scholarly journals Changes of properties of engine oils diluted with diesel oil under real operating conditions

2018 ◽  
Vol 173 (2) ◽  
pp. 34-40
Author(s):  
Artur WOLAK ◽  
Grzegorz ZAJĄC ◽  
Magdalena ŻÓŁTY
Keyword(s):  
Acid Number ◽  
Operating Conditions ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Oil Viscosity ◽  
Engine Operation ◽  
Dpf Regeneration ◽  
Total Base ◽  
Regeneration Cycle ◽  
Unburned Fuel

The aim of the article was to analyze changes in the trends of selected physical, chemical and functional properties of lubricating engine oil operating in a diesel-engine vehicle equipped with DPF. The vehicle was operated mainly in urban driving conditions (app. 70%), which impeded the DPF regeneration cycle and caused dilution of oil with unburned fuel. Changes in the following physical and chemical properties were assessed: the DF level in engine oil, viscosity (kinematic, dynamic HTHS and structural CCS), total base num-ber, acid number as well as the degree of oxidation, nitration and sulphonation. The tests have shown that the amount of unburned fuel that goes to the engine crankcase due to the unfinished DPF regeneration cycle is as high as 26.0–34.6%. Dilution of the lubricating oil with fuel leads to a significant reduction of its viscosity – about 30% of the fuel content causes a decrease in the kinematic viscosity measured at 100°C to the level of 7.7 mm2/s. There was also a significant decrease in total base number (TBN) < 2 mg KOH/g, and an increase in the total acid number (TAN). Moreover, the results obtained were analyzed for potential effects that could have been caused during prolonged engine operation by assessing the content of trace elements in the samples taken.

scholarly journals Investigation of Used Engine Oil Lubricating Performance Through Oil Analysis and Friction and Wear Measurements

2019 ◽  
Author(s):  
András Lajos Nagy ◽  
Jan Christopher Knaup ◽  
Ibolya Zsoldos
Keyword(s):  
Service Life ◽  
Friction And Wear ◽  
Boron Content ◽  
Direct Injection ◽  
Acid Number ◽  
Engine Oil ◽  
Base Number ◽  
Total Acid ◽  
Engine Operation ◽  
Total Base

Engine oil degradation during long-term engine operation is a well-researched topic, however, the effect of biofuels and synthetic compounds is not fully understood. In order to characterise novel fuel related phenomena in an engine a basis of studies should be established with state-of-the-art engines and conventional fuels and lubricants. This study aims at describing the behaviour of used engine oils throughout their service life based on friction and wear measurements with oil samples from three identical light-duty direct injection supercharged diesel engines. Oil samples were taken from each engine every 50 hours between oil changes to determine physical properties and chemical composition. Friction and wear measurements were conducted on a high-frequency reciprocating rig. The results show strong correlation between oil service life and boron content, as well as acid number and base number. A similar correlation between coefficient of friction with used samples and boron content as well as soot content was observed. A simple model based on a polynomial fitting function was proposed to predict friction and wear from boron content, total acid number and total base number.

The Influence of Lubricant Supply Conditions and Bearing Configuration on the Performance of (Semi) Floating Ring Bearing Systems for Turbochargers

2017 ◽  
Author(s):  
Luis San Andrés ◽  
Feng Yu ◽  
Kostandin Gjika
Keyword(s):  
Heat Flow ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Engine Oil ◽  
Large Temperature ◽  
Oil Viscosity ◽  
Supply Pressure ◽  
The Impact ◽  
Bearing System

Engine oil lubricated (semi) floating ring bearing (S)FRB systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermo-mechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. On occasion, the selection of one particular bearing parameter to improve a certain performance characteristic could be detrimental to other performance characteristics of a TC system. The paper details a thermohydrodynamic model to predict the hydrodynamic pressure and temperature fields and the distribution of thermal energy flows in the bearing system. The impact of the lubricant supply conditions (pressure and temperature), bearing film clearances, oil supply grooves on the ring ID surface are quantified. Lubricating a (S)FRB with either a low oil temperature or a high supply pressure increases (shear induced) heat flow. A lube high supply pressure or a large clearance allow for more flow through the inner film working towards drawing more heat flow from the hot journal, yet raises the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced much by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat flow from the shaft. The predictive model allows to identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.

Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 2—Lubricating Oil Condition Monitoring

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal
Keyword(s):  
Thermal Stability ◽  
Trace Metal ◽  
Condition Monitoring ◽  
Direct Injection ◽  
Field Testing ◽  
Ash Content ◽  
Operating Conditions ◽  
Lubricating Oil ◽  
Base Number ◽  
Oil Viscosity

Abstract This study investigated the use of biodiesel (B100) and baseline diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel’s compatibility with modern common rail direct injection (CRDI) diesel engines and its effects on lubricating oil degradation and wear. Two identical vehicles were operated for 30,000 km each under identical operating conditions on highway during a field-trial while using biodiesel (B100) and baseline mineral diesel. Exhaustive experimental results from this series of tests were divided into four segments, and this paper covers the second segment showing the effect of long-term usage of biodiesel on the lubricating oil properties and traces of wear metal addition compared to baseline mineral diesel. Lubricating oil samples were drawn periodically from these vehicles for condition monitoring such as lubricating oil viscosity, density, soot content, total base number (TBN), ash content, trace metal concentrations, and thermal stability. The viscosity of lubricating oil samples drawn from biodiesel fueled vehicles were found to be ∼10–15% lower compared to that from diesel-fueled vehicles, whereas density and ash content were relatively lower by ∼5–10%. Carbon residues of lubricating oil samples drawn from B100 fueled vehicles were lower by ∼15–20% compared to that of diesel-fueled vehicles. There was a very strong reduction (∼70%) in the soot content of lubricating oil from biodiesel fueled vehicles. Trace metal analysis to compare wear debris addition was also done for all lubricating oil samples. Thermo-gravimetric analyses of lubricating oil samples from biodiesel fueled vehicles showed lower mass loss with increasing temperature hence relatively higher thermal stability and lower deterioration. Results also suggested that operational and durability issues associated with vegetable oils as alternate fuel were completely eliminated by using them after converting them into biodiesel meeting prevailing biodiesel specifications.

Study on Wear of Piston Rings in Diesel Engines With Exhaust Gas Recirculation

2001 ◽  
Author(s):  
Tokuro Sato ◽  
Hideki Saito ◽  
Koji Korematsu ◽  
Junya Tanaka
Keyword(s):  
Diesel Engines ◽  
Time History ◽  
Acid Number ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Base Number ◽  
Piston Rings ◽  
Total Acid ◽  
Residual Content ◽  
Measured Time

Abstract The wear of piston rings in the diesel engines with EGR system is studied experimentally. In order to clarify the effect of PM on the wear, the wear of the piston rings in the test engine is measured, (1) when the non-soluble in the lubricating oil is removed by the oil filters, (2) when PM in the re-circulating gas is removed by the DPF, (3) when the carbon black is added in the lubricating oil. The experimental results are discussed with the measured time history of kinematic viscosity, total base number, total acid number, ZDTP survival rate, and carbon residual content and its particle size in the engine oil.

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.

Engine Friction Characteristics Under Cold Start Conditions

2001 ◽  
Author(s):  
Paul J. Shayler ◽  
John A. Burrows ◽  
Clive R. Tindle ◽  
Michael Murphy
Keyword(s):  
Fuel Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
Valve Train ◽  
Bulk Temperature ◽  
Oil Viscosity ◽  
Engine Operation ◽  
Warm Up ◽  
Injection Pump ◽  
Engine Friction

Abstract Most studies of engine friction have been carried out at fully-warm operating conditions. Relatively little attention has been given to frictional losses when the engine is running cold, although these can be considerably higher and have a strong influence both on cold-start characteristics and fuel consumption during warm-up. The losses which effect the indicated load on the engine are rubbing losses and loads associated with driving auxiliaries. The equivalent frictional mean effective pressures (fmep) are generally highest during the first seconds of engine operation. These decay rapidly onto a characteristic variation which depends upon oil viscosity, and which fmep follows throughout the warm-up period. The oil viscosity can be evaluated at the bulk temperature of oil in the sump or main gallery. Breakdown motoring tests have been carried out on a series of diesel engines to examine how the friction contribution of various sub-assemblies in the engine contribute to the total and how this varies with temperature and speed. Tests were carried out using a compact cold cell and engine motoring facility. The engine was cold soaked to a target test temperature and then motored to a target speed and the variation of motoring torque recorded. Sets of tests were carried out at several stages of breaking the engine down. This enables the contributions due to the valve train, piston and big end assembly, crankshaft, fuel injection pump, and auxiliary load to be determined.

Measurement of semi-volatiles in used natural gas engine oil using thermogravimetric analysis

2007 ◽  
Vol 8 (5) ◽  
pp. 439-448 ◽  
Author(s):  
G Mullins ◽  
J Truhan
Keyword(s):  
Thermogravimetric Analysis ◽  
Natural Gas ◽  
Combustion Engine ◽  
Inert Atmosphere ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Constant Rate

Semi-volatile in internal combustion engine lubricating oil may be responsible for limiting service life and can lead to in-cylinder deposit formation. In order to measure semivolatile content, a new thermogravimetric analysis (TGA) procedure has been adapted from existing soot procedures to determine the levels of semi-volatile compounds in progressively aged lubricating oil samples from a natural gas engine dynamometer test cell run. The per cent weight remaining at 550 °C, while heated at a constant rate in an inert atmosphere, varied linearly with running time, viscosity, and oxidation and nitration. The method yielded reproducible run-to-run results and showed good agreement between helium and argon atmospheres. Mass spectroscopy data confirmed increased levels of high molecular weight species during engine operation. This method may be applicable to diesel engine oil samples.

On the Influence of Lubricant Supply Conditions and Bearing Configuration to the Performance of (Semi) Floating Ring Bearing Systems for Turbochargers

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Luis San Andrés ◽  
Feng Yu ◽  
Kostandin Gjika
Keyword(s):  
Thermal Energy ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Engine Oil ◽  
Large Temperature ◽  
Oil Viscosity ◽  
Supply Pressure ◽  
Oil Flow ◽  
The Impact ◽  
Bearing System

Engine oil-lubricated (semi) floating ring bearing ((S)FRB) systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermomechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. The paper details a model to predict the pressure and temperature fields and the distribution of thermal energy flows in a bearing system. The impact of lubricant supply conditions, bearing film clearances, and oil supply grooves is quantified. Either a low oil temperature or a high supply pressure increases the generated shear power. Either a high supply pressure or a large clearance allows more flow through the inner film and draws more heat from the hot journal, thought it increases the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat from the shaft. The results identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.

scholarly journals Improvement Viscosity Index of Lubricating Engine Oil Using Low Molecular Weight Compounds

2019 ◽  
Vol 7 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Shenwar A. Idrees ◽  
Lawand L. Mustafa ◽  
Sabah S. Saleem
Keyword(s):  
Polar Solvent ◽  
Viscosity Index ◽  
Temperature Stability ◽  
Polar Molecule ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Oil Viscosity ◽  
Different Temperatures ◽  
London Dispersion ◽  
Molecular Forces

the effect of polarity of solvent on the viscosity and viscosity index of lubricating engine oil has been studied using ethanol as an example of polar solvent and toluene as an example of non-polar solvent at different solvent ratios and ambient temperature and additionally other experiments have been done at five different temperatures including 100 oC. So that, the activation energy of viscous flow (Ea) was calculated, and for this purpose Arrhenius viscosity-temperature dependence has been applied and the results were 42.128, 29.256 and 35.417KJ/mole for lubricating engine oil mixed with ethanol, toluene and no additives in turn. It additionally shows that adding polar solvent to lubrication engine oil viscosity increases this may be due to the fact of strong inter molecular forces that found in polar molecules such as hydrogen bonding in ethanol makes the solution forces stronger as a result higher viscosity. However, adding non-polar solvent decreases viscosity because of small size of toluene and both paraffinic lubricating oil and toluene have same London dispersion inter molecular forces. Last not least, the result shows that engine oil mixed with non-polar molecule gives more temperature stability than that of polar molecule giving viscosity index (VI) 366 and 580 respectively.

On the Effect of Thermal Energy Transport to the Performance of (Semi)Floating Ring Bearing Systems for Automotive Turbochargers

2012 ◽  
Author(s):  
Luis San Andrés ◽  
Vince Barbarie ◽  
Avijit Bhattacharya ◽  
Kostandin Gjika
Keyword(s):  
Heat Flow ◽  
Thermal Energy ◽  
Energy Transport ◽  
Operating Conditions ◽  
Engine Oil ◽  
Distinct Advantage ◽  
Oil Viscosity ◽  
Wide Range ◽  
Thermal Energy Transport ◽  
Bearing System

Bearing systems in engine-oil lubricated turbochargers (TCs) must operate reliably over a wide range of shaft speeds and withstanding severe axial and radial thermal gradients. An engineered thermal management of the energy flows into and out of the bearing system is paramount to ensure the components mechanical integrity and the robustness of the bearing system. The bearings, radial and thrust type, act both as a load bearing and low friction support with the lubricant carrying away a large fraction of the thermal energy generated by rotational drag and the heat flow disposed from a hot shaft. The paper introduces a thermohydrodynamic analysis for prediction of the pressure and temperature fields in a (semi) floating ring bearing system. The analysis solves simultaneously the Reynolds equation with variable oil viscosity and the thermal energy transport equation in the inner and outer films of the bearing system. Flow conditions in both films are coupled to the temperature distribution and heat flow thru the (semi)floating ring. Other constraints include calculating the fluid films’ forces reacting to the externally applied load and to determine the operating journal and ring eccentricities. Predictions of performance for a unique realistic (S)FRB configuration at typical TC operating conditions reveal distinct knowledge: (a) the heat flow from the shaft into the inner film is overwhelming, in particular at the inlet lubricant plane where the temperature difference with the cold oil is largest; (b) the inner film temperature increases quickly as soon as the (cold) lubricant enters the film and due to the large amount of energy generated by shear drag and the heat transfer from the shaft; (c) a floating ring develops a significant radial temperature gradient; (d) at all shaft speeds, low and high, the thermal energy carried away by the lubricant streams is no less that 70% of the total energy input; the rest is conducted through the TC casing. To warrant this thermal energy distribution, enough lubricant flow must be supplied to the bearing system. The efficient computational model offers a distinct advantage over existing lumped parameters thermal models and with no penalty in execution time.

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