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An automotive cockpit module is a complex assembly, which consists of components and sub-systems. The critical systems in the cockpit module are the instrument panel (IP), the floor console, and door trim assemblies, which consist of many plastic trims. Stiffness is one of the most important parameters for the plastic trims' design, and it should be optimum to meet all the three functional requirements of safety, vibration and durability. This paper presents how the CAE application and various other techniques are used efficiently to predict the stiffness, and the strength of automotive cockpit systems, which will reduce the product development cycle time and cost. The implicit solver is used for the most of the stiffness analysis, and the explicit techniques are used in highly non-linear situations. This paper also shows the correlations of the CAE results and the physical test results, which will give more confidence in product design and reduce the cost of prototype testing.

This paper discusses simplified lumped parameter thermal modeling of power train components. In particular, it discusses the tradeoff between model complexity and the ability to correlate the predicted temperatures and flow rates with measured data. The benefits and problems associated with using a three lumped mass model are explained and the value of this simpler model is promoted. The process for correlation and optimization using modern software tools is explained. Examples of models for engines and transmissions are illustrated along with their predictive abilities over typical driving cycles.

Testing of an OHC valve train with hydraulic lash adjuster in which the valve displacements, velocities and accelerations were measured and analyzed in both time and frequency domains, coupled with analysis of the frequency content of the valve acceleration function and its ramps, show that traditional designs of the opening and closing ramps used on some IC engine valve cams can exacerbate vibration in the follower system causing higher levels of spring surge and noise. Suggestions are made for improvement to the design of the beginning and ending transitions of valve motion which can potentially reduce dynamic oscillation and vibration in the follower train.

Gasoline direct injection technology is receiving increased attention among automotive engineers due to its high potential to reach future emission and fuel economy goals. This paper reports some of the design and development techniques in use at Chrysler as applied to four-stroke Direct Injection Spark Ignition (DISI) engines. The spray characteristics of Chrysler's single-fluid high-pressure injector are reported. Tools used in the design process are identified. Observations of the in-cylinder fuel/air mixing process using laser diagnostic techniques and Computational Fluid Dynamics (CFD) are described. Finally, combustion and emissions characteristics using Design of Experiment (DoE) tests are presented.

A systematic life cycle management (LCM) approach has been used by Chrysler Corporation to compare existing and alternate hydraulic fluids and lubricating oils in thirteen classifications at a manufacturing facility. The presence of restricted or regulated chemicals, recyclability, and recycled content of the various products were also compared. For ten of the thirteen types of product, an alternate product was identified as more beneficial. This LCM study provided Chrysler personnel with a practical purchasing tool to identify the most cost effective hydraulic fluid or lubricant oil product available for a chosen application on an LCM basis.

This paper discusses the feasibility and issues associated with integrating a consumer off-the shelf product into a vehicle. For this evaluation, we selected a handheld personal computer (HPC), cellular telephone and modem to integrate with the vehicle audio, climate and system controls. Connectivity between the HPC and the vehicle is established by the use of the standard infrared serial data link that comes with the HPC. Connectivity outside the vehicle uses a cellular telephone for voice and a cellular digital packet data (CDPD) modem for data. This system is built into the Dodge ESX-2 hybrid powered concept vehicle for demonstration.

This study analyzes the vibration characteristics of the valve train of a 2.0L SOHC Chrysler Corp. Neon engine over a range of operating speeds to investigate and demonstrate the advantages and limitations of various dynamic measurements such as displacement, velocity, and acceleration in this application. The valve train was tested in a motoring fixture at speeds of 500 to 3500 camshaft rpm. The advantages of analyzing both time and frequency domain measurements are described. Both frequency and order analysis were done on the data. The theoretical order spectra of cam displacement and acceleration were computed and compared to the experimental data. Deconvolution was used to uncover characteristic frequencies of vibration in the system. The theoretical cam acceleration spectrum was deconvolved from measured acceleration spectra to reveal the frequency response function of the follower system.

To understand how the passenger compartment cavity interacts with the surrounding panels (roof, windshield, dash panel, etc) a numerical panel contribution analysis was performed using FEA and BEA techniques. An experimental panel contribution analysis was conducted by Reiter Automotive Systems. Test results showed good correlation with the simulation results. After gaining some insight into panel contributions for power train noise, an attempt was made to introduce beads in panels to reduce vibration levels. A fully trimmed body structural-acoustic FEA model was used in this analysis. A network of massless beam elements was created in the model. This full structural-acoustic FEA model was then used to determine the optimal location for the beads, using the added beams as optimization variables.

The purpose of this paper is to present numerical solution for three-dimensional flow about rotating short cylinders using the computer program AIRFLO3D. The flow Reynolds number was kept at 106 for all computations. The drag forces on the cylinder were obtained for different rotational speeds. Predictions were obtained for both an isolated cylinder and a cylinder on a moving ground. The standard k-ε model was employed to model the turbulence. Computed drag coefficients agreed well with the previous experimental data up to a spin ratio (=rω/V) of 1.5.

The commercial validation of a optimized RRIM polyurethane substrate with a novel barrier coat for fascia applications is reviewed which creates cost competitiveness to thermoplastic olefins (TPO), without sacrificing performance. Meeting fascia performance requirements with thinner and lighter RRIM materials containing recyclate and the subsequent application of a barrier coat eliminating the traditional primecoat cycle was investigated.

A better understanding of turbulent kinetic energy is important for improvement of fuel-air mixing, which can lead to lower emissions and reduced fuel consumption. An in-cylinder flow study was conducted using 1548 Laser Doppler Velocimetry (LDV) measurements inside one cylinder of a 3.5L four-valve engine. The measurement method, which simultaneously collects three-dimensional velocity data through a quartz cylinder, allowed a volumetric evaluation of turbulent kinetic energy (TKE) inside an automotive engine. The results were animated on a UNIX workstation, using a 3D wireframe model. The data visualization software allowed the computation of TKE isosurfaces, and identified regions of higher turbulence within the cylinder. The mean velocity fields created complex flow patterns with symmetries about the center plane between the two intake valves. High levels of TKE were found in regions of high shear flow, attributed to the collisions of intake flows.

The flow field contained within ten planes inside a cylinder of a 3.5 liter, 24-valve, V-6 engine was mapped using a three-dimensional Laser Doppler Velocimetry (3-D LDV) system. A total of 1,548 LDV measurement locations were used to construct the time history of the in-cylinder flow fields during the intake and compression strokes. The measurements began during the intake stroke at a crank angle of 60° ATDC and continued until approximately 280° ATDC. The ensemble averaged LDV measurements allowed for a quantitative analysis of the dynamic in-cylinder flow process in terms of tumble and swirl motions. Both of these quantities were calculated at every 1.8 crank degrees during the described measurement interval. Tumble calculations were performed about axes in multiple planes in both the Cartesian directions perpendicular to the plane of the piston top. Swirl calculations were also accomplished in multiple planes that lie parallel to the plane of the piston top.

The Finite Element predictions of the physical response of foams during impact by a rigid body (such as, the Hybrid III head form) is determined by material law equations generally approximated based on the theory of elastoplasticity. However, the structural aspect of foam, its discontinuous nature, makes it difficult to apply the laws of continuum mechanics and construct constitutive equations for foam-like material. One part of the problem relates to the state of stress. In materials such as steel, the state of hydrostatic stress does not affect the stress strain behavior under uniaxial compression or tension in plastic regime. In other words, when steel is subject to hydrostatic pressures the stress strain characteristic can be predicted from a uniaxial test. However, if the stresses acting on a section of foam are triaxial, the response of a head-form may be different than predicted from uniaxial test data.

Temperature variation and heat transfer phenomena in the intake port of a spark ignition engine with port injection play a significant role in the mixture preparation process, especially during the warm up period. Cold temperatures in the intake port result in a large amount of liquid-fuel film. Since the liquid-fuel film responds at a slower speed than the gas-phase flow during transient operations, the liquid-fuel film acts as a fuel sink (or source) and can degrade the vehicle's driveability, fuel economy, and emissions control. In this work, a one-dimensional, unsteady, multicomponent, multiphase flow model has been developed to study the mixture formation process in the intake port for a modern, multipoint-fuel-injection, gasoline engine. The droplet, liquid film and gas-phase mixture temperature variations and the effects of charge air, initial fuel and port wall temperatures involved in generating the air-fuel mixture are examined.

Resistance to dents and dings, caused by plant handling and in-service use, is generally recognized as an important performance requirement for automotive outer body panels. This paper examines the dent resistance improvements that can be achieved by maximizing surface stretch, through adjustments to the press settings, and substitution of a higher strength steel grade. Initially, the stamping process was optimized using the steel supplied for production: a Ti/Nb-stabilized, ultra low carbon (ULC) grade. The stamping process was subsequently optimized with a Nb-stabilized, rephosphorized ULC steel, at various thicknesses. The formed panels were evaluated for percent surface stretch, percent thinning, in-panel yield strength after forming, and dent performance. The results showed that dent resistance can be significantly improved, even at a reduced steel thickness, thus demonstrating a potential for weight savings.

Fastener failure due to hydrogen embrittlement is of significant concern in the automotive industry. These types of failures occur unexpectedly. They may be very costly to the automotive company and fastener supplier, not only monetarily, but also in terms of customer satisfaction and safety. This paper is an overview of a program which one automotive company initiated to minimize hydrogen embrittlement in fasteners. The objectives of the program were two-fold. One was to obtain a better understanding of the hydrogen embrittlement phenomena as it relates to automotive fastener materials and processes. The second and most important objective, was to eliminate hydrogen embrittlement failures in vehicles. Early program efforts concentrated on a review of fastener applications and corrosion protection systems to optimize coated fasteners for hydrogen embrittlement resistance.

Environmental issues have significantly impacted automotive operations worldwide. Countries are continuing to ratchet down their allowable emissions and to remain competitive, all industries must take Life Cycle Management (LCM) and implement it into everyday practice. Economic competitiveness as a part of economic development is central to the nation's social and financial well-being. America must catch-up to the rest of the world in how it views government and industry relationships as well as how to focus costs within the corporate structure. The adversarial relationships between government and industry must give way to stronger partnerships. For this concept to succeed a long term view of problems must be made by a corporation and both short and long term actions taken to resolve these problems. Industry must help create the market for recycled goods and must “walk the talk” by using recycled goods where possible.

A cycle-by-cycle analysis of HC emissions from each cylinder of a four-stroke V-6, 3.3 L production engine was made during cold start. The HC emissions were measured in the exhaust port using a high frequency flame ionization detector (FID). The effect of the initial startup position of the piston and valves in the cycle on combustion and HC emissions from each cylinder was examined. The mass of fuel injected, burned and emitted was calculated for each cycle. The equivalence ratio of the charge in the firing cycles was determined. The analysis covered the first 120 cycles and included the effect of engine transients on HC emissions.

This paper outlines several methodologies which use finite element and experimental models to predict vehicle NVH responses. Trimmed body experimental modal subsystem models are incorporated into the finite element system model to evaluate engine mounting systems for low frequency vibration problems. Higher frequency noise issues related to road input are evaluated using experimentally derived acoustic transfer functions combined with finite element subsystem model responses. Specific examples of system models built to simulate idle shake and road noise are given. Applications to engine mounting, suspension design, and body structure criteria are discussed.

The low noise and linear sound level characteristics of passenger vehicles are receiving increased scrutiny from automotive journalists. A linear noise level rise with increasing engine rpm is the first basic aspect of insuring an acceptable vehicle interior engine noise sound quality. In a typical case of structural response to engine vibration input, interior noise begins to rise with rpm, remains constant or even drops as the engine continues to accelerate, and then exhibits a noise period corresponding to the structure's natural frequency. Frequently this nonlinearity is bothersome to the customer. During the development process, Chrysler's Dodge and Plymouth Neon exhibited just such a nonlinear rise in noise level, heard within the passenger compartment, when the vehicle was accelerated through 4200 rpm.