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Reduced emissions, improved fuel economy, and improved performance are a priority for manufacturers of internal combustion engines. However, these three goals are normally interrelated and difficult to optimize simultaneously. Studying the experimental heat release provides a useful tool for combustion optimization. Heavy-duty diesel engines are inherently transient, even during steady state operation engine controls can vary due to exhaust gas recirculation (EGR) or aftertreatment requirements. This paper examines the heat release and the derived combustion characteristics during steady state and transient operation for a 1992 DDC series 60 engine and a 2004 Cummins ISM 370 engine. In-cylinder pressure was collected during repeat steady state SET and the heavy-duty transient FTP test cycles.

A program has been completed to evaluate ultra-low sulfur diesel fuels and passive diesel particulate filters (DPFs) in truck and bus fleets operating in southern California. The fuels, ECD and ECD-1, are produced by ARCO (a BP Company) and have less than 15 ppm sulfur content. Vehicles were retrofitted with two types of catalyzed DPFs, and operated on ultra-low sulfur diesel fuel for over one year. Exhaust emissions, fuel economy and operating cost data were collected for the test vehicles, and compared with baseline control vehicles. Regulated emissions are presented from two rounds of tests. The first round emissions tests were conducted shortly after the vehicles were retrofitted with the DPFs. The second round emissions tests were conducted following approximately one year of operation. Several of the vehicles retrofitted with DPFs accumulated well over 100,000 miles of operation between test rounds.

Unmanned Aerial Vehicles (UAV) require simple and reliable engines of high power to weight ratio. Wankel and two stroke engines offer many advantages over four stroke engines. A two stroke engines featuring crank case scavenging, precise oiling, direct injection and jet ignition is analyzed here by using CAD, CFD and CAE tools. Results of simulations of engine performances are shown in details. The CFD analysis is used to study fuel injection, mixing and combustion. The CAE model then returns the engine performances over the full range of loads and speeds with the combustion parameters given as an input. The use of asymmetric rather than symmetric port timing and supercharging scavenging is finally suggested as the best avenue to further improve power density and fuel conversion efficiency.

The effects of fuel composition on emissions levels from compression ignition engines can be profound, and this understanding has led to mandated reductions in both sulfur and aromatic content of automotive diesel fuels. A Navistar T444E (V8, 7.3 liter) engine was installed on an engine dynamometer and subjected to transient emissions measurement using a variety of fuels, namely federal low sulfur pump diesel; California pump diesel; Malaysian Fischer-Tropsch fuel with very low sulfur and aromatic content; various blends of soy-derived biodiesel; a Fischer-Tropsch fuel with very low sulfur and 10% aromatics; and the same Fischer-Tropsch fuel with 10% isobutanol by volume. The biodiesel blends showed their ability to reduce particulate matter, but at the expense of increasing oxides of nitrogen (NOx), following the simple argument that cetane enhancement led to earlier ignition. However, the Fischer-Tropsch fuels showed their ability to reduce all of the regulated emissions.

Light duty vehicle emission standards are getting more stringent than ever before as stipulated by US EPA Tier 2 Standards and LEV III regulations proposed by CARB. The research in this paper sponsored by US DoE is focused towards developing a Tier 2 Bin 2 Emissions compliant light duty pickup truck with class leading fuel economy targets of 22.4 mpg “City” / 34.3 mpg “Highway”. Many advanced technologies comprising both engine and after-treatment systems are essential towards accomplishing this goal. The objective of this paper would be to discuss key engine technology enablers that will help in achieving the target emission levels and fuel economy. Several enabling technologies comprising air-handling, fuel system and base engine design requirements will be discussed in this paper highlighting both experimental and analytical evaluations.

Current production heavy duty diesel engines have a brake thermal efficiency (BTE) between 43-46% [1]. In partnership with the United States Department of Energy (DOE) as part of the Supertruck 2 program, Cummins has undertaken a research program to develop a new heavy-duty diesel engine designed to deliver greater than 50% BTE without the use of waste heat recovery. A system level optimization focused on: increased compression ratio, higher injection rate, carefully matched highly efficient turbocharging, variable lube oil pump, variable cooling components, and low restriction after treatment designed to deliver 50% BTE at a target development point. This work will also illustrate the system level planning and understanding of interactions required to allow that same 50% BTE heavy duty diesel engine to be integrated with a waste heat recovery (WHR) system to deliver system level efficiency of 55% BTE at a single point.

The influence of big-end bore fretting on connecting rod fatigue fracture is investigated. A finite element model, including rod-bearing contact interaction, is developed to simulate a fatigue test rig where the connecting rod is subjected to an alternating uniaxial load. Comparison of the model results with a rod fracture from the fatigue rig shows good correlation between the fracture location and the peak ‘Ruiz’ criterion, rather than the peak tensile stress location, indicating the potential of fretting to initiate a fatigue fracture and the usefulness of the ‘Ruiz’ criterion as a measure of location and severity. The model is extended to simulate a full engine cycle using pressure loads from a bearing EHL analysis. A fretting map and a ‘Ruiz’ criterion map are developed for the full engine cycle, giving an indication of a safe ‘Ruiz’ level from an existing engine which has been in service for more than 5 years.

The range-extended electric vehicle (REEV) is a complex nonlinear system powered by internal combustion engine and electricity stored in battery. This research proposed a Multiple Operation Points (MOP) control strategy of REVV based on operation features of REEV and the universal characteristic curve of the engine. The switching logic rules of MOP strategy are designed for the desired transition of the operation mode, which makes the engine running at high efficiency region. A Genetic algorithm (GA) is adapted to search the optimal solution. The fuel consumption is defined as the target cost function. The demand power of engine is defined as optimal variable. The state of charge (SOC) and vehicle speed are selected as the state variables. The dynamic performance of vehicle and cycling life of battery is set as the constraints. The optimal switching parameters are obtained based on this control strategy. Finally, a dynamic simulation model of REEV is developed in Matlab/Simulink.

Reactivity controlled compression ignition (RCCI) is a form of dual-fuel combustion that exploits the reactivity difference between two fuels to control combustion phasing. This combustion approach limits the formation of oxides of nitrogen (NOX) and soot while retaining high thermal efficiency. The research presented herein was performed to determine the influences that high reactivity (diesel) fuel properties have on RCCI combustion characteristics, exhaust emissions, fuel efficiency, and the operable load range. A 4-cylinder, 1.9 liter, light-duty compression-ignition (CI) engine was converted to run on diesel fuel (high reactivity fuel) and compressed natural gas (CNG) (low reactivity fuel). The engine was operated at 2100 revolutions per minute (RPM), and at two different loads, 3.6 bar brake mean effective pressure (BMEP) and 6 bar BMEP.

Pollutants are a major issue of diesel engines, with oxides of nitrogen (NOx) and airborne total particulate matter (TPM) of primary concern. Current emission standards rely on laboratory testing using an engine dynamometer with a standard test procedure. Results are reported as an integrated value for emissions from a transient set of engine speed and load conditions over a length of time or a set of prescribed speed-load points. To be considered a valid test by the US EPA, the measured engine speed and load are compared to the prescribed engine speed and load and must be within prescribed regression limits.

As a part of the FutureTruck 2000 advanced technology student vehicle competition sponsored by the US Department of Energy and General Motors, West Virginia University has converted a full-size sport utility vehicle into a high fuel efficiency, low emissions vehicle. The environmental impact of the Chevrolet Suburban SUV, in terms of both greenhouse gas emissions and exhaust emissions, was reduced through hybridization without losing any of the functionality and utility of the base vehicle. The approach taken was one of using a high efficiency, state-of-the-art direct injection, turbocharged diesel engine coupled to a high output electric traction motor for power assist and to recover regenerative braking energy. The vehicle employs a state-of-the-art combination lean NOx catalyst, oxidation catalyst and particulate filter to ensure low exhaust emissions.

The Quarter Wave Coaxial Cavity Resonator (QWCCR) plasma igniter is designed, from previous theoretical work, as an ignition source for an internal combustion engine. The present research has explored the implementation of the QWCCR into an internal combustion (IC) engine. The QWCCR design parameters of inner conductor length, loop geometry, and loop position were varied for two igniters of differing operating frequency. Variations of the QWCCR radio frequency (RF) parameters, as a function of engine geometry, were studied by placing the igniter in a combustion chamber and manually varying the crank position. Three identical igniters were fitted with dielectric inserts and the parameters were studied before and after ignition was sustained in a twin-cylinder engine. Optimal resonator geometries were determined. Radio frequency parameter invariance was found with respect to crank angle and piston distance. The first successful IC engine ignition using a QWCCR was achieved.

In modern engine design, downsizing and reducing weight while still providing an increased amount of power has been a general trend in recent decades. Traditionally, an engine design with superior NVH performance usually comes with a heavier, thus sturdier structure. Therefore, modern engine design requires that NVH be considered in the very early design stage to avoid modifications of engine structure at the last minute, when very few changes can be made. NVH design optimization of engine components has become more practical due to the development of computer software and hardware. However, there is still a need for smarter algorithms to draw a direct relationship between the design and the radiated sound power. At the moment, techniques based on modal acoustic transfer vectors (MATVs) have gained popularity in design optimization for their good performance in sound pressure prediction.

As fuel economy and emissions regulations increase in stringence, automakers face ever increasing difficulty in meeting government imposed standards. In this paper a study of fuel economy improving techniques used to meet these regulations, notably Corporate Average Fuel Economy (CAFE), and the upper limit on the effectiveness of these techniques is presented. The effects of external vehicle improvements, such as lightweighting, rolling resistance and aerodynamic improvements were investigated to illustrate the limitations of these methods to dramatically improve overall vehicle efficiency. Engine efficiency improvements, including the effects of compression ignition (unthrottled) versus spark ignition (throttled) engine types were examined. Other engine efficiency areas that were investigated were the implementation of cylinder deactivation and gasoline direct injection engines.

With increasing energy prices and concerns about the environmental impact of greenhouse gas (GHG) emissions, a growing number of national governments are putting emphasis on improving the energy efficiency of the equipment employed throughout their transportation systems. Within the U.S. transportation sector, energy use in commercial vehicles has been increasing at a faster rate than that of automobiles. A 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected from 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. and global economies.

As part of the 1998 Consent Decrees concerning alternative ignition strategies between the six settling heavy-duty diesel engine manufacturers and the United States government, the engine manufacturers agreed to perform in-use emissions measurements of their engines. As part of the Consent Decrees, pre- (Phase III, pre-2000 engines) and post- (Phase IV, 2001 to 2003 engines) Consent Decree engines used in over-the-road vehicles were tested to examine the emissions of oxides of nitrogen (NOx) and carbon dioxide (CO2). A summary of the emissions of NOx and CO2 and fuel consumption from the Phase III and Phase IV engines are presented for 30 second “Not-to-Exceed” (NTE) window brake-specific values. There were approximately 700 Phase III tests and 850 Phase IV tests evaluated in this study, incorporating over 170 different heavy duty diesel engines spanning 1994 to 2003 model years. Test vehicles were operated over city, suburban, and highway routes.

The free piston engine combined with a linear electric alternator has the potential to be a highly efficient converter from fossil fuel energy to electrical power. With only a single major moving part (the translating rod), mechanical friction is reduced compared to conventional crankshaft technology. Instead of crankshaft linkages, the motion of the translator is driven by the force balance between the engine cylinder, alternator, damping losses, and springs. Focusing primarily on mechanical springs, this paper explores the use of springs to increase engine speed and reduce cyclic variability. A numeric model has been constructed in MATLAB®/Simulink to represent the various subsystems, including the engine, alternator, and springs. Within the simulation is a controller that forces the engine to operate at a constant compression ratio by affecting the alternator load.

Changing diesel engine emission requirements for 2002 have led many diesel engine manufacturers to incorporate cooled Exhaust Gas Recirculation, EGR, as a means of reducing NOx. This has resulted in higher levels of soot being present in used oils. This paper builds on earlier work with fresh oils and describes a study of the effect of highly sooted oils on the low temperature pumpability in diesel engines. Four experimental diesel engine oils, of varying MRV TP-1 viscosities, were run in a Mack T-8 engine to obtain a soot level ranging between 6.1 and 6.6%. These sooted oils were then run in a Cummins M11 engine installed in a low temperature cell. Times to lubricate critical engine components were measured at temperatures ranging between -10 °C and -25 °C. A clear correlation was established between the MRV TP-1 viscosity of a sooted oil and the time needed to lubricate critical engine components at a given test temperature.

Production NO sensors have a strong cross-sensitivity to ammonia which limits their use for closed-loop SCR control and diagnostics since increases in sensor output can be caused by either gas component. Recently, Ammonia/NO Ratio (ANR) perturbation methods have been proposed for determining the dominant component in the post-SCR exhaust as part of the overall SCR control strategy, but these methods or the issue of sensor cross-sensitivity have not been critically evaluated or studied in their own right. In this paper the dynamic sensor direct- and cross-sensitivities are estimated from experimental FTIR data (after compensating for the dynamics of the gas sampling system) and compared to nominal values provided by the manufacturer. The ANR perturbation method and the use of different input excitations are then discussed within an analytical framework, and applied to experimental data from a large diesel engine.

Continuously variable transmissions promise to improve the performance and drivability of vehicles. The design and implementation of continuously variable transmissions for medium or large displacement (power) engines have been hampered by the power limitations of the belts. A continuously variable transmission with a power split design (CVPST) has been developed to minimize the loading on the belt while providing for increased power transfer compared to existing designs. To aid in the design and development of this CVPST, a simulator program has been developed. The simulator can be used to optimize the CVPST and to compare with other transmissions. Finally, an optimized CVPST design is presented.