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The warm extrusion process is described as adapted to making Ti-3A 1-2.5V tube hollows to be reduced for high-quality aircraft hydraulic tubing. The advantages of this process over conventional hot extrusion appear to be sufficient to warrant further studies aimed at improved uniformity. Alloy segregation is noted in the forged extrusion billets which can be eliminated by heat treatment. It is presumed that this segregation is related to problems encountered in fabrication to tubing and has an effect on the variability of properties in the final tubing. An approach to the problem is suggested.

Test methods and data are summarized to assist in establishing limits for defects in aircraft hydraulic tubing. The defects evaluated are (1) cracks as detectable by ultrasonic inspection after tube fabrication, and (2) service damage such as chafing and denting observed on aircraft. Permissible defect limits are listed for 6061T6 aluminum return lines, 3000 psi hydraulic tubing of 21Cr-6Ni-9Mn as well as 304 1/8 hard CRES, and 3A1-2.5V cold worked titanium. The performance requirements are outlined to which the defect samples were tested.

The development of the Stirling engine has recently gained momentum because of technological advances as well as the need to explore alternative power systems for meeting environmental concerns. An overview of the Stirling engine principles, taking into account the ideal as well as the actual cycle, is presented. The analysis examines the various design aspects and the performance and emission characteristics. A comparison is made between the Stirling and other continuous and cyclic combustion engines, such as the gasoline, diesel, gas turbine, and steam engines. This includes recent designs for the Rankine cycle and gas turbine combustors being considered for automotive applications.

The need for new urban vehicle propulsion alternatives has been spurred by the growing concern in our cities over photo-chemical smog, smoke, odor, and noise, which are to a large degree the products of present vehicle powerplants. The incorporation of practical energy-storage elements into vehicle drives offers the potential of significant reduction of objectionable vehicle emissions. The recent “rediscovery” of the kinetic energy flywheel as a highly effective energy-storage system provides several new candidate propulsion systems either in heat engine/flywheel hybrid- or pure fly-wheel-drive configurations.

Turbocharging, in addition to increasing an engine's power output, can be effectively used to maintain exhaust emission levels while improving fuel economy. This paper presents the emission and performance results obtained from a turbocharged multicylinder spark ignition engine with thermal reactors and exhaust gas recirculation (EGR) operated at steady-state, part-load conditions for four engine speeds. When comparing a turbocharged engine to a larger displacement naturally aspirated engine of equal power output, the emissions expressed in grams per mile were relatively unchanged both with and without EGR. However, turbocharging provided an average of 20% improvement in fuel economy both with and without EGR. When comparing the turbocharged and nonturbocharged versions of the same engine without EGR at a given load and speed, turbocharging increased the hydrocarbon (HC) and carbon monoxide (CO) emissions and decreased oxides of nitrogen (NOx) emissions.

Instantaneous heat transfer rates at the interface of the working gas and the walls of a motored engine were studied. This paper details the influence on heat fluxes of engine speed, compression ratio, intake pressure, swirl ratio, location on the cylinder head surface, and the shape of the piston top. Equations are given to show the method of calculation used in deriving the data on heat transfer rates.

Surface conditioning plays a significant part in the production of titanium 3A1-2.5V tubing for use in aircraft hydraulic tubing. It can be performed both mechanically and chemically, for both inside and outside surfaces. The purpose of this surface conditioning is to produce a uniform surface with no remaining defects in size or geometry that will adversely affect the tubinq performance. Several tests are then run to ensure conformance to requirements.

The subject matter for this paper deviates slightly from that of the SAE symposium, that is “Criteria for current and advanced aircraft hydraulic tubing.” Rather, this paper introduces an entirely new concept for manufacture of hydraulic tubing to satisfy the criteria, with resulting properties and characteristics equal to or superior to those currently available. In addition, it is indicated that the process potentially can manufacture such tubing at substantially lower cost. The concept of hydrostatic extrusion is based upon the phenomena associated with plasticity of metals under high pressure and in layman's terms is a substitution of pressure for temperature in the forming of metals and metal alloys. Metalworking under pressure is not necessarily a new technology; however, the application of this technology toward the production of tubing is new.

Crystallographic textures which develop in alpha titanium alloys as a result of cold reduction can cause significant anisotropy or directional properties in finished aircraft hydraulic line tubing. The directional properties can either enhance or detract from tubing fatigue life and formability depending on the type of texture built into the tube during manufacture. Previous work has shown that the texture associated with optimum tube properties is one for which the basal poles of the hexagonal cell are near perpendicular to the tube axis in the longitudinal section, and radial in the transverse section. This texture is developed by using high ratios of wall to diameter reduction during cold working. The text provides guideline data for controlling cold reduction schedules during tube making to produce an optimum texture in the final product. Both tube reducing and bench drawing are considered as cold working methods.

The purpose of this paper is to show that although “hot corrosion” (which is, in fact, a sulfidation-accelerated oxidation phenomenon) is more prevalent in gas turbine applications, diesel engines are not immune to this under certain conditions. Evidence of this type of corrosion in the case of some iron-base and nickel-base exhaust valves is presented to illustrate the point. The successive stages of the corrosion process are discussed, and the beneficial effects of some alloying elements in affording protection against hot corrosion are pointed out.

A range of noise reduction hardware is described for three production engine models, as well as the rationale for selecting noise reduction methods. Noise reductions up to 6 dB(A) were achieved with this hardware in the test cell. In many cases the modifications are more effective in vehicles. The success of the hardware in reducing overall vehicle noise is illustrated.

A large number of laboratory tests on diesel engines have proved that noise emission can be reduced by more than 10 dB by applying insulation directly to the engine or by totally enclosing the engine. However, the application of these methods on trucks involves appreciable difficulty and time-consuming design modifications. This paper describes how significant noise reduction can be attained merely by soundly designed shielding, without the need for modifying the basic design of the truck. The method is based upon experience from other types of vehicles which, for a number of years, have already been equipped as standard with similar insulation. The reduction attained in the noise emission is approximately 6 dB(A). Inconvenience during repairs and service has been reduced to a minimum by a well-planned design and simple mounting of the shields as well as ample exposure of the engine when the cab is tilted.

This paper on vehicle emissions contains actual data from 19 vehicles, taken with the intent of viewing both emissions and control device deterioration with vehicle age. In addition, valuable insight is given to the value of the 2500 rpm no-load test for emissions. It was found that the 2500 rpm, no load, is not sufficient load and/or engine speed to cause the throttle to open in all cases. The most obvious effective emission control device observed were those creating a lean air-fuel ratio, retarded spark at idle, and dashpots on the carburetor to stop rapid closing of the throttle on deceleration. These are described in detail.

This paper describes the White Motor Corp. approach to heavy-duty diesel truck noise reduction. As part of the U.S. Department of Transportation Quiet Truck Program, a unique “free field” stationary vehicle noise test facility was designed and built for noise control development. The features of this facility and the techniques employed in vehicle noise source identification are presented.

This paper reports the results of a project whose aim was to develop a quiet truck in a cost-effective manner. In the paper a method of approach to identification of noise sources and diesel truck noise control is presented, along with a demonstration of noise control techniques and the results obtained. The final drive-by noise level, as measured by SAE J366a procedures, was 72 dB(A). The approach was to take a standard production truck and modify its exhaust system, fan, transmission, and cab enclosure. Although no modifications were made to the engine, a quieting kit consisting of dampening panels was fitted to it.

There has been an accelerated growth in power of diesel engines in United States line haul trucking. This paper analyzes the effect of high power on engine-related operating variables that occur under different highway conditions and dissimilar terrain features. When properly applied, high-powered diesel engines can increase average vehicle speed and/or fuel economy.

The University of British Columbia was one of 64 schools entered in the 1972 Urban Vehicle Design Competition. This urban vehicle was the Grand Award winner at the competition. The vehicle components and design features which led to the design of a well-integrated urban vehicle are discussed. Details of the engine, chassis, body, electronics, and overall coordination of the project are outlined. The vehicle was built by the students themselves, starting with a Fiat 128 engine and drivetrain and natural gas fuel.

Higher average motor vehicle speeds, combined with wider and flatter highway pavements, have increased visibility problems for following and passing vehicles traveling on wet or snowy highways. Trucks, because of their size, configurations, and the diameter of their wheels, generally create a larger and denser splash and spray pattern than do most automobiles. Reduced speeds for all motor vehicles on wet or snow covered highways offer an immediate solution to the problem. However, most research and testing to date has concentrated on mechanical devices which can be attached to the vehicle. Some of these devices suppress splash and spray but are not practical due to adverse effects created in other important safety or operational areas.

Periodic motor vehicle inspection is one part of a balanced highway safety program. This paper uses federal safety research data to evaluate inspection and place it in perspective. The evaluation and costs of New Jersey's vehicle inspection system are described.

The Model 200CA (Choker Arch) high-speed tracklaying logging vehicle was developed by FMC Corp. specifically for the forest products industry. Its function is to haul timber efficiently from stump to landing over all types of terrain and in all environmental conditions. This paper describes the unique features of the Model 200CA and resulting production, silvicultural, and ecological benefits.