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Viewing 1 to 30 of 6758
2017-10-13
Technical Paper
2017-01-5017
Ronith Stanly, Gopakumar Parameswaran, R Rajkiran
Abstract Conventionally, influence of injector coking deposits has been studied using accelerated coking methods. For this work we used in-use vehicles fitted with Common Rail Direct injection (CRDi) injectors in “as-is where is” condition with considerable coked injector deposits. They were then cleaned with a commercial fuel system cleaning solution which did not require the removal of injectors; the influence of injector deposits on vehicular performance and spray field were studied. It was observed that the removal of coking deposits resulted in an increase in the peak power of the vehicle, a lower fuel injected quantity and lower fuel injection duration. It was also observed that the fuel system cleaning procedure resulted in better atomization of fuel spray, better uniformity of the multiple spray jets and an increase in the flow rate of the test injectors.
2017-10-08
Technical Paper
2017-01-2330
Leonardo Israel Farfan-Cabrera, Ezequiel Gallardo, José Pérez-González
Abstract Flouroelastomers and silicone rubbers are commonly employed in static and dynamic seals for automotive applications. In order to prevent premature failures and leakages caused by swelling and/or changes in their mechanical properties, materials for seals are selected according to their compatibility with the environment and fluids involved in the engine operation. Thus, in particular, the use of new fuels and additives in automotive engines requires the assessment of compatibility with common sealing elastomers to prevent failures. Currently, Jatropha oil is being used as a renewable source of fuel in diesel engines for electricity production, transport or agricultural mechanization in various countries. It is used either as biodiesel or as straight vegetable oil (SVO) since it has good heating power and provide exhaust gas with almost no sulfur or aromatic polycyclic compounds. However, the compatibility of elastomers with this SVO has not been investigated yet.
2017-10-08
Technical Paper
2017-01-2198
Zhihong Li, Guoxiu Li, Lan Wang, Hongmeng Li, Jie Wang, Haizhou Guo, Shuangyi He
Abstract The electromagnetic valve driving mechanism is the significant equipment, which plays a vital role in the unit pump injection system; therefore, the performance of the electromagnetic valve directly influences the function of the control system. Based on the operation conditions of the unit pump injection system, a steady electromagnetic valve model was modified to study the influence factors of electromagnetic force and the best combination to get the maximum electromagnetic force. The validation model was verified by experiment. The effects of some crucial parameters upon the electromagnetic force were investigated in the present paper, (including working airspace, magnetic pole’s cross-sectional area, coil position, coil turn, the armature thickness). The results show that the electromagnetic force of the solenoid valve enhanced with the increase of driving current and with the decrease of working airspace.
2017-10-08
Technical Paper
2017-01-2217
Fushui Liu, Ning Kang, Yikai Li, Pei Wang
Abstract The electronic unit pump system, which is widely applied to the heavy-duty diesel engine, belongs to the pulsating high-pressure fuel injection system, and the fuel pressure fluctuations have an essential influence on the spray and combustion in the internal combustion engine. Besides, pressure fluctuations are always aroused by the motion of actuators, such as the injector or other control valves, so it is also an advantage for fault diagnosis and feedback control to ascertain the relationship between the pressure fluctuation and the motion of the actuator. In this study, experiments and 1D-simulation were carried on to investigate the fuel pressure fluctuation characteristics and their correlations with the transient motion of the needle valve in the injector.
2017-10-08
Technical Paper
2017-01-2300
Wei Du, Juejue Lou, Fushui Liu
Abstract As known, the constant injection mass is a criterion for measuring the thermal efficiency of diesel engines. In this study, the effects of nozzle hole diameter on diesel free-spray characteristics were investigated in constant injection mass condition. The experiment was performed in a constant volume combustion chamber equipped with a high pressure common-rail injector that can change nozzles. Three single-hole axis nozzles with different hole diameters were used. High speed camera and Schlieren visualization set-up were used to capture the spray behaviors of liquid phase and vapor phase respectively. For liquid phase spray, the higher nozzle hole diameter, the higher were the liquid phase spray penetration rate and the saturated liquid phase spray penetration length. The saturated liquid phase spray penetration length wound not grow but oscillate around different mean values at the steady stage.
2017-10-08
Technical Paper
2017-01-2314
Genmiao Guo, Zhixia He, Qian Wang, Shenxin Sun, Zhou Chen
Abstract Study of the spray formation in vicinity of the nozzle is essential to better understand and predict the physical processes involved in the diesel atomization. The initial spray patterns were found to be different from one injection to another during our visualization experiments, which was carried out based on a long distance microscope with a high speed camera in this work. It was found that the initial spray might contain a clear single mushroom, tail region and intact liquid column, or have a tail in front of the mushroom without changing its direction. Occasionally, it presented as a double-mushroom shape, or did not include a clear mushroom. Our visualization results showed that the various spray structures were observed at different injection pressures and different injection cycles under the same injection pressure.
2017-10-08
Technical Paper
2017-01-2302
Tobias Knorsch, Dmitrii Mamaikin, Philippe Leick, Philipp Rogler, Jin Wang, Zhilong Li, Michael Wensing
Abstract The fuel spray behavior in the near nozzle region of a gasoline injector is challenging to predict due to existing pressure gradients and turbulences of the internal flow and in-nozzle cavitation. Therefore, statistical parameters for spray characterization through experiments must be considered. The characterization of spray velocity fields in the near-nozzle region is of particular importance as the velocity information is crucial in understanding the hydrodynamic processes which take place further downstream during fuel atomization and mixture formation. This knowledge is needed in order to optimize injector nozzles for future requirements. In this study, the results of three experimental approaches for determination of spray velocity in the near-nozzle region are presented. Two different injector nozzle types were measured through high-speed shadowgraph imaging, Laser Doppler Anemometry (LDA) and X-ray imaging.
2017-10-08
Technical Paper
2017-01-2305
Jun Yamauchi, PengBo Dong, Keiya Nishida, Youichi Ogata
Abstract The performance of a diesel engine largely depends on the spray behavior and mixture formation. Nozzle configurations and operating conditions are important factors that influence spray development. Using numerical and experimental methods, this study focused on the spray development of multi-hole nozzles under non-evaporating and evaporating conditions to compare the influence of nozzle hole diameter and injection pressure on spray characteristics. High-speed video observation was employed to study the properties of spray development under the non-evaporating condition, while the Laser Absorption Scattering technique was used in the observation and quantitative analysis of evaporating spray characteristics in the evaporating condition. In addition, computational fluid dynamics study results published previously [1] were correlated with the current experimental results to provide more detailed explanations about the mechanism of the characteristics of spray behavior.
2017-10-08
Technical Paper
2017-01-2309
Hua Wen, Shuaishuai Liang, Peng Chen, Guangjun Jiang
Abstract In this paper, a contrast experiment has been carried out for discussing the phenomenon of fuel dripping at the end of injection by using the different nozzles with varied materials. The experiment results show that the nozzle deformation has an important effect on the fuel dripping at the end of injection. The duration of the fuel shut-off process with the steel nozzle which producing smaller deformation is shorter than the polymethyl methacrylate nozzle. The mass of fuel dripping with the steel nozzle is less. For implementing a deep analysis on the experimental phenomenon about the fuel dripping with the polymethyl methacrylate nozzle, a three dimensional numerical simulation research was carried out for analyzing the influence of fuel flow inside nozzle on the solid deformation and stress distribution of the nozzle by using Fluid-Structure-Interaction method.
2017-10-08
Technical Paper
2017-01-2327
Joonsik Hwang, Choongsik Bae, Chetankumar Patel, Avinash Kumar Agarwal, Tarun Gupta
Abstract Fuel atomization and air-fuel mixing processes play a dominant role on engine performance and emission characteristics in a direct injection compression ignition engine. Understanding of microscopic spray characteristics is essential to predict combustion phenomena. The present work investigated near nozzle flow and atomization characteristics of biodiesel fuels in a constant volume chamber. Waste cooking oil, Jatropha, and Karanja biodiesels were applied and the results were compared with those of conventional diesel fuel. The tested fuels were injected by a solenoid injector with a common-rail injection system. A high-speed camera with a long distance microscopic lens was utilized to capture the near nozzle flow. Meanwhile, Sauter mean diameter (SMD) was measured by a phase Doppler particle analyzer to compare atomization characteristics.
2017-10-08
Technical Paper
2017-01-2415
Valery Dunaevsky
Abstract The film thickness-roughness ratio Λ has been used since the mid-1960s as a simplified 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 regarding 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 is lower than that of its conventional counterpart, and it overlaps 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
Abstract 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
Abstract High-speed rotating gears are generally lubricated by spray lubrication. Lubricating oil is driven by high-speed rotating gear, and some lubricating oil 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 spray lubrication cooling process is established based on the gear heat transfer behavior under the spray lubrication condition. The influence of different spray 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 spray lubrication. The calculation model of gear temperature based on spray lubrication is established, and the temperature field distribution of gear is obtained.
2017-10-08
Journal Article
2017-01-2427
Suresh Kumar Kandreegula, Rahul Jain, Shivdayal Prasad, Rahul Machiya, Avinash Mandyam
Abstract Automotive vehicle includes various systems like engine, transmission, exhaust, air intake, cooling and many more systems. No doubt the performance of individual system depends upon their core design. But for performance, the system needs to be fastened properly. In automotive, most of the joints used fasteners which helps in serviceability of the components. There are more than thousands of fasteners used in the vehicle. At various locations, we found issue of bolt loosening and because of this design intent performance has not met by the system. During product development of ECS (Engine cooling system), various issues reported to loosening the bolt. The pre-mature failure of bolt loosening, increases the interest in young engineers for understanding the behavior of fastener in vehicle running conditions. This paper focuses on the design of wedge shape of washer to avoid bolt loosening.
2017-10-08
Journal Article
2017-01-2431
Michitaka Yamamoto, Takayuki Hosogi, Tetsuji Watanabe, Yuki Nishida
Abstract Over the past decades, the automotive industry has made significant efforts to improve engine fuel economy by reducing mechanical friction. Reducing friction under cold conditions is becoming more important in hybrid vehicle (HV) and plug-in hybrid vehicle (PHV) systems due to the lower oil temperatures of these systems, which results in higher friction loss. To help resolve this issue, a new internal gear fully variable discharge oil pump (F-VDOP) was developed. This new oil pump can control the oil pressure freely over a temperature range from -10°C to hot conditions. At 20°C, this pump lowers the minimum main gallery pressure to 100 kPa, thereby achieving a friction reduction effect of 1.4 Nm. The developed oil pump achieves a pressure response time constant of 0.17 seconds when changing the oil pressure from 120 kPa to 200 kPa at a temperature of 20°C and an engine speed of 1,600 rpm.
2017-09-19
Technical Paper
2017-01-2097
Josh Elrod
Abstract Automated collar and nut installation requires complex hardware on the wet side of the spar or wing panel. Wet side automatic tool changers are becoming common but an operator is often required to connect electrical, pneumatic and fastener feed system components. This is unacceptable in a lights-out cell, and any fully automatic solution must be reliable while satisfying demanding design requirements. Figure 1 Wet side anvil for nut installation. The 737 Spar Assembly Line (SAL) is a new lights-out machine cell at the Boeing factory in Renton, Washington. The SAL machines are equipped with a unique fully automatic tool changer (ATC). The wet side ATC interface is designed to automatically connect conventional as well as more unique services such as fastener feed. The fastener feed ATC module, called the “spinner,” rotates with the machine’s wet side rotary axis (C axis). It consists of a stack of rotors that rotate inside of a stationary annulus.
2017-09-19
Technical Paper
2017-01-2094
Tyler Everhart
Abstract Electroimpact, in collaboration with Boeing, has developed an advanced robotic assembly cell, dubbed “The Quadbots.” Using Electroimpact’s patented Accurate Robot technology and multi-function end effector (MFEE), each robot can drill, countersink, inspect hole quality, apply sealant, and insert fasteners into the part. The cell consists of 4 identical machines simultaneously working on a single section of the Boeing 787 fuselage, two on the left, and two on the right. These machines employ “collision avoidance” a new feature in their software to help them work more synchronously. The collision avoidance software uses positional feedback from external safety rated encoders mounted to the motors on the robot. From this feedback, safe spaces, in the form of virtual boundaries can be created. Such that a robot will stop and wait if the adjacent robot is in, or going to move into its programmed work envelope.
2017-09-19
Technical Paper
2017-01-2098
Didier Friot, Loic Meiffre, Christophe Vandaele
Abstract With air traffic demand constantly increasing and several years of aircraft production in their backlog, major aircraft manufacturers are now shifting their focus toward improving assembly process efficiency. One of the most promising solutions, known as “One Side Assembly”, aims to perform the whole assembly sequence from one side of the structure (drilling, temporary fastener installation and removal, blind fastener installation, assembly control) and with a high level of integrated automation. A one-sided, or blind fastener that is capable of matching the performance of current two-sided structural fasteners while meeting volume and cost objectives can be a major driver for assembly process efficiency improvements. To achieve a blind fastener assembly capable of both fully automated and manual installations while providing robust cycle times and assembly cost reductions is full of challenges.
2017-09-17
Journal Article
2017-01-2523
Seonho Lee, Yoongil Choi, Kyuntaek Cho, Hyounsoo Park
Abstract Raceway Brinell damage is one major cause of wheel bearing (hub unit) noise during driving. Original Equipment Manufacturer (OEM) customers have asked continuously for its improvement to the wheel bearing supply base. Generally, raceway Brinelling in a wheel hub unit is a consequence of metallic yielding from high external loading in a severe environment usually involving a side impact to the wheel and tire. Thus, increasing the yielding strength of steel can lead to higher resistance to Brinell damage. Both the outer ring and hub based on Generation 3 (Gen. 3) wheel unit are typically manufactured using by AISI 1055 bearing quality steel (BQS); these components undergo controlled cooling to establish the core properties then case hardening via induction hardening (IH). This paper presents a modified grade of steel and its IH design that targets longer life and improves Brinell resistance developed by ILJIN AMRC (Advanced Materials Research Center).
2017-09-17
Journal Article
2017-01-2522
Chao Wen, Lu Zhang, Tong Luo, Dejie Huang, Yu Liu
Abstract The actual installed conditions of 1st, 2nd and 3rd generation of wheel bearing were introduced. The theoretical factors of the axial fastening force for the axle (or CVJ bolts) and nuts were analyzed and the requirements for building up a precise axial force test system were given out. Four testing plans were discussed for the requirements. Based on the cases, the axial force test system was built up, and the axial force test was successfully carried out for the front wheel bearing of a car.
2017-09-17
Journal Article
2017-01-2524
Sebastiano Rizzo, Stefano Pagliassotto
Abstract Wheel bearings are safety-critical automotive components. For this application, the steel rolling elements are subjected to fatigue failure and therefore play a key role in overall bearing fatigue life performance. This performance is influenced by metallurgical, mechanical, and physical properties obtained by precise manufacturing process parameters. These properties are continuously analyzed and are evolving at all bearing manufacturing companies. Last year, the Precision Bearing Components (PBC) Group of NN Inc., a global supplier of steel rolling elements for wheel bearings, developed a non-conventional heat treatment process for 100Cr6 (SAE 52100) rolling element steel for improved fatigue performance. The results of wheel bearing rolling contact fatigue (RCF) tests showed the importance of rolling element dimensional stability. As retained austenite transformed to the martensite phase, rolling element volume increase occurred, leading to fatigue failure.
2017-09-17
Journal Article
2017-01-2521
Stacey Scherer
Abstract Wheel bearing friction torque (“drag”) directly contributes to vehicle fuel economy and CO2 emissions. At the same time, one of the most important factors for long-term durability of wheel bearings is effective seal performance. Since these two factors are often in conflict, it is important to balance the desire for low friction with the need for optimal sealing. One factor that affects wheel bearing sealing performance is the distortion of the outer ring that occurs when the bearing is mounted to the steering knuckle with fasteners. Minimizing this distortion is not just important for sealing, however. This paper explores the relationship between the outer ring distortion and the resulting friction torque. A design of experiments (DOE) approach was used in order to study the effects of the fastening bolt torque, constant velocity joint (CVJ) fastening torque, and outer ring distortion on component-level drag.
2017-09-17
Journal Article
2017-01-2527
Dejie Huang, Xu Zhou, Peiqing Qian, Chao Wen, Yu Liu
Abstract The seal structure and key parameters of wheel bearing were introduced. Research on sealing failure diagnosis, abrasive scratch analysis, residual interference, and abrasion reconstruction was carried out for a typical seal structure. Based on these methods of scientific failure analysis, eight causes of seal failure were summarized systematically, which were important for the guidance of seal design and failure analysis of wheel bearings.
2017-09-17
Journal Article
2017-01-2525
Seungpyo Lee, Mincheol Park
Abstract The primary functions of bearing seals are to prevent lubrication from escaping and foreign material from entering, the effectiveness of which is determined by the design of the seal lips. Bearings with low friction rotation are in great demand in the automotive market as a direct result of enforced vehicle fuel economy and reduced CO2 emissions regulations. Therefore, bearings with good sealing function and low friction rotation are required. This makes designing a seal challenging as the ideologies of high seal-ability and low friction rotation tend to be contradictory. Current estimations of bearing seal friction or rotational torque require significant time and cost through empirical methods of trial and error. Research into the estimation of bearing rotational torque through numerical analysis, based on finite element methods, is the focal point of this paper.
2017-09-17
Journal Article
2017-01-2526
Robert G. Sutherlin
Abstract As material cleanliness and bearing lubrication have improved, wheel bearings are experiencing less raceway spalling failures from rotating fatigue. Warranty part reviews have shown that two of the larger failure modes for wheel bearings are contaminant ingress and Brinell damage from curb and pothole impacts. Warranty has also shown that larger wheels have higher rates of Brinell warranty. This paper discusses the Brinell failure mode for bearings. It reviews a vehicle test used to evaluate Brinell performance for wheel bearings. The paper also discusses a design of experiments to study the effects of factors such as wheel size, vehicle loading and vehicle position versus the bearing load from a vehicle side impact to the wheel. As the trend in vehicle styling is moving to larger wheels and low profile tires, understanding the impact load can help properly size wheel bearings.
2017-09-04
Technical Paper
2017-24-0020
Michele Becciani, Alessandro Bianchini, Matteo Checcucci, Lorenzo Ferrari, Michele De Luca, Luca Marmorini, Andrea Arnone, Giovanni Ferrara
Abstract The onset of aerodynamic instabilities in proximity of the left margin of the operating curve represents one of the main limitations for centrifugal compressors in turbocharging applications. An anticipated stall/surge onset is indeed particularly detrimental at those high boost pressures that are typical of engine downsizing applications using a turbocharger. Several stabilization techniques have been investigated so far to increase the rangeability of the compressor without excessively reducing the efficiency. One of the most exploited solutions is represented by the use of upstream axial variable inlet guide vanes (VIGV) to impart a pre-whirl angle to the inlet flow. In the pre-design phase of a new stage or when selecting, for example, an existing unit from an industrial catalogue, it is however not easy to get a prompt estimation of the attended modifications induced by the VIGV on the performance map of the compressor.
2017-09-04
Technical Paper
2017-24-0005
Guillaume Goumy, Pascal Chesse, Nicolas Perrot, Rémi Dubouil
Abstract Downsizing has nowadays become the more widespread solution to achieve the quest for reaching the fuel consumption incentive. This size reduction goes with turbocharging in order to keep the engine power constant. To reduce the development costs and to meet the ever tightening regulations, car manufacturers rely more and more on computer simulations. Thus developing accurate and predictable turbocharger models functioning on a wide range of engine life cases became a major requirement in industrial projects. In the current models, compressors and turbines are represented by look-up tables, experimentally measured on a turbocharger test bench, at steady point and high inlet turbine temperature. This method results in limited maps : on the one hand the compressor surge line and on the other hand the flow resistance curve behind the compressor. Mounted on an engine, the turbocharger encounters a wider scale of functioning points.
2017-09-04
Technical Paper
2017-24-0031
Imre Gergely Nagy, Andrea Matrisciano, Harry Lehtiniemi, Fabian Mauss, Andreas Schmid
Abstract Large two-stroke marine Diesel engines have special injector geometries, which differ substantially from the configurations used in most other Diesel engine applications. One of the major differences is that injector orifices are distributed in a highly non-symmetric fashion affecting the spray characteristics. Earlier investigations demonstrated the dependency of the spray morphology on the location of the spray orifice and therefore on the resulting flow conditions at the nozzle tip. Thus, spray structure is directly influenced by the flow formation within the orifice. Following recent Large Eddy Simulation resolved spray primary breakup studies, the present paper focuses on spray secondary breakup modelling of asymmetric spray structures in Euler-Lagrangian framework based on previously obtained droplet distributions of primary breakup.
2017-09-04
Technical Paper
2017-24-0023
Karim Gharaibeh, Aaron W. Costall
Abstract Internal combustion engines are routinely developed using 1D engine simulation tools. A well-known limitation is the accuracy of the turbocharger compressor and turbine sub-models, which rely on hot gas bench-measured maps to characterize performance. Such discrete map data is inherently too sparse to be used directly in simulation, and so a preprocessing algorithm interpolates and extrapolates the data to generate a wider, more densely populated map. Methods used for compressor map interpolation vary. They may be mathematical or physical in nature, but there is no unified approach, except that they typically operate on input map data in SAE format. For decades it has been common practice for turbocharger suppliers to share performance data with engine OEMs in this form. This paper describes a compressor map interpolation technique based on the nondimensional compressor flow and loading coefficients, instead of SAE-format data.
2017-09-04
Technical Paper
2017-24-0073
Carlo Beatrice, Giacomo Belgiorno, Gabriele Di Blasio, Ezio Mancaruso, Luigi Sequino, Bianca Maria Vaglieco
Abstract Technologies for direct injection of fuel in compression ignition engines are in continuous development. One of the most investigated components of this system is the injector; in particular, main attention is given to the nozzle characteristics as hole diameter, number, internal shape, and opening angle. The reduction of nozzle hole diameter seems the simplest way to increase the average fuel velocity and to promote the atomization process. On the other hand, the number of holes must increase to keep the desired mass flow rate. On this basis, a new logic has been applied for the development of the next generation of injectors. The tendency to increase the nozzle number and to reduce the diameter has led to the replacement of the nozzle with a circular plate that moves vertically. The plate motion allows to obtain an annulus area for the delivery of the fuel on 360 degrees; while the plate lift permits to vary the atomization level of the spray.
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