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All around the world, steps are being taken to improve the quality of our environment. Prominent among these are the definition, implementation, and attainment of increasingly stringent emissions regulations for all types of engines, including off-highway diesels. These rigorous regulations have driven use of technologies like after-treatment, advanced air systems, and advanced fuel systems. Fuel dispensed off-highway is routinely and significantly dirtier than fuel from on-highway outlets. Furthermore, fuels used in developing countries can be up to 30 times dirtier than the average fuels in North America. Poor fuel cleanliness, coupled with the higher pressures and performance demands of modern fuel systems, create life challenges greater than encountered with cleaner fuels. This can result in costly disruption of operations, loss of productivity, and customer dissatisfaction in the off-highway market.

As Electric and Hybrid Electric Vehicles (EVs and HEVs) become more prevalent, there is a need to change the power source from gasoline on the vehicle to electricity from the grid in order to mitigate requirements for onboard energy storage (battery weight) as well as to reduce dependency on oil by increasing dependency on the grid (our coal, gas, and renewable energy instead of their oil). Traditional systems for trains and buses rely on physical contact to transfer electrical energy to vehicles in motion. Until recently, conventional magnetically coupled systems required a gap of less than a centimeter. This is not practical for vehicles of the future.

The question of whether increasing the fuel economy of light-duty natural gas fueled vehicles can improve their economic competitiveness in the U.S. market, and help the US Department of Energy meet stated goals for such vehicles is explored. Key trade-offs concerning costs, exhaust emissions and other issues are presented for a number of possible advanced engine designs. Projections of fuel economy improvements for a wide range of lean-burn engine technologies have been developed. It appears that compression ignition technologies can give the best potential fuel economy, but are less competitive for light-duty vehicles due to high engine cost. Lean-burn spark ignition technologies are more applicable to light-duty vehicles due to lower overall cost. Meeting Ultra-Low Emission Vehicle standards with efficient lean-burn natural gas engines is a key challenge.

Accurate perception of the driving environment and a highly accurate position of the vehicle are paramount to safe Autonomous Vehicle (AV) operation. AVs gather data about the environment using various sensors. For a robust perception and localization system, incoming data from multiple sensors is usually fused together using advanced computational algorithms, which historically requires a high-compute load. To reduce AV compute load and its negative effects on vehicle energy efficiency, we propose a new infrastructure information source (IIS) to provide environmental data to the AV. The new energy–efficient IIS, chip–enabled raised pavement markers are mounted along road lane lines and are able to communicate a unique identifier and their global navigation satellite system position to the AV. This new IIS is incorporated into an energy efficient sensor fusion strategy that combines its information with that from traditional sensor.

A major driving force for change in light-duty vehicle design and technology is the National Highway Traffic Safety Administration (NHTSA) and the U.S. Environmental Protection Agency (EPA) joint final rules concerning Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emissions for model years 2017 (MY17) through 2025 (MY25) passenger cars and light trucks. The chief goal of this current study is to compare the already rapid pace of fuel economy improvement and technological change over the previous decade to the required rate of change to meet regulations over the next decade. EPA and NHTSA comparisons of the model year 2005 (MY05) US light-duty vehicle fleet to the model year 2015 (MY15) fleet shows improved fuel economy (FE) of approximately 26% using the same FE estimating method mandated for CAFE regulations. Future predictions by EPA and NHTSA concerning ensemble fleet fuel economy are examined as an indicator of required vehicle rate-of-change.

Previous research has shown that the homogeneous charge compression ignition (HCCI) combustion concept holds promise for reducing pollutants (i.e. NOx, soot) while maintaining high thermal efficiency. However, it can be difficult to control the operation of the HCCI engines even under steady state running conditions. Power density may also be limited if high inlet air temperatures are used for achieving ignition. A methodology using a small pilot quantity of diesel fuel injected during the compression stroke to improve the power density and operation control is considered in this paper. Multidimensional computations were carried out for an HCCI engine based on a CAT3401 engine. The computations show that the required initial temperature for ignition is reduced by about 70 K for the cases of the diesel pilot charge and a 25∼35% percent increase in power density was found for those cases without adversely impacting the NOx emissions.

Ultrasonic spot welding (USW) is a promising joining method for magnesium to steel to overcome the difficulties of fusion welding for these two materials with significant differences in melting temperatures. In a previous paper, the results of ultrasonic spot welding of magnesium to steel, with sonotrode engaged Mg piece, was presented. In this study, same material combination (0.8-mm-thick galvanized mild steel and 1.6-mm Mg AZ31B-H24) was used, but with sonotrode engaging steel piece. Various welding time, from 0.4 to 2.0 sec, were applied. Tensile lap-shear test, optical metallography, and scanning electron micrography were conducted for joint strength measurement and microstructural evaluation. The joint strength reached over 4.2 kN at 1.8 sec welding time. Mg-Zn eutectic was formed at the interface, indicating the interfacial temperature over 344°C. The study demonstrated USW to be a viable process for potential manufacturing of mixed-metal joints.

Ultrasonic spot welds were made between sheets of 0.8-mm-thick hot-dip-galvanized mild steel and 1.6-mm-thick AZ31B-H24. Lap-shear strengths of 3.0-4.2 kN were achieved with weld times of 0.3-1.2 s. Failure to achieve strong bonding of joints where the Zn coating was removed from the steel surface indicate that Zn is essential to the bonding mechanism. Microstructure characterization and microchemical analysis indicated temperatures at the AZ31-steel interfaces reached at least 344°C in less than 0.3 s. The elevated temperature conditions promoted annealing of the AZ31-H24 metal and chemical reactions between it and the Zn coating.

Exhaust gas recirculation (EGR) cooler fouling has emerged as an important issue in diesel engine development. Uncertainty about the level of impact that fuel chemistry may have upon this issue has resulted in a need to investigate the cooler fouling process with emerging non-traditional fuel sources to gage their impact on the process. This study reports experiments using both ultra-low sulfur diesel (ULSD) and 20% biodiesel (B20) at elevated exhaust hydrocarbon conditions to investigate the EGR cooler fouling process. The results show that there is little difference between the degradation in cooler effectiveness for ULSD and B20 at identical conditions. At lower coolant temperatures, B20 exhibits elevated organic fractions in the deposits compared with ULSD, but this does not appear to lead to incremental performance degradation under the conditions studied.

The friction and wear characteristics of three commercially-available, electrolytic coatings for aluminum engine cylinder bores were compared to those of cast iron liners. A Ni/SiC electrocomposite, a hard anodized treatment, and a Plasma Electrolytic Oxidation (PEO) coating were investigated. ASTM standard test method G133-95, non-firing test method, for linearly reciprocating sliding wear was modified to use segments of piston rings and cylinder liners. Tests were conducted using Mr. Goodwrench™ 5W30 as a lubricant at room temperature. The normal force was 150N, the reciprocating frequency was 15Hz, the stroke length was 8mm, and the test duration was 60 minutes. Kinetic friction coefficients ranged from 0.1 to 0.22, typical of boundary lubrication. The Ni/SiC and cast iron samples exhibited the lowest friction. The wear resistance of the Ni/SiC coating was superior to that of cast iron.

Clutches are commonly utilised in passenger type and off-road heavy-duty vehicles to disconnect the engine from the driveline and other parasitic loads. In off-road heavy-duty vehicles, along with fuel efficiency start-up functionality at extended ambient conditions, such as low temperature and intake absolute pressure are crucial. Off-road vehicle manufacturers can overcome the parasitic loads in these conditions by oversizing the engine. Caterpillar Inc. as the pioneer in off-road technology has developed a novel clutch design to allow for engine downsizing while vehicle’s performance is not affected. The tribological behaviour of the clutch will be crucial to start engagement promptly and reach the maximum clutch capacity in the shortest possible time and smoothest way in terms of dynamics. A multi-body dynamics model of the clutch system is developed in MSC ADAMS. The flywheel is introducing the same speed and torque as the engine (represents the engine input to the clutch).

This paper reports on a comprehensive, crank-angle transient, three dimensional, computational fluid dynamics (CFD) model of the complete lubrication system of a multi-cylinder engine using the CFD software Simerics-Sys / PumpLinx. This work represents an advance in system-level modeling of the engine lubrication system over the current state of the art of one-dimensional models. The model was applied to a 16 cylinder, reciprocating internal combustion engine lubrication system. The computational domain includes the positive displacement gear pump, the pressure regulation valve, bearings, piston pins, piston cooling jets, the oil cooler, the oil filter etc… The motion of the regulation valve was predicted by strongly coupling a rigorous force balance on the valve to the flow.

Low-temperature heat release (LTHR) in spark-ignited internal combustion engines is a critical step toward the occurrence of auto-ignition, which can lead to an undesirable phenomenon known as engine knock. Hence, correct predictions of LTHR are of utmost importance to improve the understanding of knock and enable techniques aimed at controlling it. While LTHR is typically obscured by the deflagration following the spark ignition, extremely late ignition timings can lead to LTHR occurrence prior to the spark, i.e., pre-spark heat release (PSHR). In this research, PSHR in a boosted direct-injection SI engine was numerically investigated using three-dimensional computational fluid dynamics (CFD). A hybrid approach was used, based on the G-equation model for representing the turbulent flame front and the multi-zone well-stirred reactor model for tracking the chemical reactions within the unburnt region.

The effects of thermal and chemical aging on the performance of cordierite-based and high-porosity mullite-based diesel particulate filters (DPFs), were quantified, particularly their filtration efficiency, pressure drop, and regeneration capability. Both catalyzed and uncatalyzed core-size samples were tested in the lab using a diesel fuel burner and a chemical reactor. The diesel fuel burner generated carbonaceous particulate matter with a pre-specified particle-size distribution, which was loaded in the DPF cores. As the particulate loading evolved, measurements were made for the filtration efficiency and pressure drop across the filter using, respectively, a Scanning Mobility Particle Sizer (SMPS) and a pressure transducer. In a subsequent process and on a different bench system, the regeneration capability was tested by measuring the concentration of CO plus CO2 evolved during the controlled oxidation of the carbonaceous species previously deposited on the DPF samples.

In this research, small, single cylinder engines have been used to simulate larger engines in the areas of aftertreatment, combustion, and fuel formulation effects. The use of small engines reduces overall research cost and allows more rapid experiments to be run. Because component costs are lower, it is also possible to investigate more variations and to sacrifice components for materials characterization and for subsequent experiments. Using small engines in this way is very successful in some cases. In other cases, limitations of the engines influence the results and need to be accounted for in the experimental design and data analysis. Some of the results achieved or limitations found may be of interest to the small engine market, and this paper is offered as a summary of the authors' research in these areas. Research is being conducted in two areas. First, small engines are being used to study the rapid aging and poisoning of exhaust aftertreatment catalysts.

On a gasoline engine platform, homogeneous charge compression ignition (HCCI) holds the promise of improved fuel economy and greatly reduced engine-out NOx emissions, without an increase in particulate matter emissions. In this investigation, a variable compression ratio (CR) engine equipped with a throttle and intake air heating was used to test the robustness of these control parameters to accommodate a series of fuels blended from reference gasoline, straight run refinery naphtha, and ethanol. Higher compression ratios allowed for operation with higher octane fuels, but operation could not be achieved with the reference gasoline, even at the highest compression ratio. Compression ratio and intake heat could be used separately or together to modulate combustion. A lambda of 2 provided optimum fuel efficiency, even though some throttling was necessary to achieve this condition. Ethanol did not appear to assist combustion, although only two ethanol-containing fuels were evaluated.

Mandated pollutant emission levels are shifting light-duty vehicles towards hybrid and electric powertrains. Heavy-duty applications, on the other hand, will continue to rely on internal combustion engines for the foreseeable future. Hence there remain clear environmental and economic reasons to further decrease IC engine emissions. Turbocharged diesels are the mainstay prime mover for heavy-duty vehicles and industrial machines, and transient performance is integral to maximizing productivity, while minimizing work cycle fuel consumption and CO2 emissions. 1D engine simulation tools are commonplace for “virtual” performance development, saving time and cost, and enabling product and emissions legislation cycles to be met. A known limitation however, is the predictive capability of the turbocharger turbine sub-model in these tools.

The deactivation of diesel oxidation catalysts (DOCs) by soot contamination and lube-oil derived phosphorus poisoning is investigated. Pt/CeO2/γ-AI2O3 DOCs aged using three different protocols developed by the authors and six high mileage field-returned DOCs of similar formulation are evaluated for THC and CO oxidation performance using a bench-flow reactor. Collectively, these catalysts exhibit a variety of phosphorus and soot morphologies contributing to performance deactivation.

Nitrites have long been added to heavy-duty coolant to inhibit iron cylinder liner corrosion initiated by cavitation. However, in heavy-duty use, nitrites deplete from the coolant, which then must be refortified using supplemental coolant additives (SCA's). Recently, carboxylates have also been found to provide excellent cylinder liner protection in heavy-duty application. Unlike nitrites, carboxylate inhibitors deplete slowly and thus do not require continual refortification with SCA's. In the present paper laboratory aging experiments shed light on the mechanism of cylinder liner protection by these inhibitors. The performance of carboxylates, nitrites and mixtures of the two inhibitors are compared. Results correlate well with previously published fleet data. Specifically, rapid nitrite and slow carboxylate depletion are observed. More importantly, when nitrite and carboxylates are used in combination, nitrite depletion is repressed while carboxylates deplete at a very slow rate.

In order to meet common fuel specifications such as cetane number and volatility, a refinery must blend a number of refinery stocks derived from various process units in the refinery. Fuel chemistry can be significantly altered in meeting fuel specifications. Additionally, fuel specifications are seldom changed in isolation, and the drive to meet one specification may alter other specifications. Homogeneous charge compression ignition (HCCI) engines depend on the kinetic behavior of a fuel to achieve reliable ignition and are expected to be more dependent on fuel specifications and chemistry than today's conventional engines. Regression analysis can help in determining the underlying relationships between fuel specifications, chemistry, and engine performance. Principal Component Analysis (PCA) is used as an adjunct to regression analysis in this work, because of its ability to deal with co-linear variables and potential to uncover ‘hidden’ relationships between the variables.