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The one-box type automobile's stability on the highway is often influenced by encountering crosswinds or when passing large automobiles such as trucks and buses. This causes the automobile to behave unexpectedly. Many experiments for improving this situation have been carried out. In this respect, the analysis of transient aerodynamic characteristics is important for automobile safety and stability on the highway. Conventional transient aerodynamic simulations require a supercomputer and about million grid points. Also there were few case studies that dealt with situations such as plunging into crosswind and passing an automobile. In this paper, a transient aerodynamic simulation by using a sliding mesh of discontinuous interface and the Arbitrary Lagrangian-Eulerian (ALE) method is presented.

The dynamic response of cars in turbulent winds is investigated in three wind-tunnel experiments: a 1:12 sharp-edged car model; a 1:10 Audi A4 model; and a racing and passenger full-scale car. The resultant side force spectra for various turbulence levels were measured which showed a phenomena not previously observed in cars: the side force spectral bandwidth becomes narrower with increase in turbulence. The vortex-shedding Strouhal number of the cars was found to be 0.27. As this can be close to the resonance of cars, it is suggested that suspensions be tuned accordingly and turbulence should be modelled in dynamic testing in wind tunnels.

Numerical investigations on motorcycle wheels are described, in order to point out their aerodynamic characteristics and their influence on the global aerodynamic behavior of the motorcycles. The trials studied the development of the design of the front mud-guard in a commercial motorcycle, that showed an undesirable lift effect during on-road and wind tunnel tests. The functionality of the mud-guard was checked, varying its shape and dimensions, in order to reduce the lift effect and eventually to improve the whole behavior of the motorcycle.

The differential equation of motion of a freely coasting vehicle is analysed and its integral solution in the form of an explicit speed-time function and then a distance-time one is derived. The latter form eliminates the traditional speed term from the equation. By making speed or deceleration measurements unnecessary, a whole set of potential error sources is eliminated, thus improving the sensivity and accuracy of the coast down method. By replacing the distance measurements with precision test track markings, the coasting data requirements are reduced to accurate measurements of time only. This simplifies both the method and the test facility, and improves the reliability of the test data. Because of the efficiency of this a significant volume of test data has been gathered, and included in this report, which characterizes vehicle aerodynamic drag and rolling resistance.

Airflow effect is one of the important functions demanded of a rear spoiler. It helps prevent mud or dust from swirling up behind the running vehicle, or in the case of driving in the rain or snow, helps prevent rain or snow from adhering to the rear window. During the design process, we often decide on the shape of a spoiler in a relatively short time, focusing primarily on its appearance. Therefore, we established a design method using the recently developed computational fluid dynamics (CFD) to determine the central cross sectional shape of a spoiler that produces a desired airflow effect. We verified its effectiveness through testing.

Currently, the recycling of automobiles can be considered to be a success story. However, it is hoped by the automakers that the current automotive recycling infrastructure can adapt to include more disassembly of plastics for recycling. The success of this option depends on the economics involved. Therefore, a method for evaluating the economics of disassembly for recycling is utilized to see how changes in recycling prices, disassembly costs, or design might affect the practices of dismantlers.

The current trend in the automotive industry is to minimize/eliminate cutting fluid use in most machining operations. Research is required prior to achieving dry or semi-dry machining. Issues such as heat generation and transfer, thermal deformation and fluid lubricity related effects on tool life and surface roughness determine the feasibility of dry machining. This paper discusses recent advances in achieving dry/semi-dry machining. As the first step, research has been conducted to investigate the actual role of fluids (if any) in various machining operations. A predictive heat generation model for orthogonal cutting of visco-plastic material was created. A control volume approach allowed development of a thermal model for convective heat transfer during machining. The heat transfer performance of an air jet in dry machining was explored. The influence of machining process variables and cutting fluid presence on chip morphology was investigated through designed experiments.

The environmental effects of a car can be significantly improved by the development of material cycles and environmental design principles. This is illustrated by a number of activities in which Netherlands Car B.V. is involved. In the dismantling study ‘Project Goes’ some 130 Volvo 440's were selectively dismantled. The results have served as a basis for a unique car recycling system in the Netherlands that is operational since 1995. A disposal levy is placed on the buyers of newly registered cars. The income is used for the payment of premiums to companies involved in the recycling of automobile materials which are not yet business-economically profitable. ‘NEUROBOT’ is a European project in which work is done together with a number of partners on the development and implementation of an autonomous robot system for the disassembly and recycling of automotive products. The system is based on neural network concepts and guided by multiple sensors. A demonstration unit has been set up.

Hand dismantling of certain automotive parts has been an accepted process to remove high value materials, but in large scale recycling this may not be economical. In plastics, a pure non contaminated material stream is critical for maintaining high material values and this means designing plastic parts that can be machine separated. One candidate for separating the plastics in vehicle subsystems such as instrument panels and door trim panels is density separation. In order to better understand what processes are required to develop design requirements for automated plastic separation methods Chrysler and the Vehicle Recycling Partnership have undertaken a major materials separation study with MBA Polymers. In this paper, we describe the material separation methods and the application of these methods to three automotive interior assemblies.

Iron-resin composites or dielectromagnetic materials are designed for AC and pulsed DC electromagnetic applications. These new materials present interesting features such as ease of shaping, high induction, low losses and isotropic electrical, thermal and magnetic properties. Compared to steel laminations, better performing and/or more compact devices may result from an optimisation of the design taking full advantage of these isotropic properties. Also, compared to soft ferrites, dielectromagnetics show higher magnetic saturation and much better machinability. In this paper, potential applications for this type of material in the automotive industry together with their specific requirements are discussed. The characteristics of a new dielectromagnetic material, ATOMET EM-1, are described.

Specular-reflectance infrared spectroscopy systems can identify the polymer material of an automotive part in about 5 seconds and are currently commercially available. Issues related to the rapid identification of plastics were recently examined at the Vehicle Recycling Development Center, which is operated by the United States Council for Automotive Research (USCAR). The accuracy of identification is a crucial concern in order to minimize co-mingling or contamination of sorted plastics in dismantling-sorting-recycling operations. Accuracy reports in the literature have ranged from 70% to >99%. Our investigation of the signal-to-noise levels of spectrometers, identification algorithms, and spectral reference libraries indicated that the quality-and-completeness of the reference library is the strongest determinant of accuracy when evaluating current commercial systems. With adequate spectral libraries, identification accuracy of 99% can be achieved.

With the increasing demand to improve recyclability of automobiles worldwide the Vehicle Recycling Partnership (VRP) a cooperative effort among Chrysler, Ford and General Motors has been formed. The VRP has been developing preferred practices for improvement of recyclability for future vehicle subsystems. These preferred practices are intended to assist engineers and designers in improving recyclability without impairing the performance of the subsystem. This paper discusses the practices of specific design for recycling of plastic bumper fascia systems and what the designer should consider in developing a design to improve and maximize recyclability.

A new recycled material has been developed by using the scrap of tail lamp assembly, made of poly(methyl methacrylate) (PMMA) for the lens and acrylonitrile-butadiene-styrene terpolymer (ABS) for the housing. Lamp scrap was extruded in a twin-screw extruder, and mechanical properties of the scrap were compared with ABS, PMMA, and an ABS/PMMA (60/40) blend. The recycled material from 100% tail lamp scrap has similar modulus to the 60/40 blend, however, notched Izod impact strength and thermal resistance were lower than that of the blend, probably due to the presence of hot melt adhesive and silver paint. Scrap/virgin polymer mixtures showed improved thermal resistance and impact strength. The effects of composition and type of mixed polymer on mechanical properties were also investigated.

The effect of steam treatment on the physical properties of powder metal parts was studied. Steam treatment increases the weight, size, density, and hardness of the parts. The strength measured in tests of standard transverse rupture specimens is not significantly affected by steam treatment. However the ductility, as measured by the deflection, is decreased after steam treatment. Part crush load can be, depending on the configuration, significantly decreased or slightly increased. Steam treatment is most effective in the first half hour. The effect of further increasing steam treatment time is not significant.

Although P/M part producers have been supplying 410 and 316-base stainless steel parts for almost fifty years, P/M versions of these materials have been excluded from many moderate to severe applications due to their marginal corrosion resistance. There have been a number of efforts targeted at improving P/M stainless corrosion properties but performance comparable to the wrought stainless products has not yet been achieved. The work reported here discusses corrosion and mechanical properties obtained for modified steel alloys which have shown significantly better resistance to corrosion in simulated sea water (5% NaCl solution) while maintaining reasonable physical and mechanical properties.

Evaluation of commercial high temperature H2-sintered 410L ABS sensor rings, after use for over 10 years and/or over 100,000 miles in various automobiles and in various locations across the USA and Canada, showed only small amounts of rusting; less than which results in a 100-hour Salt Spray Test (ASTM B117); and no loss of their mechanical strength and ductility. Although sensor rings made of 434L and 434L-Modified (18 Cr, 2 Mo) show even lesser amounts of rusting and pitting, 410L sensor rings made by the above process are deemed adequate for this application. The 1000-hour Salt Spray Test is found to be much too severe for this application. A 100-hour test is considered to be more suitable in this regard.

High performance auto parts such as aluminum composite cladding aluminum brake and Ti/Ti3/Al joined exhaust valve with localized Ti+TiC composite coating could be produced using a new manufacturing method - the CastCon process. The aluminum composite cladding aluminum brake consists of an aluminum alloy body with a cladding of SiC and graphite particulate filled aluminum composite on the friction surface of a brake disk or a drum. This structure can ensure an over-all light weight and integral strength and ductility. The SiC particulate in the cladding composite increases abrasion resistance and the graphite particulate provides required lubrication. The cladding can be as thick as desired. There is a flexibility in the manufacturing process for selecting SiC and graphite loading volumes as well as particulate size and shape. This allows the part to be engineered to achieve maximum performance.

The performance of stainless steel(SS) powder metallurgy (P/M) materials in elevated temperature applications has become a subject of interest with P/M now being considered for automotive exhaust type applications. This study will outline the results of an investigation into the properties of several P/M stainless steel materials at elevated temperatures and relate these P/M materials to ingot metallurgy counterparts. Recommendations on the manufacturing of stainless steel P/M exhaust system components will also be presented.

Turbine hubs for automatic transmission torque converters are ideal candidates for the powder metallurgy (P/M) process. The complex shape of turbine hubs is costly to produce via conventional forging and machining operations. Increases in engine size and torque requirements by automotive designers require turbine hubs to possess high levels of mechanical properties. High density P/M manufacturing techniques, in combination with high performance ferrous material produces components capable of replacing a forged and machined turbine hub. This paper will review the conversion of a conventionally forged and machined turbine hub used in a high torque automatic transmission to a single pressed and single sintered P/M turbine hub. The material used for the P/M hub was an MPIF FD-0405. Warm compaction processing achieved significantly increased overall sintered densities in the highly stressed internal spline region.

Today, light connecting rods are vital to satisfying the demands of modern internal combustion engines. HYUNDAI Motor Company (HMC) has applied powder metal forged connecting rods instead of conventional hot forged connecting rods to obtain low product costs and to improve NVH characteristics and bearing reliability. Light connecting rods were developed through optimized design with high quality and low cost. Notably, the mass of a powder metal forged connecting rod is 17.7% lighter than that of a conventional hot forged type connecting rod, and its crank end is 22.5 % lighter than that of a conventional type connecting rod. Light connecting rods result in reduced crankshaft mass, so the mass of the main moving parts can be reduced. With this mass reduction, bearing reliability and NVH characteristics can be enhanced.