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This paper discusses design parameters for automotive seats intended to simultaneously meet three design objectives: comfort, safety, and health. (“Health” refers to long-term spinal support and vibration attenuation.) For comfort, various ergonomic and human factors considerations are discussed ranging from seat dimensions and adjustments to cushioning and occupant perceptions of comfort. For safety, the principal consideration is the effectiveness of the seat in providing spinal support during accidents-particularly in rear-end collisions. An additional safety consideration is the ability of the seat to keep an occupant “in position” during an accident. Finally, for health concerns, the focus is upon maintenance of spinal stability, seat ergonomics, and road induced vibration attenuation. The paper presents design parameters satisfying these design objectives.

This paper reports test results of a compact, high pollutant conversion efficiency, catalytic muffler developed for utility engines (<19kW/25hp). Tests were conducted in-house, and at an independent laboratory under EPA supervision and funding, using a four-stroke engine generator set. The specific HC, CO and NOx emissions were reduced by 98%, 97%, and 19%, respectively. This level of reduction is thought to be sufficient for reducing such emissions from utility engines to the level of future standards such as 1999 CARB. A total of 200 hours of performance and limited durability testing were accumulated on the catalytic muffler. The prototype demonstrated successful operation by entraining fresh air and mixing with exhaust gas, converting pollutants, maintaining acceptable skin and exhaust gas temperatures, and muffling noise.

Packaging requirements to meet current and future exhaust legislations force automakers to use the given space either in the engine compartment or in underbody position as efficiently as possible. This requirement leads to substrate contours with wide ranges of different radii to fill the space with the recommended catalytic volume. Especially converters with race-track shaped substrates suffer from mechanical durability problems. They occure primarily in the region of the extreme wide radius due to erosion of the thermal expanding support mat. This is commonly known as mat erosion. A new approach to improve the durability of the substrate support system is a PatchWorkDesign support mat, which combines the advantages of an alternative fibre mat with those of the intumescent mat.

About ten years ago the major noise and vibration sources in a vehicle were the engine and the aero dynamic noise sources. During these last years the noise and vibration levels induced in the vehicle by these two sources have decreased in very high proportions. The consequence of that is that former secondary noise sources like the air-conditioning system have now become major noise and vibration sources. One of the most important noise and vibration sources in the air-conditioning unit is the blower. This component is composed of an electric motor, a fan wheel and a motor support in which the electric motor is fixed. This work only deals with the vibrations generated which are due either to the wheel unbalance or due to electric motor vibrations. The unbalance can generate vibration discomfort on the steering wheel and the electric motor vibrations are very often solid borne noises generated especially for low speeds of operation.

To be an assistance for the driver and make his journeys more comfortable are the aims of the first “ACC” (Adaptive Cruise Control). It is the first step of a new area for the automotive future. ODIN is the name of the ACC-sensor made by ADC GmbH Switzerland, which based on infrared light (IR). There are full of parameters to describe the situation in front of a vehicle. Developing an ACC-sensor, needs to define this parameters exactly. What are the requirements? This will be discussed in the first section of the lecture. The near IR is out from research and already a cheap and reliable technology. Due to the close relation between the visible light the IR technology is predestinated for an forward looking sensor. The differences between other technologies will be illustrated. ODIN has been quite a success for many ACC application at the automotive industry. ADC still improve their knowledge and wants to present how we come up to the requirements of ACC.

Compression rings for heavy duty diesel engines are traditionally made of ductile cast iron material. These rings, in general, have conservative standard dimensions limited by the strength of their base material. More recently, however, the market for heavy duty diesel engines demanded products able to cope with high levels of power density and, at the same time, lower levels of oil consumption, friction, and emissions. This paper discusses the advantages of some radical changes made on the design of compression rings in order to take advantage of steel as the base material. The superior mechanical properties of steel allow the use of rings with smaller cross sections which minimizes the friction losses caused by the combustion gas pressure pushing the ring against the liner. It also allows the use of compression rings with a free gap significantly larger than usual.

Diesel engines are used in heavy duty applications because of their high efficiency and reliability. However, their high diesel particulates and NOx emissions remain major concerns. An eight cylinder direct injection diesel engine was connected to a partial flow particulate sampling mini-dilution tunnel. Six different grades of diesel fuels were studied for their regular emissions as well as smoke and particulate emissions. Each fuel was tested at three engine speeds and full load. This paper presents the results of these tests which includes analysis of the effects of load, cetane number, 90% distillation temperature, and density for steady state conditions. A correlation was developed for converting smoke numbers in Hartridge Smoke Units (HSU) to the specific particulate emissions by evaluating results of all fuels tests. Another correlation was also developed for diesel particulates and NOx emissions trade-off.

The comparison of a light weight crankcase to the production cast iron crankcase of the new Mercedes Benz 2.9-liter direct injection (DI) five-cylinder turbo diesel engine with intercooler is described. The light weight crankcase is cast from the aluminum alloy A 356 while other engine components like oil pan, timing case cover and brackets are manufactured from a magnesium alloy. This paper describes the engine design with the simultaneous calculation, the mechanical development and the acoustic measurements. In this study an engine weight reduction of about 30 kg with comparable noise emission compared to the production engine with cast iron crankcase is realized.

Due to their inherent high efficiency and the ease of starting once the engine is hot, turbocharged direct injection (TDI) diesel engines have emerged as one of the contending powerplants for PNGV hybrid vehicles. The interest in applying diesel engines in hybrid vehicles has prompted the modeling of direct injection diesel engine fuel consumption. The empirical equation developed in this study, which models engine friction and indicated efficiency as functions of engine operating speed and load, shows excellent agreement with test data gathered from public sources. The engine speed dependence of the friction and indicated efficiency are determined by fitting available data. Several assumed load dependences are considered. (If public data were available on engine cylinder pressure by crank angle as a function of engine speed and load, the load dependence could be determined empirically.)

A complete finite element model of the BioSID side impact dummy was created using the finite element code RADIOSS. The objective of this work was to develop an accurate and stable dummy model, which can capture the dummy behavior due to a localized impact or in a full-scale side impact finite element model with reasonable CPU time. This warranted the development of a detailed dummy model which reflects the BioSID geometrically and has material characteristics similar to the physical dummy. This paper describes the stages of the model development and discusses the issues which influence the accuracy of the dummy model predictions. It also shows comparisons of the dummy model responses and kinematics with a series of sled test data and calibration tests specified in the BioSID User's Manual.

The combustion of diesel fuels injected into a bomb at 25 bar and 520°C has been modelled and studied experimentally using laser diagnostics. A CFD model of diesel spray injection was combined with a database of results from a detailed chemical kinetic model. All fuels showed the presence of small aromatics throughout combustion (i.e. the fuel aromatics were not completely broken down). The model gave good agreement on spray penetrations and soot volume fractions around the edges of the spray. Far from the spray, the model over-predicted the amount of soot due to the absence of an OH oxidation mechanism in the CFD code. This demonstrates the need to progress to the use of a reduced chemistry scheme.

Conformability Analysis is a structured technique which seeks to identify potential problems in the manufacture and assembly of the parts and expresses the outcome as a cost of quality for the design. The analysis provides process capability estimates based on key features of parts. Considerations of the severity of possible failure of each part enables this process risk to be mapped onto a cost model to assess the expected cost of failure. Given the very high proportion of product cost determined very early in a project, and the typically significant quality costs incurred, such an approach to design evaluation is important in the product introduction process. Applications illustrate how the method is used to evaluate, compare or generate designs and show how awareness of process capability is raised in the team and in discussions with suppliers.

This paper provides an exposition of the basic and some refined inertial critical speed estimation formulas. A literature review of existing inertial formulas for estimating critical cornering speed were identified for the ultimate purpose of developing a useful, compact, and more accurate speed estimation formula. Background information is presented covering the general definitions and utility of critical speed formulas. First, as a point of reference, the basic critical speed formulas are derived. Included is a list of the key assumptions on which the basic formulas are based. It is shown that the basic formulas are founded on the fundamental principles of physics and engineering mechanics; namely, Newton's Second Law and centrifugal force.

This paper covers briefly the theory of tire-road friction, coefficient of friction measurement techniques, and the vagaries of tire-road friction as they relate to critical speed estimation. A literature review of tire-road friction studies was conducted to identify the primary factors effecting the tire-road coefficient of friction. Background information is presented covering general definitions and the connection between the basic critical speed formulas and the coefficient of friction. The primary components of tire-road friction, adhesion and hysteresis, are discussed along with minor effects such as tearing, wear, waves, and roll formation. Common coefficient of friction field measuring techniques are described, including the skid-to-stop test and drag sled. Influential factors such as tire characteristics, tire inflation pressure, road conditions, and dynamic factors are reviewed.

The permeability of some airbag fabrics is determined, along with the Ergun coefficient signifying departure from purely viscous flow, from gas flow rates and pressure drop measurements. The dependency of these coefficients on the fabric temperature is also examined. Preliminary results are reported on the transient response of these fabrics to temporal changes in the gas flow rate and temperature. The temperature history is measured and compared with the predictions of some simple models. The models make various assumptions regarding the microscale of the fabrics. The preliminary results show that the very fine microscales do not control the time response of the fabric.

The objective of this study was to determine dynamic tensile characteristics of various door trim materials and to recommend a practical test methodology. In this study, Polypropylene (PP) and Acrilonitryl Butadiene Styrene (ABS) door trim materials were tested. Slow speed (quasi-static-0.021 mm/s) and high speed tests were conducted on a closed loop servo-hydraulic MTS system. The maximum stress of these materials increased from quasi-static to dynamic test conditions (as much as 100%). The dynamic stiffness of PP increased two times from quasi-static tests. No significant change in stiffness was observed for ABS during quasi-static and dynamic tests at different strain-rates. Quasi-static and medium strain-rate (10-20 mm/mm/s) tests may be adequate in providing data for characterizing the dynamic behavior of trim materials for CAE applications. Strain gages can be used to measure the quasi-static and in some cases, dynamic strain.

It is demonstrated that direct air injection leads to substantial improvement of the cold starting performance of an SI engine. Raw pollutant formation is considerably reduced and fuel conversion efficiency increased. Air is directly injected into the cylinder through a small orifice during the compression stroke. Optical measurement techniques, in particular Spontaneous Raman Scattering, are applied to elucidate the in-cylinder processes that lead to improved cold starting perfomance. It is demonstrated that air injection causes enhanced combustion via increased turbulence and this leads to rapid warm-up of the combustion chamber walls. Thus the quality of the combustion process after the first few cycles is comparable to warmed-up engine operating conditions. It turned out to be possible to avoid fuel-enrichment and start the engine with lean fuel/air mixture (at 20°C).

A new orifice plate (OP) for advanced fuel injection characteristics is presented. The OP is designed to optimize the air-fuel mixture generation and transportation within individually shaped manifold geometries of spark-ignition engines. To generate the suitable spray characteristics, the basic OP design and its flow characteristics have some features originating from the well known turbulence nozzle principle: Turbulence generating flow deflections within the OP are achieved by superimposing layers containing flow cavities, which are displaced from one another. The flow deflections effect atomization and define the spatial spray beam orientation. A great variety and a high volume of precisely structured, low cost OPs can be produced daily by micromachining the layers in electroformed nickel. The flow cavities and outer dimensions of each layer are shaped by photo-resist structures.

Foamed materials and rubbery materials have been commonly used as energy absorbers in automotive safety designs. The present study investigates the response of polyurethane, vinyl, and their laminations with aluminum panels under low-velocity impact. In addition to force history and force-deflection relation, impact parameters such as peak force, contact duration, maximum deflection, and energy absorption capability are of primary concerns. Experimental results reveal that the lamination sequence affects the impact parameters significantly, LS-DYNA3D is also used to verify the experimental findings.

The child dummy is seeing increased use in car crash testing for safety reasons. A neck of the child dummy is one of the key components for dummy design, manufacturing and testing. The testing corridor would affect the all of the procedure for the neck. This paper would discuss the testing corridor for neck calibration of the child dummy. The testing corridors should be come from biomechanical results and combine with the material property. The paper has reviewed the research result and described the dummy neck of Six-Month, Twelve-Month, Eighteen-Month Old Infant (CRABI); Three-Year Old and Six-Year Hybrid III Child (Hybrid II Child dummy will not be discussed in the paper). A series of testing has been done for finding out corridors of the neck pendulum calibrating tests. It is difficulty to match the human corridors of crash reaction. There are several methods to approach the child neck corridors such as change design, adjust testing parameter and so on.