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Operation of spark ignition engine under lean mixture condition is one of the several options that may be used to meet pollution and fuel economy standards. In such an operation various factors influence the combustion phenomonon. To examine these, a study is conducted in a static chamber using lean propane air mixtures of different stoichiometry. Effects of ignition energy, electrode geometry, location of ignition source and temperature profile in the initial reaction zone are investigated. It was found that increasing ignition energy accelerated flame up to a certain point; any futher increase in energy had little effect on the flame acceleration. The rate of pressure rise also showed similar pattern. Temperature in the reaction zone was lower when the ignition point was near the wall than away from it; the temperature profile was mapped using laser interferometer techniques. Round tipped electrodes showed better repeatability and yielded lower ignition energy than the flat tipped.

The development of vehicle combustion engines today is characterized by the effort to reduce exhaust gas emission and fuel consumption and to conserve the good properties of the combustion engine at the same time. As, at least for the years to come, there will be no chance for the utilization of the alternative special drives, PORSCHE is intensely dealing with the further development of the conventional combustion engine as well as of the stratified-charge-chamber engine. With their stratified-charge engine (SKS) PORSCHE has tried to create optimum conditions for each of the combustion phases. The result was a divided combustion chamber with a three-stage combustion. The system was tried on single-, six-, and eight-cylinder engines and led to good results under stationary conditions on the testing rig as well as under unstationary driving conditions.

The development of a hot wire anemometry system to study the turbulent flow conditions in spark ignition engine combustion chambers is described. Measurements of a ‘mean’ flow velocity and a fluctuating flow velocity within certain frequency bandpass ranges are reported under ‘motoring’ engine conditions during the ‘combustion period’ of the engine cycle. Two types of combustion chamber design have been investigated - a ‘squish’ design and a cylindrical disc design.

A method has been presented for the determination of the turbulence characteristics in engine cylinders using hot wire anemometry, and high speed random signal data processing techniques. Results obtained on two engines show agreement with the findings of other workers. Data for Micro and Macro-scales of Turbulence are presented for the first time, and evidence put forward to suggest very weak dependence of the Microtime Scale λt with either engine speed or combustion chamber geometry.

As the New Pressure Indicator is easily installed on running cars, without altering any part of the engines in question, one can observe the real working behaviour of the engines, transient as well as steady-state, and not only in laboratories but also on open roads. Some examples of indicator diagrams, unfamiliar and unexpected as well as normal, and also the interesting sequence of them, are shown.

In the design and selection of heat exchangers, three basic methods are used; namely Log Mean Temperature Difference Method, e-NTU Method or the Unit Core Heat Transfer Capability Method. In the preliminary analyses of heat exchanger core in automobile industry, the 3rd design method is generally used. The 3rd method relies on the correlation data between unit core heat transfer capability and air flow velocity in front of the core. These correlation data are usually obtained in wind tunnel using 12″ x 12″ or 6″ x 6″ basic core. When the tube length is different from the basic core length, correction of the heat transfer performance of the core should be made. This paper presents a mathematical formulation of this correction factor. These correction factor are also presented in several graphs and tables using water, 50/50 aqueous ethylene glycol solution, engine oil and hydraulic fluid as the hot side fluid.

A series of front, side, and rear impact tests was conducted by Dynamic Science, under NHTSA contract, to obtain vehicle damage and occupant crashworthiness data on two representative 1973 intermediate-size sedans. Selected evaluation variables included cost-to-repair data in dollars and crashworthiness data in terms of occupant response per FMVSS 208. The data are presented as a function of impact speed to emphasize that future vehicle evaluations must consider a broad speed range. Since only one test was conducted for each crash condition, data are not identified by vehicle model to avoid any inferences on relative vehicle standings. Additional tests are needed, under identical conditions, to determine if differences between vehicles are statistically significant. However, these data can serve as benchmarks against which future improvements in vehicle damageability and occupant crashworthiness can be measured.

This paper discusses the use of Linear and Nonlinear Curve Fitting Programs for the development of injury-prediction equations for automobile side and rear collisions. The data used are from the C.P.I.R. files at H.S.R.I. Separate equations developed for unrestrained, lap belt restrained and three-point harness restrained front seat occupants are discussed and compared.

General agreement exists that the ultimate goals of traffic accident research are to reduce fatality, mitigate injury and decrease economic loss to society. Although massive quantities of data have been collected in local, national and international programs, attempts by analysts to use these data to explore ideas or support hypotheses have been met by a variety of problems. Specifically, the coded variables in the different files are not consistent and little information on accident etiology is collected. Examples of the inadequacies of present data in terms of the collected and coded variables are shown. The vehicular, environmental and human (consisting of human factors and injury factors) variables are disproportionately represented in most existing data files in terms of recognized statistical evidence of accident causation. A systems approach is needed to identify critical, currently neglected variables and develop units of measurement and data collection procedures.

This paper is a brief review of the complex subject of human injury mechanisms and impact tolerance. Automotive accident-related injury patterns are briefly described and the status of knowledge in the biomechanics of trauma of the head, neck, chest, abdomen and extremities is discussed.

This paper discusses aspects of thermoplastic stamping as a viable economic process in the manufacture of automotive components, particularly the Chevrolet Monza Front End Retainer. This component represents a significant commercial reality for thermoplastic stamping in a high volume, structural application.

In the past 10 years a major new thermoplastics process has developed--plastics stamping. Stamping of plastics materials is not a new process, and it has developed from a simple idea: to use sheet metal processes and equipment to convert plastic sheets into parts of the right performance at the right price. This paper reviews STX stampable sheets, the part conversion processes, and some potential uses in the automotive industry.

In contrast to motorcycles with 4-stroke engines, 2-stroke engine motorcycles produce very high hydrocarbon and carbon monoxide emissions. Compared to a 1976 automobile, such motorcycles produce as much hydrocarbon emissions as ten to twenty passenger cars. Modified automobile catalyst technology with the addition of an air pump is shown to be effective in reducing the hydrocarbon and carbon monoxide emissions by 75 - 85% after mileage accumulation of 12,000 miles; these tests are in progress and are being continued. In spite of the fact that current 2-stroke engine motorcycles run rich (no excess air) hydrocarbon emissions can be reduced by 35% and higher with aged catalyst systems without the addition of air. The mechanical durability of the catalytic systems is completely satisfactory. Present data indicate that catalyst system technology has been developed to meet proposed interim EPA emission standards for 2-stroke motorcycle engines.

This paper discusses the results of studies of the exhaust HC emission of 2-stroke engines for motorcycles. The major factor producing HC emissions from 2-stroke engines is the short circuiting of fresh charge. Therefore, we made a study of the relation between the delivery ratio and the trapping efficiency by comparing the test results and the theoretical values of perfect mixing. We then verified the effects of engine speeds and irregular combustion to the trapping efficiency. Tests were conducted to clarify the relationship between the air/fuel ratio and HC concentration and mass HC emission, and the test results were compared with the theoretical values. In addition, a study was made on how to reduce the mass HC emission by optimizing air/fuel ratio. Next, we launched tests to study the effects of ignition timing on HC emissions as well as the ignition timing characteristics and throttle opening and engine speed.

This report describes a new type of simulation system - automatic operation equipment for motorcycles. In this system, all operations such as throttle, clutch and gear shifting are controlled automatically with command signals. This system could be used for the emission measurement standard modes and actual drive patterns. Therefore, this system could be used for various motorcycle simulation testing on a chassis dyanmometer. Further, durability tests for emission reduction devices could be performed with reliable and effective results using this system.

This report documents the investigation of the technical and economic feasibility of using a carbon canister on board the vehicle to retain displaced hydrocarbon vapors during refueling. Denoted by the API as an Interim Report of Project EF-14, this report is a sequel to the Project's Phase I Report of April 1973, “Cost Effectiveness of Methods to Control Vehicle Refueling Emissions.” To initiate the design of a prototype carbon canister system capable of handling refueling vapor losses, studies were undertaken on a bench-test system to define the total amount of refueling vapor to be handled, vapor retention capacity of activated carbon, and purge capacity over a range of refueling conditions and fuel system parameters. In addition, extensive exhaust and evaporative emission tests were performed on the baseline vehicle and the modified vehicle. Detailed cost and effectiveness analyses were performed.

This paper summarizes an investigation of reductions in exhaust emission levels attainable using various techniques appropriate to gasoline engines used in vehicles over 14,000 lbs GVW. Of the eight gasoline engines investigated, two were evaluated parametrically resulting in an oxidation and reduction catalyst “best combination” configuration. Four of the engines were evaluated in an EGR plus oxidation catalyst configuration, and two involved only baseline tests. Test procedures used in evaluating the six “best combination” configurations include: three engine emission test procedures using an engine dynamometer, a determination of vehicle driveability, and two vehicle emission test procedures using a chassis dynamometer. Dramatic reductions in emissions were attained with the catalyst “best combination” configurations. Engine durability, however, was not investigated.

This paper discusses the use of an oxidation type catalytic converter for medium and heavy-duty gasoline powered trucks. It offers the highest reductions of HC and CO; and it is the simplest, most durable, and most cost effective system for reducing air pollution from trucks without fuel or driveability penalties.

This is a summary compilation and analysis of exhaust-emission results and operating parameters from forty-five heavy-duty gasoline and diesel-powered vehicles tested over a 7.24-mile road course known as the San Antonio Road Route (SARR); and, for correlative purposes, on a chassis dynamometer.(2) Exhaust samples were collected and analyzed using the Constant Volume Sampler (CVS) technique similar to that used in emission testing of light-duty vehicles. On the road course, all equipment and instrumentation were located on the vehicle while electrical power was supplied by a trailer-mounted generator. In addition to exhaust emissions, operating parameters such as vehicle speed, engine speed, manifold vacuum, and transmission gear were simultaneously measured and recorded on magnetic tape. The forty-five vehicles tested represent various model years, GVW ratings, and engine types and sizes.

To meet exhaust emission standards, nearly all 1975 model U. S. passenger cars use catalytic converters in conjunction with unleaded gasoline. While it has been established that lead and phosphorus from gasoline are deleterious to catalyst performance, much less is known about any similar effect of elements normally present in conventional engine oils. In addition, the ability to protect engines from excessive deposits and wear is essentially unproved for engine oils in which the phosphorus and metals contents have been either reduced (low ash oils) or eliminated (ashless oils). To obtain catalyst and engine performance information on such oils, tests were run using 95, 1972-1973 model passenger cars, operated with unleaded gasoline in several types of service. Forty cars were equipped with 1975 production-prototype underfloor catalytic converters containing pelleted oxidation catalysts.