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Employing detailed chemistry into modern engine simulation technologies has potential to enhance the robustness and predictive power of such tools. Specifically this means significant advancements in the ability to compute the onset of ignition, low and high temperature heat release, local extinction, knocking, exhaust gas emissions formation etc. resulting in a set of tools which can be employed to carry out virtual engineering studies and add additional insight into common IC engine development activities such as computing IMEP, identifying safe/feasible operating ranges, minimizing exhaust gas emissions and optimizing operating strategy. However the adoption of detailed chemistry comes at a greater computational cost, this paper investigates the means to retain computational robustness and ease of use whist reducing computational timescales.

With the increased interest in the use of ethanol as an alternative fuel to gasoline, Original Equipment Manufacturers (OEMs) have responded by adapting their current range of vehicles to be able to run on gasoline/ethanol blends. Flex fuel vehicles are defined are defined as those that are capable of running gasoline up to 100% ethanol. Other than changes to materials compatibility, to enable the required durability targets to be met when running on ethanol, very little in the way of changes are performed to take advantage of the properties of ethanol. Calibration changes are typically limited to changes in fueling requirements and ignition timing. The physical and chemical properties of ethanol/gasoline blends offer a mixture of advantages and disadvantages. Lower energy density in the form of lower heating value reduces vehicle range whilst higher octane ratings make these excellent fuels for boosted operation.

As engines and powertrains become quieter, sound quality becomes more important as an indicator of product quality. As a consequence, there is a heightened need to reduce gear noise. The objective of this work was to identify the source and cause of a modulated gear whine. The approach taken to identify the source of the modulation involved running a full powertrain on a spin stand and minimizing the number of meshing gear pairs until the offending pairs were identified. Further experimental testing and analysis models were employed to determine the cause of the modulation. From proximity probe measurements and backed up by the analytical model, it was determined that one of the gear mesh suffered from inadequate bearing support and off-center gear loads. This condition caused a tilt in one of the meshing gears which created a sideband that modulated with the primary meshing frequency of the transfer gear at cruise speed.

1-D analysis methods are used to simulate the performance of a pneumatic valve actuation system for an internal combustion engine. Pneumatics provides an attractive alternative to the more-common hydraulic valve actuation, in part because of the insensitivity of the working fluid viscosity to changes in temperature. Technical issues and concerns introduced by the use of pneumatics are addressed and plausible workarounds presented. In the present work, an actuator is sized for the specific engine application at hand. Once the actuation is sized, an actuation concept is selected and simulations performed. Technical issues of interest are actuation rates, seating velocity control, thermal management, valve-valve interactions, and power consumption. The pneumatic actuation system selected is gauged against each of these metrics using results of the simulations and commentary provided.

In this study, a 15-L heavy-duty diesel engine and an emission control system consisting of diesel oxidation catalysts, NOx adsorber catalysts, and diesel particle filters were evaluated over the course of a 2000 hour aging study. The work is a follow-on to a previously documented development effort to establish system regeneration and sulfur management strategies. The study is one of five projects being conducted as part of the U.S. Department of Energy's Advanced Petroleum Based Fuels - Diesel Emission Control (APBF-DEC) activity. The primary objective of the study was to determine if the significant NOx and PM reduction efficiency (>90%) demonstrated in the development work could be maintained over time with a 15-ppm sulfur diesel fuel. The study showed that high NOx reduction efficiency can be restored after 2000 hours of operation and 23 desulfation cycles.

Race engine development is a complex multidimensional problem with a large number of interacting parameters. The competitiveness of the engine requires that this set of parameters be fully optimized, and the inevitable limitations of program budget require that this complex optimization task be done quickly and cost-effectively. What is described here is a methodology that has been developed as an addition to traditional techniques; to speed the development process by the use of power development knowledge and computer aided tools. A sound physical model of the engine is manipulated by the use of design of experiment (DOE) tools, and the repetitious iteration of all the calibration parameters is automated This allows for an optimized solution to be converged upon without analyzing every possible combination of parameters.

An electro-mechanical infinitely variable transmission (eVT), comprising a pair of planetary trains interconnected with two electric machines and clutches, has been proposed. The transmission leverages the advantages of an output power-split configuration for low-speed operation and a compound power-split configuration for high-speed operation. It is capable of being operated in a number of operating modes including an eVT only mode and a hybrid mode when equipped with on-board energy storage devices. The transmission provides a compact, highly efficient and potentially low cost driveline solution for both conventional vehicles and hybrid electric vehicles. A virtual transmission prototype was built in EASY51. A base vehicle model was also constructed in EASY5 environment with Ricardo Powertrain Library components.

This paper outlines the development and integration of an advanced emission control system with a modern heavy-duty diesel engine for use in a series of catalyst aging tests. The project that is discussed is one of several being conducted under the Department of Energy's Advanced Petroleum-Based Fuels - Diesel Emission Control (APBF-DEC) activity. This government/industry collaboration is examining how systems of advanced fuels, engines, and emission control systems can deliver significantly lower emissions while maintaining or improving vehicle fuel economy. This project is using a Cummins ISX EGR engine (15 L) with a secondary fuel injection system to enable NOx adsorber catalyst regeneration. Development of the strategies for NOx regeneration and sulfur removal as well as integration of the emission control hardware is discussed. Performance of oven aged systems tested over transient and steady-state cycles is summarized.

Variable valve timing technology allows more flexibility for modern engines to meet peak performance, fuel economy and low emissions targets while providing good driveability. The most common device to achieve such improvement and comply with new emissions legislation is the oil pressure actuated cam phaser. Calibration for variable valve timing using dynamometer testing at steady state is the base for mapping the intake and exhaust valves phasing positions for the range of engine speed and load. Calibration is aimed at improving fuel economy and emissions levels while avoiding combustion instabilities. During a transient however, the actuation rate limitations of the cam phasing device, which depends on available oil pressure, cause the phaser to not meet the ECU timing map request. This lag alters the engine optimum operation. A proposed solution, the Cam Torque Actuated phaser or CTA, uses available cam torque energy to sustain high actuation rates independently of oil pressure.

Both the automotive and truck industry are facing further regulated emissions legislation in the near future. Understanding the emissions and fuel consumption attributes of an engine/vehicle application during a drive cycle early in an engine development program is a critical step to steer the engine development program to a successful final product. The generally accepted approach is to calibrate an engine on a dynamometer and to adjust the operation of the engine to meet performance targets. With the current build and test approach, these adjustments may not be made until well into the development program, and this calibration is a costly and time consuming step in the engine development process.

Development of integrated engine controls, exhaust components and advanced catalytic converters was demonstrated on a 1998 full size luxury sedan with a gasoline PFI 4.4 L V8 engine. This level of emissions management was targeted for ULEV and SULEV emission standards. An air gap, dual exhaust, six-catalyst system, was modified in stages to reduce the number of catalysts and associated controls/hardware. Engine controls and calibration were developed to reduce cold-start emissions, catalyst light-off time and tailpipe emissions. Systems integration involved reduced precious metal loading, secondary AIR and modification of emission control devices. The thermal mass of the air gap exhaust pipes was reduced by approximately 30 percent, which contributed to improved catalyst heat-up time. A vacuum-insulated catalytic converter with phase change material was used to store exhaust heat and resist heat loss during times of dwell/soak.

In order to meet the legislated emissions levels, future diesel engines will likely utilize cooled exhaust gas re-circulation (EGR) to reduce emissions. The addition of the EGR cooler to the conventional vehicle coolant system creates several challenges. Firstly, the engine cooling system flow and heat rejection requirements both increase as it is likely that some EGR will be required at the rated power condition. This adversely affects packaging and fuel economy. The system design is further complicated by the fact that the peak duty of the EGR cooler occurs at part load, low speed conditions, whereas the cooling system is traditionally designed to handle maximum heat duties at the rated power condition of the engine. To address the system design challenges, Ricardo have undertaken an analytical study to evaluate the performance of different cooling system strategies which incorporate EGR coolers.

Tools for the design and evaluation of engine water pumps have been developed. These tools range from textbook calculations to 3-dimensional computational fluid dynamics methods. The choice of the tools or the combination of tools used is usually dependent upon production timelines, rather than technical merit. Therefore, the strengths and weaknesses of each of the tools must be understood, and each tool must be validated for its specific purpose, then used appropriately to aid in the design or development of a water pump suitable for production. This study was carried out to evaluate three approaches: a proprietary Ricardo approach based on 1-dimensional analysis and correlations, a 3-dimensional computational fluid dynamics approach, and a conventional prototype manufacture and test iteration approach. The analytical results were correlated to experimentally obtained pressure rise, mass flow rate, and impeller speed data.

Blower noise is the single most dominating contributor of interior noise for several operating conditions; the worst condition being low engine speed and high HVAC fan speed. The goal of the research presented in this paper is to investigate the application of an acoustical resonator to reduce HVAC blower noise. Resonator systems are constructed and objective bench tests are performed to objectively assess their effectiveness towards a specific acoustical issue within the HVAC system. In addition, HVAC performance is objectively measured to ensure that airflow has not been degraded with the addition of the resonator. Modeling and simulation are used in this research to verify the HVAC system acoustical properties and to optimize the location of the resonator.

Many general-purpose and specialized simulation tools have been developed to assist engineers analyzing vehicle systems such as the engine, transmission, or control systems. Analyses have typically been carried out using these tools individually to address specific design and development issues. This divided approach limits the treatment of integrated system dynamics that may be important in refining dynamic system or control designs. Increasingly, these modeling tools have become more flexible, allowing analyses to be carried out simultaneously and in a coupled way using co-simulation. This paper describes a typical development process and the ways in which co-simulation may be valuable in analyzing systems. A co-simulation example applied to a transmission development is given in which a complete vehicle is modeled using three simulation tools running simultaneously.

A full size V8 demonstrator was developed to exhibit technology required to target LEV II emission levels. The testing involved the system integration of a vacuum-insulated catalytic converter (VICC) technology, air gap exhaust components, optimized catalyst loading and control system and calibration. The development strategy utilizes the vacuum insulation, phase-change thermal storage capacity, and cold start calibration strategy to enable the catalyst to quickly reach light-off in 6 seconds over the FTP-75. All emission testing was conducted with two LA4 preparation cycles. This approach is able to reduce the heat loss of the catalytic converter brick during a 12 hour soak period and optimize the calibration warm-up strategy to reduce the amount of emissions during the first 60 seconds of the FTP-75. The vehicle used for the demonstration was a BMW 540I application. The modifications to the vehicle were limited to the control system, engine calibration and aftertreatment.

A flow and heat transfer model of an engine lubrication system has been developed in order to predict sump oil temperature and study heat transfer mechanisms within the lubricating oil circuit. The objective was to develop the capability of simulating all the energy transfers between the oil and the combustion process, the engine coolant, and the engine bay air. The model developed in this study simulates a V8 spark ignited engine. Included in this simulation is a bearing model for friction heat generation, a combustion heat input model, and component models for each key heat transfer site in the lubricating oil circuit. The model predicts sump oil temperatures under different engine operating conditions and simulation results were compared to test data with good agreement. The sensitivity of oil temperature to engine speed, engine load, coolant temperature, piston friction, bearing heat energy generation, piston design, water jacket depth, and oil flow rate(s) was studied.

This paper demonstrates the effect of elastic deformation of the cylinder wall on the lubrication between the skirt and cylinder with simulation results of two realistic examples. The simulation methodology is described. Cylinder flexibility caused substantial changes in slap motion, average and peak wear loads on the skirt, friction, and power losses due to asperity contact and hydrodynamic friction. Cylinder deflection due to side loads was about ten percent of the skirt deflection due to side loads, and deformation due to cylinder gas pressure was substantial.

The Automotive Market in the United States is moving in the direction of more Light Trucks and fewer Small Cars. The customers for these vehicles have not changed, only their purchase decisions. Cummins has studied the requirements of this emerging market. Design and development of an engine system that will meet these customer needs has started. The engine system is a difficult one, since the combined requirements of a very fuel-efficient commercial diesel, and the performance and sociability requirements of a gasoline engine are needed. Results of early testing are presented which show that the diesel is possibly a good solution.

Engine tests were conducted on a production 2.5-liter V-6 engine to investigate the effects of spark plug tip designs on a 4-cycle SI engine of current technology. The data suggest that cyclic variation can increase when the ground electrode faces the primary intake port. Lean-operation limits were extended by the use of J-gap spark plugs as compared to surface-gap and ring-gap spark plugs at the conditions tested. The surface-gap type spark plugs lose some energy as the arc traverses the surface of the insulator. Voltage requirements decrease for reversed polarity at the part load conditions tested but increase at wide open throttle.