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The design, finite element analysis and fabrication of graphite fiber reinforced plastic (GrFRP) for the body of the 1979 Ford LTD concept vehicle is described in Part I. One-hundred and four (104) steel body-in-white parts, weighing 423 lbs., were replaced by forty-one (41) GrFRP parts, weighing 160 lbs., for a 62% reduction in weight. The floor and body side panels represent some of the largest and most complex GrFRP automotive parts produced to date. The methodology and analysis used in developing the graphite composite lay-up design of the front end for the concept vehicle is outlined in Part II. This assembly of GrFRP components weighs 30 lbs., compared with 95 lbs. for the steel counterparts, and represents a 68% weight reduction.

Light duty diesels are often criticised for their poor specific power but boosting can be used to improve the situation. An exercise was carried out in which the performance of a naturally aspirated diesel car was compared with identical vehicles fitted with turbocharged and Comprex® boosted engines. The measures necessary to apply the two boosting systems to the engines are described and the test bed performance obtained is shown for each case. Standard vehicle tests were made with each system and the performance, fuel consumption, noise and emissions results are compared.

Experimental data are presented to show how diesel combustion systems respond to increase of fuel injection rate. Concepts of a fuel spray entrainment parameter, a maximum useful injection rate, and a condition termed ‘impingement’ are introduced to correlate and interpret widely differing responses. Best possible smoke and BSFC values in swirl type direct injection engines are obtained for injection rates 15% to 33% higher than normal values, but in practice lower rates must be used to satisfy emissions and other requirements. Engines with a high swirl rate and impingement give a superior ‘retardability’ for normal injection rates. Computer model calculations also show that there is a maximum useful injection rate and explain the relative fuel economies for different diesel combustion systems.

Experimental or observed rolling resistance data can be utilized to develop an empirical model that accurately depicts tire rolling resistance as a function of load and pressure over a wide range of load and pressure variations. This method allows the development of a graphical expression (carpet plot) or mathematical expression (computer modeled) to depict rolling resistance on three “control tires.” When the graphical or computer modeled systems are combined with a basic control tire correlation concept, a rather accurate inter-test facility prediction system does not have to rely on the sometimes inaccurate correction equations developed from theoretical modeling techniques.

A TECHNIQUE using an exponential least squares fit to analyze the behavior of measured nonsteady-state rolling resistance data and to compute the equilibrium rolling resistance force is discussed. Raw data are filtered analytically to reduce amplitude fluctuations prior to applying the technique. The method has been applied to rolling resistance tests conducted at the Calspan Tire Research Facility on tires in a free-rolling straight-ahead condition, under constant velocity and load. The use of the prediction technique is demonstrated for 12 passenger car tires that were tested under equilibrium conditions.

The U.S. Postal Service operates approximately 400 electric vehicles; predominantly AM General DJ-5E vehicles with a 1300-pound (590 kilogram), 3.22 cubic foot (9 x 10-2 cubic meter), 54-volt Gould propulsion battery. A number of the vehicles were assigned to delivery routes in low ambient temperatures which affected battery performance. The field installation of foil-faced insulation on in-service batteries maintained a 15°F (-9.5°C) to 18°F (-7.75°C) higher electrolyte temperature than unwrapped batteries exposed to 15°F (-9.5°C) ambient temperatures. Overnight “cold-soak” in 15°F (9.5°C) ambient temperature did not significantly reduce battery capacity because of the heat retained after completion of the charging cycle. Weekend “cold-soak” in 15°F (-9.5°C) ambient temperature, however, reduced battery capacity such that the vehicles could not complete assigned routes.

A formula is developed for computing the energy loss per unit distance (or the “rolling loss”) of tires operating under transient conditions. The formula is applied to two transient test schedules - a warm-up test with constant speed and zero torque (free-rolling), and an urban driving test with rapidly varying speeds and braking/driving torques. Test results indicate that the average rolling loss during warm-up is 9%, and during urban driving, 26 to 47% higher than the steady-state rolling loss. Equipment problems associated with transient testing are indicated.

The performance, reliability and maintenance and running costs of 62 battery electric delivery vans, supplied by three manufacturers, in daily use in the Greater London area are being assessed over a three year period in comparison with closely equivalent conventional vehicles on similar duties. The primary purpose is to obtain independent operational experience covering a wide variety of suitable applications over an extended period and provide reliable factual information about the performance of the vehicles in normal daily use with typical loads and drivers. Information of value to operators, the industry and Government will be produced.

ENEL, the Italian Electricity Board, has launched extensive programs of research, development and demonstration in the field of battery-powered vehicles, as the widespread use of electric vehicles should have a positive effect on the energy picture and the environment. Moreover, overnight battery recharging would contribute to the levelling of the electrical load -profile. Possible near-term applications of electric vehicles have already been pinpointed within the framework of the activities of ENEL and other important Italian utilities. Electric vans have been or are being developed in co-operation with Italian manufacturers. More than 50 electric vehicles of different types have been already assigned to ENEL operational units for demonstration purposes. Laboratory and on-the-road tests are planned to improve the vehicle and battery performance.

The developmental and operational experience with a foil air bearing in the 58,500 rpm gas generator of the Chrysler Upgraded automotive gas turbine is presented. Simulator work encompassed mating the 500°F air foil with oil-lubricated foil bearings, which then evolved into the final air bearing - rigid oil bearing engine system. Over two years of testing in engines and cars has shown the foil air bearing to have the performance requirements. Work on foil material and coating life problems is discussed. The potential of the bearing to meet the 1200°F and low power loss needs of future engines and current technology support work is presented.

The emerging national effort to commercialize electric vehicles (EVs) has significant potential for impact on utility load curves and distribution feeder systems. With the implementation of national energy goals, utilities recognize the need to identify the interactions between large-scale use of EVs and utility operations. Since utilities will have to provide the needed energy and “live with the impact”, it is appropriate and desirable that utilities participate actively in the national effort to accelerate evaluation and introduction of EVs. This paper discusses the Electric Power Research Institute (EPRI)/Tennessee Valley Authority (TVA) demonstration program, describing the initial testing and evaluation of non-prototype EVs in a real-world environment, the demonstration design, and finally the data acquisition and reporting plans.

Elimination of oil from the hot section of the engine, very low running losses and potential cost reductions are incentives to develop air bearings for the high speed rotors of automotive gas turbines. Low air bearing stiffness, start-stop wear and high starting torque are design challenges in this application. This paper outlines analytical and experimental programs undertaken by the Power Systems Department of the General Motors Research Laboratories to evaluate air bearing usage in vehicular gas turbines. Air bearing operation has been demonstrated in engine dynamometer tests. A better understanding of the many factors which affect the performance of cantilevered-leaf air bearings has been realized through extensive rotor dynamics rig testing coupled with development of bearing analysis computer programs. Measured running losses of the air bearing are much lower than those of the oil jet lubricated ball bearing it is replacing.

The feasibility of using hot pressed silicon nitride (HPSN) for rolling elements and for races in ball bearings and roller bearings has been explored. HFSN offers opportunities to alleviate many current bearing problems including DN and fatigue life limitations, lubricant and cooling system deficiencies and extreme environment demands. The history of ceramic bearings and the results of various element tests, bearing tests in rigs and bearing tests in a turbine engine will be reviewed. The advantages and problems associated with the use of HPSN in rolling element bearings will be discussed.

High-speed digital recording of cylinder pressure data at the General Motors Research Laboratories is commonplace. Improvements in transducers and data acquisition techniques over the years have allowed increasing confidence to be placed in the magnitudes of these recorded data. Current techniques for determining the correct phasing of these data with respect to crank angle, however, have not kept pace. A new phasing technique is described which involves transmission of microwave energy through the spark plug hole and into the cylinder of a motored engine. At certain piston positions, symmetric about minimum volume, microwave resonances occur. These resonances are recorded on an oscilloscope screen along with the one-degree pulses generated by the crankshaft. Analysis of these recorded data yields pressure-crank angle phasing information accurate to the order of ±0.1°CA for open-chamber engines.

The efficiency of combustion and the production of pollutants in the internal combustion engine are strongly dependent on the turbulent flow field in the engine cylinder. In most engines, turbulence is almost exclusively generated during the induction stroke. A water analog was used to visualize and study this process for a simple geometry cylinder. The flow field, during the induction process, was observed to be structured and highly repeatable from cycle to cycle. The structure was comprised of two ring vortices, of concentrated vorticity, which were of the same scale as the engine cylinder. A detailed study of the characteristics of the vortex rings was carried out for the case of an axisymmetric cylinder geometry. Inviscid scaling laws were obtained from these results that describe the development and stability of the structured flow field.

The Laser Doppler Anemometer, a new instrument capable of making non-interfering gas velocity measurements, has been used to investigate the gas behavior in the cylinder of a firing engine. First of all, the necessary conditions for a real-time measurement of the gas velocity by the LDA are examined, and thereby two typical flow, squish and torch, in the cylinder of an engine with both motoring and firing have been measured. As a result, the optical technique is ascertained to be a promising one for application to research on a firing engine.

A closed-circuit television technique has been developed for the real time viewing and recording of combustion and related processes in internal combustion engines. The technique has been applied to a transparent piston, transparent head engine, and shadowgraphs of combustion chamber events have been observed and recorded. The technique is particularly suited for the study of changes in the combustion process due to variations of engine parameters such as mixture ratio, load, speed, spark timing, injection initiation, etc., since the changes can be observed and recorded at the same time that they occur. A brief and qualitative study of flame and pressure cyclic variations is reported and discussed as an example of an application for which the television technique is particularly suited.

This research demonstrates the capability of the Laser Doppler Anemometer (LDA) for making measurements inside a piston-engine cylinder. The backscatter mode of LDA operation, requiring only a single window in the cylinder, was used. An ensemble-average data-processing technique has been developed to analyze the raw velocity-crankangle data. Single-component measurements of mean velocity and rms velocity fluctuation at a single point are presented as functions of crankangle for three engine speeds. A comparison of motored and fired results is shown for one engine speed. Measurements of two components of velocity at several locations show the basic vortical nature of the flow field in this particular engine.

Gasoline delivery-filtration systems presently used in vehicles are highly effective. Nevertheless, there is a continual evolution of the system as vehicles with improved emission profiles and fuel economy are manufactured and alternate automotive combustion fuels are being adopted. Therefore, an investigation of the fundamental parameters controlling delivery of filtered fuel to the engine is important to the engineers responsible for new designs. In this paper the basic engineering factors required to understand how in-tank fuel strainers function are discussed. Guidance in choosing fabrics that ensure optimum performance for various types of liquid fuels is also provided.

Measurements taken in a special, single cylinder, direct injection stratified-charge engine are presented. The optical measurement techniques employed include continuous-wave laser Raman spectroscopy for fuel and air concentrations, pulsed laser Raman spectroscopy for density fluctuations, high-speed cinematography for flow visualization, and laser Doppler velocimetry for velocities and turbulence intensities. More conventional data on cylinder pressure, power, and emissions levels are also given. The purpose of the study is to demonstrate the types of detailed measurements that are now possible within an engine cylinder.