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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.

A new method for detecting the low power conditions on electronically-controlled diesel engines used in on-road vehicles has been developed. The advantage of this method is that it uses readily available diagnostic tools and engine installed sensors with no necessity for a dynamometer test. Without removing the engine, it gives an estimate of the real engine power which is accurate to 5%.

This paper discusses a new approach to the finite element analysis of cylinder head gaskets. The new method is based on a feature of the ABAQUS® finite element solver which allows the user complete freedom to define unique material properties. This is an attractive option for cylinder head gasket analysis because the user has the freedom to describe materials which are non-linear and anisotropic. There is also the possibility of specifying independent loading and unloading characteristics. To ensure repeatability and avoid errors, the new method includes a user-friendly program to automate the input deck preparation procedure. In addition to offering new capabilities, the new method was found to converge more quickly than the current gasket analysis method.

Design and development of the Cummins Signature 600, a new high horsepower dual overhead cam truck diesel engine, has been completed. The Signature 600 product system includes an all-new engine, controls, fuel system, and business information systems. During product definition, particular emphasis was placed on target markets, customer input to design, engineering and manufacturing processes, concurrent engineering and extensive mechanical and thermal analyses. Cummins Signature 600 fulfills the needs of Owner-Operator and Premium Fleet linehaul trucking businesses.

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.

The cambore distortion is one of major concerns of an engine performance. A good design does not ensure a quality product. To meet product performance requirements, engineering community turns efforts to both design and manufacturing at an early stage of product development. This paper will discuss this process by providing an example of design and manufacturing of an overhead cambore. In this study a methodology to evaluate bore distortions is introduced. FEA cambore distortion analysis will use it to provide necessary data so that the product team can make a sound decision.

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.

For the 2003 model year DaimlerChrysler Corporation will launch a totally new 5.7L V-8 engine for applications of the Dodge Ram pick-up truck. The new engine was created largely within a digital environment using the latest computer aided design (CAD) and computer aided engineering (CAE) techniques and tools. Utilizing a co-located team of design engineers, designers, and CAE engineers enabled the simulations to impact the design from program inception to the assembly line, saving program time and investment. This paper describes the successful merging of design and advanced analysis techniques by highlighting examples throughout the new HEMI® program. Case studies include issues in the areas of structural optimization, engine loading, lubrication circuit, cooling circuit, and manufacturing.

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.

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.

Testing procedures to evaluate new coolant pump seal face materials and new coolant pump seal designs were evaluated. Rig testing of materials and seals followed by engine dynamometer testing enabled changes in the seal materials or design to be validated prior to field testing and limited production. These procedures were used to test and implement a coolant pump seal face material change to silicon carbide versus carbon. The change resulted in higher reliability for the coolant pump seal and reduced warranty cost for the engine.

Previous work on the cooling jackets of the Cummins L10 engine revealed flow separation, and low coolant velocities in several critical regions of the cylinder head. The current study involved the use of detailed cooling jacket temperature measurements, and finite element heat transfer analysis to attempt the identification of regions of pure convection, nucleate boiling, and film boiling. Although difficult to detect with certainty, both the measurements and analysis pointed strongly to the presence of nucleate boiling in several regions. Little or no evidence of film boiling was seen, even under very high operating loads. It was thus concluded that the regions of seemingly inadequate coolant flow remained quite effective in controlling cylinder head temperatures. The Cummins L10 upon which this study has focused is an in-line six cylinder, four-stroke direct injection diesel engine, with a displacement of 10 liters.

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.

The paper presents the latest research results on the piston ring free shape. A new free shape measurement method with optical gauging was developed. Three numerical models to compute the contact force distribution of piston ring were developed using finite element analysis (FEA). These numerical methods have been compared each other, and validated with the experimental results of ring deformation in a ring gage. The contact force distribution of a piston ring at working condition was also studied. It consists of the ring thermal boundary conditions (RTBC) validation, 3-D FEA thermal analysis and thermal contact force computation based on validated wire-cable element model. The RTBC for heavy duty diesel engine has been validated for the first time using a CUMMINS L10 engine test. Three different free shapes have been tested. The wear band measurements of tested rings all show tremendous improvements over the standard top ring.

A new telemetry system has been developed for temperature or strain measurements on a spherical joint piston. The system includes a piston mounted signal multiplexer and transmitter. A patented, piston mounted power generator operates in conjunction witii a modified cylinder liner. The telemetry system is robust, having high inertia load capability and high environmental temperature operating capability. The telemetry system was installed and operated on an engine motoring test rig. Temperature signals were transmitted at engine speeds from 400 rpm to 2100 rpm. Over 100 hours of high engine speed testing with oil sump temperatures up to 122°C were completed.

Measurements have been made to determine the effect of piston crown surface properties on combustion. Back-to-back engine tests were conducted to compare surface modified pistons to a production piston. Each modified piston was found to prolong combustion duration. Porous coatings and a non porous, roughened piston were observed to increase fuel consumption. Increase in fuel consumption was determined to be the result of increased heat release duration. The data show surface roughness alone affects the duration of heat release. The shift in magnitude of the centroid of heat release was similar to the shift observed in insulated engine experiments.

Data have been gathered to compare the performance of steel crown pistons coated with yttria stabilized zirconia or mullite to an uncoated piston. The effect of coated pistons on in-cylinder heat transfer was determined from curves of ISFC versus centroid of heat release. Error analysis of the measurements showed uncertainty of ± 3% in ISFC and ± 2 crank angle degrees in the centroid of heat release could be expected for the data. Particulate emissions increased at advanced injection timings with the mullite coated piston while the zirconia coated piston showed an increase in particulate and NOx at advanced timings.

Recent engine design trends towards increasing power, reducing weight, advancing of injection timing and increasing of injection rate and pressure could result in increased incidence of liner pitting. Liner pitting due to coolant cavitation is a complex function of many engine design parameters and operating conditions as described in reference [1]*. Traditionally, liner cavitation problems were not detected early in the development cycle. Traditional liner vibration and coolant pressure measurements in conjunction with a numerous amount of expensive engine endurance tests were then needed to resolve cavitation problems. A method newly developed by the author and described in reference [2] for cavitation intensity measurements was successfully utilized to map out engine operating condition and develop limit curves. This method could also be applied in a non intrusive fashion.