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Active regeneration experiments were performed on a production diesel aftertreatment system containing a diesel oxidation catalyst and catalyzed particulate filter (CPF) using blends of soy-based biodiesel. The effects of biodiesel on particulate matter oxidation rates in the filter were explored. These experiments are a continuation of the work performed by Chilumukuru et al., in SAE Technical Paper No. 2009-01-1474, which studied the active regeneration characteristics of the same aftertreatment system using ultra-low sulfur diesel fuel. Experiments were conducted using a 10.8 L 2002 Cummins ISM heavy-duty diesel engine. Particulate matter loading of the filter was performed at the rated engine speed of 2100 rpm and 20% of the full engine load of 1120 Nm. At this engine speed and load the passive oxidation rate is low. The 17 L CPF was loaded to a particulate matter level of 2.2 g/L.

Recognition of Dimethyl Ether (DME) as an alternative fuel has been growing recently due to its fast evaporation and ignition in application of compression-ignition engine. Most importantly, combustion of DME produces almost no particulate matter (PM). The current study provides a further understanding of the combustion process in DME reacting spray via experiment done in a constant volume combustion chamber. Formaldehyde (CH2O), an important intermediate species in hydrocarbon combustion, has received much attention in research due to its unique contribution in chemical pathway that leads to the combustion and emission of fuels. Studies in other literature considered CH2O as a marker for UHC species since it is formed prior to diffusion flame. In this study, the formation of CH2O was highlighted both temporally and spatially through planar laser induced fluorescence (PLIF) imaging at wavelength of 355-nm of an Nd:YAG laser at various time after start of injection (ASOI).

Energy management is one of the key challenges for the development of Hybrid Electric Vehicle (HEV) due to its complex powertrain structure. Hardware-In-the-Loop (HIL) simulation provides an open software architecture which enables rapid prototyping HEV energy management system. This paper presents the investigation of the energy management system for a single shaft parallel hybrid electric vehicle using dSPACE eDrive HIL system. The parallel hybrid electric vehicle, energy management system, and low-level Electronic Control Unit (ECU) were modeled using dSPACE Automotive Simulation Models and dSPACE blocksets. Vehicle energy management is achieved by a vehicle-level controller called hybrid ECU, which controls vehicle operation mode and torque distribution among Internal Combustion Engine (ICE) and electric motor. The individual powertrain components such as ICE, electric motor, and transmission are controlled by low-level ECUs.

The presented paper deals with a methodology to model cycle-to-cycle variations (CCV) in 0-D/1-D simulation tools. This is achieved by introducing perturbations of combustion model parameters. To enable that, crank angle resolved data of individual cycles (pressure traces) have to be available for a reasonable number of engine cycles. Either experimental data or 3-D CFD results can be applied. In the presented work, experimental data of a single-cylinder research engine were considered while predicted LES 3-D CFD results will be tested in the future. Different engine operating points were selected - both stable ones (low CCV) and unstable ones (high CCV). The proposed methodology consists of two major steps. First, individual cycle data have to be matched with the 0-D/1-D model, i.e., combustion model parameters are varied to achieve the best possible match of pressure traces - an automated optimization approach is applied to achieve that.

One-dimensional simulation methods for unsteady (transient) engine operations have been developed and published in previous studies. These 1-D methods utilize heat release and emissions results obtained from 3-D CFD simulations which are stored in a data library. The goal of this study is to improve the 1-D methodology by optimizing the control strategies. Also, additional independent parameters are introduced to extend the 3-D data library, while, as in the previous studies, the number of interpolation points for each parameter remains small. The data points for the 3-D simulations are selected in the vicinity of the expected trajectories obtained from the independent parameter changes, as predicted by the transient 1-D simulations. By this approach, the number of time-consuming 3-D simulations is limited to a reasonable amount.

Exhaust gas recirculation (EGR) has been employed in a diesel engine to reduce NOx emissions by diluting the fresh air charge with gases composed of primarily N2, CO2, H2O, and O2 from the engines exhaust stream. The addition of EGR reduces the production of NOx by lowering the peak cylinder gas temperature and reducing the concentration of O2 molecules, both of which contribute to the NOx formation mechanism. The amount of EGR has been typically controlled using an open loop control strategy where the flow of EGR was calibrated to the engine speed and load and controlled by the combination of an EGR valve and the ratio of the boost and exhaust back pressures. When oxygenated biofuels with lower specific energy are used, the engine control unit (ECU) will demand a higher fuel rate to maintain power output, which can alter the volumetric flow rate of EGR. In addition, oxygenated biofuels affect the oxygen concentration in the intake manifold gas stream.

Hydrotreated vegetable oil (HVO) is a high-cetane number alternative fuel with the potential of drastic emissions reductions in high-pressure diesel engines. In this study the behavior of HVO sprays is investigated computationally and compared with conventional diesel fuel sprays. The simulations are performed with a modified version of the C++ open source code OpenFOAM using Reynolds-averaged conservation equations for mass, species, momentum and energy. The turbulence has been modeled with a modified version of the RNG k-ε model. In particular, the turbulence interaction between the droplets and the gas has been accounted for by introducing appropriate source terms in the turbulence model equations. The spray simulations reflect the setup of the constant-volume combustion cell from which the experimental data were obtained.

Environmental awareness and fuel economy legislation has resulted in greater emphasis on developing more fuel efficient vehicles. As such, achieving fuel economy improvements has become a top priority in the automotive field. Companies are constantly investigating and developing new advanced technologies, such as hybrid electric vehicles, plug-in hybrid electric vehicles, improved turbo-charged gasoline direct injection engines, new efficient powershift transmissions, and lighter weight vehicles. In addition, significant research and development is being performed on energy management control systems that can improve fuel economy of vehicles. Another area of research for improving fuel economy and environmental awareness is based on improving the customer's driving behavior and style without significantly impacting the driver's expectations and requirements.

A thermal management system for heavy duty diesel engines is presented for maintaining acceptable and constant engine temperatures over a wide range of operational conditions. It consists of a computer controlled variable speed coolant pump, a position controlled thermostat, and a model-based control strategy. An experimentally validated, diesel engine cooling system simulation was used to demonstrate the thermal management system's capability to reduce power consumption. The controller was evaluated using a variety of operating scenarios across a wide range of loads, vehicle speeds, and ambient temperatures. Three metrics were used to assess the effects of the computer controlled system: engine temperature, energy savings, and cab temperature. The proposed control system provided very good control over the engine coolant temperatures while maintaining engine metal temperatures within a desired range.

The effects of a catalyzed particulate filter (CPF) and Exhaust Gas Recirculation (EGR) on heavy-duty diesel engine emissions were studied in this research. EGR is used to reduce the NOx emissions but at the same time it can increase total particulate matter (TPM) emissions. CPF is technology available for retrofitting existing vehicles in the field to reduce the TPM emissions. A conventional low sulfur fuel (371 ppm S) was used in all the engine runs. Steady-state loading and regeneration experiments were performed with CPF I to determine its performance with respect to pressure drop and particulate mass characteristics at different engine operating conditions. From the dilution tunnel emission characterization results for CPF II, at Mode 11 condition (25% load - 311 Nm, 1800 rpm), the TPM, HC and vapor phase emissions (XOC) were decreased by 70%, 62% and 62% respectively downstream of the CPF II.

A study of particle size distributions was conducted on a Cummins M11 1995 engine using the Scanning Mobility Particle Sizer (SMPS) instrument in the baseline and downstream of the Catalyzed Particulate Filter (CPF). Measurements were made in the dilution tunnel to investigate the effect of primary dilution ratio and mixture temperature on the nuclei and accumulation mode particle formation. Experiments were conducted at two different engine modes namely Mode 11 (25% load - 311 Nm, 1800 rpm) and Mode 9 (75% load - 932 Nm, 1800 rpm). The nanoparticle formation decreased with increasing dilution ratios for a constant mixture temperature in the baseline as well as downstream of the CPF II for Mode 11 condition. At Mode 9 condition in the baseline, the dilution ratio had a little effect on the nanoparticle formation, since the distribution was not bimodal and was dominated by accumulation mode particles.

In this paper, the conversion of a production SUV to a hybrid electric vehicle with a drive system utilizing a planetary power-split transmission is presented. The uniqueness of this design comes from its ability to couple the advantages of a parallel hybrid with the advantages of a series hybrid. Depending on operating conditions and recent operating history, the drive system transitions to one of several driving modes. The drive system consists of a planetary gear set coupled to an alternator, motor, and internal combustion engine. It performs the power-split operation without the need for belt drives or clutching devices. The effects on driveability, manufacturing, fuel economy, emissions, and performance are presented along with the design, selection, and implementation of all of the vehicle conversion components.

Three-dimensional diesel engine combustion simulations with single-step chemistry have been compared with two-step and three-step chemistry by means of the Laminar and Turbulent Characteristic Time Combustion model using the Star-CD program. The second reaction describes the oxidation of CO and the third reaction describes the combustion of H2. The comparisons have been performed for two heavy-duty diesel engines. The two-step chemistry was investigated for a purely kinetically controlled, for a mixing limited and for a combination of kinetically and mixing limited oxidation. For the latter case, two different descriptions of the laminar reaction rates were also tested. The best agreement with the experimental cylinder pressure has been achieved with the three-step mechanism but the differences with respect to the two-step and single-step reactions were small.

The successful implementation of a clean, quiet, four-stroke engine into an existing snowmobile chassis has been achieved. The snowmobile is easy to start, easy to drive and environmentally friendly. The following paper describes the conversion process in detail with actual engine test data. The hydrocarbon emissions of the new, four-stroke snowmobile are 98% lower than current, production, two-stroke models. The noise production of the four-stroke snowmobile was 68 dBA during an independent wide open throttle acceleration test. If the four-stroke snowmobile were to replace all current, two-stroke snowmobiles in Yellowstone National Park (YNP), the vehicles would only produce 16% of the combined automobile and snowmobile hydrocarbon emissions compared to the current 93% produced by two-stroke snowmobiles.

A modified version of the Laminar and Turbulent Characteristic Time combustion model and the Hiroyasu-Magnussen soot model have been implemented in the flow solver Star-CD. Combustion simulations of three DI diesel engines, utilizing the standard k-ε turbulence model and a modified version of the RNG k-ε turbulence model, have been performed and evaluated with respect to combustion performance and emissions. Adjustments of the turbulent characteristic combustion time coefficient, which were necessary to match the experimental cylinder peak pressures of the different engines, have been justified in terms of non-equilibrium turbulence considerations. The results confirm the existence of a correlation between the integral length scale and the turbulent time scale. This correlation can be used to predict the combustion time scale in different engines.

Diesel exhaust particle size distributions were measured using an Electrical Aerosol Analyzer (EAA) with both conventional (0.31 wt. pet sulfur) and low sulfur fuel (0.01 wt pet sulfur) with and without a ceramic diesel particle filter (DPF). The engine used for this study was a 1988 heavy-duty diesel engine (Cummins LTA10-300) operated at EPA steady-state modes 9 and 11. The particle size distribution results indicated the typical bi-modal distribution; however, there were clear differences in the number of particles in each mode for all conditions. For the baseline conditions with no DPF, there was more than one order of magnitude greater number of particles in the nuclei mode for the conventional fuel as compared to the low sulfur fuel, while the accumulation modes for each fuel were nearly identical.

An ongoing research and development activities on the scavenged pre-chamber ignition system for an automotive natural gas fueled engine is presented in this paper. The experimental works have been performed in engine laboratory at steady state conditions on a gas engine with 102 mm bore and 120 mm stroke, converted to a single cylinder engine. The in-house designed scavenged pre-chamber is equipped with a spark plug, fuel supply and a miniature pressure sensor for detailed combustion diagnostics. The engine was operated at constant speed, fully open throttle valve and four different fueling modes with or without spark discharge. A partly motored mode allowed direct evaluation of the pre-chamber heat release. The experimental data acquired in this research served as a validation data for the numerical simulations. The performed tests of prototypes and calculations have recently been expanded to include 3-D flow calculations in the Ansys Fluent software.

The present paper deals with the application of the LES approach to in-cylinder flow modeling. The main target is to study cycle-to-cycle variability (CCV) using 3D-CFD simulation. The engine model is based on a spark-ignited single-cylinder research engine. The results presented in this paper cover the motored regime aiming at analysis of the cycle-resolved local flow properties at the spark plug close to firing top dead center. The results presented in this paper suggest that the LES approach adopted in the present study is working well and that it predicts CCV and that the qualitative trends are in-line with established knowledge of internal combustion engine (ICE) in-cylinder flow. The results are evaluated from a statistical point of view based on calculations of many consecutive cycles (at least 10).

Traditional smoke opacity measurement, performed on diesel engines during regular emissions inspections, sensitive primarily to larger particles of elemental carbon, is very little sensitive to nanoparticles and to semi-volatile “organic carbon” particles. For this reason, it no longer suffices as a high emitter detection tool for modern vehicles with a particle filter or for advanced low-emissions technology where semi-volatile organic particles are the dominant fraction of particulate matter. This paper investigates the potential of common low-cost ionization type smoke detectors, produced in mass quantities for fire detection in buildings, as a tool to measure particle emissions in vehicular exhaust. Two ionization chambers were used to measure both raw and diluted exhaust of various engines powered by diesel fuel and biofuels under laboratory conditions as well as on the road.

Battery management system (BMS) plays a key role in the power management of hybrid electric vehicles (HEV). It measures the state of charge (SOC), state of health (SOH) of the battery, protects the battery package and extends cells' life cycles. For HEV applications, lithium-ion battery is usually selected as electric power source due to its high specific energy, high energy density, and long life cycle. However, the non-linear characteristic of a Li-ion battery, complicated electro-chemical model, and environmental factors, raises the difficulties in the real-time estimation of the SOC for a Li-ion battery. To address this challenge, a BMS for HEVs is modeled with MATLAB/Simulink. In addition, a regenerative braking control strategy is proposed to determine the magnitude of the regenerative torque based on the battery SOC.