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A wide range of laboratory measurements on truck tires is being carried out on a continuous basis. This paper discusses some of these related to ground contact forces and force and moment characteristics of rolling tires. New laboratory equipment to measure tires on a flat surface and on a 120 in. diameter drum is described as well as several test procedures carried out on these machines. Typical test results are shown. Potential applicability to vehicle performance is suggested. Lateral force data for a range of truck tire sizes are included for future reference.

The control of nitrogen oxides by exhaust recirculation has been evaluated theoretically by digital computer simulation of the engine cycle. Nitric oxide emission, power output, and fuel consumption have been considered. Preliminary results indicate that effectiveness of the recirculation method of nitric oxide control can be accounted for by the attendant shift in the peak temperature chemical equilibrium species distribution. The analysis reveals that nitric oxide reduction is highly dependent on fuel-air ratio, and somewhat less dependent on the temperature of recycled exhaust gases.

A new method for measuring fuel-air ratio from vehicle exhaust gas has been developed which gives quick and accurate results on both lean and rich mixtures. The method is based on measurement of exhaust gas components using nondispersive infrared and polarographic analyzers.

The influence of engine variables on the concentration of oxides of nitrogen present in the exhaust of a multicylinder engine was studied. The concentrations of nitric oxide (NO) were measured with either a mass spectrometer or a non-dispersive infrared analyzer. The NO concentration was low for rich operation (deficient in oxygen) and increased with air-fuel ratio to a peak value at ratios slightly leaner than stoichiometric proportions. A further increase in air-fuel ratio resulted in reduced NO concentrations. Advanced spark timing, decreased manifold vacuum, increased coolant temperature and combustion chamber deposit buildup were also found to increase exhaust NO concentration. These results support either directly or indirectly the hypothesis that exhaust NO concentration is primarily a result of the peak combustion gas temperature and the available oxygen.

A study was made to determine the effect of heat transfer from the backface of a poppet intake valve on the flow rate through the valve. All tests were made under steady flow conditions. The results show that for the same lift and same pressure drop across the valve, the flow rate through a hot valve is less than through a cold valve. This effect increases almost linearly with the heat transfer rate and decreases rapidly with lift. The results also show that the effective flow area is independent of pressure drop through the valve. A correlation of heat transfer from the back of the valve surface to the flowing air shows that the Nusselt number varies as the 1.27 power of the Reynolds number.

Antiglare finishes may be classified, according to their appearance, into three general groups; “dead-dull,” “textured,” and “directional.” These finishes can be applied to the stainless steel surface by the automotive trim producer, the stainless steel manufacturer, or both by mechanical. chemical, or electrochemical methods. Although the challenge of producing antiglare finishes has been met by the stainless steel industry within a year, research is continuing for the development of new finishes, new methods of applying them, as well as improving the methods and finishes now available.

The recently issued Federal Motor Standard on glare reduction does not pose a problem to the automobile stylist. However, as this standard is expanded it may call for greater restrictions on interior panels and metal components in the driver's view. These future requirements may well call for greater ingenuity on the part of the stylist and for new uses of materials. The author believes the stylist will meet the challenge.

The effects of air-fuel mixture quality and cylinder-to-cylinder air-fuel distribution on exhaust emissions have been determined on two engine-vehicle combinations. California Motor Vehicle Pollution Control Board (CMVPCB) test cycle emissions were measured on vehicles using a pre-mixed and pre-heated air-fuel charge supplied by a steam jacketed, nine cubic foot vaporization tank. The vaporization tank provided a near constant air-fuel mixture ratio for all operating modes of the 7-mode CMVPCB test cycle. The two vehicles were evaluated at nominal air-fuel ratios of 14:1, 16:1 and 18:1. Cylinder-to-cylinder air-fuel distribution during the transient operation of the 7-mode CMVPCB test cycle was measured on a 200-CID six cylinder and a 289-CID eight cylinder engine. The procedure employed was to record the total carbon emissions (CO + CO2 + CH4 equivalent) for each cylinder during successive test cycles.

A carburetor adapted to exploit the control of exhaust emissions through consistency of metering and mixture quality, particularly in conjunction with a dual bore inlet manifold, is discussed against the background problems faced by the European motor industry. The development and incidental research data which determined the design are followed by a description of production and quality assurance techniques, with special reference to the evolution of automatic flow testing apparatus.

A detailed description of a numerical method for computing unsteady flows in engine intake and exhaust systems is given. The calculations include the effects of heat transfer and friction. The inclusion of such calculations in a mathematically simulated engine cycle is discussed and results shown for several systems. In particular, the effects of bell-mouth versus plain pipe terminations and the effects of a finite surge tank are calculated. Experimental data on the effect of heat transfer from the back of the intake valve on wave damping are given and show the effect to be negligible. Experimental data on wave damping during the valve closed period and on the temperature rise of the air near the valve are also given.

Measurement of pressure-time histories in the exhaust system of a naturally aspirated internal combustion engine poses some difficult instrumentation problems. This paper describes an experimental and theoretical approach in tackling this research. The exhaust system is simulated by pulses of compressed air at a frequency of up to 4000 pulses/minute, that is, a 1 cyl 4 stroke cycle engine running at 8000 rpm. The pressure-time histories are calculated by digital computer in terms of the cylinder, exhaust valve, and pipe friction characteristics and compared with the experimental pressure-transducer records at various positions in the exhaust system.

The design and manufacture of the twist drill is described with respect to adapting to industrial progress. The extension of drill life, proper location of cutting edges, surface treatment and drill design, selection of the proper drill for the job, and the effect of vibrations on drill life are some of the subject discussed by the author.

Of the many variables involved in the problem of wet skidding, the most significant single factor is speed, since it is the one item which remains entirely within the control of each individual vehicle operator. On wet surfaces, the effects of speed on the apparent coefficient of friction are reduced as the surface texture becomes more coarse. Although more consistent frictional coefficients obtained by increasing surface coarseness would assist greatly in reducing skidding, the many other variables involved remain an integral part of the tire traction problem. Factors considered in this paper are: tread design and compound, tire construction, inflation pressure, road surface, tire load, and temperature.

Automobile owners get more luggage space when they use this space saving tire, and forgetful air inflators need never find themselves without a spare because this one is carried flat and needs only a little pressure boost to make it wheelworthy. Moreover, the capability of operating when deflated is a bonus characteristic. This is the thin tread emergency spare tire by Goodrich. Deflated, it is only slightly larger than its rim. Expanded, it is normal size and shape. The mechanics of expansion are explained here and operational data and test results are presented.

The object of this research was to learn more about the effects of mixture motion upon ignition in spark ignited piston engines, and to determine how variations in mixture velocity alter the combustion process. To provide effective means for producing and measuring the mixture velocity, all tests were made in a constant volume bomb, using mixtures of propane and air. The effects of mixture motion on the lean spark ignition limit, rate of pressure rise, and burning time were determined for mixture ratios ranging from stoichiometric to the lean limit. The mixture pressures corresponded to those in Otto cycle engines at the time of spark occurrence. The results reveal that a mixture velocity of 50 fps, relative to the spark plug, requires an enrichment of 17% with respect to the stagnant lean limit. Increases in mixture velocity were found to greatly increase the rate of pressure rise during combustion. This effect was more pronounced for lean mixtures than for stoichiometric mixtures.

Three metallurgical factors have a major influence on the machinability of aluminum castings: chemical composition, heat treatment, and foreign inclusions. Othermet-allurgical factors that may also affect machinability are generally related to one of these three items. In general, aluminum alloys have good machining characteristics, although tests indicate that they cover a range. Some of the differences that do exist are discussed and practices identified that lead to improved machinability.

This is a continuation of the presentation of thermodynamic properties of selected fuel-air mixtures in chart form, suitable for utilization in engine performance calculations. Methane and propane, representative of natural gas and LPG are the two fuels considered. Using these charts, comparisons are made between the performance to be expected with these gaseous fuels compared to octane, as representative of gasoline. Reduced engine power is predicted and this is confirmed by experience of other investigators.

The inherent advantages of quiet operation, few moving parts, and compact and lightweight construction make thermoelectric generators desirable for specialized military uses. Recent developments in the thermoelectric couple and thermopile enclosure fabrication have shown promise for successful generator sizes that can meet present military needs for portable power up to 3 kw. Design, development, and test of two 300 w portable thermoelectric generators by the U. S. Navy Marine Engineering Laboratory are described. The generator weighs only 35 lb, including diesel, kerosene, or jet fuel for 8 hr of operation. The cooling fan operating from power produced by the thermoelectric couples is the only moving part. The Laboratory is investigating minor modifications needed for units to be used by the Marine Corps in field trails. The performance characteristics of the new 300 w thermoelectric generators and other power sources presently available are compared.

The application of computers to manufacturing facilities grew out of efforts to improve management control of operations. The evolution of data acquisition, from machines connected to event recorders and mechanical counters to direct monitoring with exception reporting and process control by two back-to-back computers -- has taken nine years. Two of these years were spent evaluating the system requirements, potential growth, potential savings and cost, computer hardware and software, machine/computer interface, and use of information. An IBM 1710 system was installed in May 1964 and later replaced by two IBM 1800 systems when the total system was expanded in February 1967.