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Simplified mathematical modeling has been employed to investigate the relationship between automobile forestructure energy absorption and the restraint loads applied to passengers during a 30 mph barrier collision. A two-massmodel was developed and validated to compute restraint loading from a given passenger compartment deceleration. The effect of various deceleration curves, representing forestructure modifications, is reported. A “constant force” restraint system is also evaluated.

This paper directs attention to a specific region of the air-bag deployment process. Both experimental and analytical results are presented. Experimental procedures and their results are presented along with a two dimensional unsteady isentropic CFD model and a empirical gas-jet model.

A numerical model that utilizes Computational Fluid Dynamics (CFD) techniques has been developed for the analysis of underhood engine cooling systems of large slow moving vehicles. Several physical models have been developed and incorporated into a CFD code including; a) a model for predicting pressure losses due to screens and grills; b) a model for approximating the forces exerted by the fan on the flow; and c) a model for calculating the heat transfer inside the radiator. The CFD code and physical models have been demonstrated and validated against experimental data. Several three dimensional computational grids that represent various engine enclosures have been created and used to analyze the fluid flow and heat transfer inside the engine enclosure system. The computational results are compared to test data which were obtained for this study.

This paper presents a Computational Fluid Dynamic(CFD) model for the oil pump simulations aimed at better understanding the flow characteristics for improving their designs and reducing product development cycles. Several advanced numerical technologies have been developed to handle the complex geometries of oil pumps and the moving interfaces between the rotating and stationary parts. Two basic oil pump configurations, a vane oil pump and a gerotor oil pump, have been studied with the present method. The numerical results are compared with the existing experimental data.

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.

This paper describes techniques that predict and analyze dynamic response of vehicles traversing random rough surfaces. Road irregularities are statistically classified by frequency and amplitude distribution. This classification determines the nature of random inputs to mathematical vehicle models and allows computer prediction of dynamic response of a simulated vehicle. Once inputs and models are defined, parametric analysis with output criteria specified statistically can be performed. This allows prediction of vehicle riding quality and evaluation of design concepts. Statistical analysis of accelerometer measurements on actual vehicles permits verification of the design process and meaningful comparison between vehicles.

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.

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.

A numerical study of an automotive windshield ice-clearing was successfully accomplished. The windshield clearing process is a 3D transient, multi-medium, multi-phase heat exchange phenomenon in connection with the air flow distribution in the passenger compartment. The transient windshield clearing analysis employed conjugate heat transfer and enthalpy methods to simulate the ice-melting pattern and the melting duration. This study is a joint project between Chrysler Corporation and CFD Research Corporation. A Chrysler prototype windshield and test vehicle were utilized. The meshing was done using ICEM/CFD package by Control Data Corporation (CDC). A seamless data transfer was achieved by developing an interface between ICEM/CFD and CFD-ACE. The analysis of air flow, conjugate heat transfer, and weather clearing was performed using the multi-domain CFD-ACE code developed by CFD Research Corporation (CFDRC).

Chrysler Corporation's Jeep and Truck platform implemented a new design and prototype process for the body-in -white of a new pickup truck. A team approach achieved concurrent body design, stamping die design, assembly process development, and assembly tooling development. The first domestic US industry use of a 100% electronic design and release system was instrumental in the process. The new process produced a prototype body-in-white on time at 95 WBVP (weeks before volume production) with the highest level of production-intent components ever achieved within Chrysler at this stage of development.

Computer-aided engineering (CAE) is generally recognized as an important method of improving productivity. One of the major benefits of this technology has been to reduce the amount of manual labor spent analyzing changes made to vehicle designs. By using existing data, computer-aided design (CAD) can be used to co-ordinate the spatial relationships of the driver, passengers, engines, suspensions, tires, driver controls, and other body and chassis components. Special files containing a specific set of user-defined CAD language instructions, referred to as macros, are discussed and illustrated. Also included are tire clearance studies and master reference vehicle dimension files.

This paper discusses the development of criteria necessary to establish reliable lunar exploration and construction vehicle concepts. To establish the basis for the development of these criteria, an exploration mission using the presently conceived Apollo launch vehicle system is described. The criteria resulting from the study of the contribution made by the hostile lunar environment and the life support system requirements within the framework of the selected mission are established. Soils testing in a hard vacuum is described, as are tests of models under simulated lunar terrain environment. Two lunar vehicle configurations are reviewed, including design parameters and subsystem development.

Chrysler Corporation has developed an 8.0-liter engine for light truck applications. Numerous features combine to produce the highest power and torque ratings of any gasoline-fueled light truck engine currently available while also providing commensurate durability. These features include: a deep-skirt ten-cylinder 90° “V” block, a Helmholtz resonator intake manifold that enhances both low and mid-range torque, light die cast all-aluminum pistons for low vibration, a unique firing order for smooth operation, a “Y” block configuration for strength and durability, a heavy duty truck-type thermostat to control warm up, and a direct ignition system.

Some of Chrysler's 1988 model year vehicles contain a serial bus. This paper discusses its implementation and general usage. It describes a type of bus that was designed for smart modules to be able to cost effectively transfer data within an automotive environment. This paper is a sixty plus page users manual describing how to use both the Chrysler's C2D* bus and the C2D chip. This manual contains descriptions of the vehicle system, the information usage, the message formats, the hardware interfacing requirements, the bus speed, and the C2D chip functions. The SAE Multiplex Subcommittee is currently attempting to standardize this type of bus via SAE J1850. However, until this happens, Chrysler will continue to develop, improve, and use this bus, since it exists now! Even though this bus was designed for automotive usage, it has many other possible industry applications, especially within noisy environments. Thus, after understanding the bus, other industries may become interested.

A system for controlling gasoline evaporation losses from 1970 model Chrysler Corp. cars and light trucks was developed, certified for sale in California, and put into production. Evaporation losses from both the carburetor and the fuel tank are conducted to the engine crankcase for storage while the engine is shut down. The vapors are removed from the crankcase and utilized in the combustion process during subsequent vehicle operation. Particularly interesting in this unique, no-moving parts system, are the reliability and durability, and the vapor-liquid separator “standpipe.”

This paper presents a novel computational method for the flow simulations in the automotive oil pumps. The objective of this effort is to develop an advanced Computational Fluid Dynamics (CFD) tool to improve oil pump designs and efficiency by detailed analysis of unsteady fluid flow patterns inside stationary and rotating passages of an oil pump. To achieve this goal, several state-of-the-art computational technologies have been implemented into a general purpose unstructured grid code to handle numerical difficulties posed by complex geometry and moving parts of oil pumps. Most challenging numerical issues resolved in this paper include moving/deforming cells inside pump pockets, arbitrary sliding interface to connect moving and stationary parts and large grid distortions due to the great volume change of the pump pockets etc. A practical validation case, a vane oil pump, is studied using the presented method. The numerical results are compared with available experiment data.

In anticipation of complying with European standards for impact protection, an instrument panel design was analyzed to determine A. impact zone boundaries B. impact test velocitiesfor the head of a front seat passenger. Chrysler computer aided design (C.A.D.) surfacing capabilities were utilized in the solution. Early knowledge of impact zone location is important to intelligent design decisions; knowledge of impact velocities aids in performing compliance testing.

The basic theory and the techniques upon which the Air Conditioning Analytical Simulation Package (A/CASP) computer program system was developed is outlined. Methods for simulating car air conditioning components, systems, and cool-down performance by computerized mathematical models are presented. Solution techniques for the models of the evaporator, condenser, compressor, and vehicle are outlined. The correlation of test data and analytical predictions is demonstrated.

THE Junkers 211B engine follows the usual German practice of very large displacements and conservative mean effective pressures and rotative speeds. However, the relative light weight per unit of displacement results in a net weight per horsepower that is not far above its competitors. Fully automatic devices which control propeller speed, manifold pressure, mixture ratio, spark advance, and supercharger gear ratio follow the German policy of removing all possible distractions from the pilot. This is one of three large liquid-cooled engines known to be produced in quantity in Germany; it powers an impressive percentage of the Luftwaffe. While of external appearance and displacement that resemble the Daimler-Benz DB-601 engine, the fundamental construction, detail design practice, and metallurgy of the Junkers 211B are surprisingly different.

This paper describes the development of a rubber-like skin Finite Elements Model (FEM) for the Hybrid III headform and an experimental method to determine its material properties. The finite element modeling procedures, using material parameters derived from tests conducted on the headform skin (rubber) material, are described. Dynamic responses and computations of HIC using the developed headform model show that an Elastic-Plastic Hydrodynamic (EPH) material model of the rubber can be used for headform impact simulations. The results obtained from the headform simulation using an EPH rubber material model and drop tower tests of the headform on both a rigid and a deformable structure will be compared, in order to show the applicability of the EPH model.