport of the agitated charge and energy was presented. Using the assumption of the axial symmetry of the flow field the volumetric flow rates were determined for the four horizontal cross-sections. Regions of positive and negative values of the total pressure of the liquid were indicated. Energy dissipation rates in various regions of the agitated vessel were estimated in the range from 0.2 to 6.0 of the average value for the whole vessel. Hydraulic impeller efficiency amounting to about 68% was obtained. The mechanical energy transferred by the impellers is dissipated in the following ways: 54% in the space below the impeller, 32% in the impeller region, 14% in the remaining part of the agitated liquid.

Bearing profile of sliding tribological systems

2021 ◽  
pp. 53-56
Author(s):  
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Profile ◽  
Experimental Methods ◽  
Hydrodynamic Characteristics ◽  
Bearing Surface ◽  
Tabular Data ◽  
Sliding Bearing ◽  
Friction Process ◽  
Operational Characteristics ◽  
Wide Range

The main contours of the bearing surfaces of friction pairs with hydrodynamic lubrication are considered. Analysis of tabular data and graphs obtained by experimental methods made it possible to establish additional parameters of influence on the hydrodynamic characteristics of the friction process and the operational characteristics of tribological systems, in a wide range of load-speed modes. Keywords: sliding bearing, hydrodynamics, bushing, bearing surface, profile, circle, ellipse, wavy contour, wear. [email protected]

A Contact-Wear Model for the EHL Analysis of Engine Journal Bearings

2005 ◽  
Author(s):  
Ducai Wang
Keyword(s):  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Surface Profile ◽  
Journal Bearings ◽  
Bearing Surface ◽  
Wear Model ◽  
Contact Wear ◽  
Analysis Technique ◽  
Elastic Distortion ◽  
Account Interaction

Engine journal bearings are now routinely analysed using elasto-hydrodynamic lubrication (EHL) methods [1,2]. This analysis technique takes into account interaction of the hydrodynamic film with the elastic distortion produced in both the bearing and the journal. It has proved a robust analytic tool for designers in predicting the value and location of such parameters as minimum oil film thickness and maximum film pressure. However, for some very heavily loaded cases, the normal EHL analysis technique may fail to produce realistic solutions. Due to ‘cusping’ of the bearing surface under extreme pressures the edges of bearing may be predicted to penetrate the journal surface leading to a ‘negative’ film thickness. In reality, the surfaces will interact and a ‘running-in’ process will result in subtle changes to the bearing surface profile such that a hydrodynamic film can be maintained across the whole bearing surface. This study introduces a contact-wear model which attempts to model this situation.

scholarly journals Estimating the dynamics of a machine-tractor assembly considering the effect of the supporting surface profile

2021 ◽  
Vol 1 (7 (109)) ◽  
pp. 51-62
Author(s):  
Ivan Galych ◽  
Roman Antoshchenkov ◽  
Viktor Antoshchenkov ◽  
Igor Lukjanov ◽  
Sergey Diundik ◽  
...  
Keyword(s):  
Surface Profile ◽  
Vertical Direction ◽  
External Factors ◽  
Dynamic Loads ◽  
Theoretical Studies ◽  
Bearing Surface ◽  
Supporting Surface ◽  
Oscillation Energy ◽  
Working Bodies ◽  
Oscillatory Processes

Results of theoretical studies of dynamics of the machine-tractor assembly taking into account the influence of a bearing surface profile were presented. It was established that in the course of operation, the machine-tractor assembly is exposed to a number of external factors leading to a change of vertical loads on the chassis and the engine. Mathematical models of dynamics of a tractor and a machine and a tractor unit consisting of a tractor of pivotally connected arrangement and a trailed sower were constructed. Such models make it possible to study dynamics and oscillatory processes of multi-element units. A mathematical model of tractor wheel dynamics was formed. Speeds and angles of orientation of elements of the machine-tractor assembly in space were determined. Influence of profile of the bearing surface on the unit elements when moving in the field prepared for sowing and the field after plowing was calculated. Theoretical studies of the influence of the bearing surface profile on dynamics of the machine-tractor assembly were performed on the example of KhTZ-242K tractor and Vega-8 Profi sower (Ukraine). When moving, the sower frame has a smaller amplitude of vibration accelerations than that of the tractor. Accordingly, the tractor has higher oscillation energy because it rests on the ground through its wheels having appropriate stiffness. The sower moves with its working bodies immersed into the soil which leads to a decrease in the amplitude of oscillations. The highest energy of amplitude of oscillation accelerations of the sower frame in the vertical direction was observed at frequencies of 15.9; 23.44; 35.3 and 42.87 Hz. It was found that the increase in working speeds of agricultural units leads to the fact that oscillations of all components reach significant values. This entails an increase in dynamic loads on soil and, as a consequence, its compaction

Performance Analysis of Grooved Hydrodynamic Journal Bearing with Multi-Depth Textured Surface

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
K.M Faez ◽  
S Hamdavi ◽  
T.V.V.L.N. Rao ◽  
H.H Ya ◽  
Norani M. Mohamed
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Textured Surface ◽  
Plain Bearing ◽  
Bearing Surface ◽  
Grooved Surface ◽  
Hydrodynamic Journal Bearing ◽  
Efficiency And Reliability ◽  
Capacity Performance

In recent research, theoretical studies and investigations for the textured surface of a hydrodynamic journal bearing has been widely used. This is due to the journal bearing’s performance in terms of load capacity which affects the system performance, efficiency and reliability. It has been proven that a textured surface and grooved surface have managed to improve the performance of journal bearings to some extent. In this work, the performance of a grooved hydrodynamic journal bearing has been analysed with a multi-depth textured surface. The study has been conducted using the modified Reynolds equation to numerically solve the load capacity and pressure distribution, respectively. From the results obtained, it was found that the surface complexity features on the journal bearing lowered the load capacity performance when compared to the plain bearing. The pressure, meanwhile, was distributed throughout the textured sections on the bearing surface, even though it was lower as compared to the plain bearing.

A Quantitative Determination of the Damping Behavior of Acrylic Based Interpenetrating Polymer Networks

1986 ◽  
Vol 59 (2) ◽  
pp. 255-262 ◽  
Author(s):  
D. G. Fradkin ◽  
J. N. Foster ◽  
L. H. Sperling ◽  
D. A. Thomas
Keyword(s):  
Mechanical Energy ◽  
Polymer Networks ◽  
Chain Structure ◽  
Temperature Curve ◽  
Interpenetrating Polymer Networks ◽  
Glass Transitions ◽  
First Approximation ◽  
Damping Behavior ◽  
Secondary Transitions

Abstract The damping function, D.F., as derived from the area under the linearE″— temperature curve, expresses the amount of mechanical energy converted to heat per unit volume of material. Sometimes characteristics of the damping behavior of homopolymers and IPN's are more apparent in the linear E″—temperature plot, such as glass transitions and secondary transitions. Decrosslinking and/or annealing the IPN's have no effect on the D.F.'s, although these treatments significantly modify the shape of the E″—temperature curves as a result of molecular and phase rearrangements. Thus, to a first approximation, the area expressed by D.F. is a polymer chain characteristic, depending on the chain structure itself but not on crosslinking and/or annealing.

scholarly journals Load Distribution Behaviour of Bored Pile in Various Soil Formation: Rock Socket in Limestone, Schist and Sandstone

2016 ◽  
Vol 77 (2) ◽  
Author(s):  
Fazela Mustafa ◽  
Yasmin Ashaari ◽  
Aminuddin Baki
Keyword(s):  
Bearing Capacity ◽  
Skin Friction ◽  
Load Distribution ◽  
Soil Formation ◽  
Bearing Surface ◽  
Empirical Methods ◽  
Bored Pile ◽  
Different Types ◽  
Very High ◽  
Distribution Behaviour

Rock socketed bored pile is a solution when the load from the structure is very high and/or accessible bearing surface hasan inadequate bearing capacity. The study is based on instrumented bored pile socketing into different types of rock namely.limestone, schist and sandstone at three sites. The result for three (3) test piles namely PTP1, UTP-1 and TP2 shows most of the load are resisted by friction rather than end bearing at the pile working load. The load apportioned to end bearing at higher loads varies for the three test piles. Comparison of observed mobilised skin friction in the rocks with empirical methods indicates that prediction values from Williams and Pells [1] over design for two out of the three test piles and that by Hovarth [2] are under design for two out of the three test piles.

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