Search

A comparison of the NHTSA advanced dummy and the Hybrid III is presented in this paper based on their performance in repeated sled tests under 3 different restraint systems. The restraint systems considered are: the airbag alone, the 3-point belt alone, and a combined use of the airbag and the 3-point belt. Various time-histories pertaining to accelerations, angular velocities, deflections and forces have been compared between the two dummies in order to study their repeatability. The Hybrid III appears to be more repeatable than the NHTSA advanced dummy in its response in one case, that of restraint with the 3-point belt alone. The response of the NHTSA advanced dummy in two other restraint modes, the airbag alone and the combination of 3-point belt and airbag, appears to be no less repeatable than that of Hybrid III in this series of tests. The variability in the sled pulse appears to mask the differences, if any, in the variability of response between the two dummies in two later cases. Under some restraint configurations, for some body segments, the NHTSA advanced dummy appears to show better repeatability. In addition, it appears that the read-out of the chest-deflection measurement system in the NHTSA advanced dummy is not well defined because it is influenced by the rotation of the upper spine relative to the lower spine. (A) For the covering abstract see ITRD E106439.

A line of high-quality multigrade diesel engine oils suitable for long drain applications has been developed using hydrotreated base stock. To meet the growing demand for lubricants in Canada and to offset the high degree of reliance on imports, a new lubricant facility has been constructed in the Toronto area. The facility employs a process in which feedstock undergoes very severe hydrogenation under high pressure. Products are then fractionated, dewaxed, and again hydrogenated under more moderate conditions. Advantages of the hydrotreating process include increased yield, greater flexibility in producing various viscosity grades, and less dependence on selected lubricant crude sources. Two hydrotreated base stocks were used to conduct necessary product development prior to introducing the new lubricant facility. Laboratory and engine dynamometer tests indicated that lubricating oils using hydrotreated base stock had superior control of diesel piston deposits and oxidative viscosity increase. Excellent performance of multigrade diesel engine oils using both hydrotreated and solvent-refined base stock over extended oil change intervals was demonstrated in extensive field trials. Cold weather benefits for multigrade diesel engine oils were defined by cold room studies and outdoor trials. Low volatility, high thermal stability, and good additive response were particular features contributing to overall performance improvements. Finished lubricants formulated from hydrotreated base stocks of similar viscosity index appeared to have similar performance characteristics, regardless of crude source.

Ignition and flame inception are well recognised as affecting performance and stable operation of spark ignition engines. The very early stage of combustion is indeed the main source of cycle-to-cycle variability, in particular in gasoline direct injection (GDI) engines, where mixture formation may lead to non-homogenous air-to-fuel distributions, especially under some speed and load conditions. From a numerical perspective, 3D modelling of combustion within Reynolds Averaged Navier Stokes (RANS) approaches is not sufficient to provide reliable information about cyclic variability, unless proper changes in the initial conditions of the flow transport equations are considered. Combustion models based on the flamelet concept prove being particularly suitable for the simulation of the energy conversion process in internal combustion engines, due to their low computational cost. These models include a transport equation for the flame surface density, which needs proper initialization. A flame collocation is indeed to be properly made when starting the calculations, often just based on the user's skill and without resorting to any quantitative data derived from experiments. However, the way to define initial conditions for cyclic variability prediction is often based on just statistical considerations. This work aims at exploiting information derived from images collected in a single cylinder 4-stroke GDI engine to properly collocate the flame at the start of the combustion calculation. The considered engine is optically accessible through a wide fused-silica window fixed on the piston crown having a Bowditch design. Image processing methodologies are applied to evaluate local and integral luminous intensity, and flame morphology parameters. The collected data allows improving the numerical simulation and gaining hints about the main parameters defining the engine cyclic variability.

No two battery cells can be identical. Charging/discharging a battery pack without monitoring cell voltages or SoC (State-ofCharge) will cause cell voltages to deviate over time and the packs useable capacity to decrease quickly. To redistribute charge uniformly among cells, various cell balancing methods have been proposed in the literature. In this paper, a cell balancing method based on a single switched-capacitor is presented from a brand new perspective. Unlike the traditional balancing methods that rely on the voltage divergence criterion, this paper uses the SoC divergence criterion to shuttle charge from a highly charged cell to a poorly charged cell. Moreover, an equivalent resistance of the single-switched capacitor topology is derived in steady state. For fast cell balancing, design guidelines are provided for selecting a proper switching-time period and the capacitor parameters. Ultracapacitors are recommended to achieve this goal. To demonstrate the effectiveness of the proposed method, numerous simulations are performed on a string of five series connected Lithium-ion cells that have different initial SoCs and electrochemical parameters. Finally, the simulation results are compared with that of a traditional balancing method.

Variable compression ratio and variable displacement technologies are adopted in internal combustion engines because these features provide further degrees of freedom to optimize engine performance for various operating conditions. This paper focuses on a multiple-link mechanism that realizes variable compression ratio and displacement by varying the piston motion, specifically the Top Dead Center (TDC) and Bottom Dead Center (BDC) positions relative to the crankshaft. It is determined that a major requirement for the design of this mechanism is when the control action changes monotonically over its whole range, the compression ratio and the displacement should change in opposite directions monotonically. This paper presents an approach on how to achieve multiple-link mechanism geometric designs that fulfill this requirement. First, a necessary and sufficient condition, and a stronger sufficient condition are obtained on how the TDC and BDC positions should change with respect to the control action to fulfill the design requirement. Then Design of Experiments (DoE) methodology is used for creating sets of geometric designs of the mechanism, for which kinematics are calculated and checked against the conditions. A feasible design that satisfies the conditions is selected and detailed study on such characteristics as piston motion, stroke length, displacement, combustion chamber volume, and compression ratio etc. is performed. The design approach and obtained results serve as a basis for further analysis and optimization of the multiple-link mechanism.

The paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/engine design tools suitable for advanced combustion modes. The author would like to thank King Abdullah University of Science and Technology (KAUST) and the Clean Combustion Research Center (CCRC) for lab facilities and research support. Last but not least, the authors would like to convey gratitude towards the IC Engine Lab Safety Supervisor Adrian I. Ichim and the lab technician Riyad H. Jambi for their kind input and assistance in performing the experiments.

International audience; Increasing the degrees of freedom in the air path has become a popular way to reduce the fuel consumption and pollutant emissions of modern combustion engines. That is why technical definitions will usually contain components such as multi or single-stage turbocharger, throttle, exhaust gas recirculation loops, wastegate, variable valve timing or phasing, etc. One of the biggest challenges is to precisely quantify the gas flows through the engine. They include fresh and burnt gases, with trapping and scavenging phenomena. An accurate prediction of these values leads to an efficient control of the engine air fuel ratio and torque. Fuel consumption and pollutant emissions are then minimized. In this paper, we propose to use an artificial neural networkbased model as a prediction tool for the engine volumetric efficiency. Results are presented for a downsized turbocharged spark-ignited engine, equipped with inlet and outlet variable valve timing. The calibration process that is used in this study only requires steady-state operating points. The validation stage was conducted on both steady-state and vehicle transients. Model prediction is in very good agreement with experimental results while keeping a very low calibration effort and matching embedded computational requirements. The conclusion stresses that thanks to their generic structure, neural models offer an interesting potential for generalization to even more complex technical definitions.

The automotive industry is looking for options to reduce weight and increase engine efficiency to comply with new CO2 emission and fuel economy regulations. Increasingly, automakers are examining their use of materials even for the smallest components. Engineering thermosets are an effective lightweighting alternative to heavier conventional steel and aluminum die cast products. They combine outstanding temperature stability, long term mechanical strength, dimensional stability and high chemical resistance. This paper focuses on two recent projects where (BAKELITETM) phenolic-based engineering thermosets have successfully replaced traditional metals in automotive under-the-hood applications and outperformed engineering thermoplastics also considered for the applications. First, a water pump housing made with engineering thermoset material is shown to have good chemical resistance to coolants without additional corrosion protection and to maintain its mechanical properties. Second, a vacuum pump made with engineering thermoset material has lower overall weight, higher dimensional stability and better fatigue properties than a similar design made from die-cast aluminum. Finally, the paper describes the recycling options for engineering thermoset materials. Introduction New fuel economy and emission regulations are prompting significant changes to the way automakers design their vehicles and the components that go into them. Numerous areas of the vehicle are being redesigned to reduce weight and increase engine efficiency. In cases where aluminum has been used as a lightweighting alternative to steel, engineers are seeking even greater savings from glass and carbon reinforced composite materials. Thermoplastics work in many instances. However, applications involving corrosive chemicals, high heat or structural loads may be best suited for engineering thermosets. Case 1: Water Pump Housing Water pumps circulate coolant through the cooling system of internal combustion engines to protect them from overheating. Under-the-hood temperatures reaching more than 200°C can destroy engine parts in a short period of time if not designed with appropriate materials. Water pumps must withstand the chemical impact of newer “long life” coolants, maintain mechanical properties and hold critical dimensions even at high temperature. An automotive customer sought alternative materials for a water pump design that could maintain performance while reducing weight and cost. The incumbent material was die cast aluminum. The following paragraphs examine the behavior of various water pump housing materials under circumstances similar to the final application and were used as the basis for selecting a next generation production design.

In this paper the effects of a rough underbody on the rear wake structure of a simplified squareback model (the Windsor model) is investigated using balance measurements, base pressure measurements and two and three component planar PIV. The work forms part of a larger study to develop understanding of the mechanisms that influence overall base pressure and hence the resulting aerodynamic drag. In the work reported in this paper the impact of a rough underbody on the base pressure and wake flow structures is quantified at three different ground clearances. The underbody roughness has been created through the addition of five roughness strips to the underbody of the model and the effects on the wake at ground clearances of 10.3%, 17.3% and 24.2% of the model height are assessed. All work has been carried out in the Loughborough University Large Wind Tunnel with a scale model giving a blockage ratio of 4.4% for a smooth under-body or 4.5% with the maximum thickness roughness strips. The tests are conducted with a fixed ground plane. Results are presented for the base pressure distribution and these are compared against the stream-wise PIV results. This work demonstrates the need for rough underbody structures to be considered during base pressure investigations before any model scale work is conducted due to their influence on the wake structures. Copyright © 2013 SAE International.

※ Received 28 June 2013, Reprinted with permission, from SAE paper 2012-32-0071 (JSAE paper #20129071). Copyright © 2012 SAE International and SAE of Japan. Further use or distribution of this material is not permitted without permission from SAE International or SAE of Japan. ポート噴射インジェクタより噴射される燃料噴霧は,エンジンの出力や燃焼効率に強い影響をあたえる. よって燃料を小さな油滴にする微粒化と,エンジンより受ける温度や負圧などの環境変化に依存しない正確な 燃料供給が求められている.本報では,ニードルバルブとのシート部下流の徹底した圧力損失(エネルギーロ ス)の低減と噴孔位置の適正化による微粒化手法,及びシート部下流のデッドボリューム削減と燃料通路長短 縮による温度や負圧の変化に依存しないインジェクタを紹介する.

In upcoming and future airplanes, more nonlinear electrical loads and loads behaving nonlinearly will be connected to the power distribution network. This induces advanced demands on the network to keep the power quality. The generator design also has to face the new demands and constraints. Trade offs between performance, weight, and latterly power quality have to be made and design choices have to be backed up by qualitative and quantitative measures. In a prior study a design tool chain was elaborated for an externally excited synchronous generator. In the first part of this paper this study is concluded. An outlook is given on the generator size demanded in relation to the portion of nonlinear loads in the network, in case the industrial standards are kept unchanged. The power quality criteria can be gained by time-domain simulation. This simulation can be computationally extensive, especially in case of a large ramp up time to the operating point. Therefore in the second part of this paper an approach for advanced initialization using equivalent models in frequency domain is given. Both frequency and time domain models were embedded component wise using the modelling language Modelica. Thus, simulation based studies can be performed within a single graphical and object-oriented modelling and simulation suite. A novel rectifier model in time-domain is presented, which has benefits for the harmonic initialization.

Few previous publications investigate the possibility of combining multiple waste heat sources in a combustion engine waste heat recovery system. A waste heat recovery system for a HD truck diesel engine is evaluated for utilizing multiple heat sources found in a conventional HD diesel engine. In this type of engine more than 50% of heat energy goes futile. The majority of the heat energy is lost through engine exhaust and cooling devices such as EGRC (Exhaust gas recirculation cooler), CAC (Charge air cooler) and engine cooling. In this paper, the potential of usable heat recuperation from these devices using thermodynamic analysis was studied, and also an effort is made to recuperate most of the available heat energy that would otherwise be lost. A well-known way of recuperating this heat energy is by employing a Rankine cycle circuit with these devices as heat sources (single loop or dual loop), and thus this study is focused on using a Rankine cycle for the heat recovery system. Furthermore, this paper investigates the possibilities and challenges involved in coupling these different sources in a single Rankine cycle and the selection of suitable working fluid for this Rankine cycle. The study shows that with recuperation from these multiple sources it is possible to recover 5-10% of the otherwise wasted heat energy, which results in ~5% power increase. REFPROP was used for studying fluid properties, and the commercial software IPSEpro is used to build and simulate the Rankine cycle.

Prior papers have shown the potentials of gasoline-like internal combustion engines fitted with waste heat recovery systems (WHR) to deliver Diesel-like steady state fuel conversion efficiencies recovering the exhaust and the coolant waste heat with off-the-shelf components. In addition to the pros of the technology significantly increasing steady state efficiencies - up to 5 % in absolute values and much more in relative values - these papers also mentioned the cons of the technology, increased back pressures, increased weight, more complex packaging, more complex control, troublesome transient operation, and finally the cold start issues that prevent the uptake of the technology. This paper further explores the option to use Rankine cycle systems to improve the fuel economy of vehicles under normal driving conditions. A single Rankine cycle system is integrated here with the engine design. A latest turbocharged 1.6 liter direct injection engine has the coolant circuit modified to serve as pre-heater for the Rankine cycle fluid. This fluid is then vaporized and superheated in the boiler/super heater coaxial to the exhaust pipe located downstream of the turbocharger turbine and the closed coupled catalytic converter. The exhaust ports are insulated to reduce the heat losses.

The information provided by the in-cylinder pressure signal is of great importance for modern engine management systems. The obtained information is implemented to improve the control and diagnostics of the combustion process in order to meet the stringent emission regulations and to improve vehicle reliability and drivability. The work presented in this paper covers the experimental study and proposes a comprehensive and practical solution for the estimation of the in-cylinder pressure from the crankshaft speed fluctuation. Also, the paper emphasizes the feasibility and practicality aspects of the estimation techniques, for the real-time online application. In this study an engine dynamics model based estimation method is proposed. A discrete-time transformed form of a rigid-body crankshaft dynamics model is constructed based on the kinetic energy theorem, as the basis expression for total torque estimation. The major difficulties, including load torque estimation and separation of pressure profile from adjacent-firing cylinders, are addressed in this work and solutions to each problem are given respectively. The experimental results conducted on a multi-cylinder diesel engine have shown that the proposed method successfully estimate a more accurate cylinder pressure over a wider range of crankshaft angles. Copyright © 2012 SAE International.

Today CFD is an important tool for engineers in the automotive industry who model and simulate fluid flow. For the complex field of Under hood Thermal Management, CFD has become a very important tool to engineer the cooling airflow process in the engine bay of vehicles. To model the cooling airflow process accurately in CFD, it is of utmost importance to model all components in the cooling airflow path accurately. These components are the heat exchangers, fan and engine bay blockage effect. This paper presents CFD simulations together with correlating measurements of a cooling airflow system placed in a test rig. The system contains a heavy duty truck louvered fin radiator core, fan shroud, fan ring and fan. Behind the cooling module and fan a 1D engine silhouette is placed to mimic the blockage done by a truck engine behind the fan. Furthermore a simple hood is mounted over the module to mimic the air guiding done by the hood in an engine bay. The measurements monitor pressure and flow over the system. Supporting this examination is a set of 48 velocity probes in the radiator that measures the local velocity. The simulations of this system are correlated to measurements. Furthermore to support these simulations, specific simulations and measurements are conducted using the radiator only and the fan only. This is done to see how well each separate component is predicted in CFD and correlated back to measurements. This work is the continuation of work presented in [5] and identified in this paper is that one can simulate the cooling airflow system rather well with steady state CFD. However, fan modeling is sensitive and specific care has to be taken in order for these simulations to be accurate.

The goal of this paper is to acquire insight into the influence of cetane number (CN) and fuel oxygen on overall engine performance in the Premixed Charge Compression Ignition (PCCI) combustion mode. From literature, it is known that low reactive (i.e. low CN) fuels increase the ignition delay (ID) and therefore the degree of mixing prior to auto-ignition. With respect to fuel oxygen, it is known that this has a favorable impact on soot emissions by means of carbon sequestration. This makes the use of low CN oxygen fuels an interesting route to improve the applicability of PCCI combustion in diesel engines. In earlier studies, performed on a heavy-duty engine, cyclic oxygenates were found to consistently outperform their straight and branched counterparts with respect to curbing soot. This was attributed to a considerably lower CN. The oxygenate in question, cyclohexanone (C6H10O), has the advantage of being producible in a renewable way from lignin, a second generation biomass waste stream (e.g. paper pulp industry). To investigate the impact of cyclohexanone on diesel combustion and pollutant emissions in greater detail, a parametric test program was carried out in a joint project between Istituto Motori (Naples) and the University of Technology Eindhoven. To decouple the influence of a low cetane number and fuel oxygen content on the engine performance, diesel (commercial high quality diesel fuel), gasoline (commercial high quality gasoline) and cyclohexanone were blended into five mixtures, with varying cetane number or oxygen content. These blends were tested and compared on a modern singlecylinder light-duty (LD) direct injection (DI) research diesel engine. The results suggest that it is not possible to attribute favorable performance to either CN or fuel oxygen, but rather to the combination of both properties. In nearly all investigated work points, a decrease in CN led to a decrease in nitric oxides (NOx) and particulate matter (PM), whilst slightly increasing carbon monoxide (CO) and unburned hydrocarbons (UHC). At an equal CN, the results suggest that fuel oxygen reduces soot emissions and also plays a role in suppressing UHC and CO emissions.

Building prototype aircrafts is costly in tooling especially since only one aircraft is being built. Today's most common tooling strategy is to weld together a beam framework. Welded framework solutions have long lead times both in design and manufacturing and once the aircraft is assembled the tool becomes obsolete. Flexible tooling strategy uses non-welded tooling thus it can be changed and re-used for future products. Early version of a new aircraft model is always hampered by frequent changes in its design, which is cumbersome to handle in a welded framework solution. This paper presents a flexible assembly tooling solutions based on Flexapods and BoxJoint. The Flexapods are commercialized reconfigurable tooling units that are manually adjusted injunction with a laser tracker to a final positional accuracy of +/? 0,05 mm absolute accuracy. An operator software program called the Flexapod control panel collect metrology data in real-time and an operator screen show graphics on how to manually jog the Flexapod joints to reach the final Cartesian 3D-coordinate. The Flexapods are installed in a modular steel based framework solution called BoxJoint. A complete PLM package has been developed for the solution where the Flexapods are configured in CATIA using an add-on package to CATIA called the Flexapod configurator. All CATIA data is stored in ENOVIA. Once the Flexapod fixture is designed in CATIA a file, containing all Cartesian coordinates of the Flexapods, is exported and loaded into the Flexapod control panel on the workshop floor. A previous paper on the Flexapod as an early concept and a paper on BoxJoint have been presented at SAE Aerofast. This paper follows up on these results and presents a case study at SAAB Aeronautics for implementing the first industrial solution of Flexapods to build the military unmanned aerial vehicle - nEURON.

This paper presents the design and development of a prototype Head-Up Display (HUD) interface that offer early notification warnings of potential collisions under unfavourable weather and traffic conditions. In this work we particularly focus our effort in the embedment of traffic congestion and sharp turn visual warnings in a working prototype interface. In turn we present the results of a large scale evaluation of the system on a group of forty users, which contrasted the use of the proposed HUD against a typical HDD. Finally the paper offers suggestions for further research and a tentative plan for future work.

This paper presents the findings of the trade study to evaluate carbon dioxide (CO2) sensing technologies for the Constellation (Cx) space suit life support system for surface exploration. The trade study found that nondispersive infrared absorption (NDIR) is the most appropriate high Technology Readiness Level (TRL) technology for the CO2 sensor for the Cx space suit. The maturity of the technology is high, as it is the basis for the CO2 sensor in the Extravehicular Mobility Unit (EMU). The study further determined that while there is a range of commercial sensors available, the Cx CO2 sensor should be a new design. Specifically, there are light sources (e.g., infrared light emitting diodes) and detectors (e.g., cooled detectors) that are not in typical commercial sensors due to cost. These advanced technology components offer significant advantages in performance (weight, volume, power, accuracy) to be implemented in the new sensor. The exact sensor design (light source, transmitting optics, path length, receiving optics and detector) will be specific for the Cx space suit and will be determined by the performance requirements of the Cx space suit. The paper further identifies specifications for some of the critical performance parameters as well as discussing the engineering aspects of implementing the sensor into the Portable Life Support System (PLSS). The paper then presents testing results from three CO2 sensors with respect to issues important to Extravehicular Activity (EVA) applications; stability, humidity dependence and low pressure compatibility. The three sensors include two NDIR sensors, one commercial and one custom-developed by NASA (for a different purpose), and one commercial electrochemical sensor. The results show that both NDIR sensors have excellent stability, no dependence on ambient humidity (when the ambient temperature is above the dew point) and operate in low pressure conditions and after being exposed to a full vacuum. The commercial electrochemical sensor was not suitable for the Cx space suit for surface exploration. Finally, the paper identifies a number of techniques currently under development that offer significant advantages for EVA applications. These include miniaturized, room temperature, solid electrolyte systems and advanced optical detectors.

This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

Across the world different regulations are applicable for side impact, each require a different restraint system approach. However it would be much more cost effective to develop one single restraint system suitable for all global requirements. An efficient methodology has been to optimize the restraint system for multiple load cases simultaneously, resulting in a restraint system specification that will ensure that global targets are met. The methodology combines the use of testing and efficient numerical simulation to find a solution in the most effective way. ABSTRACT Across the world different regulations are applicable for frontal impact, each require a different restraint system approach. However it would be much more cost effective to develop one single restraint system suitable for all global requirements. Flexible and reliable development approach has to be used for quick evaluations of various safety system configurations and conditions. An efficient methodology has been developed to optimize the frontal restraint system for multiple load cases simultaneously, Resultant restraint system specification to specification to meet global targets. The methodology combines the use of testing and MADYMO modelling techniques in combination with advanced DoE (Design of Experiments) analysis to find a solution in the most effective way. ABSTRACT In frontal crashes, one of the primary reasons for occupant injuries is hard contact with the vehicle interiors. While restraints like airbags, seat belt pre- tensioners etc. help in preventing direct contact of the upper body region; vehicle interiors play a critical role in controlling the lower body region injuries. Knee injuries can be controlled in various ways as follows:? Avoiding contact with the dashboard by use of buckle pre-tensioners etc • Using restraints like knee airbags • Optimizing the dashboard profile and stiffness at the contact locations All the above options have their own advantages and limitations. This paper explains the effect of dashboard stiffness tuning for controlling knee injuries in a frontal crash. The development methodology and some validation tools are discussed using a case study. ABSTRACT Bumper systems play an important role in energy management during vehicle accidents. Bumpers beams are generally designed to withstand impacts of up to 4 km/h (ECE42, FMVSS-581) and need to withstand low speed 15 km/h offset insurance crash tests to determine damageability and repairability features (RCAR-42) of vehicle design. Globalization of Automotive industry is forcing the designers to propose those designs, which can be introduced, to market quickly and which have lower costs and better quality. This paper presents work a novel design solution of a thermoplastic solitary bumper beam intended to reduce bumper weight and cost, meeting low speed damageability and RCAR impact requirements. A thermoplastic (PC/PBT) solitary beam is proposed that

The general trend toward increased use of computer models and simulations during product development calls for accurate and reliable product models. The function of many products relies on contact interfaces between interacting components. Simulating the behavior of such products requires accurate models of both components and interfaces. Depending on the purpose of the simulation, interface models of different degrees of detail are needed. In simulating very large systems with many interfaces, it might be computationally expensive to integrate detailed models of each individual interface. Condensed models, or abstractions, that describe the interface properties with the fewest degrees of freedom are therefore required. This thesis deals with the modeling and simulation of mechanical interfaces in a systems context. The five appended papers discuss the issue from both the simulation and tribological points of view. The aim is to study how friction and wear can be modeled in the behavioral simulation of technical systems and to discuss the convenience and applicability of using different types of models as building blocks of a system model in simulations. Paper A reviews existing friction models of sliding contacts under different running conditions. Paper B uses a simplified contact model, the elastic foundation model, to model friction in a boundary-lubricated rolling and sliding contact. The model is integrated into a dynamic rigid body model of a mechanical system, and the system behavior is simulated. Paper C discusses the application of the elastic foundation model to rough surface contact problems and investigates how the error in its results depends on surface roughness. Papers D and E address how the wear of the contact surfaces at the pad-to-rotor interface in a passenger car disc brake can be simulated using finite element analysis (FEA).

This paper addresses the problem of maintaining a stable rectified DC output from the three phase AC generator in a series-hybrid vehicle powertrain. In this case, the engine/generator combination is controlled by an electronic throttle, and the system as a whole can be represented as nonlinear with significant time delay. Previously, stable voltage control of the generator output has been achieved by model predictive methods such as the Smith Predictor, which rely on accurate system and time delay models, with associated computational complexity in the real-time controller, and as a necessity relies to some extent on the accuracy of the models. Two complementary performance objectives exist in the design of the control system. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable DC supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances. In order to achieve these objectives, and reduce the complexity of implementation, in this paper a controller is designed by the use of Genetic Programming methods in Simulink, with the aim of obtaining a relatively simple controller for the time- delay system which does not rely on the implementation of real time system models or time delay approximations in the controller.

In modern four-stroke automotive engine, variable valve technology offer potential benefits for making a highperformance engine. In this paper, a novel electromechanical fully variable valve system (EMFVVS) is introduced. Just like the conventional mechanical variable valve systems, this design still uses a camshaft mechanism, but it is integrated into an electrohydraulic system to form an electromechanical system. The use of electrohydraulic system is to provide input hydraulic pulses to drive the engine valves cyclically. The output valve profile is controlled electronically by a common proportional pressure relief valve, and hence Late-ValveOpening + Early-Valve-Closing + Variable-Max-ValveLift can be achieved. The construction of the mathematical model of the variable valve system and its dynamic analysis, and some design issues are presented in this paper. Experimental and simulation results show that the novel electromechanical variable valve system can achieve fully variable valve timing and lift control without using complex control systems, and has the potential to eliminate the traditional throttle valve in the gasoline engines.

This paper will discuss how markings or observable anomalies on vehicle seat belt restraint systems can be classified into two categories: Those caused by collision forces, or "loading marks" and (2) those created by non-collision situations, or "normal usage marks." A survey was conducted of both crash-tested and non-crash-tested vehicles in order to collect data on both categories of markings. This paper examines and analyzes the markings caused by both collision and non-collision load scenarios in order to illustrate and evaluate their unique differences as well as provide a general pattern of severity relative to different loading conditions.

This paper describes how, in the I-bumper (inflatable bumper) concept, two explosive airbags are released just before the main body-to-body crash in order to absorb the kinetic energy of colliding vehicles. The release also actuates other components in the I-bumper, including a movable bumper and an energy absorption morphing lattice structure. A small explosive charge will be used to deploy the airbag. A conventional airbag model will be used to reduce the crash energy in a controlled manner and reduce the peak impact force. An analytic model of the explosive airbag is developed in this paper for the I-bumper system and for its optimal design, while the complete system design (I-bumper) will be discussed in a separate paper. Analytical formulations for an explosive airbag will be developed and major design variables will be identified. These are used to determine the required amount of explosive and predict airbag behavior, as well to predict their impact on the I-bumper system. Related design guidelines and procedures will also be introduced. This new explosive airbag model will be implemented in Matlab, and will be validated with a high-fidelity model using an LS-DYNA simulation.

Nowadays for small-scale power generation there are electrochemical batteries and mini engines. Many efforts have been done for improving the power density of the batteries but unfortunately the value of 1 MJ/kg seems to be asymptotic. If the energy source is an organic fuel which has an energy density of around 29 MJ/kg with a minimum overall efficiency of only 3.5%, this device would surpass the batteries. This paper is the fifth of a series of publications aimed to study the HCCI combustion process in the milli domain at high engine speed in order to design and develop VIMPA, Vibrating Microengine for Low Power Generation and Microsystems Actuation. Previous studies ranged from general characterization of the HCCI combustion process by using metal and optical engines, to more specific topics for instance the influence of the boundary layer and quenching distance on the quality of the combustion. The result of all these studies was that the heat losses are a formidable problem when the combustion takes place in the milli domain. The aim of this paper is to study the influence of the wall temperature and combustion chamber geometry in order to understand if it is possible to reduce the heat losses and improve the combustion process hence higher energy density. The results have shown that improvements can be achieved by an appropriate choice of the materials and minimization of the area to volume ratio but with attention to the quenching phenomenon. (Less)

This paper presents an experimental methodology which can be adopted to measure the friction torque of the bearings in the wheel hubs of passenger vehicles. The first section of the paper highlights the reasons why an experimental device is necessary to have an objective evaluation of the performance of the bearing in terms of friction. In particular, the high level of approximation of the current formulas for the estimation of the friction inside a single bearing is discussed and demonstrated. An analytical methodology for the evaluation of the distribution of the axial load between the two bearings of the wheel hub is presented. However, its practical application for the precise calculation of the distribution of the load has to be checked through experimental tests. The following part of the paper is focused on the possible solutions which can be adopted to conceive a test rig to measure friction inside the bearings of wheel hubs by considering the effect of the real loads acting on the hubs of the vehicle (due to the forces between the tires and the road surface). The most efficient solution of test rig is developed and implemented for the evaluation of the friction of the bearings of a 3-wheel low consumption vehicle. This solution, which can be properly sized according to the considered application, can be extended also to the evaluation of the performance, in terms of friction, of the hubs of series production passenger cars

Power supply systems play a very important role in everyday life applications. There are mainly two ways of producing energy for low power generation: electrochemical batteries and small engines. In the last few years, many improvements have been carried out in order to obtain lighter batteries with longer durations but unfortunately the energy density of 1 MJ/kg seems to be an asymptotic value. An energy source constituted of an organic fuel with an energy density around 29 MJ/kg and a minimum overall efficiency of only 3.5% could surpass batteries. Nowadays, the most efficient combustion process is HCCI combustion which has the ability to combine a high energy conversion efficiency with low emission levels and a very low fuel consumption. The present paper describes an investigation carried out on a modified model airplane engine, on how a pure HCCI combustion behaves in a small volume, Vd = 4.11 Cm₃, at very high engine speeds (up to 17,500 [rpm]). Using ether like fuel, for the first part of the experiments the behavior of the engine was characterized by studying the variation of IMEP, indicated power, main combustion features (temperature, duration, phasing, residuals, efficiency and heat release) and emissions. The characterization was carried out between 7,500 and 17,500 [rpm], and the speed was changed by using six different propellers. In the second part of the experiment, an optical study was performed; the main intent was to characterize the combustion structure and its transient behavior in a small volume at high engine speed. In order to achieve this, chemiluminescence images were acquired together with images of hydroxyl, formaldehyde and C2. Two sets of measurements were performed, i.e., at 6,500 and 14,000 [rpm], and in each test the behavior of the low and high temperature reactions, as well as that of C2 was studied together with the natural emitted light. This was done to understand the degree of homogeneity of the combustion and the boundary layer behavior. The third part of this paper describes the analysis of the behavior of the optical and the metal engine in order to provide an understanding to whether the use of the optical window affected the combustion event.

ILC Dover Inc. was awarded a three-year NRA grant for the development of innovative spacesuit pressure garment technology that will enable safer, more reliable, and effective human exploration of the space frontier. The research focused on the development of a high performance mobility/sizing actuation system for a spacesuit soft upper torso (SUT) pressure garment. This technology has application in two areas (1) repositioning the scye bearings to improve specific joint motion i.e. hammering (Figure 1), hand over hand translation (Figure 2), etc., and (2) as a suit sizing mechanism to allow easier suit entry and more accurate suit fit with fewer torso sizes than the existing EMU. This research was divided into three phases. In phases 1 and 2 SUT actuation technologies were developed and evaluated. In the final phase, which this paper focuses on, a field of previously selected actuation methods was narrowed to one active, pneumatically driven system, and one passive, cable driven system. These systems were developed into fully functioning prototypes which were outfitted to a table top SUT mock-up which was later integrated into a full suit and tested. Both of these systems were shown to be successful in positioning the SUT shoulder joint interface angles in a designated location and holding there until task completion. The control mechanisms used for both the active and passive system was also modeled and developed. The final phase was concluded by collecting video of a manned demonstration of two of the sizing systems in effect. This paper will summarize the findings of this three year research with emphasis on the details of the final phase.

The paper describes a new disc brake design procedure including the ADAMS model of the air-operated brake disc mechanism and its validation against the conventional hardware. A mechanical system simulation is used in the paper to forecast the full dynamic behavior of the complex brake unit system having a lot of cooperating with each other parts. INTRODUCTION The current tendencies in automotive industry need intensive investigation on problems of interaction between active safety systems and brake equipments. The special place is occupied here with creation of a new brake gear design which should possess, except for reliability and durability, such important for active safety systems properties as minimal hysteresis losses and the high response time. Nowadays brake control systems for heavy vehicles can be basically classified into two types: combined Air-Over-Hydraulic system, where the brake unit is hydraulically controlled, and Full-Air system, in which the brake unit is pneumatically controlled. Brake control system types are indicated in the Table 1. Table 1 Brake control system types Control Caliper support method Caliper slide method Fixed type Not related Pin slide type Hydraulic Floating type Rail slide type Pin slide type Pneumatic Floating type Rail slide type The influence of the brake gear on active safety systems is mainly determined through the hysteresis loop width. This parameter limits the possible frequency of cyclic braking during ABS operation. Until recently it was considered, that the disc brake design is practically optimal from the point of view of hysteresis losses. However, this statement is fair, only if to compare a design of drum and disc brake mechanisms. Really, the hysteresis losses value in a disc brake is approximately two times less than losses in a drum brake. But it can still reach 20%. An analytical dependence, which would allow defining a hysteresis value, is not received till now. In this connection manufacturers use empirical dependences or experimental characteristics at dynamic calculation of a brake gear. The presented paper makes an attempt to solve the problem under discussion using common analytical methods and simulation.

Observation problems have been garnering increasing at- tention in recent years. They can be seen as the esti- mation of a periodic output dynamics driven by periodic inputs. At various level of modelling, automotive engine dynamics can be considered as a linear periodic sys- tem mechanically coordinated through the revolution of the crankshaft. In this paper, two practical examples are addressed. The first example is the inversion of sensor dynamics. A classical way of modelling such a sensor is a first order dynamics with periodic excitations which can be, depending on the application, the intake pressure, the intake temperature, the exhaust pressure, the Air Fuel Ra- tio, or the Mass Air Flow. The second example is the es- timation of the engine speed next to the cylinder using as only sensor the easily available instantaneous crankshaft angle speed at the end of the connecting rod. The contribution of this paper is the design of a real-time observer of the periodic excitation of a linear periodic sys- tems by the estimation of the Fourier decomposition of the signal. The estimation of the coefficients of the Fourier basis decomposition of the input periodic excitation is a handy tool for engineering purposes. Indeed, the energy levels of the signal allow another interpretation of the sig- nal and can lead to detect the balance of the engine. This high frequency (6 o crankshaft estimation) information can be used for imbalance diagnosis and torque balance con- trol. Real application observation problems are exposed in their practical context and illustrated by experimental results on a 4 cylinder HCCI engine.

Disc brake squeal is a very complicated phenomenon, and the influence of insulators in suppressing squeal is not fully understood. The aim of this paper is increase the understanding of the effect of insulators. A previous paper [1] presented an experimental technique for measuring the frequency- and temperature- dependent properties of viscoelastic materials currently used in insulators. The present work continues by considering the coupled vibrations of the brake pad and insulator. A comparison of natural frequencies found from experimental modal analysis and finite element modeling indicates agreement to with 5%. Experimentally determined modal loss factors of the brake pad vary dramatically with frequency, changing by a factor of 2 over the frequency range 2-11 kHz. A method for including this frequency dependence, as well as the frequency dependence of the insulator material, in state-of-the-art finite element software is proposed. This method uses forced response vectors from the complete frequency-dependent model to construct a reduced-order model with frequency-independent matrices. Agreement between the complete and reduced models is analytically guaranteed and numerically observed at a number of frequencies in the band of interest.

The paper details two phases of work completed by Airbus UK to create a standard deployment platform for robotic processes. The initial part of the paper focuses on an aerospace capability study developed to benchmark a number of robot models. The tests define absolute accuracies within full and restricted work envelopes, static and dynamic flexure, and temperature effects on the robot manipulator. The second part of the paper describes the development of an adaptive control process to accurately position singular or cooperating robots within a large working envelope. The solution is not dependent on complex software algorithms within the robot controller or restrictive laser metrology interfaces. The paper illustrates how a number of standard industrial products can be 'fused together' to provide a robust industrial solution.

In this paper we present a unique nondestructive inspection (NDI) system for inspection of Al/SiC metal matrix composite (MMC) inserts in cast aluminum tank track shoes (TTS). The system is based on two different nondestructive inspection methods, ultrasonics (UT) and eddy current (EC), which are capable of detecting and identifying defects in MMC, such as porosity, debonding, and cracking. This paper also discusses results obtained during inspections of AI/SiC MMC samples with different levels of porosity, and debonds using UT and EC inspection. The prototype version of the system is designed to perform an acceptance inspection after TTS manufacturing and before deployment. Other potential applications of this system are in the evaluation of complex MMC parts in the automotive industry.

While the development of Diesel engine market leads to significant CO 2 emission reduction, customers are now demanding for more driving pleasure and comfort. Renault and Nissan have therefore decided to develop a new 2 liter 4 cylinder Diesel engine family in order to comply with future customer requirements and to prepare more stringent emission regulation like Euro 4. This paper presents the main characteristics of the combustion system (injector, cylinder head and piston) and explains the technical choices made in accordance with design and cost constraints. The distinctive characteristics of this new engine are: ■ Low compression ratio (16) and high maximum cylinder pressure level; ■ Third generation common-rail FIE (piezoelectric with a maximum rail pressure of 1600 bar); ■ Multiple injection strategies; ■ Refined design of the combustion chamber: bowl shape of the piston, valve pockets depth, cylinder head swirl level and injector number of holes. The optimum matching of combustion chamber design and injection system characteristics leads to a very good trade-off between performance at full load and pollutant emission at part load: a maximum specific power of 65 kW per liter has been reached in compliance with Euro 4 exhaust gas emissions regulation. This paper outlines the optimization of the combustion system and describes its relevant characteristics.

This paper describes the results of the first stage of an integrated experimental and modelling programme on a gasoline engine with Twin Mechanical Variable Lift (TMVL) capability. The engine used for this work was a modified version of a 4 cylinder, 2.0 litre BMW engine. The modified engine has the "Valvetronic" continuously variable lift valvetrain on both the inlet and exhaust valves and dual independent cam phasers with 60 crankshaft degrees of phasing authority. The Valvetronic system allows continuous variation of the valve lift from a minimum of 0.25 mm to a maximum of 9.7 mm. Three operating modes were investigated with port fuel injection: • Conventional throttling with dual cam phasers spark ignition combustion • Inlet valve throttling with dual cam phasers -spark ignition combustion • Inlet valve throttling with Controlled Auto Ignition (CAI) combustion For the spark ignition cases, a Design-of-Experiments (DoE) approach using in-house Stochastic Process Modelling (SPM) and optimiser tools was used to optimise the control variables for best fuel economy and to gain an understanding of the trade-offs between economy, emissions and combustion stability. Inlet, exhaust and cylinder pressure data was recorded from all 4 cylinders for combustion and pumping work analysis. In parallel to the experimental programme, a 1-D gas dynamic simulation was carried out using the Ricardo WAVE code. The model was validated using the measured cylinder, inlet and exhaust system instantaneous pressures. The model was used to derive in-cylinder conditions at the experimental test points. The paper contains a description of the engine and the test and modelling methods. Part load fuel consumption, emissions and combustion characteristics are compared for the three operating modes investigated. The advantages of valve throttling and CAI combustion are quantified.

Trucks parked at idle create excessive fuel consumption and exhaust emissions. One of the solutions to this issue is to institute a separate power system, the APU. It will be in operation when vehicle is parked and engine is off to provide the electricity and support the necessary needs (refrigerator, air conditioning, TV, etc.). This paper offers the insight of development of an Electrical Power Cell (EPC) as the candidate of the APU. The device consists of a unique Opposed Piston and Opposed Cylinder (opoc) engine and a high speed rotary generator. An extensive investigation has been conducted during the engine development program to create a special unniflow scavenging process of this two stroke engine. As the result, it realizes zero fresh charge loss with high scavenging efficiency. This paper provides the technical challenges and solutions in achieving the design targets.

Controlled Auto Ignition (CAI) as a promising future combustion process is a concept to strongly reduce fuel consumption as well as NO x emissions. The acceptance and the potential of this combustion process depends on the possible CAI operation range in the engine map and the fuel consumption benefit, as well as the complexity of the variable valve train which is necessary to realize the CAI combustion process. The thermodynamic investigations presented in this paper were done on an engine equipped with an electro-mechanical valve train (EMVT), featuring Port Fuel Injection (PFI) and direct Injection. They show that the electromechanical valve train is an excellent platform for developing the CAI process. Controlled Auto Ignition has been realized with port fuel injection in a speed range between 1000 and 4500 rpm and in a load range between approximately 1 and 6 bar BMEP (about 5 bar BMEP for pressure gradients lower than 3 bar/°CA) depending on engine speed. In a wide range of the engine map NO x emission reduction of 90-99 % was realized, fuel consumption in the New European Driving Cycle (hot test) can be reduced by approximately 15 % (w/o cylinder deactivation) compared to a standard production engine. Tests performed with direct injection with the injector in the central position have shown a significant extension of the CAI operation range in the engine map while the fuel consumption is also reduced. Further potential can be seen using split injection and multi stroke operation. Especially 2-stroke and 6/8-stroke operation with dual combustion show high potential for stable CAI operation and an extension of the Controlled Auto Ignition map area. In the 6/8-stroke with dual combustion mode a combination of stratified combustion process and homogenous combustion process with Controlled Auto Ignition is realized. Based on the thermodynamic investigations the necessary variability of a mechanical variable valve train is identified, giving distinct targets for a mechanical variable valve train enabling CAI. Possible mechanical valve train concepts to realize the CAI combustion process are presented in the paper. The influence of these systems due to the changed variability of the valve train on the operation range and the fuel consumption benefit as well as on the transient behavior and system costs is discussed.

Experiments were conducted with a single cylinder heavy duty research engine, based on the geometry of a Volvo Powertrain D12C production engine. For these tests the engine was configured with a low compression ratio, low swirl, common rail fuel injection system and an eight-orifice nozzle. The combustion process was visualized by video via an inserted endoscope. From the resulting images temperatures were evaluated with the two-color method. In addition, the combustion and emission formation were simulated using the multiple flamelet concept implemented in the commercial CFD code STAR-CD. The models used in this paper are considered state-of-the-art. The purpose of this paper is to demonstrate the possibilities offered by combining several methods in the evaluation of novel engine concepts. Therefore, results from the optical measurements, the CFD simulations and global emission experimental data were compared. Combining the methods shows a great opportunity to understand phenomena associated with new combustion concepts involving long ignition delay, low temperature, and ultra low emissions.

The Curtain Airbag (CAB) is used currently to provide head and neck protection for the front-seat and rear-seat vehicle occupants during side-impact collisions and vehicle rollovers. The coated fabric materials are used in CABs for occupant protection in side impact and rollover events. In this paper the design and development study of CABs is described by using simulation and physical tests. The mechanical properties for the airbag material are determined by uniaxial test in the fill and warp directions. Shear strength is also evaluated by using the uniaxial test, but the specimen is cut along 45° angle. These test values are used in the finite element (FE) simulations. In this paper, a methodology of the design study is discussed. A Free Motion Headform (FMH) impacting a pole with a pillow shaped airbag is used in the design study. The influences of CAB design parameters such as pressure, chamber width, impact speed and hit location are evaluated. The simulations were correlated with actual tests under various conditions such as impact speeds, hit locations and various pressures in the airbag. The simulation results were compared to the physical test by Computer Aided Engineering (CAE) model correlation grading system.

This paper proposes the use of support vector machines to reconstruct the indicated torque from crankshaft velocity in a six-cylinder spark ignition engine. Real-time knowledge of indicated torque is typically important for engine diagnostics, and recently, an engine idle speed controller capable of reducing the effects of cyclic combustion variability through the use of indicated torque information was proposed. While measurements of in-cylinder pressure can be used to determine indicated torque, these sensors are generally deemed prohibitively expensive for implementation in a production engine. Estimation methods, particularly traditional model based estimation, are typically computationally expensive and require independent data throughout the cylinder expansion stroke. Overlap of the expansion strokes in a six-cylinder engine complicates the problem and limits the ability of traditional model based approaches in fully reconstructing the torque production process. Intelligent estimation techniques can identify the key characteristics of the instantaneous engine speed as a function of crank angle for the combustion stroke, thereby allowing an optimal subset of the available information to be utilised. A support vector machine approach is used in this paper due to the inherent optimisation of the training procedure, resulting in an optimised prediction matrix. Torque estimation is then obtained through simple mathematical evaluations, allowing fast reconstruction of indicated torque. A comparison between reconstruction performances at different operating points is presented as an evidence of the capabilities of the support vector machines. This paper demonstrates that indicated torque reconstruction with support vector machines in a sixcylinder engine is not only possible, but it can be done with sufficient accuracy for the purpose of advanced engine control applications. INTRODUCTION Combustion in an engine cylinder, even at a fixed operating point, is subject to cycle-by-cycle variations, due to factors such as internal exhaust gas recirculation, uneven air-fuel mixture distribution, and variations in mixture density. During low-load idle conditions, air density and fuel mass fed into the cylinder are at their lowest, thereby increasing the likelihood of uneven distribution of the mixture throughout the cylinder. Consequently, this causes variability in combustion process, and subsequently, indicated torque. As variations in combustion or torque production directly influence engine speed, fluctuations of the crankshaft speed are also increased. These speed fluctuations may lead to unnecessary control action at idle [1], or requirements such as higher idle set points to counteract engine stall, and reduce vehicle noise vibration and harshness quality (NVH). Obviously, increasing idle set points also increases emissions and fuel consumption, and should be avoided. Knowledge of indicated torque generated during the combustion process is desirable for several key applications, such as idle speed control and engine diagnostics. Recently, an engine idle speed controller capable of reducing the effects of cyclic combustion variability was proposed [1]. This relies on information about indicated torque in order to predict and compensate for cyclic variations. While there exist incylinder pressure sensors, and there is a direct correlation between in-cylinder pressure and indicated torque, these sensors are generally deemed too expensive and impractical for implementation in a production line engine. Torque sensors, while available, generally have complicated construction, and their realworld production line performance and reliability are yet to be established. Consequently, there is considerable research into methods that will allow the indicated torque to be inferred from available measurements. Downloaded from SAE International by University of Melbourne, Tuesday, January 07, 2014 06:17:04 PM

This paper is concerned with the simulating and optimising research of light optical systems of car lighting projectors. In the paper an attempt was made to use all accessible information about relationships between elements in a vehicle reflector system, an engineer can choose and change (manipulate) using computer aided design systems and often he has no possibility to use it. Computer science achievements and neural networks were used to optimize automobile lighting of the road in front of a moving vehicle.

The tightening of emissions regulations has required changes in many areas of vehicle systems, including calibration strategies, catalytic converter strategies and exhaust configurations. Engine calibration strategies can be engineered to complement the performance parameters of the converter. Knowledge of the precise window of converter performance for different substrates can therefore provide guidance in targeting engine calibration strategies as well as selecting compatible converter systems within calibration constraints. In a previous paper [5], we explored the effect of thermal mass on emissions performance in the context of the FTP. This paper expands on the previous work and explores the effect of the aging cycle and thermal mass differences on CO-NOx crossover and light-off profiles. This analysis provides a tool to assist in design by defining a window of performance in the converter to be used in matching to a window of operation in the calibration. The substrate configurations studied in the analysis are 400/4, 900/2 and 900/1. These represent a direct comparison of constant cell density on the one hand and constant bulk density on the other. The air/fuel sweeps and light-off ramps were performed at steps throughout the aging cycle, yielding information not only on the comparison between the products but also on how their relative performances change over the life of the converter. Emissions and temperature were examined to evaluate the performance.

This technical paper continues a sequence of previous SAE Technical Papers that document progress of wheel bearing adjustment on tractor/trailer combination vehicles. In an earlier SAE paper, 2000-01-3496, misinformation provided was recognized. This material is reviewed following the conclusion of this technical paper and corrections are offered. However, of primary importance, disclosure will be made of new developments accomplished in wheel bearing preload adjustment procedures since December 2000. The intent of this paper is to advise the means by which selected amounts of preload can be introduced into trailer wheel assemblies. These are identified as axle nut adjustable systems that are serviceable by mechanics in commercial carrier fleet operations. No commentary will be presented relative to the permanent type of wheel bearing adjustment systems that are factory installed and are unable to be adjusted while in service. Since SAE Technical Paper, 2000-01-3496 was presented, the SAE Standard, J2535, Setting Preload in Heavy-Duty Wheel Bearings was issued. SAE member engineers associated with the tapered roller bearing manufacturing industry produced this document. Following J2535, the recommended practice RP-640 was published by the Technology and Maintenance Council of the American Trucking Associations (TMC) acknowledging the allowable range of preload presented in the SAE document. It is now possible for a mechanic to use the information provided by the SAE and the TMC to install acceptable and desirable preload within trailer axle assemblies using an adjustable type of nut system as long as the results are manageable. It has been a firm requirement by all tapered roller bearing manufacturers that the installed range of preload be controlled at the time the wheel components are installed. Because of this, both the SAE and the TMC require that those who install wheel end fasteners follow specific instructions provided by the spindle nut manufacturers. That being said, this technical paper will describe a new method to achieve accurate preload adjustment.

The penetration of hybrid or purely electric drivetrain solutions in automotive applications increases continuously, benefiting also from the rapid advancements in the complementary technologies related to the on-board electric energy generation and storage. The automotive community has made a strong commitment to the development of fuel cells into viable products during the next decade, and there are already several hybrid vehicle designs successfully commercialized. The current electric drive configurations are susceptible to significant improvements with respect to weight and envelope dimensions versus torque and power capacity. This paper introduces a compact wheel end power unit concept that Integrates advanced motor, package bearing, and gear technologies, and summarizes the development work related to its integration with the specific components of an automotive driveline. The resultant electric drive is evaluated under different technical and commercial criteria, including performance, power density, ease of assembly, complexity and cost. Based on both analytical model predictions and performance test results, the wheel-end electric drives presented in the paper are very well suited for a wide range of vehicle platforms, as compact and efficient drive modules.

This paper deals with the problem of cyclic irregularities during idling in relation with port to port fuel delivery variation of rotary Fuel Injection Pump (FIP) for a diesel engine. The relation is demonstrated on a two cylinder engine, where problem of high cyclic irregularities was observed for which the root cause was identified as the fuel delivery variation from the FIP, which was later taken up for the improvements in the design. This paper discusses the technical approach used in identifying the root cause for the high cyclic irregularities and the solution of the problem. It is demonstrated how angular acceleration of the crankshaft free end can be used to diagnose the non-uniformity of combustion in different cylinders which leads to higher cyclic irregularities. The solution discusses the improvements done in the hydraulic passages of the head and rotor of the FIP for line to line fuel delivery variation control.