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Viewing 1 to 30 of 3208
2017-10-08
Technical Paper
2017-01-2422
Na Li, Fenlian Huang, Yuhua Bi, Yueqiang Xu, Lizhong Shen, Dewen Jia
The assembly of connecting rod bearing and crankpin is a key friction pair which offers an important guarantee for stable operation of diesel engine. Specific to the non-road 2-cylinder diesel engine developed independently and based on the theory of elasto-hydrodynamic lubrication as well as multi-body dynamics, this paper establishes a multi-body dynamics model for connecting rod bearing of the 2D25 horizontal diesel engine and makes a research on the influence of bearing width, bearing clearance, and oil inlet position and diameter upon lubrication of connecting rod bearing, taking into consideration that of the surface appearance of bearing bush and the elastic deformation of bearing bush and axle journal upon the same. Research results show that bearing width and bearing clearance are the major factors that influence lubrication characteristics of connecting rod bearing while oil inlet position and diameter only have a small influence on such characteristics.
2017-10-08
Technical Paper
2017-01-2358
Michael P Gahagan
The automotive transmission market has seen an increase in the number of hybrid electric vehicles (HEV), and forecasts predict additional growth. In HEVs, the hybrid drivetrain hardware can combine electric motor, clutches, gearbox, electro-hydraulics and the control unit. In HEV hardware the transmission fluid can be designed to be in contact with an integrated electric motor. One transmission type well-suited to such hybridization is the increasingly utilized dual clutch transmission (DCT), where a lubricating fluid is in contact with the complete motor assembly as well as the DCT driveline architecture. This includes its electrics, and therefore raises questions around the suitability of standard transmission fluids in such an application. This therefore drives the need for further understanding of fluid electrical properties in addition to the more usually studied engineering hardware electrical properties.
2017-10-08
Technical Paper
2017-01-2357
Mark Devlin, Jeffrey Guevremont, Chip Hewette, Marc Ingram, Grant Pollard, William Wyatt
Different mechanical components in a vehicle can be made from different types of steel and can even contain different steel alloys or coatings. Lubricant technology is needed to prevent wear and control friction on all of these different surfaces. Phosphorus compounds are the key additives that are used to control wear and they do this by forming tribofilms on surfaces. It has been shown that different operating conditions (pressures and loads) can influence the formation of tribofilms formed by different anti-wear additives. The effect of surface metallurgy and morphology on tribofilm formation is described in this paper. Our results show that additive technology can form proper tribofilms on various surfaces and the right combination of additives can be found for current and future surfaces.
2017-10-08
Technical Paper
2017-01-2347
Kazushi Tamura, Kenji Sunahara, Motoharu Ishikawa, Masashi Mizukami, Kazue Kurihara
Modern lubricants such as fuel economy engine oils control friction through tribofilms formed by functional additives mixture. Although many cases on synergistic or antagonistic effects of additives on friction have been reported, their mechanisms are poorly understood. Here we found that some of the detergent additives with metallic soap reduced friction synergistically with molybdenum dithiocarbamate (MoDTC), which is a widely-used friction modifier additive that forms slippery tribofilm, while detergents themselves increased friction without MoDTC. These results indicate that detergents enhance friction-induced formation of slippery tribofilms by MoDTC. To reveal this mechanism, using surface force apparatus equipped with a resonance shear measurement system (SFA-RSM), we examined mechanical properties of detergent-containing oils confined at single-asperity contact.
2017-10-08
Technical Paper
2017-01-2350
Chalermwut Wongtaewan, Umaporn Wongjareonpanit, Komkrit Sivara, Ken Hashimoto, Yoichiro Nakamura
In Thailand, most heavy-duty trucks were equipped with diesel engine, while a small portion was equipped with compressed natural gas (CNG) engine. However, in the past few years the number of CNG fuel trucks in Thailand has increased significantly due to the cheaper cost of CNG. In general, the emphasis of heavy-duty diesel engine oil performance is on piston cleanliness and soot handling properties, while thermal and anti-oxidation properties are most critical for CNG engine oil performance. For truck fleet owners who operate both types of trucks, using the inappropriate oil that is not fit-for-purpose can adversely affect engine performance and reduce engine service lifespan under prolonged usage. A novel CNG/diesel engine oil has developed by PTT to meet both JASO DH-2 performance for heavy-duty diesel engine oils and OEM requirements for CNG engine oils.
2017-10-08
Technical Paper
2017-01-2333
Marcos Gutierrez, Andres Castillo, Juan Iniguez, Gorky Reyes
The aim for cleaner and more efficient energy from the internal combustion engines makes necessary to ensure the conditions for the exploitation of alternative fuels. The vibrations on engines are primarily understood as effects of mechanical failures, but the engine vibration is subject of the fuel combustion effects too. This effects will depend on the fuel type and its capacity to be burned. The vibrations of a diesel engine were measured and analyzed with a frequency spectrum calculated with Fast Fourier Transforms. The engine was operated with a fuel blend from 10 % recycled lubricating oil with 90% diesel as well as only diesel. It was found the engine operation with this fuel blend has a lower vibration level in comparison with the use of pure diesel. The goal of this research is to determine the properties of the fuel blend, which provides more stability to the engine by means of vibrations reduction.
2017-10-08
Technical Paper
2017-01-2415
Valery Dunaevsky
The film thickness–roughness ratio Λ has been used since the mid-1960s as a criterion for the lubrication conditions in rolling bearings. However, due to an assumed Gaussian distribution of the roughness height amplitudes of the functional surfaces of rolling bearings and other unsubstantiated assumptions concerning the mechanisms of contact interaction, concerns have arisen about the representability of Λ in terms of lubrication. In this study, a more objective Λ-type ratio that does not depend on the law of roughness height distribution and the peculiarities of contact mechanics is introduced and defined as Λz. The relevant range of the new Λ ratio, which identifies a full-film lubrication, is lower than that of its conventional counterpart, and it coincides directionally with contemporary theoretical and experimental results. The study exhibits unique profilometric data of the functional surfaces of the roller bearings, produced by the major bearing manufacturers.
2017-10-08
Technical Paper
2017-01-2423
Xiaoming Ye, Yan Fu, Wei Li, Yuze Jiang, Shixin Zhu
As the key components of internal combustion engine(ICE), the crankshaft main bearings are used to support the crankshaft and connecting rod mechanism whose rotary motion realizes the energy conversion from heat energy to mechanical power in cylinder. The lubrication performances and wear life of crankshaft main bearings directly affect ICE working efficiency and reliability. Therefore, it is very important to study the lubrication performances of crankshaft main bearings. In this paper, a 16V marine diesel engine was studied. Based on the AVL-Designer software platform, a dynamic model of crankshaft and connecting rod mechanism and a hydrodynamic lubrication model of crankshaft main bearing were built. The numerical analyses were carried out on the lubrication performances of crankshaft main bearings under different speed conditions.
2017-10-08
Technical Paper
2017-01-2444
Yanzhong Wang, Guanhua Song
High-speed rotating gears are generally lubricated by fuel injection. Lubricating oil is driven by high-speed rotating gear, and some lubricants will be excited into oil mist, so that the gears are in the gas-liquid mixed environment. In this paper, the computational fluid dynamics model of the fuel injection cooling process is established based on the gear heat transfer behavior under the fuel injection condition. The influence of different fuel injection parameters on the liquid-solid two-phase convective heat transfer coefficient is obtained. On this basis, the accurate boundary conditions of gear temperature field calculation are analyzed by studying the heat transfer behavior of high speed gear injection lubrication. The calculation model of gear temperature based on fuel injection lubrication is established, and the temperature field distribution of gear is obtained.
2017-10-08
Technical Paper
2017-01-2349
Sarita Seth, Swamy Maloth, Prashant Kumar, Bhuvenesh Tyagi, Lokesh Kumar, Rajendra Mahapatra, Sarita Garg, Deepak Saxena, R Suresh, SSV Ramakumar
Automobile OEMs are looking for improving fuel economy of their vehicles by reducing weight, rolling resistance and improving engine and transmission efficiency apart from the aerodynamic design. Fuel economy may be improved by using appropriate low viscosity and use of friction reducers (FRs) in the engine oils. The concept of high viscosity index is being used for achieving right viscosity at required operating temperatures. In this paper performance properties of High Viscosity Index engine oils have been compared with conventional VI engine oils. Efforts has been made to check the key differentiation in oil properties and finally into oil performance w.r.t. low temperature fluidity, high temperature high shear viscosity/deposits, friction behavior, oxidation performance in bench tribological /engine/chassis dyno tests. Three candidates of SAE 0W-30 grade oil with ACEA C2/API SN credentials have been chosen using various viscosity modifiers.
2017-10-08
Technical Paper
2017-01-2231
Yongquan Chen, Liguang Li, Qing Zhang, Jun Deng, Wei Xie, Erbao Zhang, Sunyu Tong
Low speed pre-ignition (LSPI) may lead to extreme knock (superknock or megaknock) which has a severe influence on engine performance and service life thus limits the development of downsized GDI engine. One reason for LSPI is auto-ignition occurs in the region where the contaminants, such as lubricants or heavy ends of gasoline, are rich. In this paper, 8 groups of lubricants are injected into a hot co-flow by a single-hole nozzle with a diameter of 0.2 mm under 20 MPa injection pressure. The ignition delays and lifted flames of lubricants with additives of calcium, magnesium and ZDDP (Zinc Dialkyl Dithiophosphates) under the hot coflow 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 study shows that the ignition delays of lubricants decline sharply with the increase of co-flow temperature in the whole temperature range.
2017-10-08
Technical Paper
2017-01-2353
Bernardo Tormos, Leonardo Ramirez, Guillermo Miró, Tomás Pérez
Attending the oncoming licensing of API F4K oil category for Heavy duty Vehicles, which main objective is to embrace the opportunity to reduce fuel consumption and CO2 emissions lowering the High Temperature High Shear (HTHS) oil viscosity a fleet test was performed during 2016 in a fleet of urban buses in the city of Valencia. This paper describes the results of a comparison test where the effect of the use of API FA4 like engine oils are used to measure their fuel consumption benefits over the fleet. The aim was to verify and quantify the theoretical benefits in terms of fuel consumption in Heavy Duty applications. The study was performed using 48 urban buses which include diesel and CNG models of the city of Valencia. These buses were divided in two groups; a control and a test group, using regular oils and API FA4. The fuel consumption of buses was calculated with distance and refueling.
2017-10-08
Technical Paper
2017-01-2351
Bernardo Tormos, Guillermo Miró, Leonardo Ramirez, Tomás Pérez
Low viscosity engine lubricants (LVO) are considered a possible solution for improving fuel economy in ICE. So, the aim of this study was to verify experimentally the performance of low viscosity lubricants regarding engine wear, since the use of LVO could imply unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, a non-desired effect. In addition, currently limited data are available regarding “real-world” performance of LVO in a real service fleet. In this particular case, there were included out-of-specifications oils in terms of HTHS dynamic viscosity, where low viscosity was considered (3.0 cP), making this test highly interesting for industry.
2017-10-08
Technical Paper
2017-01-2344
Robert Taylor, Hua Hu, Carl Stow, Tony Davenport, Robert Mainwaring, Scott Rappaport, Sarah Remmert
Future scenarios prepared by Shell anticipate that worldwide energy demand will approximately double by 2050, whilst at the same time, CO2 emissions need to be halved. Therefore, there is great pressure on improving efficiency of all machines, and clearly there is great focus on improving the fuel efficiency of passenger cars. The use of downsized, boosted, gasoline engines, can lead to exceptional fuel economy, and on a well-to-wheels basis, can give similar CO2 emissions to electric vehicles (depending, of course, on how the electricity is generated). A study is reported on a low weight Shell concept car, equipped with a three-cylinder 0.6 litre gasoline engine, which has achieved over 100 miles per imperial gallon, in real world driving conditions.
2017-10-08
Technical Paper
2017-01-2352
Gongde Liu, Li Wang, Runxiang Zhang, Chao Yang, Tengfei Shao
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 10k kilometers to 60k/80k/100k or even 120k kilometers 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.
2017-10-08
Technical Paper
2017-01-2437
Renjith S, Vinod Kumar Srinivasa, Umesh Venkateshaiah
The jet lubrication method is extensively used in the constant mesh high performance transmission system operating at range of speeds though it affects mechanical efficiency through spin power loss. The lubrication jet has a key role to maintain the meshing gears at non-fatal thermal equilibrium by effectively dissipating the heat generated to the surrounding. Heat Transfer coefficient (HTC) is the indicator of the thermal behavior of the system, which provides great insight of efficient lubrication system that needs to be employed for prescribed type of transmission. 1D and 3D simulations are of countless value in optimizing the automotive power train transmission system performance parameters. Thermal performance prediction of the jet lubricated transmission system through 3D CFD analysis is quite comprehensive task compared to 1D analysis. Both 1D and 3D methods complement each other to great extent in design process and one such exercise is demonstrated in the current activity.
2017-10-08
Journal Article
2017-01-2348
Michael Clifford Kocsis, Peter Morgan, Alexander Michlberger, Ewan E. Delbridge, Oliver Smith
Increasingly stringent fuel economy and emissions regulations around the World have forced the further optimization of nearly all vehicle systems. Many technologies exist for improvement in fuel economy; however, only a smaller sub-set are commercially feasible due to cost of implementation. One area that can provide a small but significant improvement in fuel economy is the lubrication system of an internal combustion engine. Benefits in fuel economy may be realized by the reduction of engine oil viscosity and the addition of friction modifying additives. In both cases, advanced engine oils allow for a reduction of engine friction. Generally speaking, the impact of chemical additives such as friction modifiers (FMs) is to reduce friction in tribocouples which experience metal-to-metal contact. These conditions commonly occur in valvetrain contacts and between the piston rings and cylinder bore at Top Dead Center (TDC).
2017-10-08
Journal Article
2017-01-2356
Hyun-Soo Hong, Christopher Engel, Brian Filippini, Sona Slocum, Farrukh Qureshi, Tomoya Higuchi
Due to strict government legislation around the world to control carbon dioxide (CO2) emissions and their detrimental effects on climate change, improving fuel economy has become a major consideration in vehicle design. Original Equipment Manufacturers (OEMs) have started using lower viscosity oils as engine, transmission and axle lubricants. For example, North American heavy duty OEMs started moving away from high viscosity SAE 75W-140 axle oils in the past decade, and now most OEMs use lower viscosity SAE 75W-90 as fuel efficient axle oils. OEMs also demanded an extended drain interval to address their customer’s needs. These trends forced the lubricant industries to use Group III and/or Group IV base oils in axle oils. Group II base oils have higher traction coefficients in comparison to group III and group IV base oils. Higher traction can lead to higher operating temperatures, which can impact fuel economy and oxidation performances of axle oils.
2017-10-08
Journal Article
2017-01-2346
Hong Liu, Jiajia Jin, Hongyu Li, Kazuo Yamamori, Toyoharu Kaneko, Minoru Yamashita, Liping Zhang
According to the Toyota gasoline engine oil requirements, this paper describes that the low viscosity engine oil of 0W-16 has been developed jointly by Sinopec and Toyota,which also conforms to the Toyota specification. As we know, the development of low viscosity gasoline engine oils should not only focus on fuel economy improvement, but shear stability and low speed pre-ignition (LSPI) prevention property should be taken into consideration. The main elements content in the formulation was determined according to the results of Toyota’s previous LSPI research and the initial 0W-16 engine oil had passed Toyota LSPI test. Based on all above, viscosity index improver (VII) with better friction reduction property was selected by the Mini-traction Machine (MTM) and the High-frequency Reciprocating Rig (HFRR) tests.
2017-10-08
Journal Article
2017-01-2343
Nicolas Champagne, Nicolas Obrecht, Arup Gangopadhyay, Rob Zdrodowski, Z Liu
The oil and additive industry is challenged to meet future automotive legislations aimed at reducing worlwide CO2 emissions levels. The most efficient solution used to date has been to decrease oil viscosity leading to the introduction of new SAE grades such as SAE 0W-8. However this solution may soon reach its limit due to potential issues related to wear with lower engine oil viscosities. In this paper, an innovative solution is proposed that combines the use of a new tailor-made polyalkylene glycol with specific anti-wear additives. Valvetrain wear measurements using radionuclide technique demonstrates the robustness of this solution. The wear performance was also confirmed in normalized GF-5 testings. An extensive tribological evaluation (film formation, wear testing and tribofilm surface analysis) of the interactions between the base oil and the anti-wear additives lead us to propose an underlying mechanism that can explain this performance benefit.
2017-10-08
Journal Article
2017-01-2341
Kongsheng Yang, Kristin A. Fletcher, Jeremy P. Styer, William Y. Lam, Gregory H. Guinther
Countries from every region in the world have set aggressive fuel economy targets to reduce greenhouse gas emissions. To meet these requirements, automakers are using combinations of technologies throughout the vehicle drivetrain to improve efficiency. One of the most efficient types of gasoline engine technologies is the turbocharged gasoline direct injection (TGDI) engine. The market share of TGDI engines within North America and globally has been steadily increasing since 2008. TGDI engines can operate at higher temperature and under higher loads. As a result, original equipment manufacturers (OEMs) have introduced additional engine tests to regional and OEM engine oil specifications to ensure performance of TGDI engines is maintained. One such engine test, the General Motors turbocharger coking (GMTC) test (originally referred to as the GM Turbo Charger Deposit Test), evaluates the potential of engine oil to protect turbochargers from deposit build-up.
2017-09-17
Journal Article
2017-01-2480
Roberto Dante, Andrea Sliepcevich, Marco Andreoni, Mario Cotilli
Abstract Tin sulfides (SnS and SnS2), represent a safer and greener alternative to other metal sulfides such as copper sulfides, and MoS2 etc. Their behavior is usually associated to that of solid lubricants such as graphite. A mixture of tin sulfides, with the 65 wt% of SnS2, has been characterized by scanning electron microscopy and by thermal gravimetric analysis (TGA). In order to investigate the effect of tin sulfides upon two crucial friction material ingredients, two mixtures were prepared: the former was made by mixing tin sulfides with a natural flake graphite and the latter was made mixing tin sulfides with a straight novolak. They were analyzed by TGA and differential thermal analysis (DTA) in both nitrogen and air. Some interferences were detected between tin sulfides and graphite in air.
2017-07-10
Technical Paper
2017-28-1934
Anil Thakur, Md Tauseef Alam, Venkatesh Kumar PS, P D Kulkarni, Senthur Pandian
Abstract Current high rating thermal loaded engines must have super-efficient lubrication system to provide clean oil at appropriate pressure and appropriate lube oil temperature to every part of the engine at all engine RPM speeds and loads. So oil pump not only have to satisfy above parameters but also it should be durable till engine life. Gerotor pumps are internal rotary positive-displacement pumps in which the outer rotor has one tooth more than the inner rotor. The gear profiles have a cycloidal shape. Both are meshed in conjugate to each other. Gerotor takes up engine power through crankshaft and deliver to various engine consumers at required pressure and required time. Over the complete engine rpm speed and loads range, oil pump need to perform efficiently to provide proper functioning of the engine.
2017-07-10
Technical Paper
2017-28-1954
Premkumarr Santhanamm, K. Sreejith, Avinash Anandan
A local and global environmental concern regarding automotive emissions has led to optimize the design and development of Power train systems for IC engines. Blow-by and Engine oil consumption is an important source of hydrocarbon and particulate emissions in modern IC engines. Great efforts have been made by automotive manufacturers to minimize the impact of oil consumption and blow-by on in-cylinder engine emissions. This paper describes a case study of how simulation played a supportive role in improving piston ringpak assembly. The engine taken up for study is a six cylinder, turbocharged, water cooled diesel engine with a peak firing pressure of 140 bar and developing a power output of 227 KW at 1500 rpm. This paper reveals the influence of stepped land, top groove angle, ring face profile, twist features with regard to tweaking of Blow-by & LOC. Relevant design inputs of engine parameters were provided by the customer to firm up the boundary conditions.
2017-07-10
Technical Paper
2017-28-1964
Rajaganesh Ramamoorthy, T. Venkatesan, R. Rajendran
Abstract Machining of materials has received significant consideration due to the increasing use of machining processes in various industrial applications. In machining, the heat generated in the cutting zone during machining is critical in deciding the work piece quality. Lubricants are widely used to reduce the heat generation. Their usage poses threat to environment and health hazards. Hence, there is a need to identify eco-friendly and user-friendly alternatives to conventional cutting fluids. Modern tribology has facilitated the use of solid lubricants such as graphite, calcium fluoride, molybdenum disulphide, and boric acid as an alternative to cutting fluids in machining. Solid lubricant assisted machining is an environmental friendly clean technology for improving the surface quality of the machined work piece.
2017-07-10
Technical Paper
2017-28-1975
ANIL P M, K Nantha Gopal, B. Ashok
Abstract The present research deals with study of pongamia oil methyl ester as a lubricant by blending with anti-wear additive ZDDP. The experimental work carried in this work aims to investigates the friction and wear characteristics by blending zinc diakyldithio phosphates (ZDDP) with pongamia oil methyl ester as lubricant under various loading conditions and temperatures. The coefficient of friction and wear scar depth were determined using pongamia biodiesel blended with 0.3%, 0.6% and 1 % ZDDP by concentration through high frequency reciprocating wear testing machine for 2 h duration. The reciprocating wear tests were performed on an engine liner-piston ring contact under the loads of 40 N, 60 N and 80 N for 2 h duration at temperatures of 100°C, 125°C 150° C with 10 Hz oscillation frequency. The addition of ZDDP with pongamia biodiesel showed marginal reduction in friction coefficient and wear scar depth under all loads and temperatures.
2017-06-29
Journal Article
2017-01-9376
Alexander Weinebeck, Olivier Reinertz, Hubertus Murrenhoff
Abstract The cluster of excellence “Tailor-Made Fuels from Biomass” (TMFB) at RWTH Aachen University seeks to identify and investigate new potential biofuels and their production routes. To ensure a safe handling in common-rail systems the lubricity of future biofuels is part of the investigations. To further deepen the understanding of the behaviour of such fluids in the regime of boundary lubrication a group of twelve potential biofuels and systematically derived fluids was investigated by a modified version of the standardised High Frequency Reciprocating Rig test procedure for Diesel lubricity. Insufficient lubricity is observed for most biofuels whereas linear molecules with polar head groups provide good or very good lubrication. For all studied groups longer molecules provide better lubricities. The position of the functional group significantly influences the overall lubricity and impact of the carbon chain length.
2017-06-05
Technical Paper
2017-01-1801
Sivasankaran Sadasivam, Aditya Palsule, Ekambaram Loganathan, Nagasuresh Inavolu, Jaganmohan Rao Medisetti
Abstract Powertrain is the major source of noise and vibration in commercial vehicles and has significant contribution on both interior and exterior noise levels. It is vital to reduce the radiated noise from powertrain to meet customer expectations of vehicle comfort and to abide by the legislative noise requirements. Sound intensity mapping technique can identify the critical components of noise radiation from the powertrain. Sound intensity mapping has revealed that oil sump as one of the major contributors for radiated noise from powertrain. Accounting the effect of dynamic coupling of oil on the sump is crucial in predicting its noise radiation performance. Through numerical methods, some amount of work done in predicting the dynamic characteristics of structures filled with fluid.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu, Xiuyong Shi, Jimin Ni, Jiaqi Li, Xiaochuan Xu Sr.
Abstract Oil pump is a critical part of engine lubrication system. The performance and efficiency of oil pump are greatly affected by vibration and noise, which would lead to the pump service life decreasing and pump body easily wearing. Hence the vibration and noise of oil pump is of great importance to study. In this paper, a FEA model of the variable displacement oil pump(VDOP) was established to carry on the modal and noise analysis, while the geometric structure was optimized with test verification. The modal analysis of VDOP was carried out by ABAQUS software, the 3-D unsteady flow field in VDOP was simulated by Pumplinx software, and the sound field was analyzed by ACTRAN acoustic module. Using a special oil pump test bench combined with B&K PULSE vibration and noise test equipment, the NVH and comprehensive performance experiment of the VDOP were carried out here.
2017-03-28
Technical Paper
2017-01-0364
Hiroko Ohtani, Kevin Ellwood, Gustavo Pereira, Thiago Chinen, Siddharthan Selvasekar
Abstract 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.
Viewing 1 to 30 of 3208