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In a Spark-Ignited engine, there will come a point, as load is increased, where the unburned air-fuel mixture undergoes auto-ignition (knock). The onset of knock represents the upper limit of engine output, and limits the extent of engine downsizing / boosting that can be implemented for a given application. Although effective at mitigating knock, requiring high octane fuel is not an option for most markets. Retarding spark timing can extend the high load limit incrementally, but is still bounded by limits for exhaust gas temperature, and spark retard results in a notable loss of efficiency. Likewise, enriching the air-fuel mixture also decreases efficiency, and has profound negative impacts on engine out emissions. In this current work, a Direct-Injected, Boosted, Spark-Ignited engine with Variable Valve Timing was tested under steady state high load operation. Comparisons were made among three fuels; an 87 AKI, a 91 AKI, and a 110 AKI off-road only race fuel.

In this paper, a model-based linear estimator and a non-linear control law for an Fe-zeolite urea-selective catalytic reduction (SCR) catalyst for heavy duty diesel engine applications is presented. The novel aspect of this work is that the relevant species, NO, NO2 and NH3 are estimated and controlled independently. The ability to target NH3 slip is important not only to minimize urea consumption, but also to reduce this unregulated emission. Being able to discriminate between NO and NO2 is important for two reasons. First, recent Fe-zeolite catalyst studies suggest that NOx reduction is highly favored by the NO 2 based reactions. Second, NO2 is more toxic than NO to both the environment and human health. The estimator and control law are based on a 4-state model of the urea-SCR plant. A linearized version of the model is used for state estimation while the full nonlinear model is used for control design.

Commercial vehicles carry more than 10 billion tons of goods - approximately 70 percent of all freight shipped and travel over 450 billion miles each year in the United States. These vehicles are the exclusive mode of delivery in over 75 percent of U.S. communities. Such utilization and dependency demand commercial vehicles be reliable, durable, and cost effective. The heart of these commercial vehicles (Classes 3-8) is the diesel engine. The widespread use of the diesel engine can be attributed to its reliability, durability, and cost effectiveness. However, the 2007 and 2010 EPA emissions regulations are creating significant challenges for diesel-powered commercial vehicles. Engine and vehicle manufacturers must strike a balance between emissions, performance, and affordability. A consequence of the evolution of the diesel engine to meet the increasingly stringent emissions regulations is that more effort to accommodate the associated changes is driven to the vehicle manufacturers.

This paper presents a compact temperature control device to cool down hot exhaust gas coming out of an aftertreatment emission control system. Active DPF (Diesel Particulate Filter) regeneration is required for aftertreatment emission controls to meet the 2007 EPA (Environmental Protection Agency) PM(Particulate Matter) standard. However, regeneration of the DPF temporarily elevates temperatures in the filter to eliminate accumulated soot. This can increase the temperature of the exhaust gas. The temperature control device in this paper draws ambient air into the hot exhaust stream and mixes them together in such a fashion to maximize temperature drop and minimize back pressure for a limited space without any moving parts or supply of extra power. The simple and compact design of the device makes it a cost-effective candidate to retrofit to an existing aftertreatment system.

Laboratory Simulation Testing is widely accepted as an effective tool for validation of automotive designs. In a simulation test, response data are measured whilst a vehicle is in service or tested at a proving ground. These responses are reproduced in the laboratory by mounting the vehicle or a subassembly of the vehicle in a test rig and applying force and displacements by servo hydraulic actuators. The data required as an input to the servo hydraulics, the drive files, are determined by an iterative procedure which overcomes the non linearity in the test specimen and the test rig system. Under certain circumstances, the iteration does not converge, converges too slowly or converges and then diverges. This paper uses mathematical and computer models in a study of the reasons why systems fail to convergence and makes recommendations about the management of the simulation test.

A bridged valve train configuration exhibits complex dynamic behavior due to the uniqueness of the special elephant foot/bridge/valve structure. Consequently, this system arrangement presents significant design challenges in system stability at high speed, high load, wear, no-follow and valve seating velocity, etc. An efficient way to gain a thorough understanding of the behavior of this type of valve train system and to drive the valve train design improvement is through the use of an effective dynamic simulation tool. In this paper, an advanced CAE tool developed by Ford Motor Company for the bridged type valve train simulations has been described. This automated CAE tool provides a complete virtual ADAMS-based simulation environment for the pushrod bridged valve train system analysis. This paper also presents the correlation and validation between the simulations and the measurements. The design analysis for the bridged valve train has been discussed briefly in this paper.

A Mega-bracket is a cast bracket which connects a chassis frame of a truck to the front bumpers and usually there are two of these for a truck. The mega-brackets help provide clearance for the engine radiator and hence it has a curved shape. It is usually designed to support the towing load when a fully loaded truck needs to be towed following a break-down. A general method of designing a mega-bracket, using shape optimization techniques, is described with a case study. A preliminary design was found to be unsatisfactory to support the tow loads. Finite Element (FE) Topology optimization techniques were used to give us directions as to where ribs should be provided to support the tow loads. FE Shape optimization techniques were then applied to size the ribs and also the rest of the structure using shape variables, which are possible design variations. Since the mega-bracket is irregular in shape, it is extremely difficult and time consuming to generate shape vectors.

Model-based control strategies are important for meeting the dual objective of maximizing NOx reduction and minimizing NH3 slip in urea-SCR catalysts. To be implementable on the vehicle, the models should capture the essential behavior of the system, while not being computationally intensive. This paper discusses the adequacy of two different reduced order SCR catalyst models and compares their performance with a higher order model. The higher order model assumes that the catalyst has both diffusion and reaction kinetics, whereas the reduced order models contain only reaction kinetics. After describing each model, its parameter identification and model validation based on experiments on a Navistar I6 7.6L engine are presented. The adequacy of reduced order models is demonstrated by comparing the NO, NO2 and NH3 concentrations predicted by the models to their concentrations from the test data.

Direct needle control (DNC) has been the enabling technology for diesel fuel injection systems in recent years. It allows for pressurized fuel to be delivered in a concise, controllable manner. Most common rail systems (CRS) utilize 2-way valve principles, which tend to be inefficient and slow relative to 3-way, but robust in implementation. Integration of a DNC valve into a unit injector application has proven to be a challenge to the diesel industry, and most unit injectors have accomplished this using a 2-way valve with flow controlling orifices. 3-way digital spool valves are currently being used in production on hydraulically intensified unit injector applications as a hydraulic intensifier valve for fuel pressurization. 3-way non-latching (NL), single coil spring return (SCSR) DNC valves offer performance advantages over 2-way SCSR DNC valves in the areas of hydraulic efficiency and actuation speed.

The successful development of new products is contingent on clearly understanding product requirements and defining appropriate design activities to deliver the right product. Even if one can clearly understand the abstract requirements implied by the voice-of-customer (VOC), engineers still work best to a set of specifications that define the product in objective measures. The task of extracting the systems specifications from text versions of product requirements is not trivial. Full order dynamic models of mass, springs and dampers provide understanding of vehicle performance; however, the engineer has to define the dynamic characteristics based on his understanding of requirements and translate them into technical specifications. The result can be too dependent on human assumptions and judgments at this point. This work was done to understand how to apply Object Oriented Design (OOD) methodology to trace requirements of a mechanical system to design parameters.

In the present work computational fluid dynamics (CFD) simulations of the flow field around a generic tractor-trailer truck are presented and compared with corresponding experimental measurements. A generic truck model was considered which is a detailed 1/8th scale replica of a Class-8 tractor-trailer truck. It contained a number of details such as bumpers, underbody, tractor chassis, wheels, and axles. CFD simulations were conducted with wind incident on the vehicle at 0 and 6 degree yaw. Two different meshing strategies (tet-dominant and hex-dominant) and three different turbulence models (Realizable k-ε, RNG k-ε, and DES) are considered. In the first meshing strategy an unstructured tetrahedral mesh was created over a large region surrounding the vehicle and in its wake. In the second strategy the mesh was predominantly hexahedral except for a few narrow regions around the front end and the underbody which were meshed with tetrahedral cells owing to complex topology.

The Fischer-Tropsch (FT) process can be used to synthesize diesel fuels from a variety of energy sources, including coal, natural gas and biomass. Diesel fuels produced from the FT process are essentially sulfur-free, have very low aromatic content, and have excellent ignition characteristics. Because of these favorable attributes, FT diesel fuels may offer environmental benefits over transportation fuels derived from crude oil. Previous tests have shown that FT diesel fuel can be used in unmodified engines and have been shown to lower regulated emissions. Whereas exhaust emissions reductions from these previous studies have been impressive, this paper demonstrates that far greater exhaust emissions reductions are possible if the diesel engine is optimized to exploit the properties of the FT fuels. A Power Stroke 7.3 liter turbocharged diesel engine has been modified for use with FT diesel.

A droplet deformation and rotation model (DDR) has been developed and implemented in the KIVA II CFD code for better describing characteristics of liquid fuel sprays in diesel engines, including the distribution of sprays in combustion chamber space and the spray/wall impingement. The DDR model accounts for the effects of both the droplet's frontal area and its drag coefficient as a function of its deformation and rotation on droplet drag and droplet breakup. Therefore, the DDR model can be used for calculating the fuel droplet's drag and breakup in the process of combustion in diesel engines. This makes it possible to model the highly distorted droplet's frontal area variation and its effect on the drag coefficient in sprays. The new version of the KIVA II code with the DDR model has been tested for a case of the spray/wall impingement and a case of the combustion process in a diesel engine.

Product configurators are employed to select and spread bills of material for production builds. Service parts and aftermarket parts typically do not participate in the product configuration process. It is assumed that service parts are identical to, or directly related to, the parts used in production. This is not always the case. Often service requires a bill of material that differs significantly from the production bill - most commonly when customers request add on features at the dealership. Requests for add on features may occur soon after the delivery of a newly built vehicle to a dealer or any point in the operational life of the vehicle. There is an opportunity to leverage production order coding and product configuration processes to support the product after production build. Products with significant complexity and variation may benefit from a ‘service configuration’ process in addition to the ‘production configuration’ process.

This oil category was driven by two new cooled exhaust gas recirculation (EGR) engine tests operating with 15% EGR, with used oil soot levels at the end of the test ranging from 6 to 9%. These tests are the Mack T-10 and Cummins M11 EGR, which address ring, cylinder liner, bearing, and valve train wear; filter plugging, and sludge. In addition to these two new EGR tests, there is a Caterpillar single-cylinder test without EGR which measures piston deposits and oil consumption control using an articulated piston. This test is called the Caterpillar 1R and is included in the existing Global DHD-1 specification. In total, the API CI-4 category includes eight fired-engine tests and seven bench tests covering all the engine oil parameters. The new bench tests include a seal compatibility test for fresh oils and a low temperature pumpability test for used oils containing 5% soot. This paper provides a review of the all the tests, matrix results, and limits for this new oil category.

This paper discusses the guiding philosophy, industry standards, and process and organizational elements utilized by International to shift to a systems engineering approach, within a ‘pull-through’ supply structure. The importance of requirements management in systems engineering, and associated methods are also discussed. The paper also highlights tools and techniques that support systems engineering. Additionally, the benefits of systems engineering are contrasted with the consequences of component-centric product engineering.

This paper discusses a practical use of the Systems Engineering Process as it is implemented in a Truck OEM. The process presented is focused on the Electrical and Electronics area, but can be applied to other systems on the vehicle and to the vehicle level requirements. Systems Engineering rationale is summarized based upon historical impacts and the application of Systems Engineering to address those impacts. Prior System Development Processes are reviewed in light of modern Systems Engineering approaches, leading to the synthesis of the Systems Engineering Documentation Set for the Vehicle and the Vehicle's Electrical and Electronic Systems. The analysis for this approach looks at the application of Systems Engineering Principles throughout the lifecycle of the vehicle, going beyond the boundaries of traditional requirements gathering and analysis.

In the United States, most school buses are powered by diesel engines. Some have advocated replacing diesel school buses with natural gas school buses, but little research has been conducted to understand the emissions from school bus engines. This work provides a detailed characterization of exhaust emissions from school buses using a diesel engine meeting 1998 emission standards, a low emitting diesel engine with an advanced engine calibration and a catalyzed particulate filter, and a natural gas engine without catalyst. All three bus configurations were tested over the same cycle, test weight, and road load settings. Twenty-one of the 41 “toxic air contaminants” (TACs) listed by the California Air Resources Board (CARB) as being present in diesel exhaust were not found in the exhaust of any of the three bus configurations, even though special sampling provisions were utilized to detect low levels of TACs.

Customer feedback indicated that there was a difference in noise levels and frequency content between nominally identical diesel engines manufactured in two different plants. A test program was created to determine whether this perceived difference was real. This program opened the opportunity to investigate several levels of variability in SAE J-1074 noise measurements. From the data, estimates of confidence intervals were developed to predict true mean noise levels in the presence of back-to-back, install-test-remove, and sample-to-sample test variability. The data from this project can be used to estimate the number of tests required in order to achieve a given level of accuracy in estimating the true mean noise level of an engine or of an engine population. The results can also be used to design a test program that will provide a given level of confidence in determining whether there is a statistically significant difference between two engine populations.

Impingement of jet-to-jet has been found to give improved spray penetration characteristics and higher vaporization rates when compared to multi-hole outwardly injecting fuel injectors which are commonly used in the gasoline engine. The current work studies a non-reacting spray by using a 5-hole impinging-jet style direct-injection injector. The jet-to-jet collision induced by the inwardly opening nozzles of the multi-hole injector produces rapid and short jet breakup which is fundamentally different from how conventional fuel injectors operate. A non-reacting spray study is performed using a 5-hole impinging jet injector and a traditional 6-hole Bosch Hochdruck-Einspritzventil (HDEV)-5 gasoline direct-injection (GDI) injector with gasoline as a fuel injected at 172 bar pressure with ambient temperature of 653 K and 490 K and ambient pressure of 37.4 bar and 12.4 bar.