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The overall suitability of various steels (strain-aging steels such as capped nitrogenized and rephosphorized steels, killed rephosphorized and microalloyed steels) for automobile body-panel applications is assessed by comparing their characteristics with the performance requirements (formability, weldability, paintability, etc.). The formability of the steel sheets is perhaps the most important requirement for body-panel applications. To minimize the loss of formability that occurs as strength is increased, steels having yield strengths of 40 to 50 ksi are considered the primary candidates for use in body panels. Of the different types of 40- to 50-ksi steels reviewed, the killed rephosphorized steels (especially a silicon-containing version) show the best combination of formability and weldability.

The advent of electronic control systems has enabled automobile manufacturers to consider a vast variety of fuel, ignition, and exhaust gas recirculation system calibrations. Given a control system providing satisfactory performance, it is important to determine the calibration of that system which minimizes fuel consumption while meeting emission control standards. The disadvantage function technique enables an engineer to determine such an optimal calibration through an iterative procedure, interacting with a computer program. This paper describes the technique, illustrates it by example, and compares it with well-known optimization methods.

Many studies have been launched to determine whether it is possible to achieve 0.4 gms/mile Nox. Most of those studies question or deny the ability to design and develop a system to reliably maintain 0.4 gms/mile Nox. This paper reviews the factors requiring consideration towards accomplishing that Nox objective and theoritizes a system which should properly accommodate these considerations. Actual performance data is then presented on a commercially manufacturable system that demonstrates conformance to the 0.4 Nox requirement without penalty to economy or driveability. Finally, considerations toward even superior performance are presented.

Previous investigations have shown that fuel economy gains are possible in vehicles with increased compression ratio engines that meet 1978 Federal emission standards using oxidizing converter-EGR emission control systems. There has been no incentive to raise compression ratios, however, since the vehicle gains are offset by energy losses in the refinery due to refining the higher octane unleaded fuel required by high compression ratio engines. This paper discusses the application of an electronic closed loop knock control system to a higher compression ratio engine to allow operation on 91 Research Octane Number fuel. Two cars with different compression ratios are compared with both oxidizing converter - EGR and 3-way oxidizing-reducing converter-EGR closed loop carburetor emission control systems.

Automotive electronic engine control systems require complex interactive software designs which must provide appropriate responses to a variety of engine conditions. Software design verification will help achieve a high level of confidence in the released product. Several approaches to software design verification are discussed. Each technique provides an additional degree of confidence with a corresponding level of effort. Primary attention is given to the time based stimulus generation, the real time performance measurements, time based tolerance generation, and data reduction of a real time software design verification test system. A recommendation for future software design verification system capabilities is made.

Thermal management studies of the Lithium-Aluminum/Metal Sulfide Battery demonstrate the need for a light weight, high thermal efficiency case for electric batteries. Calculations based upon the rectangular configured MK IA battery using vacuum-foil insulation, show that the heat loss rate goal of 400 watts can be met. Experimental studies directed at the determination of the reversible T▵S heating gave results that compared within 8% with theoretically derived values. Calculations based upon the 50-kWh MK II battery and a 10,000 miles driven/year show that by utilizing the thermal storage capacity of the system, essentially no additional energy is needed to keep the battery hot.

Report sums up performance data obtained on lead-acid batteries and accessories especially designed for electric road vehicles. Also encompasses special technologies such as central electrolyte refilling system, forced cooling and central venting. Further describes VARTA'S latest accomplishments for reduced maintenance and improvement in reliability. Another objective is exploitation of improved technologies for motive power batteries for applications such as fork lift trucks. Furthermore, it presents development stage of VARTA'S improved nickel-iron FENOX-battery.

Various types of lead-acid batteries have developed because of different market needs. The small, uncertain market for electric vehicles has been met by modifying traction-type or golf-car type lead-acid batteries. Recently, governmental stimulation of the market for passenger electric vehicles has resulted in the design and development of batteries to meet specific performance goals for electric vehicle propulsion. The approach which the Eltra Electric Vehicle Group/C&D-Prestolite has taken toward meeting the governmental goals involves the use of expanded metal, non-antimonial grids, overpasted plates, reduced electrolyte and an enveloped, glass mat retention system.

THE BATTERY is the primary component limiting electric vehicle performance that equals today's standard of expectations as defined by the I. C. engine powered vehicles. Efforts to optimize the electric vehicle performance is leading many people to select and assemble the highest efficiency components available. High voltage electric vehicle power system can provide performance advantages over lower voltage systems, but only if this voltage is in balance with the total system. Mixing high efficiency components does not Insure total system efficiency optimization. The ability of a battery to release its stored energy is a function of its demand. Higher current demands will reduce the efficiency of a battery. This paper reveals how such a mismatch occurred and its reflection on what appeared to be a battery problem.

Milled fiberglass or mica flake reinforcement can be used to control the physical properties of RIM urethanes. The addition of these reinforcements results in increased flexural modulus, decreased coefficient of linear thermal expansion, decreased elongation and decreased impact strength. Milled fiberglass is shown to orient during injection into the mold causing anisotropic behavior in the physical properties. Mica flake reinforced urethanes do not show the orientation effects found with milled fiberglass, but mica flake, causes a greater reduction in elongation and impact than does milled fiberglass. Several urethane systems are examined and the general effects of mica flake or milled fiberglass are found to be reasonably independent of the base urethane system.

General guidelines are provided in this paper that can minimize the weight of aluminum body panels. Denting, local stiffness, torsional and/or bending stiffness, strength, and vibration of body panels are considered. High strength alloys will provide the least panel weight when the governing criteria are denting, permanent set and crippling. Redesign to reduce size of unsupported outer panel areas or to increase inner panel rib size will provide the least weight when the governing criterion is stiffness.

The Reaction Injection Molding (RIM) process is being used extensively for the production of soft urethane bumper fascias and offers many advantages compared to other polymer processes. The addition of fiber reinforcement to R.I.M. urethanes has resulted in significant improvements in physical properties, making additional automotive applications possible. The development of Reinforced R.I.M. technology is currently underway at General Motors Manufacturing Development with a production scale mix-metering unit that was installed in September 1977. Reinforcement length and loading limitations, equipment wear and durability, and Reinforced R.I.M. physical properties are discussed. The advantages of Reinforced R.I.M. materials are also described along with potential automotive applications.

A high energy lead-acid battery was developed to provide, at no extra cost, a 1800 kg (4000 lb) payload electric delivery van with a driving range of 80 - 90 km (50 - 55 miles). In addition to the new high performance electrodes, an integrated approach to the total power source concept evolved new lightweight designs for battery packaging and a system engineered battery charger and an automatic topping-up facility. Despite the 40% improvement in range compared with 55 - 65 km (35 - 40 miles) for conventional traction batteries, a 4 year battery life is expected due to the reinforcing features of the tubular design adopted for the positive electrode.

In view of the problems associated with obtaining broad compressor range and efficiency at high pressure ratio and the ever-present requirements for durable, low cost and low inertia turbochargers, it is logical to examine the performance benefits to be derived from series turbocharging. The merits and demerits of series turbocharging are reviewed. With respect to efficiency, range, transient response, and pressure ratio capability, it is practical to use currently available vehicular turbocharger technology to provide optimum solutions for near term, higher pressure ratio turbocharger capability.

Performance of both radial and axial turbines under non-steady flow conditions is of considerable interest to the mechanical engineer. In this paper a new method of estimating turbine performance under such conditions, based on the authors idea of ‘mean effective turbine expansion ratio’ (m.e.t.e.r) has been described and a digital computer programme to evaluate the ‘pulse factor’ presented. The method has been sucessfully used by the author in real-time digital, hybrid and analog computer simulations for the prediction of transient performance of a turbocharged diesel engine. Good agreement was achieved between the predicted and test-bed results.

A tuned intake induction system using a Helmholtz resonator was applied to an in-line six cylinder, four cycle heavy duty diesel engine. The system adopted was designed to maximize the engine breathing performance at the peak torque engine speed. Significant advantages noted were improvements in volumentric efficiency by 12 percent, improved cylinder-to-cylinder air distribution and faster turbocharger response. The increased trapped air-fuel ratio also results in improved combustion efficiency and reduction of smoke emissions. Additional improvements appeared feasible by compressor redesign and optimization of valve timing. The primary disadvantage was the space claim the system required; however, compact designs can be achieved without great difficulty.

A reduction in death and injury rates of child vehicle occupants is being experienced in Australia by a unique child restraint device which is compatible with all motor vehicles. Basic parameters, product development and extensive dynamic sled test programs are explained. Concluding with the achieved benefits which include excellent crash performance, simplicity, versatility and public acceptance of a totally new concept.

Due to the combined effects of economic pressure, fuel consumption and emissions goals, turbochargers are now used on gasoline and diesel engines covering the power range from around 100 to 50,000 hp. The requirements placed on turbocharging systems in the very different applications of automobiles (gasoline and diesel), trucks and off-highway vehicles are reviewed. The developments that will be required in the 1980's are highlighted, together with an analysis of current limitations and future potential. These developments relate not just to turbo-machinery, but to matching, system design and maximizing exhaust gas energy utilization.

As a result of dimensional and cost limitations, the specific speed of today's turbochargers for vehicular diesel engine applications are higher than optimum. Performance of turbochargers therefore falls below the state-of-the-art. According to the analysis presented in this paper, one avenue for improvement of turbocharger overall efficiency is reduction of compressor and turbine specific speed. A technique for optimizing turbocharger overall performance is presented, based on variation of component specific speed. It is concluded that the concept of lower specific speed turbochargers deserves further study. It is essential that the balance between the advantages and disadvantages of this concept be carefully evaluated by turbocharger and diesel engine manufacturers.

A variable geometry diffuser was developed for a centrifugal compressor with the objective of meeting the surge regulation and air flow requirement of the Army's Variable Area Turbocharger Program. Two types of compressor rotors were built and tested: a radial-bladed impeller design and a backswept impeller. Results of the performance test program indicated that the variable geometry compressor met the range and efficiency goals over most of the required operating conditions. The backswept impeller was found to be superior to the radial-bladed impeller over the entire operating map. Compressor efficiencies as high as 80% were demonstrated in the high airflow operating regime (rated engine speed). At very low airflows corresponding to the lowest engine speed operation, the onset of impeller stalling caused an efficiency loss. It is believed that the complexity of variable geometry is justified where maximum efficiency and range is mandatory.