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Viewing 271 to 300 of 15278
Technical Paper
2014-04-01
Guenter Bischof, Karl Reisinger, Thomas Singraber, Andreas Summer
In this work, we investigate the rotor bearing loads of a flywheel-based KERS that are caused by dynamic forces and gyroscopic torques during representative driving maneuvers. Based on the governing equations of motion of a gyroscope, the equations for the rotor-platform interactions are developed. These equations, which relate the vehicle's roll, pitch and yaw rate with the internal transverse torques on the flywheel, are integrated into a commercial vehicle dynamics program. An average passenger car model equipped with a typical high-speed flywheel energy storage system is used for the numerical investigations. The flywheel bearing loads produced by some selected, representative driving maneuvers are simulated for different orientations of the flywheel spin axis relative to the body frame. In addition, the dynamic response of the vehicle to the reaction torques is investigated in open and closed-loop vehicle dynamics simulations. Thus, the steering response of a driver model to the gyrodynamics of a flywheel-based KERS is obtained for fully charged KERS as well as during braking and under acceleration boosts.
Technical Paper
2014-04-01
Ralph S. Shoberg, Jeff Drumheller
Abstract Reliable wheel attachment must start with proper tightening of the lug nuts in order to achieve the clamping force necessary to hold the vehicle's wheels securely for all operating conditions. It is the purpose of this paper to provide a complete overview of the theory and practice of using torque-angle signature analysis methods to examine the installation and audits of wheel lug nuts. An accurate estimate of clamp load can be determined without actually measuring the clamp load. The torque-angle signature analysis, known as “M-Alpha”, performed on tightening and loosening curves provides a powerful tool to understand the integrity of a bolted joint when clamp load data is not available. This analysis technique gives insight into the frictional effects, material properties, and geometric factors that can affect the clamp load attained during the installation process.
Technical Paper
2014-04-01
Kenji Matsumoto, Yuki Ono, Yoichi Kojima
In order to maintain the performance of push belt Continuously Variable Transmissions (CVT) over a long period of time, it is important to acquire a fundamental understanding of lubrication performance between a pulley and a metal V-belt. This work examined oil film thickness using the contact pressure on a sliding surface of pulley sheave during driving, which was obtained with an uniquely developed measurement technique. The contact between a belt element and a pulley sheave was treated as a group of small elliptical contact zones. The pressure-viscosity characteristics of lubricant were assigned to Reynolds equation with Roelands experimental formula. Also, in order to increase convergence of the calculation, a multigrid method was used. Calculation results indicate that the oil film thickness at a peak contact pressure measured was approximately 0.3-0.4 μm.
Technical Paper
2014-04-01
Norihiro Hamada, Kiyohiro Suzuki
Abstract ADC12 is one of the common aluminum alloys for automobiles because it has suitable for casting and machining. However, the corrosion resistance of ADC12 is insufficient in comparison with other aluminum alloys. The corrosion depends on chemical composition of aluminum and circumstance around aluminum. It was considered that a crevice such as a seal gap accelerates corrosion rate. Therefore, the corrosion at a sealing gap between ADC12 and rubber gasket was investigated. Salt water corrosion tests were carried out with an o-ring compressed between ADC12 plate and plastic plate. Corrosion depth and corrosion area at sealing surface were measured with a microscope. The corrosion depth at the sealing surface was deeper than that outside it. Since smooth surface of aluminum prevented the sealing surface from corrosion, it was considered that the narrow sealing gap enabled to decrease in the corrosion rate.
Technical Paper
2014-04-01
Robert V. Petrach, David Schall, Qian Zou, Gary Barber, Randy Gu, Laila Guessous
Coatings have the potential to improve bearing tribological performance. However, every coating application process and material combination may create different residual stresses and coating microstructures, and their effect on bearing fatigue and wear performance is unclear. The aim of this work is to investigate coating induced residual stress effects on bearing failure indicators using a microstructural contact mechanics (MSCM) finite element (FE) model. The MSCM FE model consists of a two-dimensional FE model of a coated bearing surface under sliding contact where individual grains are represented by FE domains. Interactions between FE domains are represented using contact element pairs. Unique to this layered rolling contact FE model is the use of polycrystalline material models to represent realistic bearing and coating microstructural behavior. The MSCM FE model was compared to a second non-microstructural contact mechanics (non-MSCM) model. Results show tensile residual stresses induced by the coating have a negative impact on the bearing performance indicated by the increase in subsurface localized plastic strains.
Technical Paper
2014-04-01
Michele Battistoni, Qingluan Xue, Sibendu Som, Eric Pomraning
The internal structure of Diesel fuel injectors is known to have a significant impact on the nozzle flow and the resulting spray emerging from each hole. In this paper the three-dimensional transient flow structures inside a Diesel injector is studied under nominal (in-axis) and realistic (including off-axis lateral motion) operating conditions of the needle. Numerical simulations are performed in the commercial CFD code CONVERGE, using a two-phase flow representation based on a mixture model with Volume of Fluid (VOF) method. Moving boundaries are easily handled in the code, which uses a cut-cell Cartesian method for grid generation at run time. First, a grid sensitivity study has been performed and mesh requirements are discussed. Then the results of moving needle calculations are discussed. Realistic radial perturbations (wobbles) of the needle motion have been applied to analyze their impact on the nozzle flow characteristics. Needle radial motions are based on high-speed X-ray phase-contrast imaging collected at Argonne National Laboratory.
Technical Paper
2014-04-01
Federico Brusiani, Gian Marco Bianchi, Stefania Falfari, Angelo Onorati, Tommaso Lucchini, Rita Di Gioia
Abstract Today, multi-hole Diesel injectors can be mainly characterized by three different nozzle hole shapes: cylindrical, k-hole, and ks-hole. The nozzle hole layout plays a direct influence on the injector internal flow field characteristics and, in particular, on the cavitation and turbulence evolution over the hole length. In turn, the changes on the injector internal flow correlated to the nozzle shape produce immediate effects on the emerging spray. In the present paper, the fluid dynamic performance of three different Diesel nozzle hole shapes are evaluated: cylindrical, k-hole, and ks-hole. The ks-hole geometry was experimentally characterized in order to find out its real internal shape. First, the three nozzle shapes were studied by a fully transient CFD multiphase simulation to understand their differences in the internal flow field evolutions. In detail, the attention was focused on the turbulence and cavitation levels at hole exit. The adopted simulation strategy was previously validated against experimental data.
Technical Paper
2014-04-01
David Greif, Wilfried Edelbauer, Jure Strucl
Abstract The paper addresses aspects of modeling cavitating flows within high pressure injection equipment while considering the effects of liquid compressibility. The presented numerical study, performed using the commercial CFD code AVL FIRE®, mimics common rail conditions, where the variation in liquid density as a function of pressure may be relevant owing to very high pressure injection scenarios. The flow through the injector has been calculated and the conditions at the outlet of the nozzle orifice have been applied as inlet condition for subsequent Euler-Lagrangian spray calculations to investigate the effects of liquid compressibility treatment on spray propagation. Flows of such nature are of interest within automotive and other internal combustion (IC) related industries to obtain good spray and emissions characteristics. In the development process of the injection equipment, predictive methods using Computational Fluid Dynamics (CFD) contribute to lower development costs, improved engine efficiency, decreased emissions and nevertheless shorter development cycles.
Technical Paper
2014-04-01
Mark A. Shost, Ming-Chia Lai, Bizhan Befrui, Peter Spiekermann, Daniel L. Varble
Abstract Development of in-cylinder spray targeting, plume penetration and atomization of the gasoline direct-injection (GDi) multi-hole injector is a critical component of combustion developments, especially in the context of the engine downsizing and turbo-charging trend that has been adopted in order to achieve the European target CO2, US CAFE, and concomitant stringent emissions standards. Significant R&D efforts are directed towards the optimization of injector nozzle designs in order to improve spray characteristics. Development of accurate predictive models is desired to understand the impact of nozzle design parameters as well as the underlying physical fluid dynamic mechanisms resulting in the injector spray characteristics. This publication reports Large Eddy Simulation (LES) analyses of GDi single-hole skew-angled nozzles, with β=30° skew (bend) angle and different nozzle geometries. The objective is to extend previous works to include the effect of nozzle-hole length over diameter ratio (l/d) and fuel injection pressure on spray skew angle, spray plume cone angle and primary breakup length.
Technical Paper
2014-04-01
Akihiro Honda, Motoichi Murakami, Yuichiro Kimura, Katsuhiro Ashihara, Shinichi Kato, Yuichiro Kajiki
Fuel efficiency improvement measures are focusing on both cold and hot conditions to help reduce CO2 emissions. Recent technological trends for improving fuel economy such as hybrid vehicles (HVs), engine start and stop systems, and variable valve systems feature expanded use of low-temperature engine operation regions. Under cold conditions (oil temperature: approximately 30°C), fuel consumption is roughly 20% greater than under hot conditions (80°C). The main cause of the increased friction under cold conditions is increased oil viscosity. This research used the motoring slipping method to measure the effect of an improved crankshaft bearing, which accounts for a high proportion of friction under cold conditions. First, the effect of clearance was investigated. Although increasing the clearance helped to decrease friction due to the oil wedge effect, greater oil leakage reduced the oil film temperature increase generated by the friction. Consequently, the friction reduction effect was less than that predicted by the lubrication calculation.
Technical Paper
2014-04-01
Shigenori Ichinose, Kiyoshi Iwade, Yoshiharu Hata
Abstract The oil flow in the oil ring groove was observed in order to improve the oil ejection efficiency in the oil ring groove. The oil flow was visualized with a clear head piston using fluorescing agent and particles under motoring condition. The influences of oil ring specification on the direction and the velocity of the oil flow were evaluated. The velocity of the oil ring with oil vent holes was faster than that of the oil ring without oil vent holes. In the case of the oil ring with vent holes, the reverse flow of the oil toward the front side was observed in the back clearance. Therefore, oil vent holes can change the oil flow and improve the oil ejection efficiency in the oil ring groove.
Technical Paper
2014-04-01
Jingru Bao, Yi Ding, Sibo Hu, Ping Hu
As one of the most important auto-body moving parts, door hinge is the key point of door design and its accessories arrangement, also the premise of the door kinematic analysis. We proposed an effective layout procedure for door hinge and developed an intelligent system on CATIA CAA platform to execute it. One toolbar and five function modules are constructed - Axis Arrangement, Section, Parting Line, Kinematic, Hinge Database. This system integrated geometrical algorithms, automatically calculate the minimum clearances between doors, fender and hinges on sections to judge if the layout is feasible. As the sizes of the clearances are set to 0s, the feasible layout regions and extreme start/end points are shown in parts window, which help the engineer to check the parting line and design a new one. Our system successfully implemented the functions of five modules for the layout of door hinge axis and parting line based on a door hinge database. An instance is carried out and the result shows that our system has great feasibility and validity to arrange the door hinge and shorten the design periods.
Technical Paper
2014-04-01
Qingluan Xue, Michele Battistoni, Sibendu Som, Shaoping Quan, P. K. Senecal, Eric Pomraning, David Schmidt
Abstract This paper implements a coupled approach to integrate the internal nozzle flow and the ensuing fuel spray using a Volume-of-Fluid (VOF) method in the CONVERGE CFD software. A VOF method was used to model the internal nozzle two-phase flow with a cavitation description closed by the homogeneous relaxation model of Bilicki and Kestin [1]. An Eulerian single velocity field approach by Vallet et al. [2] was implemented for near-nozzle spray modeling. This Eulerian approach considers the liquid and gas phases as a complex mixture with a highly variable density to describe near nozzle dense sprays. The mean density is obtained from the Favreaveraged liquid mass fraction. The liquid mass fraction is transported with a model for the turbulent liquid diffusion flux into the gas. Simulations were performed in three dimensions and the data for validation were obtained from the x-ray radiography measurements Kastengren et al. [3] at Argonne National Laboratory for a diesel fuel surrogate n-dodecane.
Technical Paper
2014-04-01
Yannick Baubet, Carl Pisani, Phil Carden, Lex Molenaar, Adam Reedman
Rolling element bearings are known to give reduced friction losses when compared to the hydrodynamic bearings typically used to support the crankshaft in multi-cylinder engines. This paper describes the design, manufacturing and testing of a modified 4 cylinder light duty Diesel production engine with rolling element bearings applied at the crankshaft main bearings in view of CO2 emission reduction. Selection of the most suitable type of roller bearings for this specific application was made. Technology development through multi-body dynamic simulation and component testing was done to assess the effect on rolling elements performance due to the key challenges inherent to such bearing solution: high instantaneous combustion load, lubrication with low viscosity and contaminated oil, and the cracking process to split the bearing outer raceway. Compared to the baseline production engine with hydrodynamic bearings, a clear cranktrain friction reduction (−58% at ambient and −30% at 90°C) was measured under motored conditions.
Technical Paper
2014-04-01
Mathieu Picard, Camille Baelden, Tian Tian, Takayuki Nishino, Eiji Arai, Hiroyuki Hidaka
The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. A model of the oil seals is developed to calculate internal oil consumption (oil leakage from the crankcase through the oil seals) as a function of engine geometry and operating conditions. The deformation of the oil seals trying to conform to housing distortion is calculated to balance spring force, O-ring and groove friction, and asperity contact and hydrodynamic pressure at the interface. A control volume approach is used to track the oil over a cycle on the seals, the rotor and the housing as the seals are moving following the eccentric rotation of the rotor. The dominant cause of internal oil consumption is the non-conformability of the oil seals to the housing distortion generating net outward scraping, particularly next to the intake and exhaust port where the housing distortion valleys are deep and narrow. Simulation with housing transverse waviness shows that increasing spring force can lead to an unexpected increase in internal oil consumption.
Technical Paper
2014-04-01
Subrata Sarkar, Kailash Golecha, Surbhi Kohli, Vaughn Mills, Mustafa Huseyin, Pritam Bhurke, Stefan Walter, Ravikumar S. Dinni, Shrikrishna Jaywant Deshpande
Abstract The primary objective of this study was to provide an efficient system solution for the removal of fuel from an Active Drain Liquid Trap (ADLT), used in automotive vent systems; using a Jet Pump. The Voice of Customer was collected and analyzed. The two major focus areas identified were - improvement in robustness of Jet Pump performance and maximization of induced flow. Robust design of such a Jet Pump was carried out using Taguchi's Orthogonal Crossed Array based parameter design, through computer simulation. Two Jet Pumps were designed for Gasoline based vehicles; one with the conventional approach and the other with the robust design approach. Both were put on a field trial, integral with the vent system. The robust design showed a tremendous improvement in performance over the conventional design, due to the elimination of cavitation and insensitivity to noises.
Collection
2014-04-01
This technical paper collection will cover a very broad range of applications, processes and technologies on plastic components.
Standard
2014-03-31
This specification covers a tetrafluoroethylene/propylene rubber (FEPM) in the form of molded rings. These rings have been used typically as static sealing rings for continuous use from -5 to +232 degrees C (+23 to +450 degrees F) in dry air, hydraulic fluids, synthetic lubricants, and high pH chemical decontamination fluids, but usage is not limited to such applications.
WIP Standard
2014-03-25
The purpose of this document is to provide a listing for current commercial and military aircraft landing gear systems and their types and manufacturers. Data has been provided for the following aircraft types: wide body jet airliners, narrow body jet airliners, turboprop/commuter aircraft, cargo/transport aircraft and fighter/attack aircraft. The aircraft that have been included in this document are in operational service either with airlines, business, cargo or military operators. No information is presented for aircraft that are currently being developed or that are not in extensive usage. This document will provide an informational reference for landing gear engineers to access when evaluating other gear and aircraft systems.
Standard
2014-03-25
This SAE Aerospace Standard (AS) establishes the requirements for self-aligning, self-lubricating plain spherical bearings incorporating polytetrafluoroethylene (PTFE) in a liner between the ball and the outer race for use in a temperature range of -65 to +250 °F (-54 to +121 °C).
Technical Paper
2014-03-24
Pawut Namklang, Vitoon Uthaisangsuk
Abstract Ultra-High Strength Steels (UHSSs) have been widely used to reduce car body weight and to increase crashworthiness of new generation vehicles. To manufacture such components, hot stamping or press hardening process was developed, in which sheet metal forming at high temperature and quenching procedure were performed successively in a single step. Generally, hot stamped parts exhibit exceptionally high strength properties and low springback effect. In this work, a direct hot stamping process of boron-alloyed steel with a thickness of 1.4 mm was investigated. Temperature evolutions on blank and tools were determined during the experiments. Afterwards, microstructure analysis, hardness measurement and tensile test for different locations, namely, at the bottom and flange of the formed samples were carried out. It was found that final parts after the hot forming mostly showed a fully martensitic microstructure. Yield strength and tensile strength up to 1100 and 1500 MPa, respectively, could be obtained.
Standard
2014-03-23
This specification covers a tetrafluoroethylene/propylene rubber (FEPM) in the form of molded rings. These rings have been used typically as static sealing rings for continuous use from -5 to +232 degrees C (+23 to +450 degrees F) in dry air, in hydraulic fluids, synthetic lubricants, and high pH chemical decontamination fluids, but usage is not limited to such applications.
Standard
2014-03-23
This standard establishes the inspection requirements and acceptance standards for optimum surface finish O-ring packings and gaskets. (This is not an O-ring specification per se). This standard must be used in conjunction with an O-ring drawing and/or material specification. This standard is to be specified only where stringent performance requirements are necessary.
Standard
2014-03-19
This specification covers a nitrile (NBR) rubber in the form of sheet, strip, tubing, extrusions, and molded shapes. Primarily for hose, packings, bushings, grommets, and seals in contact with hot, petroleum-base lubricating oils and glycol-type coolants from -40 degrees to +100 degrees C (-40 degrees to +212 degrees F).
Standard
2014-03-19
This specification covers 45 durometer hardness, high strength silicone rubber.
Standard
2014-03-19
This specification covers a nitrile (NBR) rubber in the form of sheet, strip, tubing, extrusions, and molded shapes. These products have been used typically for parts, such as gaskets, diaphragms, bushings, grommets, and sleeves, requiring resistance to aromatic and aliphatic fuels when continuously or alternately exposed to both, but usage is not limited to such applications.
Standard
2014-03-19
This specification covers established metric (SI) manufacturing tolerances applicable to non-cellular rubber products ordered to metric dimensions. These tolerances apply to all conditions, unless otherwise noted. The term "exclusive" applies only to the higher figure of the specified range.
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