ABSTRACT A Joint Aircraft Survivability Program (JASP) project was awarded in 2014 in order to accelerate the research and development on military helicopter transmission loss of lubrication survivability. This JASP project, "Helicopter Transmission Loss-of-Lubrication" was a collaboration between the US Army, US Navy, and NASA and completed in 2018. The approach for the effort was to first screen emerging technologies using coupon-level methods, then test those showing the most promise at the component level, and finally to downselect and evaluate these technologies at the system level. Several concepts to reduce heat generation, increase heat rejection, increase material tolerance to higher temperatures, and increase material resistance to damage were evaluated for this effort. Included in this evaluation were: a ceramic material for bearings, four different gear steels, various levels of gear surface roughness, six gear coatings, five lubricant and lubricant additive variations, and gearbox noble gas injection. After gear testing at the component level, isotropic superfinishing and ionic liquid lubricant additive were down selected as the two most suitable technologies for the system level testing. These technologies underwent loss of lubrication testing to failure in an intermediate gearbox from a standard configuration medium lift helicopter. A baseline loss of lubrication test, without these technologies, was also performed for comparison.

Berkebile, Stephen, Colon-Rivera, Radames, Fetty, Jason, Murthy, Nikhil, Radil, Kevin, Dykas, Brian

An Experimental Investigation of Tribological Performance of a Lubricant Using Different Nano Additives

2018-01-08334/3/2018

A novel solution to anti wear-additives is to add relatively small amounts of effective Nano Additives to the main content of lubricants. Such supplement would offer an enhancement to their tribological and thermal properties as wear resistance and friction surface temperature. In this work, different types of Nano additives are used to investigate their effect on the tribological properties of a certain lubricant (TOTAL FLUIDE AT42). Three main Nano additive materials were used with two different concentration for each; Gamma aluminum oxide (Alumina Al2O3), Copper Oxide (CuO) and one-dimensional carbon Nano tubes (CNT). A pin on disc equipment fitted out with circulated lubricant system was operated for 140 hours with normal lubricant, and for 140 hours for each case of the three Nano additives, with a total working time of 980 hours. Weight loss of the pin, friction surface temperature and friction force were measured every 20 working hours. Results showed that there is an improvement in lubricant properties especially in the case of Copper oxide Nano additives, which had decreased the average weight loss of the pin and friction force by 60.83% and 33.06% respectively. Also, a remarkable decrease in friction surface temperature was achieved for all cases of nano additives.

Akl, Sayed Y., Abdel-Rehim, Ahmed A., Elsoudy, Sherif

Steric Effects on Tribochemical Reactivity in Detergent-Containing Lubricants under Nanoconfinement

2017-01-234710/8/2017

Modern formulation in a wide variety of lubricants including engine oils and transmission fluids is designed to control friction through film-forming tribochemical reactions induced by the functional additives mixtures. Although many cases on the synergistic or antagonistic effects of additives on friction have been reported, their mechanisms are poorly understood. This study focused on the influences of metallic detergents on tribochemical reactions. We examined the mechanical properties of detergent-containing lubricants confined at a single-asperity contact and their contributions to tribochemical phenomena. We found that detergents enlarged the confinement space required for generating repulsive force and shear resistance. This means that these detergents provide steric effects under nanoconfinement at interfacial contacts. These detergents reduced friction synergistically with molybdenum dithiocarbamate (MoDTC), which is a widely used friction modifier additive that forms a slippery tribofilm. When detergents and MoDTC were mixed together in lubricants, their friction coefficient was very well correlated with the steric size. The steric size was similar to the spatial particle size of detergents measured by dynamic light scattering experiments. This suggested that steric effects were based on mechanical interference between contacting surfaces. We also found a correlation between steric size and synergy with MoDTC on non-detergent nanoparticles in the same way as detergents. These results led us to the conclusion that tribochemical reactivity of the lubricants containing detergents and MoDTC was enhanced by the steric effects under nanoconfinement. We consider that the microscopic friction between nanoparticles and solid surfaces helps MoDTC receive frictional energy to form slippery tribofilms, resulting in a synergistic reduction in friction. Such concept based on steric effects may be applicable to control many other tribochemical reactions.

Tamura, Kazushi, Sunahara, Kenji, Ishikawa, Motoharu, Mizukami, Masashi, Kurihara, Kazue

Effects of Lubricant Additives on Auto-Ignition under a Hot Co-Flow Atmosphere

2017-01-223110/8/2017

Pre-ignition may lead to an extreme knock (super-knock or mega-knock) which will impose a severe negative influence on the engine performance and service life, thus limiting the development of downsizing gasoline direct injection (GDI) engine. More and more studies reveal that the auto-ignition of lubricants is the potential source for pre-ignition. However, pre-ignition is complicated to study on the engine test bench. In this paper, a convenient test method is applied to investigate the influence of lubricants metal-additives on pre-ignition. 8 groups of lubricants are injected into a hot co-flow atmosphere which generated by a burner. A single-hole nozzle injector with a diameter of 0.2 mm at 20 MPa injection pressure is utilized for lubricants' injection and spray atomization. The ignition delays of lubricants with different additives of calcium, ZDDP (Zinc Dialkyl Dithiophosphates) and magnesium content under the hot co-flow atmosphere are recorded with a high-speed camera. The experiments are carried out at one atmospheric pressure and the co-flow temperature varies from 1123 K to 1223 K. The result shows that the ignition delays of lubricants decline sharply with the increase of co-flow temperature in the whole temperature range. There is one critical temperature about 1173K in this study. Under this temperature, effects of calcium content on the auto-ignition delay are significant; over this temperature, its effect is much smaller and almost no difference. Lubricants with higher content of ZDDP present a longer ignition delay over the entire temperature range. And the experimental result also indicates that the ignition delay is not sensitive to the magnesium content.

Chen, Yongquan, Li, Liguang, Zhang, Qing, Deng, Jun, Xie, Wei, Zhang, Erbao, Tong, Sunyu

Long Life Engine Oil in China

2017-01-235210/8/2017

Fuel economy, Emission regulation and extended oil drain intervals (ODI) are the three key driving forces for engine oil development. More and more attentions have been focused on long ODI diesel engine oil both from the domestic OEMs and oil suppliers, and the ODI was being periodically improved from a normal mileage of about 1×104 kilometers to 6/8/10×104 km or even 12×104 km just within several years on China market. Lots and lots of factors may affect the oil life including oil properties, engine technologies, after-treatment devices and engine working conditions and so on. While from the oil side, the main factors contribute to the oil drain intervals may be the oil nitration and oxidation, soot contamination, base number deterioration and sludge accumulation and etc. There are two strategies to extend the oil longevity applied currently. One is the use of slow-release lubricant additives filters, in which the additives are incorporated into the oil filters, which slowly release it into the oil at elevated engine temperatures. The main additives used were Base Number (BN) promoters and anti-oxidation (AO) reinforcements. The other way is to improve the oil performance with elaborating formula technologies to provide support for extension of engine oil drain intervals. Use of super base stocks and advanced additive system specifically tailored for ODI ensures its excellent performance all through the service life. At drain intervals up to several times those normally recommended, excellent engine wear, good TBN retention, oil-thickening and sludge control have been demonstrated the extension of oil drain intervals has no significant negative impact on engine durability. An example of one such long oil-drain-interval oil is given.

Liu, Gongde, Wang, Li, Zhang, Runxiang, Yang, Chao, Shao, Tengfei

Extensional Rheology: New Dimension of Characterizing Automotive Fluids

2017-01-03643/28/2017

This paper describes the basic principles of extensional rheometry, and the successful application to a variety of automotive fluids, including gear lubricants, paints, and forming lubricants. These fluids are used under very complex flow fields containing strong extensional (elongational) components. While exact derivation of extensional viscosities involves sophisticated theories, the measurement of liquid filament break-up time can provide fruitful information. Gear lubes showed different break-up time according to the kinematic viscosities. Addition of viscosity modifier (acrylic copolymer) significantly increased the breakup time, whereas surfactants had little effect. Clearcoat paint sample increased the breakup time, perhaps due to the deterioration. The waxy stamping lubricant showed remarkable change in the extensional properties as the temperature is raised. The extensional data obtained showed the promise of the technique to understand the performance of these fluids in working conditions (e.g. spraying, coating, and stamping).

Ohtani, Hiroko, Ellwood, Kevin, Pereira, Gustavo, Chinen, Thiago, Selvasekar, Siddharthan

Experimental Investigation on the Influence of Engine Oil Additives on Silicone Rubber

2017-01-08773/28/2017

In developing engine oils, it is crucial to consider their compatibility with the rubbers used for seals. Among the different seal rubbers, silicone rubber is particularly susceptible to attack by acids and bases, which means it would be more likely to be affected by certain engine oil additives. In this study, the effects of some major additives, namely detergents, zinc dialkyl-dithiophopshate (ZDDP) and molybdenum dithiocarbamate (MoDTC), on silicone rubber were investigated. Silicone rubber test specimens were immersed in sample oils containing these additives for a prescribed period at 150°C, then the physical properties of the test specimens were measured to compare the effects of the different additives. It was found that ZDDPs dramatically reduce the tensile strength of silicone rubber, with primary ZDDP having a greater effect than secondary ZDDP. Analyses of the test specimens by means of Fourier Transform Infrared Spectroscopy (FT-IR) revealed that the silicone rubbers had degraded, causing changes in the polymer structure. The test specimen immersed in sample oil containing primary ZDDP was degraded to a deeper section than that immersed in secondary-ZDDP-containing oil. This may be because primary ZDDP reduces tensile strength more than secondary ZDDP. In addition, analyses of the sample oils were conducted in order to determine which of the ZDDP-derived species were degrading the silicone rubber. The phosphorus compounds in the sample oils after immersion were identified by means of 31P NMR. When silicone rubber specimens were immersed in sample oils containing these phosphorus compounds, it was found that acidic phosphorus compounds, such as alkyl acid phosphate and phosphorothioate, had major effects. It would appear that these are the compounds which degrade the silicone rubber. Silicone rubber specimens were also immersed in test oils containing a detergent together with ZDDP or an acidic phosphorus compound. In these cases, the drop in tensile strength of the silicone rubber was much smaller. The reason may be that the overbased salt in the detergent neutralizes the acidic phosphorus compound to help prevent degradation of the silicone polymer.

Yoshimura, Kenichi, Kunieda, Kenichi, Suzuki, Nozomu, Kusuhara, Shintaro, Matsuki, Shingo, Shitara, Yuji

HARD, SLICK AND READY TO ROLL

17AUTP03_033/1/2017

A tough, self-renewing catalyst coating developed at Argonne National Laboratory provides unprecedented friction and wear protection for vehicle powertrains, the inventors claim. Powertrain system engineers know that of the energy consumed in transportation, 10% to 15% is lost due to parasitics in engines and drivelines. Researchers at Argonne National Laboratory have developed a new breed of nanocomposite coatings, which are made of the nitrides of transition metals and metal catalysts. These coatings provide a catalytically active, hard, and slick surface on metal components. They could have a major impact on improving the efficiency of automotive engines and gearboxes. Transportation vehicles account for about 19% of annual world energy consumption and approximately 23% of total greenhouse gas emissions. With the global vehicle parc steadily growing, these numbers will likewise swell and present serious challenges for a sustainable mobility future. The new nanocomposite coatings also can work in concert with engine start-stop, downspeeding and cylinder-deactivation systems to further reduce vehicle fuel consumption.

Erdemir, Ali

Optimizing engine oil warm-up strategies for ‘real-world’ driving

16AUTP11_0611/1/2016

Optimizing engines for the new era of ‘real-world’ driving cycles will require new lubrication strategies-fast warm-up being a particular area of focus. A recent U.K. government survey showed that the average car journey time has fallen to only 22 minutes and average distance to 12 km (7.5 m), most of it in urban areas. And such extreme duty cycles are increasingly typical in other global regions. They emphasize rapid warm-up for reducing emissions and fuel consumption, faster cabin heating and reduced maintenance. But the contribution to warm-up time due to heating the oil within the engine is often under-estimated, experts note.

Birch, Stuart

Electrical Conductivity of New and Used Automatic Transmission Fluids

2016-01-220510/17/2016

Hybrid drivetrain hardware combines an electric motor and a transmission, gear box, or hydraulic unit. With many hybrid electric vehicle (HEV) hardware designs the transmission fluid is in contact with the electric motor. Some OEMs and tier suppliers have concerns about the electrical properties of automatic transmission fluids (ATFs). Lubrizol has conducted a fundamental research project to better understand the electrical conductivity of ATFs. In this paper, we will present conductivity data as a function of temperature for a range of commercially available ATFs. All fluids had conductivities ranging from 0.9 to 8x10-9 S/cm at 100 °C and can be considered insulators with the ability to dissipate static charge. Next we will deconstruct one ATF to show the relative impact of the various classes of lubricant additives. We find that more polar additives have a larger effect on conductivity on a normalized (per weight %) basis. Finally, we will show conductivity data for ATFs taken from field trial vehicles and present data to demonstrate that the increase in conductivity is due to oil oxidation and a reduction in viscosity, not the presence of metallic wear particles or dissolved metals.

McFadden, Chris, Hughes, Kevin, Raser, Lydia, Newcomb, Timothy

Engine Oil Additive Impacts on Low Speed Pre-Ignition

2016-01-227710/17/2016

Low speed pre-ignition (LSPI) is an undesirable combustion phenomenon that limits the fuel economy, drivability, emissions and durability performance of modern turbocharged engines. Because of the potential to catastrophically damage an engine after only a single pre-ignition event, the ability to reduce LSPI frequency has grown in importance over the last several years. This is evident in the significant increase in industry publications. It became apparent that certain engine oil components impact the frequency of LSPI events when evaluated in engine tests, notably calcium detergent, molybdenum and phosphorus. However, a close examination of the impact of other formulation additives is lacking. A systematic evaluation of the impact of the detergent package, including single-metal and bimetal detergent systems, ashless and ash-containing additives has been undertaken using a GM 2.0L Ecotec engine installed on a conventional engine dynamometer test stand. Consistent with previous reports, the detergent system was found to have the largest impact on LSPI frequency. Furthermore, once a balanced detergent system was identified and its LSPI impact was minimized, the effect of other additives, ash-containing as well as ashless, became apparent. In order to develop a robust additive package that maintains performance in critical bench and engine tests while offering optimal LSPI protection, consideration must be given to the impact of all lubricant additives not simply the detergent type and treat rate.

Fletcher, Kristin A., Dingwell, Lisa, Yang, Kongsheng, Lam, William Y., Styer, Jeremy P.

Physicochemical Mechanisms for Fluoroelastomer Seal Failures

2016-01-227210/17/2016

Elastomer compatibility is an important property of lubricants. When seals degrade oil leakages may occur, which is a cause of concern for original equipment manufacturers (OEMs) because of warranty claims. Leakage is also a concern for environmental reasons. Most often, the mechanical properties and fitting of the oil seals is identified as the source of failure, but there are cases where the interaction between the lubricant and the seal material can be implicated. The performance of seal materials in tensile testing is a required method that must be passed in order to qualify lubricant additive packages. We conducted an extensive study of the interactions between these elastomeric materials and lubricant additive components, and their behavior over time. The physicochemical mechanisms that occur to cause seal failures will be discussed.

Bennett, Carl, Bell, Jason, Guevremont, Jeffrey

Acid Neutralization and Engine Hardware Corrosion Protection through Heavy-Duty Diesel Lubricant Additive Chemistry

2016-01-231810/17/2016

One of the primary functions of modern heavy duty diesel (HDD) lubricants is to protect the engine against corrosion, which is typically accomplished by additives providing alkaline material, commonly represented as total base number (TBN). The majority of the TBN in HDD lubricants comes from ash-containing over-based detergents, with various metallic base and soap chemistries. In this publication, we discuss several overbased detergents and their efficacy in acid neutralization, as well as the resulting impact on corrosion protection. The performance differences are compared in a number of stationary API CJ-4 and CK-4 HDD engine screener tests. Furthermore, these results are confirmed with field trial data, including a comparison of CJ-4 oils with the upcoming API FA-4/CK-4 oils. The selection of overbased detergent type provides varying levels of acid neutralization and corrosion protection. Within a constrained sulfated-ash environment, TBN can be maximized via the use of magnesium-based detergents. In fact, the use of magnesium and salicylate chemistries provide the optimum performance, thus enabling improved extended protection over the lubricant’s life in the field for FA-4/CK-4 oils.

Lin, Wangkan, Diggs, Nancy, Frampton, Catherine

Advanced Lubrication - Enabling and Protecting Turbocharged, Direct Injection Gasoline Engines for Optimum Efficiency

2016-01-227510/17/2016

There has been a global technology convergence by engine manufacturers as they strive to meet or exceed the ever-increasing fuel economy mandates that are intended to mitigate the trend in global warming associated with CO2 emissions. While turbocharging and direct-injection gasoline technologies are not new, when combined they create the opportunity for substantial increase in power output at lower engine speeds. Higher output at lower engine speeds is inherently more efficient, and this leads engine designers in the direction of overall smaller engines. Lubricants optimized for older engines may not have the expected level of durability with more operating time being spent at higher specific output levels. Additionally, a phenomenon that is called low-speed pre-ignition has become more prevalent with these engines. While more pre-ignition may be expected with highly-boosted engines, an especially destructive version of this has been found to be related to some of the essential compounds that comprise the lubricant additive package. Newly introduced OEM specifications have been designed to anticipate the needs of these downsized, down-speeded, turbocharged direct injection engines. New areas of protection include: low speed pre-ignition, enhanced protection against turbocharger deposits, and timing chain wear. Since lubricants must still protect and enable many other items associated with durability like sludge, piston deposits, wear, and resistance to oxidation, we discuss a holistic formulation strategy that ensures a maximum level of engine protection and oil durability to enable the highest degree of fuel economy.

Yang, Kongsheng, Fletcher, Kristin A., Styer, Jeremy P., Lam, William Y., Guinther, Gregory H.

Research on the Effect of Lubricant Oil and Fuel Properties on LSPI Occurrence in Boosted S. I. Engines

2016-01-229210/17/2016

The effects of lubricant oil and fuel properties on low speed pre-ignition (LSPI) occurrence in boosted S.I. engines were experimentally evaluated with multi-cylinder engine and de-correlated oil and fuel matrices. Further, the auto-ignitability of fuel spray droplets and evaporated homogeneous fuel/oil mixtures were evaluated in a combustion bomb and pressure differential scanning calorimetry (PDSC) tests to analyze the fundamental ignition process. The work investigated the effect of engine conditions, fuel volatility and various lubricant additives on LSPI occurrence. The results support the validity of aspects of the LSPI mechanism hypothesis based on the phenomenon of droplets of lubricant oil/fuel mixture (caused by adhesion of fuel spray on the liner wall) flying into the chamber and autoigniting before spark ignition. Combustion bomb experiments confirmed that lubricant oil sprays have higher auto-ignitability than gasoline fuel components, and no particular effects of lubricant additives on ignitability were observed. However, under the conditions of the PDSC test, it was shown that the oxidative stability of fuel/oil mixtures is lower as the fuel/oil ratio is increased, and higher levels of calcium lubricant additives can bestow enhanced oxidation stability on some mixtures. These results indicate that calcium may promote autoignition during combustion under preheated and premixed mixture conditions, even though it plays an active role in preventing liquid phase oxidation. From this analysis, it is hypothesized that in real engines, certain lubricant additives, initially preheated by the autoignition of oil derived droplets, may give a greater propensity for subsequent flame propagation and abnormal combustion phenomena.

Kassai, Masaharu, Torii, Ken, Shiraishi, Taisuke, Noda, Toru, Goh, Tor Kit, Wilbrand, Karsten, Wakefield, Shaun, Healy, Adam, Doyle, David, Cracknell, Roger, Shibuya, Masahiko

Characteristics of Lubricants on Auto-ignition under Controllable Active Thermo-Atmosphere

2016-01-08894/5/2016

Downsizing gasoline direct injection engine with turbo boost technology is the main trend for gasoline engine. However, with engine downsizing and ever increasing of power output, a new abnormal phenomenon, known as pre-ignition or super knock, occurs in turbocharged engines. Pre-ignition will cause very high in-cylinder pressure and high oscillations. In some circumstances, one cycle of severe pre-ignition may damage the piston or spark plug, which has a severe influence on engine performance and service life. So pre-ignition has raised lots of attention in both industry and academic society. More and more studies reveal that the auto-ignition of lubricants is the potential source for pre-ignition. The auto-ignition characteristics of different lubricants are studied. This paper focuses on the ignition delay of different lubricants in Controllable Active Thermo-Atmosphere (CATA) combustion system. In this study, many tests were conducted in the CATA combustion system .The result of tests shows that with the increase of the temperature, the ignition delay of the oil decrease obviously. And the results of tests show that with the increase of the kinematic viscosity, the ignition delay increase. But with the increase of the calcium content, the ignition delay decrease drastically. And the evaporation loss has almost no influence on the ignition delay of the oil. Different lubricants have different auto-ignition characteristics, which may influence the pre-ignition frequency in gasoline engine. The Controllable Active Thermo-Atmosphere (CATA) is proved to be an effective facility to study the auto-ignition characteristics of lubricants.

Fan, Chuang, Tong, Sunyu, Xu, Xiaohong, Li, Jing, He, Xiao Yu, Deng, Jun, Li, Liguang

Methods for Rating the Viscosity-Temperature Behavior of Polymer-Containing Lubricants

2015-01-20489/1/2015

The Viscosity Index (VI, ASTM D2270) has a long and widespread history as a rating scale for the viscosity-temperature behavior of lubricants. However, the method has serious technical deficiencies which can lead to misleading conclusions. We have examined alternatives to the VI scale in an effort to more accurately characterize the viscometric behavior of modern lubricants, which are formulated with highly refined base oils and advanced polymers. We have found that the VI method can actually mask improved viscosity-temperature behavior for certain highly additized polymer-containing lubricants. We examine two different methods, the Roelands Slope Index and the Proportional VI, as an alternative to VI. It is important for lubricant developers and consumers to be aware of the limitations of the VI scale in describing the viscometric qualities of modern, high performance lubricants.

Zakarian, Jack, Webb, Michael E., Hunter, Brett

Effects on Tribology Performance of a Reducing Additive for Automobile Lubricant

2015-01-20479/1/2015

We developed a unique reducing additive composed primarily of polyolester, diester, and vegetable oil-based ester compounds in order to switch from boundary to fluid lubrication and improve tribology performance, and chemically and experimentally investigated its effects on tribology performance. To confirm the lubrication effects of this reducing additive, we added it to oil and chemically investigated the cleaning and dissolving of the ultra-fine particle layer of contaminants, etc., adhering to lubrication pathways and sliding surfaces, and performed commercialization testing using actual vehicles. We found that this additive washed away and dissolved sludge, varnish, and other contaminants from lubricated surfaces, improving their lubrication properties and their tribology performance by reducing abrasion and friction.

Satonaga, Noriaki, Watanabe, Takashi

Oxidation Stability Study of Biobased Lubricant Basestocks

2015-01-20469/1/2015

One of the concerns for biolubricants is the improvement of their oxidation resistance. In this paper the oxidative behavior of seven different types of biobased lubricants basestocks is examined. The aim was to study their relative oxidation stability and also to investigate their response to various antioxidants. The renewable lubricants were treated with four antioxidant additives at a concentration of 0.5% wt. and a comparative assessments of the latters' effectiveness in suppressing the oxidation rate was carried out. Alterations in the acid value were examined as well as relative changes of the oxidized samples by FTIR spectroscopy. The oxidation stability was assessed by employing a Rapid Small Scale Oxidation Test (RSSOT) apparatus according to the accelerated oxidation stability standard method ASTM D7545/EN16091. RSSOT is a relatively new method and thus the behaviour of biobased lubricants and antioxidant agents in this accelerated method has not been thoroughly examined.

Dodos, George S., Anastopoulos, George, Zannikos, Fanourios E., Lois, Evripidis

A Study on the Effect of Zn- and Mo-Based Engine Oil Additives on Abnormal SI Engine Combustion using In-Cylinder Combustion Visualization

2014-32-009611/11/2014

Spontaneous low-speed pre-ignition, strong knock and other abnormal combustion events that occur in supercharged direct-injection engines are viewed as serious issues. The effects of the engine oil and the components of engine oil additives have been pointed out as one cause of such abnormal combustion. However, the mechanisms involved have yet to be elucidated, and it is unclear how the individual components of engine oil additives influence autoignition. This study investigated the effect on autoignition of boundary lubricant additives that are mixed into the engine oil for the purpose of forming a lubricant film on metal surfaces. A high-speed camera was used to photograph and visualize combustion through an optical access window provided in the combustion chamber of the four-stroke naturally aspirated side-valve test engine. Spectroscopic measurements were also made simultaneously to investigate the characteristics of abnormal combustion in detail. We mixed Zinc additive into primary reference fuel (PRF50) at zinc concentration of 115 ppm, 570 ppm and 800 ppm. In addition, we mixed Molybdenum additive into PRF 50 at molybdenum concentration of 140 ppm, 700 ppm and 980 ppm. Combustion experiments were conducted in this condition. The experimental results revealed that both the Zinc and Molybdenum additives had little effect on abnormal combustion.

Hayakawa, Norikuni, Miura, Kenta, Miyasaka, Tomomi, Ishino, Takashi, Iijima, Akira, Shoji, Hideo, Tamura, Kazushi, Utaka, Toshimasa, Kamano, Hideki

Tribological Properties of Automotive Lubricant SAE 20W-40 Containing Nano-Al ₂ O ₃ particles

2014-01-278110/13/2014

The need for advanced lubricants is increasing rapidly due to the current wide range of operational usage, i.e., high loads and speeds of motion between friction pairs, broader temperature range, and the overall requirements for increased reliability and service life of machinery. It is essentially important to develop specialized anti-friction and anti-wear materials that will help in preventing wear and decreasing friction, thereby saving fuel and electricity. Simultaneously, such materials are also expected to reduce vibration, noise and maintenance of machine parts. Thus, the research into extending the service life of such materials continues to be imperative. Nanoparticles (NPs) present a novel approach in this regard, as they can be used in lubricants in between two mating contact surfaces as a third body. When compared with the widely used conventional micro-particles for tribological applications, NPs have unique features owing primarily to their much higher specific surface area. This is true for studies of both nanostructured coatings of friction surfaces as well as for new lubricant compositions containing Nanoparticles. When compared to a pure fluid, this category of fluids containing nanoparticles (1-100 nm) has displayed fascinating behavior during experiments including augmented heat transfer coefficient and higher thermal conductivity. The products so developed can find applications in metal working fluids, industrial gear oils, and automotive gear lubricants, either alone or in formulations. Present research investigates the influence of NPs as lubricant additive on the relative motion of a plane surface over the other having circular surface in contact. A pin-on-disk setup as per ASTM G99 has been used to conduct the experiments in starved and fully flooded conditions at various loads and relative speeds at the pin and disc contact. The lubricant SAE 20W-40 with nano-additives has been used to study the influence on friction and specific wear rate at the interface. Based on the experiments, tribological behavior of lubricant with NPs has been compared with the lubricant without NPs. The coefficient of friction and specific wear rate were found to be decreased in lubricant containing NPs. The addition of NPs to the lubricant SAE 20W40 has proved to be profoundly promising in reducing the friction and specific wear rate.

Mohan, Nishant, Sharma, Mayank, Singh, Ramesh, Kumar, Naveen

Minimizing Diesel Particulate Filter Incombustibles by Using Ultra Low Ash - Zero Phosphorus Oil

2014-01-279810/13/2014

Due to engine oil consumption, over 90% of the incombustibles in the diesel particulate filters (DPF) are derived from organometallic lubricant additives. These components are derived from calcium and magnesium detergents, zinc dithiophosphates (ZnDTP) and metal-containing oxidation inhibitors. They do not regenerate as they are non-volatile metals and salts. Consequently, the DPF has to be removed from the vehicle for cleaning. Ashless oil could eliminate the need for cleaning. This study initially focused on development of an ashless oil, but eventually concluded that this oil could not meet the valve-train wear requirements of the API CJ-4, SN/ACEA E9 oil categories. However, a zero-phosphorus oil with no ZnDTP and an extremely low sulfated ash of 0.4% demonstrated that it could meet critical engine tests in API CJ-4/ACEA/SN. The above oil, which has been optimized at 0.3% sulfated ash, has proven field performance in Cummins ISX with DPF using ultra low sulfur diesel (ULSD). This was verified by engine inspections and used oil analysis at 60,000 miles (97,000 km) oil drains. DPF cleaning determined at 95% confidence level that the 0.3% ash oil produced less incombustibles than a 1.0% ash API CJ-4 oil. Reducing the engine oil's ash by 70% resulted in a 78% reduction in DPF incombustibles. Consequently, the 0.3% ash oil will minimize DPF maintenance while also providing engine durability.

McGeehan, James A., Van Dam, Wim, Nelson, Ken, Boffa, Alex, Carabell, Kevin, Walker, Andrew, Caserta, Jon, Conway, Raymond

Frictional Characteristics of Crystalline Calcium Sulfonate Detergent in Engine Oil by Mini-Traction Machine

2014-01-278910/13/2014

Cao, Congrui, Liu, Gongde, Zhang, Runxiang, She, Haibo, Tao, Qiangqiang

Tribological Characteristics of Yttria Stabilized Zirconia Nanolubricants

2014-01-279010/13/2014

Nanolubricants are suspensions of nanoparticles in base fluids, a new challenge for thermal sciences provided by nanotechnology. The objective of this work is to analyze the thermal and tribological properties of yttria stabilized zirconia (YSZ) nanolubricants. Nanosized YSZ particles were prepared by milling YSZ (10μm) in a planetary ball mill equipped with vials using tungsten carbide balls. After 40 hrs, milled YSZ nanoparticles of sizes ranging from 70-90nm were obtained. The nanoparticles were characterized by Energy Dispersive X-ray analysis (EDXA), Scanning Electron microscope (SEM), Transmission Electron Microscope, Thermo Gravimetric-Differential Scanning Calorimeter and non contact 3D surface profilometer and the images of the same were obtained. The heat transfer properties of automotive engine lubricants were determined by utilization of measured thermal conductivity, viscosity index, density, flash point, fire point and pour point, which revealed that lubricants with additive constituents have a significant effect on the resultant heat transfer characteristics of the lubricants. The YSZ nanoparticles incorporated lubricants were evaluated for their potentials as effective solid lubricants at room temperature by using ball-on-disk tribometer. The lubricant without nanoparticles has a co-efficient of friction of 0.08-0.1 and a wear rate in the order of 10-4 mm3/Nm, while the lubricant with yttria stabilized zirconia nanoparticles exhibits a steady state co-efficient of friction of less than 0.07 and a wear rate in the order of 10−6 mm3/Nm at room temperature. Scratches and furrows are considered as the dominating wear mechanism of the disc applied with lubricants. However, for the disc applied with YSZ nanolubricants, the formation and effective spreading of the YSZ lubricating films are the most important factor to reduce the friction and wear rate.

Ganapathy Pandian, Sakthinathan

Effects of Combustion Parameters and Lubricating Oil on Particulate Matter Emissions from a Turbo-Charged GDI Engine Fueled with Methanol/Gasoline Blends

2014-01-284110/13/2014

The aim of this research is to experimentally investigate the effects of combustion parameters [ignition timings, injection timings, excess air ratio (λ)] and lubricating oil on particulate matter (PM) emissions from a 2.0 L turbo-charged gasoline direct injection (T-GDI) engine fueled with gasoline (octane number = 97), methanol/gasoline blends and pure methanol. The results of this paper show that the PM number concentration mostly presents a typical bimodal distribution in figures. The particle number concentration mainly concentrates in the nucleation mode. With the increase of methanol volume fraction in the blended fuel, the PM emissions decrease significantly. Furthermore, there are few particles when the engine fueled with pure methanol. As advancing ignition timing, the total PM number rises by over about 200%. Under the pre-ignition condition, the higher in-cylinder temperature may also accelerate the formation of the nucleation mode particles. As advancing injection timing, PM emissions decrease first, and then increase. As decreasing λ, the total PM number would be more than doubled due to the rich air-fuel mixture. The lower λ may significantly decelerate the oxidation trend of the PM in the combustion process, so that the PM number increases rapidly. The existence of lubricating oil shows a very great impact on PM emissions of T-GDI engine. As increasing a small volume fraction of lubricating oil in the fuel, the PM number significantly increases by several times, especially for accumulation mode particles.

Qin, Jing, Li, Xiang, Pei, Yiqiang

Radio Frequency Diesel Particulate Filter Soot and Ash Level Sensors: Enabling Adaptive Controls for Heavy-Duty Diesel Applications

2014-01-23499/30/2014

Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system. Conventional DPF control systems predominantly rely on a combination of filter pressure drop measurements and predictive models to indirectly estimate the soot loading state of the filter. Over time, the build-up of incombustible ash, primarily derived from metal-containing lubricant additives, accumulates in the filter to levels far exceeding the DPF's soot storage limit. The combined effects of soot and ash build-up dynamically impact the filter's pressure drop response, service life, and fuel consumption, and must be accurately accounted for in order to optimize engine and aftertreatment system performance. This work applied a radio frequency (RF) sensor to directly monitor diesel particulate filter soot and ash levels, thereby enabling direct feedback control of the filter based on its actual loading state. Results from fleet tests with Volvo/Mack trucks, over predominantly urban drive cycles, indicated the potential to decrease regeneration duration and associated fuel consumption by 50% to 75%, depending on operating conditions, and also to extend the time between active filter regenerations. Additional testing evaluated the performance of the sensor to distinguish soot from ash and define the DPF ash cleaning based on the actual measured ash load, as opposed to a prescribed filter maintenance interval. The results are useful to develop advanced control strategies to minimize the DPF-related fuel penalty, extend the service life of the filter, and identify anomalies indicative of filter failures or engine malfunctions.

Sappok, Alexander, Bromberg, Leslie

Effect of Accelerated Aging Rate on the Capture of Fuel-Borne Metal Impurities by Emissions Control Devices

2014-01-15004/1/2014

Small impurities in the fuel can have a significant impact on the emissions control system performance over the lifetime of the vehicle. Of particular interest in recent studies has been the impact of sodium, potassium, and calcium that can be introduced either through fuel constituents, such as biodiesel, or as lubricant additives. In a collaboration between the National Renewable Energy Laboratory and the Oak Ridge National Laboratory, a series of accelerated aging studies have been performed to understand the potential impact of these metals on the emissions control system. This paper explores the effect of the rate of accelerated aging on the capture of fuel-borne metal impurities in the emission control devices and the subsequent impact on performance. Aging was accelerated by doping the fuel with high levels of the metals of interest. Three separate evaluations were performed, each with a different rate of accelerated aging. The aged emissions control systems were evaluated through vehicle testing and then dissected for a more complete analysis of the devices. Results from these experiments show that increasing the rate of acceleration impacts the amount of fuel-borne metals that are captured by the catalyst, which subsequently impacts the catalyst performance. Beyond a certain threshold, the acceleration rate creates an artificial mechanism for catalyst deactivation. In the range of acceleration rates that were examined in this study, these effects were primarily isolated to the inlet of the catalyst whereas performance further down the length of the catalyst was mostly unaffected.

Williams, Aaron, McCormick, Robert, Lance, Michael, Xie, Chao, Toops, Todd, Brezny, Rasto

Methodology to Compare Effectiveness of Lubricating Additives in a Polymeric Matrix

2014-01-10344/1/2014

A majority of the plastics manufacturing operations are dependent on the formability of the molten thermoplastics. Ability of the material to flow at a set temperature influences the formability and the overall polymer melt process. Lubricating additive technologies are being developed to engineer the melt flow performance of the resin, promoting the compounding and molding process such as to reduce torque on the motor, reduced shear degradations, enhance uniform filling of hard-to-fill section, promoting thin wall molding, and influence the overall cycle time. Various lubricants are used in formulations to supplement superior flow and metal release with minimal effect on mechanical properties. This paper discusses the methodology to characterize the effectiveness of melt flow additives through comparing two different processing aids in Polybutylene terephthalate (PBT) polyester filled and unfilled matrix and imply differences in processing. The learning from findings in this paper can be adapted to other resin systems as applicable.

Shrivastava, Anshuman, Scheel, Mark, Strama, Julie

Direct Measurements of Soot/Ash Affinity in the Diesel Particulate Filter by Atomic Force Microscopy and Implications for Ash Accumulation and DPF Degradation

2014-01-14864/1/2014

Inorganic engine lubricant additives, which have various specific, necessary functions such as anti-wear, leave the combustion chamber bound to soot particles (approximately ≤1% by mass) as ash [13], and accumulate in aftertreatment components. The diesel particulate filter (DPF) is especially susceptible to ash-related issues due to its wall-flow architecture which physically traps most of the soot and ash emissions. Accumulated lubricant-derived ash results in numerous problems including increased filter pressure drop and decreased catalytic functionality. While much progress has been made to understand the macroscopic details and effects of ash accumulation on DPF performance, this study explores the nano- and micron-scale forces which impact particle adhesion and mobility within the particulate filter. Several recent studies have revealed several important mechanisms influencing the nature of the soot and ash deposits, which if manipulated, could yield means of actively minimizing the ash-related impact on aftertreatment system performance [1, 2, 3, 4, 5,13]. The aim of this study is to measure and manipulate the attractive forces relevant to the soot/ash/DPF system and to identify their role in ash accumulation and catalyst aging. Interaction force measurements can be made directly in nano- and micron-scale agglomerated particle systems by use of atomic force microscopy (AFM). In this case single particles and small micron-sized particle clusters of both soot and ash are attached to AFM tipless cantilevers, where the particles act as the AFM probe tips. AFM force measurement is then used to measure several specific attractive interaction forces including those at the following interfaces: soot-soot, soot-ash, soot-DPF, ash-ash and ash-DPF. In this case, ‘attractive interaction forces’ includes the summation of most likely Van der Waals and electrostatic interaction. The aim of introducing this new experimental approach is to first, contribute to the fundamental understanding of the ash agglomeration process within emissions aftertreatment systems, specifically the DPF, and second, to suggest potential design characteristics and strategies for both lubricant formulations and aftertreatment system components to reduce the effects of lubricant-derived ash accumulation.

Kamp, Carl Justin, Sappok, Alexander, Wang, Yujun, Bryk, William, Rubin, Avery, Wong, Victor

Demonstration of Fuel Economy Benefit of Friction Modifier Additives via Fuel-to-Lubricant Transfer in Euro-5 Gasoline Fleet

2013-01-261110/14/2013

Improved fuel economy is a key measure of performance in the automotive industry, driven both by market demand and increasingly stringent government emissions regulations. In this climate, targeting even small benefits to fuel consumption (FC) can have a large impact when considering fleet average CO2 emissions. Lubricant properties over the course of an oil drain interval (ODI) directly influence long-term fuel consumption. Furthermore, viscosity control gasoline additives have been shown to provide FC benefit via fuel-to-lubricant transfer. This study investigated whether consistently fueling with gasoline containing friction modifier (FM) additives could provide a long-term fuel consumption benefit via a lubricant transfer mechanism. A robust fleet trial method was employed to quantify fuel consumption benefits of two friction modifier additive packages relative to a baseline deposit control additive (DCA) package in a 95 RON, E5 fuel. FC was measured for 32 market relevant vehicles over the course of a European ODI. The test was performed with 12,000 mile on-road accumulation in a 60/40 urban/high speed driving route. Changes in FC were measured periodically on a chassis dynamometer (CD) using the industry standard New European Drive Cycle (NEDC) procedure. NEDC emissions results demonstrated statistically significant FC benefits for fuels containing FM additives relative to a DCA only reference fuel, with 0.60% and 0.71% benefit at the 95% confidence level. Lubricant analysis confirmed transfer of FM additives to the lubricant sump, providing support for a fuel-lubricant interaction mechanism. This study thus demonstrates that statistically significant long-term fuel consumption benefits can be obtained by consistent fueling with FM dosed gasoline.

Remmert, Sarah M., Felix-Moore, Alison, Nattrass, Steven R., Buttery, Ian, Ziman, Pauline, Smith, Sue J.

Assessment of Low Temperature Viscosity Performance in Modern Engine Oils

2013-01-256510/14/2013

Control of oil viscosity increase at low temperature, which derives from the wax crystallization behaviors of various formulation components, is a critical performance criterion in modern engine oil lubricants. Failure to manage viscosity increase will result in high oil viscosity and poor oil pumpability under cold start conditions, and eventually may lead to catastrophic damage to the engine. The importance of oil low temperature rheology gained further attention when the ILSAC GF-4 specification implemented an aged oil low temperature viscosity limit to guarantee performance retention during operation. This requirement continues in ILSAC GF-5 and is regarded as one of the key benchmarks of modern passenger car engine oils. Pour point depressants (PPDs) are polymeric additives that help alleviate viscosity increase under tcold climate conditions through interaction and control of wax crystallization growth. With increasingly diverse base stock supplies and quality standards, different wax characteristics of formulation components, and various testing methods (fresh and aged oils), achieving robust and consistent low temperature performance can be a challenging task for engine oil formulators. Consequently, appropriate PPD selection is imperative to guarantee this consistency. In this paper, conclusions drawn from the evaluation of a comprehensive set of engine oils will first be presented and discussed to illustrate the importance of low temperature performance. We will then consider the use of polyalkylmethacrylate (PAMA) PPDs in engine oil formulations and discuss selection guidelines to meet the stringent modern engine oil cold flow standard including the Romaszewski Bench Oxidation (ROBO) test. ROBO, which was developed by Evonik Oil Additives to simulate Sequence IIIGA engine tests, is currently listed in the ILSAC GF-5 specification as one of two methods to generate aged oil for low temperature property evaluation. This paper will report results using the ROBO test to assess the effect of aging processes on engine oil low temperature properties (MRV TP-1 viscosity). The influence of oil aging on PPD appetite will also be discussed.

Wang, Jen Lung

Effect of Low Viscosity Passenger Car Motor Oils on Fuel Economy Engine Tests

2013-01-260610/14/2013

The fuel economy performance of passenger car vehicles has been an area of keen focus due to recent environmental regulations. Various efforts such as the development of new engine technologies have been undertaken to improve the fuel economy performance of these vehicles. Engine oils have also been targeted to contribute to better fuel efficiency. This has been done by introducing new lubricant additive technologies and low viscosity grade oils. In the latter case, passenger car motor oils are about to enter into a new generation in which the lower viscosity grade SAE 16 has been approved and discussion has started on the specification of viscosity grades lower than SAE 16, although SAE 0W-20 viscosity grade is the lowest in the SAE J300 specification during last decade. Nevertheless, additive technology is also important, as we previously reported that simple reduction of viscosity grade is not a solution to improve fuel economy performance in the Sequence VID test. In this paper, the increase in the severity of boundary lubrication conditions with the use of lower viscosity grades is shown. Lower viscosity grade oils such as 0W-16, 0W-12 and 0W-4 were also evaluated on the motored engine friction torque test and showed similar behavior to the Sequence VID test. Friction modifiers were demonstrated to improve the friction properties under boundary lubrication conditions while retaining the benefit at hydrodynamic lubrication conditions.

Ushioda, Nobuo, Miller, Trevor W., Sims, Carrie B., Parsons, Gary, Sztenderowicz, Mark

Sensitivity Analysis of Ash Packing and Distribution in Diesel Particulate Filters to Transient Changes in Exhaust Conditions

2012-01-10934/16/2012

Current CJ-4 lubricant specifications place chemical limits on diesel engine oil formulations to minimize the accumulation of lubricant-derived ash in diesel particulate filters (DPF). While lubricant additive chemistry plays a strong role in determining the amount and type of ash accumulated in the DPF, a number of additional factors play important roles as well. Relative to soot particles, whose residence time in the DPF is short-lived, ash particles remain in the filter for a significant fraction of the filter's useful life. While it is well-known that the properties (packing density, porosity, permeability) of soot deposits are primarily controlled by the local exhaust conditions at the time of particle deposition in the DPF, the cumulative operating history of the filter plays a much stronger role in controlling the properties and distribution of the accumulated ash. Results of this work indicate that short-duration, transient, high temperature events can have a profound impact on ash packing and DPF pressure drop, while exposure to transient high flow rate conditions produce only marginal changes. The tests conducted in this work utilized core samples, removed from DPFs containing known ash levels, to study the effect of transient changes in exhaust conditions on ash properties using a flow bench. Use of the core samples enabled more precise control of DPF exposure to transient variations in exhaust flow and temperature conditions. In addition to the filter performance characterization, application of advanced diagnostics including scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and x-ray diffraction (XRD) provide insights into the changes in ash properties induced by the variations in exhaust conditions, useful to explain the observed results. Enhanced understanding of the fundamental mechanisms controlling ash properties and their impact on DPF performance is useful to not only extend the filter's service life, but more importantly to improve both DPF control and on-board diagnostic capabilities.

Sappok, Alexander, Kamp, Carl, Wong, Victor

Management of Lubricant Fuel Economy Performance over Time through Fuel Additives

2012-01-12704/16/2012

Government regulations and market demands continue to emphasize conservation of fossil fuels in the transportation industry. As a consequence, any incremental improvement in fuel economy (FE) is of great importance in the automotive sector. For instance, lower viscosity lubricants have been shown to improve FE but the longevity of such improvement is compromised by viscosity increases often observed as a lubricant ages during an oil drain interval (ODI). To address this issue, an option to manage lubricant viscometrics via fuel is proposed. In order to investigate such mitigation of viscosity increase during an ODI, and potentially the delivery of an ODI-averaged FE benefit, a fleet test was conducted with a fuel-borne additive intended to control increases in lubricant viscosity. The fleet test compared a market-representative reference fuel to a fuel containing a viscosity control additive (VCA). Five different European vehicle models were tested over a 15,000 mile ODI using a “quad” fleet testing protocol previously described. The FE evolution of each vehicle was determined by the NEDC (New European Drive Cycle) procedure at intervals throughout the fleet test and supported by a range of snapshot oil analyses. The fleet test showed the VCA fuel was able to mitigate lubricant viscosity increase and deliver an increasing fleet-average fuel economy improvement with respect to the reference fuel throughout the trial. Consequently, the benefits of both lubricant viscosity control and associated FE were greatest at the end of the trial where the reference fuel vehicles showed the greatest lubricant viscosity increase. These observations were supported by increasing concentration of VCA within the lubricant of the VCA-fuelled vehicles and by modeling of vehicle FE in conjunction with lubricant-VCA blending considerations. Subsequent lubricant and engine analyses showed no evidence of undesired effects from the VCA (e.g. enhanced wear rates). It is concluded that the fleet test demonstrated that VCA fuel additive package can limit the viscosity-increase tendency of engine oil during its lifetime and so enhance longevity of fuel economy performance.

Rappaport, Scott, Nattrass, Steve, Smith, Sue, Brewer, Mark, Buttery, Ian, Ma, Hongrui

Study of Lower Viscosity Motorcycle Engine Oils for Fuel Saving-Anti-fatigue Performance-

2011-32-063411/8/2011

1 Fuel savings by engine oil have been requested for two-wheeled vehicles from the viewpoint of environmental issues. In four-wheeled vehicles, reduction of oil viscosity and addition of friction modifiers have been effective in improving fuel efficiency. However, direct application of engine oil for four-wheeled vehicles to two-wheeled vehicles is difficult. In a four-cycle two-wheeled vehicle, the transmission, gears, and a wet clutch system are imbedded within the engine1). Engine oil must display a remarkable performance as it is required to function as transmission oil and to improve anti-metal fatigue life and clutch performance2), 3). If fuel efficiency is improved by reducing the viscosity of engine oil used in two-wheeled vehicles, the fatigue life tends to worsen. Therefore, reduction in oil viscosity is difficult to achieve. In this study, the anti-metal fatigue life of an engine oil was evaluated using a gear or a rolling bearing in a crankshaft where fatigue failures may occur due to the reduction in oil viscosity. Measures to prolong fatigue life were examined by testing different engine oil formulations, including single-grade oils and multi-grade oils to which polymers were added as viscosity index improvers (VIIs). The viscosity characteristics and oil film formability of test oils were measured, and their effects on the fatigue life were analyzed. The use of olefin co-oligomer as a VII improved the oil film formability of engine oil and prolonged the fatigue life of the needle bearing.

Watanabe, Nobuaki, Inuzuka, Maiko, Mitarai, Akira

Research on Emissions and Engine Lube Oil Deterioration of Diesel Engines with BioFuels (RME)

2011-01-13024/12/2011

In the diesel sector the fatty acid methyl esters (FAME's) - in Europe mostly RME (rapeseed methyl ester) and in US mostly SME (soja oil methyl ester) - are used as a various share, % volume blends with the diesel fuel (B5, B7, B10, B20, Bxx). The present joint project focuses on RME being the most important representative of the biofuels of 1st generation in Europe. The influences of RME blend fuels on emissions and on lube oil deterioration are emphasized. Emissions were investigated on a modern engine with exhaust gas aftertreatment devices like SCR and (DPF+ SCR). Beside the legally limited exhaust emission components some non-legislated like NO₂, N₂O, NH₃ and nanoparticles were measured at stationary and dynamic engine operation. The most important findings are: - the increased percentage of RME w/o aftertreatment causes an increase of NOx by higher engine load and reduction of CO & HC; at transient operation (ETC) these tendencies are less pronounced and only B100 shows an increase of NOx, - with SCR alone there are no differences of NOx and of NOx reduction rate (KNOX) with increasing RME portion; there is lowering of CO & HC, - with DPF+SCR KNOX-values are slightly higher, than with SCR alone, due to the production of NO₂ in the catalytic DPF (upstream of SCR), - there is excellent count filtration efficiency of DPF, up to 99.9%; with SCR alone there is usually a small reduction of nanoparticles concentrations (in the range of 10-20%, similar like a usual oxidation catalyst). The paper describes as well significant problems related to the influences of biofuels on engine lube oils deterioration demonstrated by monitoring the engine lube oil aging during its operation in heavy-duty (HD) and modern high speed direct injection (HSDI) light-duty (LD) engine through the bench tests. Subject to the long run durability engine tests were both: mineral and synthetic engine lube oils with different improved additives packages and viscosity ranges and with different RME-blending ratios in fuel. The research methodology used: standard analysis as well as in-house-developed innovative methods, extensive analysis of engine lubricants oxidation stability - thin lubricant film oxidation tests and bulk lubricant oxidation tests. It can be stated that: - the presence of bio-components in the fuel has significant impact on multidirectional hastening of engine lube oil destruction processes, - kind of base lube oil, lube oil additives components and RME-portion, as well as engine design and its operating conditions are very essential factors influencing the engine lube oil performance, - the processes taking place in an engine lubricant, influence adversely the limited possibilities of bio-components evaporation from engine lube oil and contribute to initiation of accelerated, deeper engine lube oil oxidation and degradation.

Stepien, Zbigniew, Urzedowska, Wieslawa, Oleksiak, Stanislaw, Czerwinski, Jan

Waste Lubricating Oil as a Source of Hydrogen Fuel using Chemical Looping Steam Reforming

2010-01-219210/25/2010

Initial results are presented for the production of hydrogen from waste lubricating oil using a chemical looping reforming (CLR) process. The development of flexible and sustainable sources of hydrogen will be required to facilitate a "hydrogen economy." The novel CLR process presented in this paper has an advantage over hydrogen production from conventional steam reforming because CLR can use complex, low value, waste oils. Also, because the process is scalable to small and medium size, hydrogen can be produced close to where it is required, minimizing transport costs. Waste lubricating oil typically contains 13-14% weight of hydrogen, which through the steam reforming process could produce a syngas containing around 75 vol% H₂, representing over 40 wt% of the fuel. The waste oil was converted to a hydrogen-rich syngas in a packed bed reactor, using a Ni/ Al₂O₃ catalyst as the oxygen transfer material (OTM). An oil conversion rate based on carbon species (CO, CO₂ and CH₄) of up to ~95% was achieved. The steam to hydrogen conversion of 53%, accounted for 63% of the total H₂ produced, compared to the theoretical ideal of 67.4%. The syngas composition was initially ≻65 vol% H₂, 15 vol% CO, 15 vol% CO₂, and ≺5 vol% CH₄. Deterioration of the reactants conversion, specifically steam, was observed over repeated cycles indicating fouling of the catalyst. This was not by carbonaceous deposits, which were eliminated during the cycle's alternated oxidation steps, but could be by trace additives within the lubricating oil. Further work is planned in order to overcome this issue.

Lea-Langton, Amanda, Giannakeas, Nikolaos, Rickett, Gavin, Dupont, Valerie, Twigg, Martyn

Role of Fuel Decomposition Products on Formation of Sequence IIIG Piston Deposits

2010-01-225910/25/2010

Previous research to understand the mechanism for piston deposit formation in the Sequence IIIG engine test has focused on characterizing the piston deposits. These studies concluded that, in addition to lubricant derived materials, Sequence IIIG piston deposits contain a significant amount of fuel-derived carbonaceous material. The presence of fuel degradation by-products in Sequence IIIG deposits shows that blow-by is a significant contributor to deposit formation. However, blow-by can either assist in the degradation of the lubricant or can simply be a source for organic material which can be incorporated into the deposits. Therefore, a series of modified Sequence IIIG engine tests were conducted to better determine the effect of blow-by on deposit formation. In these studies deposit formation on different parts of the piston assembly were examined since different parts of the piston assembly are exposed to different amounts of blow-by. Furthermore, the rate of deposit formation in the Sequence IIIG engine test was examined to determine if the rate of lubricant degradation is related to the rate of deposit formation.

Devlin, Mark T., Dvorak, Todd, Sheets, Roger, Bell, Ian, Loper, John, Guevremont, Jeffrey, Guinther, Gregory

Study of Lower Viscosity Motorcycle Engine Oils for Fuel Saving

2010-32-01239/28/2010

As well as a four-wheeled vehicle, in the field of motorcycle, development of the CO₂ reduction technology and practical use are required for global environment protection. Therefore the energy conserving by engine oil is required. There are several technologies which have been applied to the passenger car engine oils using lower viscosity base oils and some friction modifier additives. However, these technologies might bring difficulties or problems to apply to the motorcycle engine oils. Since motorcycles normally have transmission gears and a wet clutch system inside the crankcase, the gear lubricity and clutch friction performance are additionally required for motorcycle engine oils. Motorcycle engine oils are also used under severer conditions than passenger car engine oils. Therefore, lower volatility performance at higher temperature conditions, higher shear stability, anti-wear performance and gear pitting toughness are needed. In this study, we report the results of motorcycle engine oil performance evaluation with engine oils containing high quality mineral base oils and specially selected polymers. The high quality base oil contributed to reduce oil consumption, compared with the current 10W-30 grade motorcycle engine oil. The moderate selection of polymers can increase oil film thickness and also improve shear stability. Additionally, actual motorcycle engine test was conducted. The candidate oil showed better fuel saving and better effect for gear fatigue and noise prevention.

Watanabe, Nobuaki

Limited Slip Additive Testing and Development: New Products with Improved Thermal Stability

2007-01-19887/23/2007

Limited slip differentials, developed over 40 years ago to counter drive wheel slippage when different traction conditions exist on either side of an axle, are still widely employed by the automotive industry to improve driving control. In a limited slip differential (LSD) frictional couplings connect the axle shafts to the differential and provide the means of transmitting power to the wheels. The friction plates in the coupling may contain a variety of friction materials including metal, paper, sintered bronze, and carbon. Each one of these materials has very different frictional and wear characteristics and each one requires a different response from the gear additive package. Each plate must be durable over the course of the vehicle lifetime irrespective of the material used. As the demands on rear axles increases with the application of greater horsepower and the increasing requirements of aerodynamic engineers, the lubrication of these friction plates remains an ongoing challenge. Lubricant frictional characteristics are very important in determining the quiet and smooth operation of LSD's. Fully formulated API GL-5 J 2360 gear lubricants are unable to fulfill all the lubrication requirements of LSD's. Special additives have therefore been developed to improve the frictional response in the coupling to eliminate noise, vibration, and stick slip problems. There is a requirement to provide limited slip additives that give excellent friction plate lubrication. The goal of lubricant formulators is to develop new products that retain frictional performance with minimal effect on the thermal stability of the gear lubricant. Test methodology has been developed that correlates friction characteristics with known field performance and testing has been performed on a variety of friction plate materials. The results of testing with current commercially available limited slip additives and new additives with much improved thermal characteristics in different gear lubricants and with different hardware configurations are discussed. This paper adds to previous work in this area and brings to a conclusion the development, design and experimentation associated with this extensive program.

Vettel, Paula, Lindsay, David

Physical and Chemical Properties of Engine Oils

J357_200611 (Historical)

11/6/2006

This SAE Information Report reviews the various physical and chemical properties of engine oils and provides references to test methods and standards used to measure these properties. It also includes general references on the subject of engine oils, base stocks, and additives.

Fuels and Lubricants TC 1 Engine Lubrication

The Impact of Some Gear Lubricants on the Surface Durability of Rolling Element Bearings

2006-01-03574/3/2006

The additive chemistry of some gear lubricants can have a major impact on the surface durability of rolling element bearings (1). Lubricant formulation has been slanted heavily toward protecting gear concentrated contacts from galling and wear. As such, much of the performance differentiation of lubricants has been dependent on highly accelerated, standardized laboratory tests related to gears. Methods have been proposed to evaluate and quantify a lubricant's performance characteristics as they relate to rolling element bearings (2). Results from several lubricant performance evaluations are presented. The implications of these findings suggest that the detrimental performance effects on rolling element bearings need further fundamental study by the lubricant industry.

Nixon, Harvey P.

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