The Influence of Temperature and Shear Rate on the Viscosity of Selected Motor Oils

2013 ◽  
Vol 199 ◽  
pp. 188-193 ◽  
Author(s):  
Adam Czaban
Keyword(s):  
Diesel Engine ◽  
Shear Rate ◽  
Sliding Friction ◽  
Full Range ◽  
Lubricating Oil ◽  
Initial Structure ◽  
Oil Viscosity ◽  
Lubricating Oils ◽  
Shear Rates ◽  
Motor Oils

One of the most important physical quantities which has an influence on bearings and micro-bearings functioning is the viscosity of a lubricant. The data about a viscosity value dependence on temperature and shear rate are essential for designing sliding friction pairs. In design calculations usually there is assumed that a lubricant is a Newtonian fluid, therefore viscosity is constant over the full range of shear rates. During operation of friction pairs the contamination particles get into a lubricant and this causes that the lubricant becomes a non-Newtonian pseudoplastic or viscoelastic fluid. A similar effect on lubricating oil properties have combustion products or special performance additives. Furthermore, a lubricating oil ages and wears out, i.e. during its operating the initial structure of a particles is destroyed which can cause the change of the oil viscosity and lubricity values. The aim of this work is to determine the dynamic viscosity values in dependence on temperature and shear rate for selected new and used lubricating oils. In this research motor oils for passenger vehicles and tractors were investigated. This paper presents the results of measurements of the viscosity changes, in dependence on shear rate and temperature, made for the new and used oils. One of the investigated oils is Superol CC-40, which was used in four-stroke 4562 cm3 diesel engine for twenty months, which corresponds to 250 hours of operating. The second of investigated oils is Shell Helix Ultra AV-L which was used in four-stroke 2000 cm3 diesel engine for ten months at a distance of 15 000 kilometers. The viscosity measurements for the new and used lubricating oils were made with the Thermo Scientific Haake Mars III rheometer, in the range of temperatures from 10°C to 120°C and of shear rates to 51000 1/s. Moreover, the analysis of wear products, contaminants and additives in the investigated new and used lubricating oils was made with the rotating disc electrode atomic emission spectrometer Spectro Incorporated Spectroil Q100, which gives possibility to determine 22 most common elements which occur in motor, turbine and gear oils. The obtained information will be used in future studies related to hydrodynamic lubrication of slide bearings and micro-bearings. It also may be useful for designing bearings and sliding friction pairs.

Viscosity in Exploitation Time Analysis of the Lubricating Oil Used in the Combustion Engine of the Personal Car

2015 ◽  
Vol 220-221 ◽  
pp. 271-276 ◽  
Author(s):  
Grzegorz Sikora ◽  
Andrzej Miszczak
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Combustion Engine ◽  
High Shear Rate ◽  
Engine Oil ◽  
Lubricating Oil ◽  
High Shear ◽  
Oil Viscosity ◽  
Peltier Element ◽  
Engine Model

The aim of this study is to develop a mathematical model of the lubricating oil viscosity changes during the exploitation time of the engine.The aim was achieved by measurements of dynamic viscosity of engine oil used in a passenger car Volkswagen Touran equipped with a turbocharged diesel engine with a capacity of 2.0 liters. The recommended interval for oil change in this engine model is 30000 km. Oil used in this study was Shell Helix AV-L (viscosity grade SAE 5W30, designation VW: 50700).Viscosity tests were made on a Haake MARS III using two measuring systems. The first consisted of a plate-cone system with Peltier element for temperature stabilization. The second one is the high shear rate chamber with temperature control thermostat co-operating with ultra-A40 AC200 which can operate at temperatures ranging from-40 °C to +200 °C. The high shear rate chamber, consisting of a measuring cylinder and the rotor, the shear rate can achieve up to 200000 s–1.Dynamic viscosity measurements were performed at temperatures ranging from 20 °C to 90 °C.The results of the research are shown in the graphs and in tabular form. Obtained graphs made it possible to determine characteristics of the oil ageing for each mileages, temperatures and shear rates.

scholarly journals Viscosity and biodiesel characteristics of wild Canarium schweinfurthii Engl. fruit oil  

2018 ◽  
Vol 64 (No. 4) ◽  
pp. 169-175
Author(s):  
Ehiem James Chinaka
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Medical Model ◽  
Temperature Stability ◽  
Oil Viscosity ◽  
Shear Rates ◽  
Flow Behaviour Index ◽  
Different Temperatures ◽  
Fruit Oil ◽  
Behaviour Index

The viscosity of two varieties of Canarium schweinfurthiiEngl. fruits oil (large and long) were studied at four different temperatures (30, 40, 50 and 60<sup>o</sup>C) and three shear rates (7.91, 15.82 and 39.54 s<sup>–1</sup>). SurgiFriend Medical (model NDJ-5S) viscometer was used to carry out the study. Biodiesel characteristics of the oil were also investigated. The results showed that variety had no effect (P &lt; 0.05) on the viscosity of Canarium schweinfurthii Engl. fruit while temperature had especially at 50<sup>o</sup>C and above. The shear rate of 15.82 s<sup>–1 </sup>(12 rps) gave the lowest oil viscosity for both varieties. The oil from large fruit had the best temperature stability, low percentage viscosity (6.33%) variation and least activation energy (796.51 J·mol<sup>–1</sup>·K<sup>–1</sup>) while long variety had best biodiesel characteristic for safe handling. Temperature had no significant (P &lt; 0.05) effect on the consistency coefficient (C) and flow behaviour index (n) of both varieties of Canarium schweinfurthii Engl. fruits oil. Besides, oil from both fruit varieties is Newtonian fluids.

The Selection of Lubricating Oils for Industrial Plant: The User's Point of View

1973 ◽  
Vol 187 (1) ◽  
pp. 493-500
Author(s):  
D. Summers-Smith
Keyword(s):  
Point Of View ◽  
Lubricating Oil ◽  
Industrial Plant ◽  
Oil Viscosity ◽  
Industrial Plants ◽  
Lubricating Oils ◽  
Oil Additives ◽  
Lubricating Oil Additives ◽  
Selection Of

It is shown that a small number of oil viscosity grades should satisfy the lubrication requirements of most industrial plants. Problems with lubricating oil additives are discussed and it is concluded that such materials should only be used where proven essential.

scholarly journals Fractal theory of non-Newtonian oil viscosity based on the mutual interaction of colloidal particles: a review and new results

2021 ◽  
pp. 26-46
Author(s):  
V.I. Lesin
Keyword(s):  
Shear Rate ◽  
Physical Model ◽  
Colloidal Particles ◽  
Fractal Structure ◽  
Fractal Theory ◽  
Experimental Studies ◽  
Oil Viscosity ◽  
Shear Rates ◽  
Model Sample ◽  
Individual Particles

To describe the viscosity of oil, the author proposed a theory based on a new physical model, which takes into account the interaction of individual colloidal particles and their aggregates of fractal structure. This process is accompanied by the addition of individual particles to aggregates and by their separation under the action of shear stress, which is reflected in the energy consumption of the fluid movement and manifests itself as a dependence of the viscosity on the shear rate. The purpose of the review is to demonstrate the application of fractal viscosity theory to interpret the results of known experimental studies. The review also contains the results of new experimental studies of a model sample of oil to illustrate a number of statements of the theory. The detailed parameters of the physical model are specified, on the basis of which a fractal theory of viscosity is proposed; a system of two equations is obtained that allows to describe the dependence of viscosity on the shear rate and time. It is demonstrated that the conclusions drawn from the theory correspond to the known and newly obtained experimental data. The regularities of viscosity relaxation predicted experimentally by the theory with increasing and decreasing shear rates are confirmed. A methodology based on the laws of thermodynamics is proposed that allows to select the mode of shear rate action on heavy oil to reduce its viscosity.

Analysis of Oil Film Thickness and Heat Transfer on a Piston Ring of a Diesel Engine: Effect of Lubricant Viscosity

2002 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Shear Rate ◽  
Film Thickness ◽  
Piston Ring ◽  
Unsteady State ◽  
Oil Viscosity ◽  
Oil Film ◽  
Higher Temperature ◽  
Lubricant Viscosity

The effect of lubricant viscosity on the temperature and thickness in oil film on a piston ring in a diesel engine was analyzed by using unsteady state thermohydrodynamic lubrication analysis, that is Reynolds equation and an unsteady state two-dimensional (2-D) energy equation with heat generated from viscous dissipation. The oil film viscosity was then estimated by using the mean oil film temperature and the shear rate for multi grade oils. The shear rate between the ring and liner becomes higher, so that the viscosity for the multi grade oil is affected by the oil film temperature and shear rate, and the viscosity becomes lower. Under low temperature condition, the viscosity becomes lower due to viscous heating and shear rate and under higher temperature condition, the viscosity affected by the shear rate becomes lower. The oil film thickness between the ring and liner decreases with decrease of the oil viscosity, and it is the thinnest that the oil film thickness is calculated by using the viscosity estimated by both the shear rate and the oil film temperature. Moreover, the heat transfer at ring and liner surfaces was examined.

The Selection of Lubricating Oils for Industrial Plant: The User's Point of View

1973 ◽  
Vol 187 (1) ◽  
pp. 493-500 ◽  
Author(s):  
D. Summers-Smith
Keyword(s):  
Point Of View ◽  
Lubricating Oil ◽  
Industrial Plant ◽  
Oil Viscosity ◽  
Industrial Plants ◽  
Lubricating Oils ◽  
Oil Additives ◽  
Lubricating Oil Additives ◽  
Selection Of

It is shown that a small number of oil viscosity grades should satisfy the lubrication requirements of most industrial plants. Problems with lubricating oil additives are discussed and it is concluded that such materials should only be used where proven essential.

Implications of Non-Bingham Rheology

2019 ◽  
Author(s):  
Leonard F. Pease ◽  
Judith A. Bamberger ◽  
Michael J. Minette
Keyword(s):  
Experimental Data ◽  
World War Ii ◽  
Shear Rate ◽  
Yield Stress ◽  
Full Range ◽  
Poor Quality ◽  
Department Of Energy ◽  
Glass Waste ◽  
Shear Rates ◽  
Yield Phenomena

Abstract One of the key challenges now facing the US Department of Energy (DOE) is the fate of radioactive waste remaining from World War II and the Cold War, which is stored underground in tanks some 75 feet in diameter and over 30 feet tall. Over time, the waste has segmented into multiple layers with sludges and slurries at the bottom with salt crust layers often at the top and liquid in between. DOE’s current official baseline plans call for remaining sludges and slurries to be removed from the tanks and converted into a stable glass waste form. Minimizing worker exposure to radiation drives DOE to use slurry processing techniques to suspend, mobilize, transport, mix, and process the waste. Therefore, a clear and quantitative understanding of Hanford waste rheology is essential for the success of the DOE mission. Historically much of the waste has been characterized using Eugene Bingham’s century old model that provides a straight line fit to higher shear rate data with the intercept suggesting a yield stress and the slope providing the consistency. Yet, Bingham fits overestimate the shear stress at a given shear rate for low to intermediate shear rates, exactly the range of shear rates typically encountered in pipe flow, where shear rates peak along the pipe wall and vanish in the center. This model produces a fictitious yield stress for some of the wastes that do not exhibit yield phenomena. While overestimating the yield stress may be prudent, safe, and conservative for some applications (e.g., pump sizing to ensure that pumps can handle yield stresses), overestimating the rheology may be inaccurate and non-conservative for other applications (e.g., eroding settled particle beds). Therefore, this paper evaluates the slurry rheology of Hanford and Savannah River wastes using a more modern rheological model that fits the full range of experimental data. Although a bias has been recognized and alternative models proposed, the magnitude of this bias and the implications for tank waste have only been qualitatively suggested. The purpose of this paper is to evaluate quantitatively implications of the poor quality of fit between a Bingham model for rheology and experimental data at modest shear rates. We first demonstrate the magnitude of the bias between the data and the Bingham extrapolation. We then evaluate quantitatively the velocity profile under laminar conditions. This analysis shows that the bias may be large (hundreds of percent or more) at modest shear rates and that modest shear rates dominate pipe velocity profiles.

Lubricating Oil Condition Monitoring Using Vibration and Air-Borne Acoustic Measurements

Volume 3 ◽  
2004 ◽  
Author(s):  
A. Albarbar ◽  
R. Gennish ◽  
F. Gu ◽  
A. Ball
Keyword(s):  
Diesel Engine ◽  
Condition Monitoring ◽  
Frequency Band ◽  
High Reliability ◽  
Fault Detection And Diagnosis ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Oil Viscosity ◽  
Oil Condition Monitoring ◽  
Engine Maintenance

Modern diesel engine maintenance programs incorporate various methods and techniques for early fault detection and diagnosis to maintain efficiency, low pollution and high reliability and to avoid catastrophic failures. This study has been conducted aiming at engine oil condition monitoring and quality evaluation by analysing the engine block vibration and its induced noise. The vibration signals were measured using an accelerometer mounted on the thrust side of the first cylinder in a four cylinder diesel engine, and the noise was recorded using a microphone facing the cylinder. The signals are then band pass filtered and transformed to the frequency domain, where the amplitudes of the different frequency components of the vibration and noise waveforms are analysed and compared to the vibration and noise baseline signatures. The mean amplitudes of the spectral components in the frequency band 900 Hz to 2.5 kHz were found linearly proportional to the engine speed and load. It was also found that the RMS values of this frequency band are affected by the oil viscosity. These results show that it is possible to use vibration and airborne acoustics to predict the quality of lubrication.

Adenosine Diphosphate-Induced Aggregation of Human Platelets in Flow Through Tubes: III. Shear and Extrinsic Fibrinogen-Dependent Effects

1994 ◽  
Vol 71 (01) ◽  
pp. 078-090 ◽  
Author(s):  
H L Goldsmith ◽  
M M Frojmovic ◽  
Susan Braovac ◽  
Fiona McIntosh ◽  
T Wong
Keyword(s):  
Shear Rate ◽  
Single Cells ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Size Analysis ◽  
Fibrinogen Concentration ◽  
Human Fibrinogen ◽  
Shear Rates ◽  
Rate Dependent ◽  
Induced Aggregation

SummaryThe effect of shear rate and fibrinogen concentration on adenosine diphosphate-induced aggregation of suspensions of washed human platelets in Poiseuille flow at 23°C was studied using a previously described double infusion technique and resistive particle counter size analysis (1). Using suspensions of multiple-centrifuged and -washed cells in Tyrodes-albumin [3 × 105 μl−1; (17)] with [fibrinogen] from 0 to 1.2μM, the, rate and extent of aggregation with 0.7 μM ADP in Tyrodes-albumin were measured over a range of mean transit times from 0.2 to 43 s, and at mean tube shear rates, Ḡ, = 41.9, 335 and 1,335 s−1. As measured by the decrease in singlet concentration, aggregation at 1.2 μM fibrinogen increased with increasing Ḡ up to 1,335 s1, in contrast to that previously reported in citratcd plasma, in which aggregation reached a maximum at Ḡ = 335 s−1. Without added fibrinogen, there was no aggregation at Ḡ = 41.9 s1; at Ḡ = 335 s1, there was significant aggregation but with an initial lag time, aggregation increasing further at Ḡ = 1,335 s−1. Without added fibrinogen, aggregation was abolished at all Ḡ upon incubation with the hexapeptide GRGDSP, but was almost unaffected by addition of an F(ab’)2 fragment of an antibody to human fibrinogen. Aggregation in the absence of added fibrinogen was also observed at 37°C. The activation of the multiple-washed platelets was tested using flow cytometry with the fluorescently labelled monoclonal antibodies FITC-PAC1 and FITC-9F9. It was shown that 57% of single cells in unactivated PRT expressed maximal GPIIb-IIIa fibrinogen receptors (MoAb PAC1) and 54% expressed pre-bound fibrinogen (MoAb 9F9), with further increases on ADP activation. However, incubation with GRGDSP and the F(ab’)2 fragment did not inhibit the prebound fibrinogen. Moreover, relatively unactivated cells (8% expressing receptor, 14% prebound fibrinogen), prepared from acidified cPRP by single centrifugation with 50 nM of the stable prostacyclin derivative, ZK 36 374, and resuspension in Tyrodes-albumin at 5 × 104 μl−1, aggregated with 2 and 5 μM ADP at Ḡ = 335 and 1,335 s−1 in the absence of added fibrinogen. We therefore postulate that a protein such as von Willebrand factor, secreted during platelet isolation or in flow at sufficiently high shear rates, may yield the observed shear-rate dependent aggregation without fibrinogen.

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