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ERRATUM: In the article Reference 24 should read as follows: 24. Han, T., Booth, A., Song, S., Styles, D., and Hoard, J., “Review and A Conceptual Model of Exhaust Gas Recirculation (EGR) Cooler Fouling Deposition and Removal Mechanism” Proceedings of the Int. Conf. on Heat Exchanger Fouling and Cleaning, 2015”

Engine cooling module air flows depend on package components and vehicle front end geometry. For years, in the early stages of vehicle development, front end geometry air flows were determined from 3/8 scale models or retrofit of similar existing vehicles. As time to market has become much shorter, finite element modeling of air flows is the only tool available. This paper describes how finite element simulations of front end air flows can be run early in the development program independent of any specific engine cooling module configuration and then coupled with traditional one-dimensional component performance models to predict cooling module air flows. The CFD simulation thus replaces the previous scale model testing process. The CFD simulations are used to determine the two parameters that characterize the front end geometry flow resistance (recovery coefficient and internal loss coefficient).

An automated process was developed for the calibration of numerical aftertreatment models. The chemical kinetic mechanism examined in this case was part of a simplified SCR model. The process adopted for calibrating the SCR model was based on a micro-population multi-objective genetic algorithm. The algorithm developed was used to calibrate the SCR model using data derived from another, more detailed model to ensure that the evaluation focused only on the effectiveness of the calibration process and was not affected by issues of experimental inaccuracies or details of the model chemistry involved.

Premixed Charge Compression Ignition (PCCI), a Low Temperature Combustion (LTC) strategy for diesel engines is of increasing interest due to its potential to simultaneously reduce soot and NOx emissions. However, the influence of mixture preparation on combustion phasing and heat release rate in LTC is not fully understood. In the present study, the influence of injection timing on mixture preparation, combustion and emissions in PCCI mode is investigated by experimental and computational methods. A sequential coupling approach of 3D CFD with a Stochastic Reactor Model (SRM) is used to simulate the PCCI engine. The SRM accounts for detailed chemical kinetics, convective heat transfer and turbulent micro-mixing. In this integrated approach, the temperature-equivalence ratio statistics obtained using KIVA 3V are mapped onto the stochastic particle ensemble used in the SRM.

The effect that thermally and compositionally stratified flowfields have on the spatial progression of iso-octane-fueled homogeneous charge compression ignition (HCCI) combustion were directly observed using highspeed chemiluminescence imaging. The stratified in-cylinder conditions were produced by independently feeding the intake valves of a four-valve engine with thermally and compositionally different mixtures of air, vaporized fuel, and argon. Results obtained under homogeneous conditions, acquired for comparison to stratified operation, showed a small natural progression of the combustion from the intake side to the exhaust side of the engine, a presumed result of natural thermal stratification created from heat transfer between the in-cylinder gases and the cylinder walls. Large differences in the spatial progression of the HCCI combustion were observed under stratified operating conditions.

Measurement of particle number was introduced in the Euro 5/6 light duty vehicle emissions regulation. Although particle number measurement systems have to be calibrated by the manufacturers, labs have to validate the proper operation of their systems within one year of the emissions test. The systems must achieve a >99% reduction of an aerosol containing 30 nm tetracontane (CH3(CH2)38CH3) particles (C40) with an inlet concentration >104 #/cm3. They must also include an initial heated dilution stage with dilution of at least 10 which outputs a diluted sample at a temperature of 150°C–400°C. The system as a whole must achieve a particle number concentration reduction factor for particles of 30 nm and 50 nm electrical mobility diameters, that is no more than 30% and 20% respectively higher, and no more than 5% lower than that for particles of 100 nm.

Exhaust gas recirculation, fuel injection strategy and boost pressure are among the key enablers to attain low NOx and soot emissions simultaneously on modern diesel engines. In this work, the individual influence of these parameters on the emissions are investigated independently for engine loads up to 8 bar IMEP. A single-shot fuel injection strategy has been deployed to push the diesel cycle into low temperature combustion with EGR. The results indicated that NOx was a stronger respondent to injection pressure levels than to boost when the EGR ratio is relatively low. However, when the EGR level was sufficiently high, the NOx was virtually grounded and the effect of boost or injection pressure becomes irrelevant. Further tests indicated that a higher injection pressure lowered soot emissions across the EGR sweeps while the effect of boost on the soot reduction appeared significant only at higher soot levels.

A realistic modeling of the wall heat transfer is essential for an accurate analysis and simulation of the working cycle of internal combustion engines. Empirical heat transfer formulations still dominate the application in engine process simulations because of their simplicity. However, experiments have shown that existing correlations do not provide satisfactory results for all the possible operation modes of hydrogen internal combustion engines. This paper describes the application of a flow field-based heat transfer model according to Schubert et al. [1]. The models strength is a more realistic description of the required characteristic velocity; considering the influence of the injection on the global turbulence and on the in-cylinder flow field results in a better prediction of the wall heat transfer during the compression stroke and for operations with multiple injections. Further an empirical hypothesis on the turbulence generation during combustion is presented.

LCDs are effective to display abundant information in a compact space. Therefore, the use of TFT or DOT metric displays in dashboard instrument display is getting popular in recent years. However, it is important issue for car makers how to let users know information about vehicle functions or outside environment and manage plentiful information. In this paper, the Rapid Control Prototyping (RCP) tool is proposed to design and standardize HMI logic associated with display contents in TFT or dot type LCD applied to an instrument cluster. In addition, it is possible to estimate HMI logic in advance by using this RCP. By this process, we can minimize the design and validation time of the vehicle specific HMI logic and improve the quality. As a result, we can dramatically reduce the total period of developing an instrument cluster.

The internal combustion engine and associated powertrain are likely to remain the mainstay of mobility over the next twenty years and to remain a significant portion of the portfolio of technologies employed over a much longer period of time. Efficient combustion of all fuels (petroleum based or alternative) requires copious amounts of air particularly with downsized engines. Turbocharging technology thus becomes an even more critical part of reducing both global warming gas and urban pollutant emissions from IC engines. Gasoline engine downsizing and turbocharging have been shown to improve fuel economy by ∼20% in production vehicles. In addition to data over a wide range of engines/vehicles, the results of a simple analysis done on vehicles/engines/drive cycles are presented to show the benefits of turbocharging and downsizing in a parametric variation of downsizing in combination with other technologies.

Selective catalytic reduction (SCR) is allowing diesel engines to reach NOx emission levels which are unachievable in-cylinder. This technology is still evolving, and new catalyst formulations which provide higher performance and greater durability continue to be developed. Usually, their performance is measured on a flow reactor using ammonia as the reductant. However, in mobile applications a urea-water solution is used instead, and urea decomposition by thermolysis and hydrolysis provides the required ammonia to the catalyst. It is well known that urea decomposition is incomplete by the inlet face of the converter, and this is at least one reason why on-engine performance is generally lower than would be expected from reactor tests. Previous modeling of urea-water droplets has focused on developing detailed sub-models that can be implemented into computational fluid dynamics (CFD) codes.

The use of catalyzed diesel particulate filter (CDPF) systems in light duty diesel (LDD) vehicles is becoming increasingly common. The primary functions of the system are to remove carbon monoxide (CO) and hydrocarbons (HC) from the vehicle exhaust stream, while simultaneously reducing the level of particulate matter (PM) emissions to ambient background levels. These systems can comprise either a separate diesel oxidation catalyst (DOC) and a downstream CDPF, or a single unit CDPF with the DOC functions incorporated within the CDPF. The single CDPF unit provides higher regeneration efficiency as it is located nearer to the engine and also cost benefits, as only a single unit is required compared to the alternative separate DOC and CDPF arrangement. A model describing the performance of the single unit CDPF for emissions control has been developed, with particular emphasis on achieving predictions of the CO and HC emissions over transient vehicle drive cycles.

Diesel Particulate Filters (DPF) are widely used to meet 2007 and beyond EPA Particulate Matter (PM) emissions requirements. During the soot loading process, soot is collected inside a porous wall and eventually forms a soot cake layer on the surface of the DPF inlet channel walls. A densely packaged soot layer and reduced pore size due to Particulate Matter (PM) deposition will reduce overall DPF wall permeability which results in increasing pressure drop across the DPF substrate. A regeneration process needs to be enacted to burn out all the soot collected inside the DPF. Soot mass is not always evenly distributed as the distribution is affected by the flow and temperature distribution at the DPF inlet. As a result, the heat release which is determined by the burn rate is locally dependent. High temperature gradients are often found inside DPF substrate as a result of these locally dependent burn rates.

Wet clutches are widely used in automotive systems. They are essential parts of automatic transmissions, modern All-Wheel-Drive systems or dual-clutch transmissions. Regardless of the area of application, a good knowledge of clutch friction behaviors is crucial for the clutch control system development. This paper considers two important factors of the wet clutch dynamics: coefficient of friction behavior and thermal dynamics. An Active Limited Slip Differential wet clutch with carbon fiber-based friction lining material is experimentally characterized by using a precise wet clutch setup. The characterization of the coefficient of friction behavior includes influence of clutch slip speed, applied force, and friction surface temperature. The clutch thermal dynamics is characterized based on the heat power balance law applied to the clutch separator plate with a variable heat transfer coefficient. The results of the thermal model experimental validation are presented, as well.

Diesel injection parameters effect on liquid-phase diesel spray penetration after the end-of-injection (EOI) is investigated in a constant-volume chamber over a range of ambient and injector conditions typical of a diesel engine. Our past work showed that the maximum liquid penetration length of a diesel spray may recede towards the injector after EOI at some conditions. Analysis employing a transient jet entrainment model showed that increased fuel-ambient mixing occurs during the fuel-injection-rate ramp-down as increased ambient-entrainment rates progress downstream (i.e. the entrainment wave), permitting complete fuel vaporization at distances closer to the injector than the quasi-steady liquid length. To clarify the liquid-length recession process, in this study we report Mie-scatter imaging results near EOI over a range of injection pressure, nozzle size, fuel type, and rate-of-injection shape. We then use a transient jet entrainment model for detailed analysis.

The local equivalence ratio, Φ, was measured in fuel jets using laser-induced spontaneous Raman scattering in an optical heavy duty diesel engine. The measurements were performed at 1200 rpm and quarter load (6 bar IMEP). The objective was to study factors influencing soot formation, such as gas entrainment and lift-off position, and to find correlations with engine-out particulate matter (PM) levels. The effects of nozzle hole size, injection pressure, inlet oxygen concentration, and ambient density at TDC were studied. The position of the lift–off region was determined from OH chemiluminescence images of the flame. The liquid penetration length was measured with Mie scattering to ensure that the Raman measurement was performed in the gaseous part of the spray. The local Φ value was successfully measured inside a fuel jet. A surprisingly low correlation coefficient between engine-out PM and the local Φ in the reaction zone were observed.

Automotive engines are regularly utilized in the material handling market where LPG is often the primary fuel used. When compared to gasoline, the use of gaseous fuels (LPG and CNG) as well as alcohol based fuels, often result in significant increases in valve seat insert (VSI) and valve face wear. This phenomenon is widely recognized and the engine manufacturer is tasked to identify and incorporate appropriate valvetrain material and design features that can meet the ever increasing life expectations of the end-user. Alternate materials are often developed based on laboratory testing – testing that may not represent real world usage. The ultimate goal of the product engineer is to utilize accelerated lab test procedures that can be correlated to field life and field failure mechanisms, and then select appropriate materials/design features that meet the targeted life requirements.

In this work a detailed model to simulate the transient behavior of catalytic converters is presented. The model is able to predict the unsteady and reacting flows in the exhaust ducts, by solving the system of conservation equations of mass, momentum, energy and transport of reacting chemical species. The en-gine and the intake system have not been included in the simulation, imposing the measured values of mass flow, gas temperature and chemical composition as a boundary condition at the inlet of the exhaust system. A detailed analysis of the diffusion stage triggering is proposed along with simplifications of the physics, finalized to the reduction of the calculation time. Submodels for water condensation and its following evaporation on the monolith surface have been taken into account as well as oxygen storage promoted by ceria oxides.

The challenges of flex-fuel vehicle (FFV) emissions measurements have recently come to the forefront for the emissions testing community. The proliferation of ethanol blended gasoline in fractions as high as 85% has placed a new challenge in the path of accurate measures of NMHC and NMOG emissions. Test methods need modification to cope with excess amounts of water in the exhaust, assure transfer and capture of oxygenated compounds to integrated measurement systems (impinger and cartridge measurements) and provide modal emission rates of oxygenated species. Current test methods fall short of addressing these challenges. This presentation will discuss the challenges to FFV testing, modifications made to Ford Motor Company’s Vehicle Emissions Research Laboratory test cells, and demonstrate the improvements in recovery of oxygenated species from the vehicle exhaust system for both regulatory measurements and development measurements.

The upcoming Euro VI emission legislation for Heavy Duty Diesel engines can be complied with by using a combination of a wall flow DPF and a UREA SCR-system. This paper describes investigations of NOx and PM reduction by a combination of SCR-catalyst and an (uncoated) Diesel particulate filter (DPF), performed on a fully transient heavy-duty test bench. Soot loading and passive regeneration of the DPF for different configurations of both components and active regeneration by fuel injection into the exhaust gas line were investigated. The impact of DPF on SCR-catalyst as well as SCR-catalyst impact on DPF was analyzed in terms of NOx-conversion and regeneration efficiency of the filter under steady-state and transient operating conditions. The NOx-conversions for the configuration SCR-catalyst in front of DPF were higher for all operating conditions than for the combination DPF in front of SCR-catalyst.