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Since transient vehicle HVAC computational fluids (CFD) simulations take too long to solve in a production environment, the goal of this project is to automatically create a lumped-parameter flow network from a steady-state CFD that solves nearly instantaneously. The data mining algorithm k-means is implemented to automatically discover flow features and form the network (a reduced order model). The lumped-parameter network is implemented in the commercial thermal solver MuSES to then run as a fully transient simulation. Using this network a “localized heat transfer coefficient” is shown to be an improvement over existing techniques. Also, it was found that the use of the clustering created a new flow visualization technique. Finally, fixing clusters near equipment newly demonstrates a capability to track localized temperatures near specific objects (such as equipment in vehicles).

Traditional vehicle air conditioning systems condition the entire cabin to a comfortable range of temperature and humidity regardless of the number of passengers in the vehicle. The A/C system is designed to have enough capacity to provide comfort for transient periods when cooling down a soaked car. Similarly for heating, the entire cabin is typically warmed up to achieve comfort. Localized heating and cooling, on the other hand, focuses on keeping the passenger comfortable by forming a micro climate around the passenger. This is more energy efficient since the system only needs to cool the person instead of the entire cabin space and cabin thermal mass. It also provides accelerated comfort for the passenger during the cooling down periods of soaked cars. Additionally, the system adapts to the number of passengers in the car, so as to not purposely condition areas that are not occupied.

Copper- and Iron- based metal-zeolite SCR catalysts are widely used in US and European diesel aftertreatment systems to achieve drastic reduction in NOx emission. These catalysts are highly selective to N2 under wide range of operating conditions. Nevertheless, the type of transition metal has a significant impact on the key performance and durability parameters such as NOx conversion, selectivity towards N2O, hydrothermal stability, and sensitivity to fuel sulfur content. In this study, we explained the differences in the performance characteristics of these catalysts based on their relative acidic-basic nature of transition metal present in these catalysts using practically relevant gas species present in diesel exhaust such as NO2, SOx, and NH3. These experiments show that Fe-zeolite has relatively acidic nature as compared to Cu-zeolite that causes NH3 inhibition and hence explains low NOx conversion on Fe-zeolite at low temperature under standard SCR conditions.

Traditionally, most charge air coolers (CACs) have been constructed using the Nocolok aluminum brazing process. The Nocolok process uses flux, some of which remains after the manufacturing process, and migrates through the intake tract to the engine during normal use. This migration and deposition on engine components can cause a variety of issues with engine operation. Currently the only alternative to Nocolok brazed CACs for engines sensitive to flux migration is vacuum brazing, which comes at a significant price increase. In the effort to reduce cost and increase efficiency, there is interest in whether a Nocolok brazed CAC with a reduced amount of flux residue can be successfully applied to flux-sensitive engines.

Rear Window Buffeting (RWB) is the low-frequency, high amplitude, sound that occurs in many 4-door vehicles when driven 30-70 mph with one rear window lowered. The goal of this paper is to demonstrate that the mechanisms of RWB are similar to that of sun roof buffeting and to describe the results of several actions suspected in contributing to the severity of RWB. Finally, the results of several experiments are discussed that may lend insight into ways to reduce the severity of this event. A detailed examination of the side airflow patterns of a small Sport Utility Vehicle (SUV) shows these criteria exist on a small SUV, and experiments to modify the SUV airflow pattern to reduce RWB are performed with varying degrees of success. Based on the results of these experiments, design actions are recommended that may result in the reduction of RWB.

The study aims at analyzing the tool utilization by using a real-time machining simulation and investigating the behavior of the parameters which affect the tool wear based on the results of the analysis. In this study, the method of calculation of parameters which are necessary to predict the tool wear by using Z-map based machining simulation is developed. Furthermore, the possibility of estimating the tool wear from the results of the simulation was also examined by performing the real cutting experiments.

Engineering education at the University level is enhanced by competition-based projects. The SAE Clean Snowmobile Challenge is a prime example of how competition-based engineering education benefits the small engines industry and improves the engineering talent pool of the nation in general. For the past several decades, SAE has encouraged young engineers to compete in designing off road vehicles (Baja SAE ®), small race cars (Formula SAE ®), remote control airplanes (Aero Design ®), high mileage vehicles (Supermileage ®) and robots (Walking Robot ®). Now a new competition, the SAE Clean Snowmobile Challenge ™ (CSC), based on designing a cleaner and quieter snowmobile has led to a new path for young engineers to explore the challenges of designing engines that emit less pollution and noise. The paper will summarize the results of the most recent Clean Snowmobile Challenge 2006 and document the successes of the past seven years of the Challenge.

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.

The performance characteristics of a commercial lean-NOX trap catalyst were evaluated between 200 and 500°C, using H2, CO, and a mixture of both H2 and CO as reductants before and after different high-temperature aging steps, from 600 to 750°C. Tests included NOX reduction efficiency during cycling, NOX storage capacity (NSC), oxygen storage capacity (OSC), and water-gas-shift (WGS) and NO oxidation reaction extents. The WGS reaction extent at 200 and 300°C was negatively affected by thermal degradation, but at 400 and 500°C no significant change was observed. Changes in the extent of NO oxidation did not show a consistent trend as a function of thermal degradation. The total NSC was tested at 200, 350 and 500°C. Little change was observed at 500°C with thermal degradation but a steady decrease was observed at 350°C as the thermal degradation temperature was increased.

Considerations follow [1] on the development of the carbon/epoxy body of the Lamborghini Murcièlago. Laminate lay-up and material selection for stiffness criteria are reviewed. Engineering solutions for tooling operations in order to achieve class A surface certification are analyzed. Design for environmental aging is also discussed and accelerated degradation testing methods are described. Finally, the program that lead to the adoption of hybrid adhesive bonding as sole method of joining the composite body components to the tubular steel frame is reviewed.

The amount of ammonia stored on the walls of the catalyst (or ammonia storage) is a parameter with significant impact on NOx reduction efficiency and undesired ammonia slip of Selective Catalytic Reduction catalysts. This makes the ammonia storage interesting for utilization in urea injection control. However, ammonia storage is not directly measurable onboard vehicles, it can only be estimated. Model-based online estimation requires models that are capable of capturing the main phenomena of the SCR and at the same time can be computed onboard vehicle. While the modeling of SCR and model-based control is well present in the literature, it is apparent that few attempts of implementing the models on production ECUs were published. This paper reviews literature on ammonia storage, outlet NH3 and NOx concentration estimation in SCR and SCR/DPF systems-including the estimation of NOx sensor cross-sensitive to NH3-in order to present the state of the art.

Oxygen storage capacity (OSC) is one of the most critical characteristics of a three-way catalyst (TWC) and is closely related to the catalyst aging and performance. In this study, a dynamic OSC model involving two oxygen storage sites with distinct kinetics was developed. The dual-site OSC model was validated on a bench reactor and a natural gas engine. The model was capable of predicting temperature dependence on OSC with H2, CO and CH4 as reductants. Also, the effects of oxygen concentration and space velocity on the amount of OSC were captured by the model. The validated OSC model was applied to simulate lean breakthrough phenomena with varied space velocities and oxygen concentrations. It is found that OSC during lean breakthrough is not a constant for a particular TWC catalyst and is dependent on space velocity and oxygen concentration. Specifically, breakthrough time exhibits a non-linear, inverse correlation to oxygen flux.

Commercial Cu-Zeolite SCR catalyst can store and subsequently release significant amount of H2O. The process is accompanied by large heat effects. It is critical to model this phenomenon to design aftertreatment systems and to provide robust tuning strategies to meet cold start emissions and low temperature operation. The complex reaction mechanism of water adsorption and desorption over a Cu-exchanged SAPO-34 catalyst at low temperature was studied through steady state and transient experiments. Steady state isotherms were generated using a gravimetric method and then utilized to predict water storage interactions with respect to feed concentration and catalyst temperature. Transient temperature programmed desorption (TPD) experiments provided the kinetic information required to develop a global kinetic model from the experimental data. The model captures fundamental characteristics of water adsorption and desorption accompanied by the heat effects.

Engine noise is one of the significant aspects of product quality for light and medium duty diesel engine market applications. Gear whine is one of those noise issues, which is considered objectionable and impacts the customer’s perception of the product quality. Gear whine could result due to defects in the gear manufacturing process and/or due to inaccurate design of the gear macro and micro geometry. The focus of this technical paper is to discuss gear whine considerations from the production plant perspective. This includes quick overview of the measurement process, test cell environment, noise acceptance criteria considerations. A gear whine case study is presented based on the data collected in the test cell at the engine plant. Gear whine data acquired on current product and next generation of prototype engines is analyzed and presented. This paper concludes by highlighting the lessons learned from the case study.

Test and verification procedures are a vital aspect of the development process for embedded control systems in the automotive domain. Formal requirements can be used in automated procedures to check whether simulation or experimental results adhere to design specifications and even to perform automatic test and formal verification of design models; however, developing formal requirements typically requires significant investment of time and effort for control software designers. We propose Signal Template Library (ST-Lib), a uniform modeling language to encapsulate a number of useful signal patterns in a formal requirement language with the goal of facilitating requirement formulation for automotive control applications. ST-Lib consists of basic modules known as signal templates. Informally, these specify a characteristic signal shape and provide numerical parameters to tune the shape.

The aging impact on oxygen storage capacity (OSC) and catalyst performance was investigated on one degreened and one aged (hydrothermally aged at 955 °C for 50 h) commercial three-way catalyst (TWC) by experiments and modeling. The difference of OSC between the degreened and aged TWCs was dependent on catalyst temperature. The largest difference was found at 600 °C, at which the amount of OSC decreased by 45.5%. Catalyst performance was evaluated through lightoff tests at two simulated engine exhaust conditions (lean and rich) on a micro-reactor. The aging impact on the catalyst performance was different under lean and rich environments and investigated separately. At the lean condition, oxidation of CO and C3H6 was significantly suppressed while oxidation of C3H8 was relatively less degraded. At the rich condition, the inhibition effect was more pronounced on the aged TWC and inhibiting hydrocarbon species from C3H6 partial oxidation can survive at temperatures up to 450 °C.

This paper presents an experimental setup and an equivalent FEM simulation methodology to accurately predict the response of Engine Control Module (ECM) assembly mounted on a commercial vehicle subjected to road vibrations. Comprehensive vibration study is carried out. It involved Modal characteristics determination followed by random vibration characterization of the ECM assembly. A hammer impact experiment is first performed in lab to estimate the natural frequencies and mode shapes of ECM assembly. Mounting conditions in test specimen are kept similar to the actual mounting settings on vehicle. Natural frequencies and mode shapes predicted from free vibration experiment are compared with finite element (FE) based modal analysis. The importance of capturing the assembly stiffness more accurately by incorporating pre-stress effects like bolt-pretension and gravity, is emphasized.

Increasing fuel injection pressure has enabled reduction of diesel emissions while retaining the advantage of the high thermal efficiency of diesel engines. With production diesel injectors operating in the range from 300 to 2400 bar, there is interest in injection pressures of 3000 bar and higher for further emissions reduction and fuel efficiency improvements. Fundamental understanding of diesel spray characteristics including very early injection and non-vaporizing spray penetration is essential to improve model development and facilitate the integration of advanced injection systems with elevated injection pressure into future diesel engines. Studies were conducted in an optically accessible constant volume combustion vessel under non-vaporizing conditions. Two advanced high pressure multi-hole injectors were used with different hole diameters, number of holes, and flow rates, with only one plume of each injector being imaged to enable high frame rate imaging.

This paper presents a driver assistance system designed to minimize the effect of driver reaction time on lane and speed maintenance operations. Nearly-instantaneous correcting actions are provided through a hierarchical arrangement of behaviors, by avoiding the time lag associated with deliberative or planning steps found in many control algorithms. Concepts originating in the field of robotics, including artificial potential fields and behavior-based systems, are interpreted for application to automotive control, where vehicle dynamics places considerable practical constraints on implementation. Ideas found in the study of emergent behavior in nature provide continuous, non-stepwise control signals, suitable for additive corrective inputs at highway velocities. This approach is effective for a substantial subset of road automobiles operating over a variety of speeds.

The U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Longer chain alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Higher carbon number alcohols can be utilized to improve the energy content, knock resistance, and/or petroleum displacement of gasoline-alcohol blends compared to traditional ethanol blends such as E10 while maintaining desired and regulated fuel properties. Part I of this paper focuses on the development of scenarios by which to compare higher alcohol fuel blends to traditional ethanol blends. It also details the implementation of fuel property prediction methods adapted from literature. Possible combinations of eight alcohols mixed with a gasoline blendstock were calculated and the properties of the theoretical fuel blends were predicted.