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Laboratory and field tests were conducted to determine how changes in some gasoline compositional factors might affect atmospheric visibility and soiling caused by exhaust particulate matter emitted from late model automobiles. In the laboratory tests, measurements of light scattering, soiling index, and mass emission rates of air-suspendible particles were made on diluted exhaust from cars driven on a programmed chassis dynamometer. These tests showed that light scattering, and also soiling, were increased by increasing the aromatic content, removing lead antiknocks, or increasing the combined amounts of sulfur and phosphorus in gasoline. Field tests in a turnpike tunnel used two 4-car fleets operating on leaded and unleaded premium gasoline of high and average aromatic content. The air in the tunnel sampled during the tests with the cars using the unleaded gasolines soiled the filters 57% more than the air sampled during the tests with the cars using the leaded gasolines.

A proposed set of modifications, which, in combination with a mixture-Optimizer, enables a spark-ignition engine to accept air-fuel mixtures as lean as 22 - 23-1/2:1 without impairment of drivability, will permit the simultaneous reduction of all pollutant exhaust emissions, HC, CO, and NOx, to a very low level. Under such circumstances, the true best economy mixture largely coincides with the mixture ratio that minimizes the exhaust emissions. The mixture-Optimizer is a feedback type of electronic control device which automatically selects for a carburetor or fuel injection system the air-fuel ratio that yields the minimum fuel consumption for any given power output. For all driving conditions, other than idling and coasting, the minimum fuel consumption occurs at mixture ratios close to the borderline misfire limit. Therefore the mixture-Optimizer, by seeking these mixture ratios, tends to reduce all pollutant exhaust emissions that are under legal control.

The interactions of a marine propeller and its propulsion engine are surveyed, with particular concern for the interaction as seen from the engine end. It is pointed out that linking characteristics of engine and propeller should be considered together when marine engineers design a propulsion plant. Propeller characteristics and engine characteristics are reviewed, with a suggestion that, as a compromise between efficiency and vibration excitation, the designer choose from a number of blades, the area of the blades being a compromise between efficiency and having sufficient thrust area to avoid cavitation. Matching of engine and propeller in several situations is then discussed. Problems of off-design and margin allowance are included.

An interview survey of 1200 respondents in three cities identified 12 vehicle type/noise source/operating mode situations causing various degrees of annoyance. Each situation was assigned to one of three categories of annoyance sensitivity depending upon the attitudinal factors related to the source. Each category had a linear relationship between noise intensity and annoyance. Noise measurements indicated that the respondents, in general, properly identified the types and magnitudes of noise sources found at their sites.

Procedures for measurement of noise emitted by various automotive vehicles have been developed and refined by various technical committees of the SAE. These procedures are used for evaluation of vehicles during development and also as the basis for noise regulations. Recent work on the parameters of these procedures indicates that the site used, the vehicle operator, and the ambient weather conditions are all significant factors in the accuracy of test results. Variation between samples of like vehicles also is a significant factor in the attempt to determine noise level characteristics of a given model. Revision of these procedures to minimize the variation in results attributable to variation in test parameters, and to become more representative of typical operating modes of the vehicle, is essential.

A drive-by exterior noise program was conducted to determine the contribution of each car noise source-engine/exhaust, fan, and tire/roadway-to the total exterior drive-by noise of a passenger vehicle. A 1970 high- and low-power sedan and a 1970 high- and low-power sporty compact were utilized in the test sequence. Octave-band and dBA sound levels were recorded with the microphone positioned 25 ft away for various modes of vehicle operation at cruise and wide-open-throttle conditions. Results indicate for cruise (road-load) conditions that: 1. Except for high-performance vehicles, the predominant source of exterior vehicle noise above 500 Hz is tire/roadway noise. 2. The major sources of exterior noise below 500 Hz are both engine/exhaust noise and tire/roadway noise. 3. Fan noise is an insignificant contributor to passenger vehicle exterior noise at present noise levels.

A colorful series of 150 slides was presented tracing 5 HP to 1200 HP marine gear design evolution beginning in 1906, followed by pre-WWI developments, Liberty Aircraft engine usage and a 1924 to 1972 series of pleasure boat and work boat marine gear photographs. The entire slide presentation is available in 35 m.m. film strip and may be ordered (at cost) from the author, R. C. McRoberts, Twin Disc, Incorporated, Racine, Wisconsin, 53403, U.S.A. For short time usage, a loan film is available. This history of U. S. marine gear development includes information contributed by the Snow-Nabstedt Gear Corp., Capitol Gears, Inc., Paragon Gears, Inc., The Walter Machine Co., Inc., Detroit Diesel Allison Div. of General Motors Corp., Caterpillar Tractor Co., Warner Gear Div. Borg-Warner Corp. and Twin Disc, Incorporated.

To meet the initial needs of the automotive electronic control and warning system designers, standard linear integrated-circuit building blocks are recommended. These provide both design flexibility and quick reaction to change requests. Many new circuit approaches to single power supply operational amplifiers, comparators, lamp and/or relay drivers, timing circuits, and voltage regulators are presented and typical performance characteristics are given. Simplicity is emphasized to allow multiple circuits in a single package to reduce the cost/circuit function.

The study discussed in this paper has been made to illustrate the ease with which engineers can choose propellers described in available literature to match high-speed ship designs, saving time and cost incurred in waiting for individual computer services. Specifically an investigation was made utilizing current literature to determine the performance of supercavitating versus conventional propeller in relation to hydrofoil craft. Powering requirements are given for a typical hydrofoil craft, and a preliminary choice of propeller diameter and pitch ratio has been made from published series and experimental work. It is shown that the supercavitating propeller already documented fulfills the requirements of high-speed craft at speeds exceeding 100 knots, whereas at speeds greater than 60 knots the conventional propeller fails. This paper also shows that supercavitating sections have good drag-to-lift ratios when the propeller is driven at high rotative speeds.

A decade's evolution and application of practical waterjet propulsion is described. Reasons for selecting types of pump elements are identified on the basis of efficiency and flexibility to suit the most commonly encountered engines and craft types. Preferred configurations for water inlets and control devices are described. Experience with propulsive efficiency, reliability, cost, boat and engine matching, maintenance, maneuverability, cavitation, and corrosion is discussed. Favorable performance in these areas compared with existing propeller systems is shown.

The pitting fatigue of carburized 8620 steel in lubricated concentrated contact has been investigated over a range of case carbon contents (0.72-1.2%) and after direct quench and re-heat treatments. Several surface finishes were used, including the as-heat treated surface, ground finishes, and polished finishes. Testing was carried out on geared roller test machines. Surface finish was found to be the variable having the most pronounced effect on fatigue resistance, the as-heat treated surface having the greatest resistance to pitting failure. Pitting fatigue also decreases with increase of case carbon content.

Fatigue tests have been conducted on low carbon steel butt welds containing lack of penetration defects. The growth of fatigue cracks from the lack of penetration defects was monitored by radiography. These measurements allowed the total fatigue life to be separated into periods of crack initiation and crack propagation. It was found that the rate of crack growth conformed to the expression: The initiation period was found to occupy approximately one-half of the total fatigue life and to consist of the cycle necessary to shake down the residual stresses in the weld and to form the lack of penetration defect into an active fatigue crack.

The people reports data on block program fatigue testing of a simple cantilever specimen with a stress concentration, the specimen being made of SAE 1530 steel. The various programs investigated were based on a normal distribution with a crest factor of 4 and were aimed at accelerating fatigue testing. From tests on programs with 4,8, and 16 stress levels, it was concluded that at least 8 stress loads were required to stimulate accurately the normal distribution. Tests in which various stress levels were omitted showed that stress levels S/σ< 1.75 contributed nothing to fatigue damage, and consequently they could be omitted from the program, resulting in a saving of 87% in testing time. Stress level in range 1.75 S/σ<=4 had a damaging effect, and even the one of S/σ=4 in each full program of 4000 cycles caused significant damage. This indicates the great importance of the choice of crest factor.

A procedure for designing against fatigue failure of notched parts is presented. It is based on measuring nominal loads or strains and estimating notch root stresses and strains using Neuber's rule. Other inputs to the procedure are axial smooth specimen cyclic stress-strain response, fatigue properties, and fatigue notch factor. Miner's cumulative damage rule is applied to the local stress-strain history and fatigue life predicted. Examples are given where life predictions are compared to laboratory test results.

In May 1969, the Department of Transportation initiated a study on the magnitude of the transportation noise problem and its potential abatement. This study has resulted in the first comprehensive review and analysis of transportation noise in the United States. As an aid in conducting the analysis, and for continuing use in noise reduction efforts, four computer simulation models were developed. By using the models, it was possible to establish the noise levels which might be expected for different transportation modes as a function of the traffic characteristics peculiar to that mode. In addition, an understanding was developed of the technical, economic, and legal limits of potential abatement means for each transportation mode. The study also dealt with the responsibility and ability of public and private groups to provide the necessary implementation programs to achieve noise abatement.

The success of urban automated vehicle networks will depend very strongly on the availability of an efficient traffic management strategy for such networks. Previous papers have discussed an automated network traffic management strategy, known as cycle preprogramming, which appears potentially capable of accomplishing the necessary coordination of vehicle flows in a large automated network. This paper develops a methodology by means of which the efficiency of the cycle preprogramming strategy in managing traffic in a large network can be studied. The methodology is then used to analyze the operating conditions on an example automated network for the Detroit area.

A number of new concepts for moving people by means of automatically controlled vehicles on separated automated roadways have emerged in the last few years. The Metro Guideway transportation system concept described in this paper makes use of a common automated roadway and an integrated multimode system of automatically controlled vehicles for public transportation, personal private transportation, and goods movement. The objectives for the multimodal Metro Guideway system concept are reviewed and a methodology is presented for system evaluation from the perspective of user costs and benefits and nonuser impacts. Transportation facility considerations are developed and technology design choices are illustrated.

This paper discusses the development and preparation for a simulation on the digital computer of an automated roadway network for a new urban transportation system concept called the Metro Guideway, using the 1990 Detroit region as the case study area. The objectives of the simulation are to determine the performance of the system as a function of various design parameters, to develop operational computer programs, and to evaluate the computer hardware needs of a real-world system. The discussion includes a brief description of the case study area and an overview of the mathematical and computer models.

The success of any organization or nation is in proportion to the effort exerted by the people involved. To exert full effort, people must be motivated. The more one is motivated, the more effort is expended. The will and desire to move is enhanced by a motivating stimulus. Man will find his own stimulus, but the organization involved must provide or show that stimuli are available. There is evidence of people apathy slowly creeping into all the professions and we dare not permit this to happen in the engineering profession. This paper offers some suggestions for creating motivating stimulus.

The UACL JT15D-1 engine is a 2200 lb thrust turbofan engine of the high bypass ratio type, the first small engine of the type to be certified and placed in production. The engine is briefly described, and the scope of development testing and resources applied is reviewed. A selection of major development problems is covered, and future developments are indicated.