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We propose a composite thermal model of the vehicle passenger compartment that can be used to predict and analyze thermal comfort of the occupants of a vehicle. Physical model is developed using heat flow in and out of the passenger compartment space, comprised of glasses, roof, seats, dashboard, etc. Use of a model under a wide variety of test conditions have shown high sensitivity of compartment air temperature to changes in the outside air temperature, solar heat load, temperature and mass flow of duct outlet air from the climate control system of a vehicle. Use of this model has subsequently reduced empiricism and extensive experimental tests for design and tuning of the automatic climate control system. Simulation of the model allowed several changes to the designs well before the prototype hardware is available.

Homogenous Charge Compression Ignition (HCCI) combustion offers significant efficiency improvements compared to conventional gasoline engines. However, due to the nature of HCCI combustion, traditional HCCI engines show some degree of sensitivity to in-cylinder thermal conditions; thus higher cylinder-to-cylinder variation was observed especially at low load and high load operating conditions due to different injector characteristics, different amount of reforming as well as non-uniform EGR distribution. To address these issues, a cylinder balancing control strategy was developed for a multi-cylinder engine. In particular, the cylinder balancing control strategy balances CA50 and AF ratio at high load and low load conditions, respectively. Combustion noise was significantly reduced at high load while combustion stability was improved at low load with the cylinder balancing control.

Magnesium alloy extrusions offer potentially more mass saving compared to magnesium castings. One of the tasks in the United States Automotive Materials Partnership (USAMP) ?Magnesium Front End Research and Development? (MFERD) project is to evaluate magnesium extrusion alloys AM30, AZ31 and AZ61 for automotive body applications. Solid and hollow sections were made by lowcost direct extrusion process. Mechanical properties in tension and compression were tested in extrusion, transverse and 45 degree directions. The tensile properties of the extrusion alloys in the extrusion direction are generally higher than those of conventional die cast alloys. However, significant tension-compression asymmetry and plastic anisotropy need to be understood and captured in the component design.

Magnesium alloys are the lightest structural metal and recently attention has been focused on using them for structural automotive components. Fatigue and durability studies are essential in the design of these load-bearing components. In 2006, a large multinational research effort, Magnesium Front End Research & Development (MFERD), was launched involving researchers from Canada, China and the US. The MFERD project is intended to investigate the applicability of Mg alloys as lightweight materials for automotive body structures. The participating institutions in fatigue and durability studies were the University of Waterloo and Ryerson University from Canada, Institute of Metal Research (IMR) from China, and Mississippi State University, Westmorland, General Motors Corporation, Ford Motor Company and Chrysler Group LLC from the United States.

Fully Flexible Valve Actuation (FFVA) systems provide maximum flexibility to adjust lift profiles of engine intake and exhaust valves. A research grade electro-hydraulic servo valve based FFVA system was designed to be used with an engine in a test cell to precisely follow desired lift profiles. Repetitive control was chosen as the control strategy. Crank angle instead of time is used to trigger execution to ensure repeatability. A single control is used for different engine speeds even though the period for one revolution changes with engine speeds. The paper also discusses lift profile extension, instantaneous lift profile switching capability and built-in safety features.

Brake caliper and corner behavior in the off-brake condition can lead, at times, to brake system performance issues such as residual drag (and related issues such as pulsation, judder, and loss of fuel economy), and caliper pryback during aggressive driving maneuvers. The dynamics in the brake corner can be strikingly complex, with numerous friction interfaces, rubber component and grease dynamics, deflections of multiple components, and significant dependence on usage conditions. Displacements of moving parts are usually small, and the residual forces in the caliper interfaces involved are also small in comparison with other forces acting on the same components, making direct observation very difficult. The present work attempts to illuminate off-brake behavior in two different conditions - residual drag and pryback - through the use of low-range pressure distribution sensors placed in between the caliper (pistons and fingers) and the brake pad pressure plates.

In response to the TREAD act of 2002, ASTM F09.30 Aged Tire Durability Task Group was formed with the objective of developing a scientifically valid, short duration aged durability test which correlates to field behavior. The target end-of-test condition was belt edge separation (or related damage). One strategy, driven by that objective, has been a steady state design of experiment investigating aging temperature and duration as well as roadwheel speed, pressure and deflection. The rationale behind investigating a steady state test and selecting these parameters and methodology for setting their initial values is reviewed.

In the work leading to the TREAD Act, some members of Congress expressed the need for some type of aging test on light vehicle tires. Since no industry-wide recommended practice existed, the ASTM F09.30 Aged Tire Durability task group was established in 2002 to develop a scientifically valid, short duration, laboratory aged tire durability test which correlates to in-service aging. The target end-of-test condition was belt edge separation (or related tire conditions). One strategy, driven by that objective, has been a Steady State DOE investigating aging temperature and duration, as well as, roadwheel speed, pressure and deflection. Testing was performed on three tire types, including two where relevant field aging data was publicly available from NHTSA studies. A region of interest, within the design space, was identified where target end-of-test conditions were possible and undesirable (non-target or non-representative of those seen in consumer use) were avoided.

Basic automotive steering wheel armature design has been largely unchanged for years. A cast aluminum or magnesium armature is typically used to provide stiffness and strength with an overmolded polyurethane giving shape and occupant protection. A prototype steering wheel armature made from a unique recyclable thermoplastic eliminates the casting while meeting the same stiffness, impact, and performance criteria needed for the automotive market. It also opens new avenues for styling differentiation and flexibility. Prototype parts, manufacturing, and testing results will be covered.

Since 1997, General Motors Body Manufacturing Engineering - Die Engineering Services (BME-DES) has been working jointly with our software vendor to develop and implement a parallel version of stamping simulation software for mass production analysis applications. The evolution of this technology and the insight gained through the implementation of DMP/MPP technology as well as performance benchmarks are discussed in this publication.

The automotive industry continues to strive for mold-in-color (MIC) solutions that can provide metallic flake appearances. These MIC solutions can offer a substantial cost out opportunity while retaining a balance of weathering performance and physical properties. This paper discusses a predictive engineering package used to hide, minimize and eliminate flow lines. Material requirements and the methods used to evaluate flowline reduction and placement for visual inspection criteria are detailed. The Nissan Quest® luggage-rack covers are used to illustrate this application. The paper also explores how evolving predictive packages offer expanding possibilities.

A spectroscopic diagnostic system was designed to study the effects of different engine parameters on the chemiluminescence characteristic of HCCI combustion. The engine parameters studied in this work were intake temperature, fuel delivery method, fueling rate (load), air-fuel ratio, and the effect of partial fuel reforming due to intake charge preheating. At each data point, a set of time-resolved spectra were obtained along with the cylinder pressure and exhaust emissions data. It was determined that different engine parameters affect the ignition timing of HCCI combustion without altering the reaction pathways of the fuel after the combustion has started. The chemiluminescence spectra of HCCI combustion appear as several distinct peaks corresponding to emission from CHO, HCHO, CH, and OH superimposed on top of a CO-O continuum. A strong correlation was found between the chemiluminescence light intensity and the rate of heat release.

A numerical simulation of the flow structure around an idealized automotive A-pillar rain-gutter and the sound radiated from it is reported. The idealized rain-gutter is an infinitesimally thin backward facing elbow mounted on a flat plate. It is kept in a virtual wind-tunnel with rectangular cross-section. The transient flow structure around the rain-gutter is described and time-averaged pressure distribution along the base plate is provided. Time-varying static pressure was recorded on every grid point on the base-plate as well as the rain-gutter surfaces and used to calculate sound pressure signal at a microphone held above the rain-gutter using the Ffowcs-Williams-Hawkings (FWH) integral method was used for calculating sound propagation. Both the transient flow simulation as well as the FWH sound calculation were performed using the commercial CFD code FLUENT6.1.22.

The ozone forming potential (OFP) and specific reactivity (SR) of tailpipe exhaust are among the factors that determine the environmental impact of a motor vehicle. OFP and SR measurements require a lengthy determination of about 190 non-methane hydrocarbon species. A rapid gas chromatography (GC) instrument has been constructed to separate both the light (C2 - C4) and the midrange (C5 - C12) hydrocarbons in less than 10 minutes. The limit of detection is about 0.002 parts per million carbon (ppmC). Thirty exhaust samples from natural gas vehicles (NGV's) were analyzed to compare the rapid GC method with the standard GC method, which required 40-minute analyses on two different instruments. In general, evaluation of the commercial prototype from Separation Systems, Inc., indicates that a high speed, high resolution gas chromatograph can meet the need for fast, efficient exhaust hydrocarbon speciation.

The goal of this study is to assess the total Life Cycle Global Warming Impact of the current HFC-134a (R134a) refrigeration system and compare it with the effect of proposed alternatives, HFC-134a Enhanced, HFC-152 (R152a), R744, R744 Enhanced and R290, based on life cycle analysis (LCA). The enhanced systems include control strategies to elevate the compressor suction pressure as the evaporator load is reduced. The hydrofluorocarbons HFC-134a and HFC-152a are greenhouse gases (GHGs) and are subject to the Kyoto Protocol timetables, which when the treaty takes effect will require participating developed countries to reduce their overall CO2 equivalent emissions of six GHGs by at least 5% by 2012 from 1990 levels.

A previous paper reported (SAE Paper 2002-01-2884) that it was possible to decrease mode-weighted NOx emissions compared to the OEM calibration with corresponding increases in particulate matter (PM) emissions. These PM emission increases were partially overcome with the use of oxygenated diesel fuel additives. We wanted to know if compounds of toxicological concern were emitted more or less using oxygenated diesel fuel additives that were used in conjunction with a modified engine operating strategy to lower engine-out NOx emissions. Emissions of toxicologically relevant compounds from fuels containing triproplyene glycol monomethyl ether and dibutyl maleate were the same or lower compared to a low sulfur fuel (15 ppm sulfur) even under engine operating conditions designed to lower engine-out NOx emissions.

Currently, automobile manufacturers receive automotive headlamp assemblies from headlamp manufacturers with outer lenses produced of clear or slightly blue tinted polycarbonate. Such headlamp designed to provide optimized light output have very similar aesthetics, and leave little room to differentiate one car platform from another, using the outer lens color. With edge glow technology a car manufacturer can provide an appealing aesthetic look (edge glow effect) from the outer lens. Additionally, this technology can be used to improve the quality of the beam color emitted through the outer lens. Dependent on the chosen combination of halogen source and lens formulation, a range of beam colors spanning from halogen to HID is attainable, where the beam pattern and color continue to conform to the applicable SAE and ECE beam photometry and color standards and regulations.

This report summarizes the methodology used in automotive industry for virtual evaluation of vehicle structural integrity under abusive load cases. In particular, the development of a nonlinear finite element (FE) centric approach is covered that is based on the functions implemented in ABAQUS (by ABAQUS Inc.). An overview is also given for comparative study of the ABAQUS capability with the existing ADAMS (MSC Software) based methods.

OEM and Tier One integrated suppliers are in constant search of cockpit system components that reduce the overall number of breaks across smooth surfaces. Traditionally, soft instrument panels with seamless airbag systems have required a separate airbag door and a tether or steel hinge mechanism to secure the door during a deployment. In addition, a scoring operation is necessary to ensure predictable, repeatable deployment characteristics. The purpose of this paper is to demonstrate the development and performance of a cost-effective soft instrument panel with a seamless airbag door that results in a reduced number of parts and a highly efficient manufacturing process. Because of the unique characteristics of this material, a cost-effective, lightweight solution to meet both styling requirements, as well as safety and performance criteria, can be attained.

To determine what effect (measured in haze), UV exposure has on polycarbonate inner lenses (coated and uncoated), when positioned behind qualifying (UV absorbent) and non-qualifying (UV transmitting) outer lens materials (clear and red). Plastic inner lenses are those covered by another material and are not exposed directly to sunlight.