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A prototype 2007 ISL Cummins diesel engine equipped with a diesel oxidation catalyst (DOC), diesel particle filter (DPF), variable geometry turbocharger (VGT), and cooled exhaust gas recirculation (EGR) was tested at Southwest Research Institute (SwRI) under a high-load accelerated durability cycle for 1000 hours with B20 soy-based biodiesel blends and ultra-low sulfur diesel (ULSD) fuel to determine the impact of B20 on engine durability, performance, emissions, and fuel consumption. At the completion of the 1000-hour test, a thorough engine teardown evaluation of the overhead, power transfer, cylinder, cooling, lube, air handling, gaskets, aftertreatment, and fuel system parts was performed. The engine operated successfully with no biodiesel-related failures. Results indicate that engine performance was essentially the same when tested at 125 and 1000 hours of accumulated durability operation.

The presented work describes how numerical modeling techniques were extended to simulate a full Selective Catalytic Reduction (SCR) NOx aftertreatement system. Besides predicting ammonia-to-NOX ratio (ANR) and uniformity index (UI) at the SCR inlet, the developed numerical model was able to predict NOx reduction and ammonia slip. To reduce the calculation time due to the complexity of the chemical process and flow field within the SCR, a semi-1D approach was developed and applied to model the SCR catalyst, which was subsequently coupled with a 3D model of the rest of the exhaust system. Droplet depletion of urea water solution (UWS) was modeled by vaporization and thermolysis techniques while ammonia generation was modeled by the thermolysis and hydrolysis method. Test data of two different SCR systems were used to calibrate the simulation results. Results obtained using the thermolysis method showed better agreement with test data compared to the vaporization method.

The electrification of accessories using a fuel cell as an auxiliary power unit reduces the load on the engine and provides opportunities to increase propulsion performance or reduce engine displacement. The SunLine™ Class 8 tractor electric accessory integration project is a United States Army National Automotive Center (NAC™) initiative in partnership with Cummins Inc., Dynetek™ Industries Ltd., General Dynamics C4 Systems, Acumentrics™ Corporation, Michelin North America, Engineered Machine Products (EMP™), Peterbilt™ Motors Company, Modine™ Manufacturing and Masterflux™. Southwest Research Institute is the technical integration contractor to SunLine™ Services Group. In this paper the SunLine™ tractor electric Air Conditioning (AC) system is described and the installation of components on the tractor is illustrated. The AC system has been designed to retrofit into an existing automotive system and every effort was made to maintain OEM components whenever modifications were made.

Water injection is an effective method for knock control in spark-ignition engines. However, the requirement of a separate water source and the cost and complexity associated with a fully integrated system creates a limitation of this method to be used in volume production engines. The engine exhaust typically contains 10-15% water vapor by volume which could be condensed and potentially stored for future use. In this study, the exhaust condensate composition was assessed for its use as an effective replacement for distilled water. Specifically, condensate samples were collected pre and post-three-way catalyst (TWC) and analyzed for acidity and composition. The composition of the pre and post-TWC condensates was found to be similar however, the pre-TWC condensate was mildly acidic. The mild acidity has the potential to corrode certain components in the intake air circuit.

As the efforts to push capabilities of current engine hardware to their durability limits increases, more accurate and reliable analysis is necessary to ensure that designs are robust. This paper evaluates a method of Conjugate Heat Transfer (CHT) analysis for a gasoline and a diesel engine that combines combustion Computational Fluid Dynamics (CFD), engine Finite Element Analysis (FEA), and cooling jacket CFD with the goal of obtaining more accurate temperature distribution and heat loss predictions in an engine compared to standard de-coupled CFD and FEA analysis methods. This novel CHT technique was successfully applied to a 2.5 liter GM LHU gasoline engine at 3000 rpm and a 15.0 liter Cummins ISX heavy duty diesel engine operating at 1250 rpm. Combustion CFD simulations results for the gasoline and diesel engines are validated with the experimental data for cylinder pressure and heat release rate.

With the increasing level of electrification of on-road, off-road and stationary applications, use of larger lithium-ion battery packs has become essential. These packs require large capital investments on the order of millions of dollars and pose a significant risk of self-annihilation without rigorous safety evaluation and management. Testing these larger battery packs to validate design changes can be cost prohibitive. A reliable numerical simulation tool to predict battery thermal runaway under various abuse scenarios is essential to engineer safety into the battery pack design stage. A comprehensive testing & simulation workflow has been established to calibrate and validate the numerical modeling approach with the test data for each of the individual sub model - electrochemical, internal short circuit and thermal abuse model. A four-equation thermal abuse model was built and validated for lithium-ion 21700 form factor cylindrical cells using NCA cathodes.

A novel continuous inductive discharge ignition system has been developed that allows for variable duration ignition events in SI engines. The system uses a dual-coil design, where two coils are connected by a diode, combined with the multi-striking coil concept, to generate a continuous current flow through the spark plug. The current level and duration can be regulated by controlling the number of re-strikes that each coil performs or the energy density the primary coils are charged to. Compared to other extended duration systems, this system allows for fairly high current levels during the entire discharge event while avoiding the extremely high discharge levels associated with other, shorter duration, high energy ignition systems (e.g. the plasma jet [ 1 , 2 ], railplug [ 3 ] or laser ignition systems [ 4 , 5 , 6 , 7 , 8 ].

General agreement exists that the ultimate goals of traffic accident research are to reduce fatality, mitigate injury and decrease economic loss to society. Although massive quantities of data have been collected in local, national and international programs, attempts by analysts to use these data to explore ideas or support hypotheses have been met by a variety of problems. Specifically, the coded variables in the different files are not consistent and little information on accident etiology is collected. Examples of the inadequacies of present data in terms of the collected and coded variables are shown. The vehicular, environmental and human (consisting of human factors and injury factors) variables are disproportionately represented in most existing data files in terms of recognized statistical evidence of accident causation. A systems approach is needed to identify critical, currently neglected variables and develop units of measurement and data collection procedures.

Southwest Research Institute (SwRI) converted a 2012 Buick Regal GS to use an engine with Dedicated EGR™ (D-EGR™). D-EGR is an engine concept that uses fuel reforming and high levels of recirculated exhaust gas (EGR) to achieve very high levels of thermal efficiency [1]. To accomplish reformation of the gasoline in a cost-effective, energy efficient manner, a dedicated cylinder is used for both the production of EGR and reformate. By operating the engine in this manner, many of the sources of losses from traditional reforming technology are eliminated and the engine can take full advantage of the benefits of reformate. The engine in the vehicle was modified to add the following components: the dedicated EGR loop, an additional injector for delivering extra fuel for reformation, a modified boost system that included a supercharger, high energy dual coil offset (DCO) ignition and other actuators used to enable the control of D-EGR combustion.

Until recently, U.S. government efforts to dramatically reduce emissions, greenhouse gases and vehicle fuel consumption have primarily focused on passenger car applications. Similar aggressive reductions need to be extended to heavy vehicles such as delivery trucks, buses, and motorhomes. However, the wide range of torques, speeds, and powers that such vehicles must operate under makes it difficult for any current powertrain system to provide the desired improvements in emissions and fuel economy. Hybrid electric powertrains provide the most promising, near-term technology that can satisfy these requirements. This paper highlights the configuration and benefits of a hybrid electric powertrain capable of operating in either a parallel or series mode. It describes the hybrid electric components in the system, including the electric motors, power electronics and batteries.

A 13 L HD diesel engine was converted to run as a flame propagation engine using the HEDGE™ Dual-Fuel concept. This concept consists of pre-mixed gasoline ignited by a small amount of diesel fuel - i.e., a diesel micropilot. Due to the large bore size and relatively high compression ratio for a pre-mixed combustion engine, high levels of cooled EGR were used to suppress knock and reduce the engine-out emissions of the oxides of nitrogen and particulates. Previous work had indicated that the boosting of high dilution engines challenges most modern turbocharging systems, so phase I of the project consisted of extensive simulation efforts to identify an EGR configuration that would allow for high levels of EGR flow along the lug curve while minimizing pumping losses and combustion instabilities from excessive backpressure. A potential solution that provided adequate BTE potential was consisted of dual loop EGR systems to simultaneously flow high pressure and low pressure loop EGR.

SwRI has developed the DCO® ignition system, a unique continuous discharge system that allows for variable duration/energy events in SI engines. The system uses two coils connected by a diode and a multi-striking controller to generate a continuous current flow through the spark plug of variable duration. A previous publication demonstrated the ability of the DCO system to improve EGR tolerance using low energy coils. In this publication, the work is extended to high current (≻ 300 mA/high energy (≻ 200 mJ) coils and compared to several advanced ignition systems. The results from a 4-cylinder, MPI application demonstrate that the higher current/higher energy coils offer an improvement over the lower energy coils. The engine was tested at a variety of speed and load conditions operating at stoichiometric air-fuel ratios with gasoline and EGR dilution.

Vehicle designers make use of vehicle performance programs such as RAPTOR™ to predict the performance of concept vehicles over ranges of industry standard drive cycles. However, the accuracy of such predictions may be greatly influenced by factors requiring more specialist simulation capabilities. For example, fuel economy prediction will be heavily influenced by the performance of the engine cooling system and its impact on the vehicle's aerodynamic drag, and the load from the air-conditioning system. To improve the predictions, specialist simulation capabilities need to be applied to these aspects, and brought together with the vehicle performance calculations through co-simulation. This paper describes the approach used to enable this cosimulation and the benefits achieved by the vehicle designer.

The automotive sector is rapidly transitioning to decarbonized, electric vehicles solutions. However, due to challenges with such rapid adoption, Internal combustion engines (ICE) are expected to be used for decades to come. In this transition period it is important to continue to improve ICE efficiency. A key design parameter to increase ICE efficiency is the compression ratio. For gasoline engines, the compression ratio is limited so as to avoid knock. Engine designers can employ several strategies to mitigate knock and enable higher compression ratios. In this study, a new methodology has been developed to compare various knock mitigation strategies. By comparing the knock limited load at a given combustion phasing the expected compression ratio increase can be inferred.

Next generation vehicles are under environmental and economic pressure to reduce emissions and increase fuel economy, while maintaining the same ride and performance characteristics of present day combustion engine automobiles. This has prompted researchers to investigate hybrid vehicles as one possible solution to this challenge. At Southwest Research Institute (SwRI), a unique parallel hybrid drivetrain was designed and prototyped. This hybrid drivetrain alleviates the disadvantages of series hybrid drivetrains by directly coupling the driving wheels to two power sources, namely an engine and an electric motor. At the same time, the design allows the engine speed to be decoupled from the vehicle speed, allowing the engine to operate at its most efficient state. This paper describes the drivetrain, its components, and the test stand that was assembled to test the parallel hybrid drivetrain.

A physics-based spark ignition model was developed and integrated into a commercial CFD code. The model predicted the spark discharge process based on the electrical parameters of the secondary ignition circuit, tracked the spark motion as it was stretched by in-cylinder gas motion, and determined the resulting energy deposition to the gas. In concert with the existing kinetic solver in the CFD code, the resulting ignition and flame propagation processes were simulated. The model results have been validated against both imaging rig experiments of the spark in moving air and against engine experimental data. The model was able to replicate the key features of the spark and to capture the cyclic variability of high-dilution combustion when multiple engine cycles were simulated.

Existing expert systems have a high percentage agreement with human experts in a particular field in many situations. However, in many ways their overall behavior is not like that of a human expert. These areas include the inability to give flexible, functional explanations of their reasoning processes and the failure to degrade gracefully when dealing with problems at the periphery of their knowledge. These two important shortcomings can be improved when the right knowledge is available to the system. This paper presents an expert system design, called the Integrated Diagnostic Model (IDM), that integrates two sources of knowledge: a shallow, empirically-oriented, experiential knowledge base and a deep, functionally-oriented, physical knowledge base. To demonstrate the IDM's usefulness in the problem area of diagnosis and repair of electrical and mechanical devices, two implementations and our experience with them is described.

A Single Cylinder Medium Speed diesel engine research facility has been developed for investigating areas of current technical concern to the rail, marine and stationary power industries. The design and operation of this Single Cylinder Research Engine (SCRE) is described. The facility is centered around a Bombardier model 251-plus 11.0 L engine which is representative of four stroke multi-cylinder railroad, marine and small stationary powerplant engines. All engine support systems (air, cooling water, fuel oil and lubricating oil pumps) operate independent of the engine enabling a wide range of adjustments in flow, pressure and temperature. Current program areas for which this system is used include alternative fuels evaluation, combustion analyses, fuel injection system development, component wear and durability studies, engine friction analyses, lubricant testing and emissions evaluations.

An airflow-dominant control system was developed to provide precise engine and exhaust treatment control with low air fuel ratio alternative combustion. The main elements of the control logic include a real-time state observer for in-cylinder oxygen mass estimation, a simplified packaging scheme for all air-handling and fueling parameters, a finite state machine for control mode switching, combustion control models to maintain robust alternative combustion during transients, and smooth rich/lean switching during lean NOx trap (LNT) regeneration without post injection. The control logic was evaluated on a passenger car equipped with a 4-way catalyst system with LNT and was instrumental in achieving US Tier II Bin 5 emission targets with good drivability and low NVH.

Fuel costs to operate large trucks have risen substantially in the last few years and, based on petroleum supply/demand curves, that trend is expected to continue for the foreseeable future. Non-propulsion or parasitic loads in a large truck account for a significant percentage of overall engine load, leading to reductions in overall vehicle fuel economy. Electrification of parasitic loads offers a way of minimizing non-propulsion engine loads, using the full motive force of the engine for propulsion and maximizing vehicle fuel economy. This paper covers the integration and testing of electrified accessories, powered by a fuel cell auxiliary power unit (APU) in a Class 8 tractor. It is a continuation of the efforts initially published in SAE paper 2005-01-0016.