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The turbocharger, consisting of a radial or axial flow turbine and an radial flow compressor presents perhaps one of the most challenging tasks to the turbomachinery designer. Due to the necessity of speed changes in the diesel engine, the turbocharger transits a wide variety of operating points in its normal operation. During an engine speed acceleration or deceleration there will be a lag in the required air delivery to the engine, resulting in increased smoke emission and limiting the power delivered by the engine. In order to investigate the dynamic performance of a turbocharged engine, an essential first step must be the development of an adequate model for transient characteristics of the turbocharger. One of the significant problems that must be overcome for the modeling effort to be successful is a detailed experimental description of the transient performance of the device.

We have developed a vehicle test system called the Vehicle Dynamics Simulator (VDS). The system measures the handling characteristics in a transient state in the laboratory. The automobile suspensions are moved as on a road with the machine providing relative motion by force transducer platform beneath each tire. The detailed measurements of transitive motions and forces given to the wheel clarify the kinematics and compliance characteristics contributed to the good handling performance and stability. This paper presents the system introduction and the results of analyzing the suspensions characteristics by the new analytical technique for breaking down into a variety of compliance components in a transient state.

With the advent of stricter vehicle emission standards, the improvement of three way catalyst performance and durability remains a pressing issue. A critical consideration in catalyst design is the potential for variations in fuel sulfur levels to have a significant impact on the ability to reach TLEV, LEV, and ULEV emission levels. As a result, a better understanding of the role of PGM composition in the interplay between thermal durability and sulfur tolerance is required. Three way catalysts representative of standard Pd-only, Pd/Rh and Pt/Rh formulations were studied over a variety of aging and evaluation conditions. The parameters investigated included aging temperature, air fuel ratio and sulfur level. Evaluations were performed on a 1994 TLEV vehicle using different sulfur level fuels. The effect of PGM loading was also included within the study.

The veiling glare effect in automotive vehicles consists of diffuse and specular scattering of sunlight onto and from the windshield. This effect occurs over a wide range of solar elevation angles and increases with increased degree of inclination of the windshield. Thus its effect on visual acuity must be considered in automotive design. The present research on the subject of veiling glare only addresses scattering from a clean windshield and ignores the larger effect of scattering from dust, dirt or haze on the front and back faces of the windshield since the latter is operator dependent (can be removed by cleaning the windshield). In this paper, we present an analysis of autmotive veiling glare that takes into account windshield reflectivity without and with coatings, and the characteristics of dashboard cover materials.

Under inflated or deflated tires are known to cause increased forward drag and lateral steering effects on vehicles. These effects are commonly suggested to be the cause of driver loss of control and subsequent vehicular accidents. The increased drag and steering effects of under inflated or deflated tires are frequently an issue in an accident reconstruction. This paper documents the results of a series of tests conducted to determine the magnitude and effects of under inflated or deflated tires on cars and light trucks. The test also establishes a method of testing that can be used to determine steering effects for other vehicles and speed conditions. Six vehicles ranging from a compact passenger car to a 3/4 ton pickup truck were tested. The test methodology was simple and produced repeatable test results up to the 45 mph speed defined as a limit for the tests.

Safety systems in the automotive area become more and more important. New sensors inside the passenger compartment evaluate additional information about the occupants. Forward-looking sensors identify the crash severity before the crash really happens. The variety and also the number of safety units per vehicle continues to rise. Some of these units get smarter than the current units. To control the actuators, a firing bus system is designed. The common part philosophy allows an easy adaptation of this system to different platforms. An image of the safety system is stored in the non volatile memory of the Central Control Unit (C2U). The External Remote Firing Circuits (ERIC) are connected at the desired locations along the bus line(s).

Since 1995, Bosch has produced the Vehicle Dynamics Control Systems for passenger cars. In these systems the Steering Wheel Angle Sensors are used as the reference for other sensors, and for the whole system. The main requirements for these sensors are a high level of inherent safety and the absolute measuring of the steering wheel position, within the whole steering range, immediately after power on. The other requirements are as usual for automotive applications mass producibility, low cost and a high resistance against environmental influences. This paper describes a new steering wheel angle sensor that is under development, in comparison to the sensor in production.

The paper describes the activities of the ZF company in the field of continuously variable transmissions, especially for passenger cars in the past, the present and the near future. As an independent supplier of transmissions for the car manufacturers ZF has to be prepared for the questions and demands of the car industry in the near future. The near future is the time for CVT's and the ZF engineers developed a strategy and a program of continuously variable transmissions for every driveline system. This program and strategy is also described in this paper.

The Montreal Protocol phase-out of chlorofluorocarbons (CFCs) has led manufacturers to develop refrigeration and air-conditioning systems that use refrigerants that do not damage stratospheric ozone. Most refrigeration industries have adapted their designs to use hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) refrigerants; new automobile air-conditioning systems use HFC-134a. These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; 1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; 2) the efficiency of the cooling equipment (due to the emission of CO2 from burning fuel to power the system); and 3) the emission of CO2 from burning fuel to transport the system.

This paper describes the results of an experiment concerning driver behavior in car following tasks. The motivation for this experiment was a desire to understand typical driver car following behavior as a guide for setting the automatic control characteristics of an ACC (Adaptive Cruise Control) system. Testing was conducted under both test track and open road driving conditions. The results indicate that car following is carried out under much lower bandwidth conditions than typical steering processes. Dynamic analysis shows driver time delay in response to lead vehicle velocity change on the order of several seconds. Typical longitudinal acceleration distributions show standard deviations of less than 0.05 g (acceleration due to gravity).

A Kinematics and Compliance (K&C) facility is a test rig which undertakes quasi-static testing of vehicles to measure the K&C characteristics of the suspension and steering systems. This paper describes a new K&C test facility which is a four wheel station machine designed to accommodate automobiles and light trucks. It is electro-mechanically operated, fully automated and computer controlled, and will complete a full suite of measurements in hours rather than days. The first installation, at MIRA England, was commissioned in January 1996. Since then it has been in almost continuous use and a variety of vehicles have been tested; typical results are presented. A second machine is now installed at the facilities of Goodyear Tire & Rubber Company in Akron, Ohio, USA.

Adult volunteers occupied vans and pickup trucks in a series of repeated low speed aligned front and rear collisions. Occupant response was examined and compared to our physician test volunteer's subjective evaluation of the level of induced disturbance. The data base correlating collision severity with damage has been expanded to include vehicles equipped with rigidly mounted bumper assemblies. A procedure is proposed to predict the severity of collisions (a parameter critical in evaluating injury potential) using data from repeated low speed impacts. No injuries were reported by our test volunteers indicating the test conditions were at a level where the potential for injury is remote.

A phenomenological description, or “conceptual model,” of how direct-injection (DI) diesel combustion occurs has been derived from laser-sheet imaging and other recent optical data. To provide background, the most relevant of the recent imaging data of the author and co-workers are presented and discussed, as are the relationships between the various imaging measurements. Where appropriate, other supporting data from the literature is also discussed. Then, this combined information is summarized in a series of idealized schematics that depict the combustion process for a typical, modern-diesel-engine condition. The schematics incorporate virtually all of the information provided by our recent imaging data including: liquid- and vapor-fuel zones, fuel/air mixing, autoignition, reaction zones, and soot distributions.

General Motors Powertrain Group (GMPTG) has developed an all new small block V8 engine, designated LS1, for introduction into the 1997 Corvette. This engine was designed to meet both customer requirements and competitive challenges while also meeting the ever increasing legislated requirements of emissions and fuel economy. This 5.7L V8 provides increased power and torque while delivering higher fuel economy. In addition, improvements in both QRD and NVH characteristics were made while meeting packaging constraints and achieving significant mass reductions.

One of the challenges for accident reconstructionists is creating accurate accident scene diagrams from photographs. The biggest challenge is when only one photograph is available, and information about the camera that took the photograph is not available. The authors will present a unique technique that enables the user to create an accurate accident scene diagram from only one unknown photograph of the accident scene, by using a combination of processes called Inverse Camera Projection and Photographic Rectification. Inverse Camera Projection allows the user to determine the unknown camera characteristics, which then through Photographic Rectification, the photograph can be rectified and traced to create accurate scene diagrams.

It was presented in the previous paper (1) that oil leakage from valve stem seal (VSS) can be controlled by design and the characteristics of the newly designed composite VSS with a filled polyetrafluoroethylene (PTFE) layer lip are: a constant lower limit of oil leakage, minimal loss of power at low speed due to low friction, extended life over 300,000 km of vehicle traveled distance. It was also reported that oil leakage for lubrication can be determined by the stress distribution across the seal lip contact width touching the valve stem under a certain interference. However, the variable pressure inside Intake and Exhaust ports of an engine will affect the stress distribution of the seal lip causing the change in oil leakage. This report presents the design evaluation method and results of the improved VSS with filled PTFE layer lip which keeps the oil leakage constant even though the inside pressure of the engine port changes.

There has been considerable experimental research of cars crashing into roadside curbs such as Transport and Road Research laboratory experiments of the 1950s and the Californian tests in 1957. This paper uses all the published information to establish a relationship to estimate the ability of a curb to safely redirect a vehicle. A curb's ability to redirect a vehicle depends upon the speed and angle of impact, the surface material, if it is wet or dry and the radius of the impacting tire. There are other factors such as the aggressiveness of the tire tread and the tire pressure that are thought to be important but have not been incorporated into the analytical procedure. The equations may be used in accident reconstruction to estimate a minimum vehicle's speed to mount a curb.

Many reports and papers have been published discussing light bulb filament deformation including incandescent/non-incandescent bulbs at impact and hot shock versus cold shock. The focus of the present research is to evaluate impact pulse as it applies to the time relationship between energy application/deapplication and filament deformation in brake/signal light bulbs. Also, the deformation characteristics of average tail light, brake/signal light, marker light, and halogen bulbs were examined. The study will record filament behavior of these light bulbs during impacts produced by a pendulum impact apparatus. Results of the subject research indicate that filament deformation can be expected in a light bulb operating in flashing mode at the time it is impacted. Additionally, deformation characteristics of interchangeable light bulbs produced by different manufacturers showed widely varied results relative to filament deformation when subjected to similar impact pulses.

Methods for the design and analysis of engine lubrication systems have been developed and illustrated in a case study - a four cylinder high speed direct injection (HSDI) diesel engine for passenger car applications. The paper gives design methods and strategies for pump sizing and flow balance, including allowance for the worn engine applicable to a variety of engine classes. In addition the paper gives mathematical models for oil flows through piston cooling jets and plain journal bearings - fully grooved, partially grooved and plain bearings with a single oil hole feed. Methods presented can be used to design lubrication systems for optimum and practical specification of oil pump size, pressure relief valves, by-pass filtration, gallery sizes, oil flow through bearings in the cylinder head and cylinder block and piston cooling jets as well as calculating parasitic losses in the engine due to hydrodynamic pumping.

This paper reports the results of testing conducted to determine the post-upset sliding friction factor on asphalt pavement for a sport motorcycle equipped with a full coverage fairing. A literature review revealed limited data regarding this type of motorcycle. Therefore, these tests were conducted and are reported in the interest of adding to the database available to accident investigators.