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To meet the stringent NOx and particulate emissions requirements of Euro 6 and China 6 standard, Selective Catalyst Reduction (SCR) catalyst integrated with wall flow particulate filter (SCR-DPF) has been found to be an effective solution for the exhaust aftertreatment systems of diesel engines. NOx is reduced by ammonia generated from urea injection while the filter effectively traps and burns the particulate matter periodically in a process called regeneration. The engine control unit (ECU) effectively manages urea injection quantity, timing and soot burning frequency for the stable functioning of the SCR-DPF without impacting drivability. To control the NOx reduction and particulate regeneration process, the control unit uses lookup tables generated from extensive hardware testing to get the current soot load and NOx slip information of SCR-DPF as a function of main exhaust state variables.

Diesel engines have better fuel economy over comparable gasoline engines and are useful for the reduction of CO2 emissions. However, to meet stringent emission standards, the technology for reducing NOx and particulate matter (PM) in diesel engine exhaust needs to be improved. A conventional selective catalytic reduction (SCR) system consists of a diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and urea-SCR catalyst. Recently, more stringent regulations have led to the development of SCR systems with a larger volume and increased the cost of such systems. In order to solve these problems, an SCR catalyst-coated DPF (SCR/DPF) is proposed. An SCR/DPF system has lower volume and cost compared to the conventional SCR system. The SCR/DPF catalyst has two functions: combustion of PM and reduction of NOx emissions.

Ammonia-selective catalytic reduction (SCR) systems have been introduced commercially in diesel vehicles, however catalyst systems with higher conversion efficiency and better control characteristics are required to know the actual emissions during operation and the emissions in random test cycles. Computational fluid dynamics (CFD) is an effective approach when applied to SCR catalyst development, and many models have been proposed, but these models need experimental verification and are limited in the situations they apply to. Further, taking account of redox cycle is important to have better accuracy in transient operation, however there are few models considering the cycle. Model development considering the redox reactions in a zeolite catalyst, Cu-ZSM-5, is the object of the research here, and the effects of exhaust gas composition on the SCR reaction and NH3 oxidation at high temperatures are investigated.

This work presents a general model for the prediction of octane numbers and knock propensity of different fuels in SI engines. A detailed kinetic scheme of hydrocarbon oxidation is coupled with a two zone, 1-D thermo-fluid dynamic simulation code (GASDYN) [1]. The validation of the kinetic scheme is discussed on the basis of recent experimental measurements. CFR engine simulations for RON and MON evaluation are presented first to demonstrate the capabilities of the coupled model. The model is then used to compare the knock propensity of a gasoline “surrogate” (a pure hydrocarbon mixture) and PRFs in a current commercial engine, resulting in a simulation of “real world” octane number determination, such as Bench Octane Number (BON). The simulation results agree qualitatively with typical experimental trends.

In this study, Partially Premixed Combustion (PPC) on a modified heavy-duty diesel engine was realized by hybrid combustion control strategy with flexible fuel injection timing, injection rate pattern modulation and high ratio of exhaust gas recirculation (EGR) at different engine loads. It features with different degrees of fuel/air mixture stratifications. The very low soot emissions of the experiments called for further understanding on soot formation mechanism so that to promote the capability of prediction. A new soot model was developed with highlight in effects of surface activity on soot growth for soot formation prediction in partially premixed combustion diesel engine. According to previous results from literatures on the importance of acetylene as growth specie of PAH and soot surface growth, a gas-phase reduced kinetic model of acetylene formation was developed and integrated into the new soot model.

Aim of this work is to present and discuss the possibility and the limits of two zone models for spark-ignition engines using a detailed kinetic scheme for the characterization of the evolution of the air-fuel mixture, while an equilibrium approach is used for the burnt zone. Simple experimental measurements of knocking tendency of different fuels in ideal reactors, such as rapid compression machines and shock tube reactors, cannot be directly used for the analysis of octane numbers and sensitivity of hydrocarbon mixtures. Thus a careful investigation is very useful, not only of the combustion chamber behavior, including the modelling of the turbulent flame front propagation, but also of the fluid dynamic behavior of the intake and exhaust system, accounting for the volumetric efficiency of the engine.

A nonequilibrium approach for the instantaneous calculation of the composition of 29 chemical species is used in this work to simulate the evolution of the gas composition in a Diesel engine cylinder from the start of combustion to the exhaust opening. A discretization of the heat release law is used as a sequential source of combustion products, which are then subjected the evolution of pressure directly measured from the cylinder engine, and to the evolution of a burnt-zone temperature obtained from the same pressure signal through a diagnosis thermodynamic model. For each burning fuel package, the equilibrium composition and the corresponding adiabatic flame temperature are considered as initial conditions for the kinetic calculation of the gas composition evolution.

Successful automotive weight reduction with high strength-to-weight ratio steels has caused re-evaluation of the basic structural design parameters. This paper introduces the new concept of “Kinetic Modulus” which describes the nature of materials in motion. Kinetic modulus is influenced by stress and strain amplitude, yield strength and the number of loading cycles. The scope of kinetic modulus encompasses: elastic, secant, dynamic and tangent moduli; each of which is a specific case of kinetic modulus at a particular condition. Theoretical and experimental results are presented to support this concept. They show that high strength steel has higher dynamic stiffness and improved vibration response in structures as compared to that of lower strength steel. Thus, high strength steel (“Stiff Steel”) can be used advantageously in stiffness controlled automotive structures to achieve greater weight reductions.

The simulation of combustion in the internal combustion engines (ICE) is very important for an accurate prediction of engine performance and pollutant formation. These engines simulation help to gain a better understanding of the coupling between the various physical and chemical processes. The objective of the present paper is to study turbulent combustion in IC engine. A lagrangian eulerian model coupled with presumed pdf is used to study the problems of chemical kinetics (and), while the k-ε model is used for the modeling of the turbulence. We got the reduced mechanism through the reduction of detailed mechanism of the methane (GRI 3.0) combustion by using the Principal Component Analyses (PCAF). It is considered the first point for the application of the Computational Singular Perturbation method (CSP). We used this method (CSP) to reduce the detailed mechanism of the methane that is already reduced by PCAF to a mechanism containing 9-Steps.

A computer model was used to predict perpendicular flame quenching distances for methanol-air mixtures at a variety of conditions. A detailed kinetic reaction mechanism has allowed the study of aldehyde formation. Aldehydes were found to increase an order of magnitude over bulk gas concentrations as the flame quenches but this concentration is insufficient to account for measured exhaust aldehydes. A flow reactor study showed additional aldehydes being formed from the unburned quench layer when it mixes with the hot exhaust gases during the expansion and exhaust strokes. Quenching distance decreases with increasing pressure and increasing wall temperature, and increases with lean and very rich equivalence ratios and increasing exhaust gas recirculation. Water addition shows only a slight increase in quenching distance for up to 30% of the fuel by volume.

The paper considered a scheme of hybrid energy storage device «superconductor-superflywheel» (SC-SFW), which was be able simultaneously of the kinetic energy so and the electrical current to accumulate. Possibility of using of the SC-SFW wich high-Tc superconductors (HTSC) for stationary and transport installations for different purposes are discussed.

An anthropomorphic test device (ATD) which accurately models the kinematic and kinetic responses of human subjects during head restraint contact in low-speed rear-end collisions is needed to evaluate present and future seat and vehicle designs. The primary goal of this study was to quantify the biofidelity of a new rear-impact ATD, the RID2a, by comparing its dynamic response to those of human subjects under identical test conditions. For this study, a RID2a and a Hybrid III ATD were each exposed to 10 low-speed rear-end collisions: five at a speed change of 4 km/h and five at a speed change of 8 km/h. Sagittal plane kinematics of the head and upper torso, head restraint contact forces, and the reaction loads and moment at the atlanto-occipital joint were determined and compared to the response of eleven male human subjects. Both ATDs produced repeatable response corridors. As observed by others, the Hybrid III did not replicate many features of the human response.

The kinetics of moisture adsorption is studied for copper-free brake pads. The pad weight gain is found to increase linearly with the square root of exposure time to humidity at a given temperature in the initial stage of adsorption - the higher the humidity, the higher the weight gain. Pads cured at 150°C adsorb less moisture than pads cured at 220°C. As the moisture content in the pad increases, the tangent modulus increases while the secant modulus decreases, resulting in decreasing compressibility associated with the tangent modulus of compression and increasing compressibility associated with the secant modulus of compression - compressibility defined as a reciprocal of compression modulus. Static modulus of compression, dynamic modulus of compression and hardness measurements are compared, and they all show the same trend. A rate constant of adsorption is proposed to define and compare moisture sensitivity of friction material

Chassis dynamometer testing of two 60 foot articulated transit busses, one conventional and one hybrid, was conducted at the National Renewable Energy Laboratory's, ReFUEL facility. Both test vehicles were 2004 New Flyer busses powered by Caterpillar C9 8.8L engines, with the hybrid vehicle incorporating a GM-Allison advanced hybrid electric drivetrain. Both vehicles also incorporated an oxidizing diesel particulate filter. The fuel economy and emissions benefits of the hybrid vehicle were evaluated over four driving cycles; Central Business District (CBD), Orange County (OCTA), Manhattan (MAN) and a custom test cycle developed from in-use data of the King County Metro (KCM) fleet operation. The hybrid vehicle demonstrated the highest improvement in fuel economy (mpg basis) over the low speed, heavy stop-and-go driving conditions of the Manhattan test cycle (74.6%) followed by the OCTA (50.6%), CBD (48.3%) and KCM (30.3%).

Thermoplastics and composites are increasingly becoming popular among automotive design engineers because of their high specific stiffness and flexibility in manufacturing. While plastics like composites are orthotropic, unfilled thermoplastics like ABS Cycolac may be considered isotropic as they show little variation in properties between the flow direction and the direction transverse to the flow. However, this assumption is not enough to treat the latter as metals in finite element analysis. Metals like mild steel, offer considerable ductility, while thermoplastics show limited ductility and begin to fracture with several cracks appearing on the surface. Therefore, in the case of such plastics, it is important to consider the degradation of material properties in nonlinear finite element analysis using Damage Mechanics material law.

Two-point restrained and unrestrained 50 percentile male dummy tests were conducted on the Hyge Sled in a typical package configuration at 56 and 48 km/h respectively, with corrugated paper knee bolster simulations located close and far from the dummy's knees. The effect of bolster location on the various dummy measurements were compiled and trends were evaluated. Comparisons also were made between the performance of the Hybrid II and Hybrid III dummies. The Ford “Chest Load Distribution Transducer” also was used to infer changes in loading patterns on the lower rib cage as bolster spacing was varied. Bolster location affected many of the dummy measurements for the restrained tests and indicated the possible desirability for even further dummy measurement capability than used in this test program. Bolster location effects were masked in the unrestrained dummy tests by extreme dummy kinematics.

This study presents an efficient method for forensic engineers to determine the expected forward knee and hip displacements of automobile occupants who are restrained by seat belts during frontal impacts. The amount of knee displacement sustained by an occupant in a vehicular collision must be determined in order to assess seat belt usage and benefit. The results of this study may be referenced to model the lower body motion of vehicle occupants in frontal impacts for a range of impact severities. Previous research has empirically determined hip and limited knee displacements for subjects restrained in frontal impacts of specific severities; however, these research results have not been directly compared to produce a simple and practical model that is applicable for a range of collision severities.

Late model passenger cars and light trucks incorporate occupant protection systems with airbags and knee restraints. Knee restraints have been designed principally to meet the unbelted portions of FMVSS 208 that require femur load limits of 10-kN to be met in barrier crashes up to 30 mph, +/- 30 degrees utilizing the 50% male Anthropomorphic Test Device (ATD). In addition, knee restraints provide additional lower-torso restraint for belt-restrained occupants in higher-severity crashes. An analysis of frontal crashes in the University of Michigan Crash Injury Research and Engineering Network (UM CIREN) database was performed to determine the influence of vehicle, crash and occupant parameters on knee, thigh, and hip injuries. The data sample consists of drivers and right front passengers involved in frontal crashes who sustained significant injuries (Abbreviated Injury Scale [AIS] ≥ 3 or two or more AIS ≥ 2) to any body region.

The turning point in the process of nonlinear aging is a key feature to identify the nonlinear aging behavior of lithium-ion batteries. In order to identify the knee-point online, this paper studies the capacity “diving” phenomenon of the battery during the experiment and the regulation of the appearance of the turning point during the nonlinear aging process. Then, a knee-point identification method based on constant voltage charging capacity is proposed, and the linear and nonlinear stages of battery decay are redefined. Based on the change of constant voltage charging capacity in the constant current and constant voltage charging strategy, the method defines the aging process in which the constant voltage charging capacity remains invariant as the linear decay stage of the battery, and the aging process in which the constant voltage charging capacity rises rapidly as the nonlinear decay stage.

Equations predicting cord length per hose pitch, weight per unit hose length, and percent inner-liner coverage for plain stitch knitted automotive heater hoses are presented. These equations help hose manufacturers to determine the reinforcement cost for knitted hoses. A spreadsheet using these derived equations plus a hose burst equation from the literature also offers insight into key cord physical properties for knitted hoses. Cord loop tenacity (loop break strength) falls out as a key element in controlling knitted hose burst pressure.