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Dynamic and quasi-static axial cutting of circular AA6061-T6 extrusions with variable instantaneous wall thickness in the axial direction was completed to investigate the capability of controlling the load/displacement responses of the extrusions. Circular specimens considered for this research had an original nominal wall thickness of 3.175 mm, an external diameter of 50.8 mm, and a tube length of 300 mm. Variations of the wall thickness were completed by material removal of the extrusions using a CNC machine. Specially designed cutters having a block height of 20 mm, a blade tip width of 1.0 mm and a blade shoulder width of 3.0 mm were employed to generate the axial cutting deformation mode. Either one or two cutters were selected to initiate a single or dual cutting deformation. A curved deflector with a profile radius of 50.8 mm was used to flare the cut petalled sidewalk and facilitate the cutting system.

The statistical analysis of vehicle crash accident data is generally problematic. Data from commonly used sources is almost never without error and complete. Consequently, many analyses are contaminated with modeling and system identification errors. In some cases the effect of influential factors such as crash severity (the most significant component being speed) driver behavior prior to the crash, etc. on vehicle and occupant outcome is not adequately addressed. The speed that the vehicle is traveling at the initiation of a crash is a significant contributor to occupant risk. Not incorporating it may make an accident analysis irrelevant; however, despite its importance this information is not included in many of the commonly used crash data bases, such as the Fatality Analysis Reporting System (FARS). Missing speed information can result in potential errors propagating throughout the analysis, unless a method is developed to account for the missing information.

Mini and micro-scale channels have drawn researchers' attention in the past three decades. The use of these tiny channels in a heat exchanger is considered as one of the pioneered works on the narrow channels as minichannels provide high heat transfer rates per unit volume. Motor oil, known as engine oil, is one of the vital fluids in automotive applications. Its cooling process is confronted by its thermo-physical properties, especially viscosity, which makes this process difficult. In current investigations, experimental endeavors have been performed using a closed loop thermal wind tunnel to verify the aptness of cooling the motor oil through a cross-flow minichannel heat exchanger. The prototype heat exchanger consists of 3 circuits; each circuit has five slabs which are connected to each other by four serpentines. There are 68 channels of 1 mm circular diameter drilled through each slab. The minichannel heat exchanger comprises of wavy fins arranged parallel to the flow of air.

Superior NVH performance is a key focus in the development of new powertrains. In recent years, computer simulations have gained an increasing role in the design, development, and optimization of powertrain NVH at component and system levels. This paper presents the results of a study carried out on a 4-cylinder in-line spark-ignition engine with focus on growl noise. Growl is a low frequency noise (300-700 Hz) which is primarily perceived at moderate engine speeds (2000-3000 rpm) and light to moderate throttle tip-ins. For this purpose, a coupled and fully flexible multi-body dynamics model of the powertrain was developed. Structural components were reduced using component mode synthesis and used to determine dynamics loads at various engine speeds and loading conditions. A comparative NVH assessment of various crankshaft designs, engine configurations, and in- cylinder gas pressures was carried out.

Polyurethane (PU) foam is used for many automotive applications with the benefits of being lightweight, durable, and resistant to heat and noise. Applications of PU foams are increasing to include non-traditional purposes targeting consumer comfort. An example of this is the use of PU foam between the engine and engine cover of a vehicle for the purpose of noise abatement. This addition will provide a quieter ride for the consumer, however will have associated environmental impacts. The additional weight will cause an increase in fuel consumption and related emissions. More significant impacts may be realized at the end-of-life stage. Recycling PU foams presents several challenges; a lack of market for the recyclate, contamination of the foams, and lack of accessibility for removal of the material.

In this paper a design methodology for automotive heat exchangers has been applied which brings robustness into the design process and helps to optimize the design goals: as to maintain an optimal coolant temperature and to limit the vehicle underhood air temperature within a tolerable limit. The most influential design factors for the heat exchangers which affect the goals have been identified with that process. The paper summarizes the optimization steps necessary to meet the optimal functional goals for the vehicle as mentioned above. Taguchi's [1] Design for Six Sigma (DFSS) methods have been employed to conduct this analysis in a robust way.

In this paper, thermal models are developed based on experimental test data, and the physics of thermal systems. If experimental data is available, the data can be fitted to mathematical models that represent the system response to changes in its input parameters. Therefore, empirical models which are based on test data are developed. The concept of time constant is presented and applied to development of transient models. Mathematical models for component temperature changes during transient vehicle driving conditions are also presented. Mathematical models for climate control system warm up and cool-down are also discussed. The results show the significance of adopting this concept in analysis of vehicle test data, and in development of analytical models. The developed models can be applied to simulate the system or component response to variety of changes in input parameters. As a result, significant testing and simulation time can be saved during the vehicle development process.

Taguchi method is a technology to prevent quality problems at early stages of product development and product design. Parameter design method is an important part in Taguchi method which selects the best control factor level combination for the optimization of the robustness of product function against noise factors. The air induction system (AIS) provides clean air to the engine for combustion. The noise radiated from the inlet of the AIS can be of significant importance in reducing vehicle interior noise and tuning the interior sound quality. The porous duct has been introduced into the AIS to reduce the snorkel noise. It helps with both the system layout and isolation by reducing transmitted vibration. A CAE simulation procedure has been developed and validated to predict the snorkel noise of the porous ducted AIS. In this paper, Taguchi's parameter design method was utilized to optimize a porous duct design in an AIS to achieve the best snorkel noise performance.

Accurate numerical prediction of an engine thermal map at a wide range of engine operating conditions can help tune engine performance parameters at an early development stage. This study documents the correlation of an engine thermal simulation using the conjugate heat transfer (CHT) methodology with thermocouple data from an engine operating in a dynamometer and a vehicle drive cell. Three different operating conditions are matched with the simulation data. Temperatures predicted by simulation at specific sections, both at the intake and the exhaust sides of the engine are compared with the measured temperatures in the same location on the operating engine.

This paper describes the application of the Fourier Amplitude Sensitivity Test (FAST) method [1] to investigate the effect of uncertainty in design parameters on the thermal system performance of vehicle underbody components. The results from this study will pinpoint the design parameters which offer the greatest opportunity for improvement of thermal system performance and reliability. In turn, this method can save engineering time and resources. An analytical model was developed for a vehicle underbody system consisting of a muffler, heat shield, and spare tire tub. The output from this model was defined as the temperature of the spare tire tub. The majority of the input parameters in this model deviate from their nominal values due to environmental factors, wear and ageing, and/or variation in the manufacturing process.

In this work, an active injection control strategy is developed for enabling clean and efficient combustion on an ethanol-diesel dual-fuel engine. The essence of this active injection control is the minimization of the diffusion burning and resultant emissions associated with the diesel injection while maintaining controllability over the ignition and combustion processes. A stand-alone injection bench is employed to characterize the rate of injection for the diesel injection events, and a regression model is established to describe the injection timings and injector delays. A new combustion control parameter is proposed to characterize the extent of diffusion burning on a cycle-to-cycle basis by comparing the modelled rate of diesel injection with the rate of heat release in real time. The test results show that the proposed parameter, compared with the traditional ignition delay, better correlates to the enabling of low NOx and low smoke combustion.

Advanced combustion engines dominate all automotive applications. Future high efficiency clean combustion engines can contribute significantly to sustainable transportation. Effective ignition strategies are studied to enable lean and diluted combustion under considerably high-density mixture and strong turbulences, for improving the efficiency and emissions of future combustion engines. Continuous discharge and multi-site ignition strategies have been proved to be effective to stabilize the combustion process under lean and EGR diluted conditions. Continuous discharge strategy uses a traditional sparkplug with a single spark gap and multiple ignition coil packs. The ignition coil packs operate under a specific time offset to realize a continuous discharge process with a prolonged discharge duration. Multi-site ignition strategy also uses multiple ignition coil packs.

The use of renewable fuels in place of conventional hydrocarbon fuels can minimize the carbon footprint of internal combustion engines. DME has been treated as a suitable surrogate to diesel fuel because of its high reactivity and soot-less combustion characteristics. The lower energy density of DME fuel demands a higher fuel supply rate to match the engine loads compared to diesel, which was achieved through prolonged injection duration and larger nozzle holes. When used as a pilot fuel to control the combustion behavior in a dual-fuel application, the fuel energy delivery rate becomes less critical allowing the use of a standard diesel common-rail injector for DME direct injection. In this work, the combustion of DME-Ethanol dual-fuel reactivity-controlled compression ignition was experimentally investigated.

Many experiments have demonstrated that clutch overheating is a major cause of clutch deterioration. Clutch friction material deterioration not only leads to clutch failure, but also causes poor shift quality. Unfortunately, it is not practical to monitor each individual clutch temperature in a production vehicle due to high costs or technical challenges. This paper introduces a proposal for a virtual clutch temperature sensor to monitor the real time clutch temperature changes in Chrysler transmissions with PWM solenoid based control systems. Both vehicle and laboratory dynamometer (dyno) tests demonstrate that the model results match very closely with the thermocouple temperature measurements under many different driving conditions. The real time virtual temperature sensor provides a tool for clutch surface overheat protection and for design improvement and enhancement to shift quality.

In order to define and to optimize a thermal management system for a high voltage vehicular battery, it is essential to understand the environmental factors acting on the battery and their influence on battery life. This paper defines a calendar life aging model for a battery, and applies real world environmental and operating conditions to that model. Charge and usage scenarios are combined with various cooling/heating approaches. This set of scenarios is then applied to the calendar life model, permitting optimization of battery thermal management strategies. Real-world battery life can therefore be maximized, and trade-offs for grid energy conversion efficiency and fuel economy/vehicle range can be determined.

Proposed LEV-III emission level will require improvements in NMOG, CO and NOx emissions as measured over FTP and US06 emission cycles. Incremental improvements in washcoat technologies, cold start calibration and catalyst system design are required to develop a cost effective solution set. New catalyst technologies demonstrated both lower HC and NOx emissions with 25% less platinum group metals (PGM). FTP and US06 emissions were measured on a 4-cylinder 2.4L application which compares a close-coupled converter and close-coupled + underfloor converter systems. A PGM placement study was performed with the close-coupled converter system employing these new catalyst technologies. Emissions results suggest that the placement of PGM is critical in minimizing emissions and PGM costs.

This paper studies the effects of various types of parking brake cable construction on parking brake system efficiency. Testing was conducted on a variety of common cable constructions from several industry sources. Cable construction variables include different types of conduit and wire strand. Input travel, input force, output travel, and output force were carefully measured under controlled conditions. Force, travel and hence work efficiencies were calculated and analyzed to identify any differences that might exist under the defined test conditions. Conclusions were drawn that might provide direction for improving parking brake system designs that have performance issues caused by poor cable efficiency.

The fuel air ratio imbalance between individual cylinders can result in poor fuel economy and severe exhaust emissions. Individual cylinder fuel air ratio control is one of the important techniques used to improve fuel economy and reduce exhaust emission. California Air Resources Board (CARB) also has required automotive manufacturers to equip with on-board diagnosis system for cylinder fuel air ratio imbalance detection starting in 2011. However, one of the most challenging tasks for the individual cylinder fuel air ratio control and cylinder imbalance diagnosis is how to retrieve the cylinder fuel air ratio information effectively at low cost. This paper presents a novel and practical signal processing based fuel air ratio estimation method for individual cylinder fuel air ratio balance control and on-board fuel air ratio imbalance diagnosis.

Due to the multitude of external design constraints, such as increasing fuel economy standards, and the increasing number of global vehicle programs, developers of automotive transmission controls have to cope with increasing levels of powertrain system complexity. Achieving these requirements while improving system quality, reducing development cost and improving time to market is a very challenging task. To achieve this goal, a rapid prototype controller was used to develop a new transmission clutch temperature model. This model is used to detect clutch surface overheating, improve design and enhance shift quality.

A body mount joint is a typical clamped joint that is under severe loading conditions, due to its structural function services as a gateway of load path between body and frame of an automotive vehicle. Stresses/strains on durability concerned components at the joint cannot be captured accurately by using the pseudo stress analysis approach because of the complexity of stress state generated by the pre-stress from clamp load, contacts between the components and nonlinear material properties. In this paper, development of a technique for fatigue life estimation of the joint is described in detail.