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A method is presented for computing the energy dissipation rate in a wet clutch that is part of a vehicle transmission system. This method takes into account the transients in the vehicle prime mover, the hydraulic torque converter, the powershift transmission, and the vehicle load. The clutch energy rate is then used as an input to attempt to predict the interface temperature at the clutch surface. The solution of the Fourier-Poisson unsteady state heat conduction equation is carried out using a finite difference method. The calculation of this interface temperature, called temperature index, is then correlated to actual clutch failure through experimental laboratory clutch testing. Results show a temperature index level above which failure is likely to occur regardless of the variation of clutch parameters.

Primarily a review of hardware details that allow quick changes and high utilization of dynamometers and kindred equipment. Discussed are tachometry, torque measurement quick disconnects (electrical and shaft), desirable control system characteristics, and chassis dynamometers.

Farm tractor cab design with respect to quiet comfort and convenience is discussed. The areas of visibility, accessibility, environmental control, and noise suppression are investigated. Various approaches to accomplish optimum conditions in these areas are analyzed, components are evaluated, and design recommendations are made.

The engineer is often faced with the problem of forecasting the effects on human beings of the sound produced by equipment operating within the environment in which they live or work. A detailed measurement of sound pressure levels throughout the frequency spectrum is necessary for a complete analysis, but the standard sound level meter is probably adequate for most purposes and nearly as accurate as more complex computations. This paper provides useful criteria for specifying performance of equipment or for limiting the exposure of human beings to noise in certain acoustical environments.

For the cab isolated operator to monitor properly the operation of his machine requires a new complexity of early warning signals, failure warning signals, and process monitoring signals. This paper discusses the operator’s requirements and the signal sending and readout hardware available and/or required to meet those requirements.

Has the wheel taken us to the end of our road? Biomechanics’ functional morphologic approach to problems reveals the feasibility of machine designs through studying living phenomena. In addition to the solution of standing problems, the method leads to a series of advanced concepts -- from a one-man cupola simulating an arthropod claw to a weapons firing platform based on the structure, form, and movement found in a snake -- which are useful for new weapons development in the light of our rapidly advancing technology. Outgrowths are expected from this type of investigation through design ingenuity.

Formaldehyde is an intermediate in the synthesis of edible carbohydrates from CO2, O2, and H2 derived from crew member metabolic wastes on spacecraft missions. Methods of accomplishing the synthesis of formaldehyde were studied, and the CO2 → CH4 → CH2O route was selected as the most suitable for spacecraft conditions. Partial oxidation of methane using heterogeneous solid catalysts, ozonated oxygen, and gaseous nitric oxide was investigated. The highest yield achieved was with nitric oxide, amounting to 2.5% of the methane admitted to a single pass reactor. The feasibility of converting CO2 into formaldehyde was demonstrated with a recycle system entailing two reactors. A methanation reactor converted feed and by-product CO2 into CH4; the CH4 in turn was oxidized to formaldehyde in an oxidation reactor. With recycling, essentially 100% conversion of CO2 to formaldehyde was achieved at ambient pressures.

Secondary power generating systems for use in flight and on the ground should be integrated into a unified system for minimum redundancy. The auxiliary power system which is normally used during ground operation of the aircraft can be an effective means of providing power for use in flight in the event of failure of the primary power system. An emergency power source for flight controls in the event all engines fail may be required on aircraft powered by high bypass turbofan engines due to the inherent low windmilling horsepower capability of these engines.

This paper presents the primary categories required for the successful organization of an airline terminal systems approach. Emphasis is placed on the importance of designing airports, air terminals, and associated logistics to accommodate the everincreasing sizes of aircraft and payloads, and to facilitate passenger and cargo transport within the terminals.

Current trends in military combat aircraft are clearly toward increased emphasis on multimission capability. This requires an engine that is considerably oversized when compared with the subsonic cruise or dash requirements of the aircraft. With oversized engines, engine performance is no longer an isolated element. A new approach is needed. This paper analyzes the inlet portion of the installed propulsion system. An assessment is made of the magnitude of the inlet drag associated with oversized engines for typical multimission aircraft. Some thoughts are presented on inclusion of inlet drag considerations into the engine cycle optimization process.

The implementation and installation of Boeing's 747 auxiliary power unit (APU) was the result of efforts tailored to the 747 airplane's needs. Greater power requirement of the plane and its size made unique demands in formulating an APU design specification. Testing, specifications, and mounting of the APU are discussed as well as considerations of safety and fire protection.

The mechanical environment of the astronaut has been made safer by use of rounded edges of corners, tethering of pull pins, selection and incorporation of fire-resistant materials, and 1/6 G empirical data for tool/handle design. The safeguards against ordnance, thermal, and topographical hazards, as incorporated in the ALSEP, are also discussed.

The C-5A bleed air control, air conditioning, temperature control, and fuselage pressurization systems are described. Peculiar design problems of this mammoth cargo transport are discussed with respect to the effect on system configurations and equipment design. A brief review is also presented on the development test programs conducted by the subsystem contractor and the air vehicle manufacturer.

A new concept for approaching the problems of the airshipment of perishables, based on their physiological characteristics, is presented. This concept consists of grouping perishables into classes with common physiological characteristics and defining for each class its environmental requirements. The effects of temperature, atmospheric composition, and relative humidity are discussed in relation to respiratory and microbial decomposition for each class. Three basic handling systems are identified for the airshipment of perishable commodities, as well as considerations for container requirements and cargo compatibility.

Despite the speed involved in air transportation, control of shipping environment is a necessity to handle the varied perishables using this form of shipment. Air transportation allows the shipper to take advantage of premium markets as well as opening new markets in diverse geographic locations. New products conducive to air shipment are frozen foods, fresh meats, tropical fruits, and high density type vegetables. A new accomplishment during the past two years is the development of intermodal containers specifications to take advantage of the jumbo air freighters of the future. In order for the perishable market to benefit fully complete cooperation is needed between the airline, the shipper, the delivery driver, and the engineer who will meet the challenge of providing proper type containers as well as the means of conveyance.

TRW, under NASA sponsorship, is developing an on-board aircraft oxygen generation system. Oxygen is generated by water electrolysis and carbon dioxide is removed from the rebreather loop by an electrochemical carbon dioxide concentrator. The design objectives are to develop a safe, reliable, compact system which would replace the present LOX system, thereby minimizing the need for ground support facilities and reduce time and effort required for servicing. The only periodic servicing required is to refill a water reservoir between flights. The system, with the rebreather loop, requires only the generation of oxygen at a rate equal to approximately 1.5 times that metabolically consumed by the user. This system is also applicable for use in closed environments such as spacecraft and submarines. This paper describes the oxygen system and its design. Projected sizes and weights for a fully-developed prototype are presented. Other applications are discussed.

Experimental research on an integrated Bosch reactor and water-vapor electrolysis unit for oxygen recovery from carbon dioxide is described. A principal feature of the integration is the use of regenerable solid absorbent for periodic water-vapor transfer in a gravity-independent manner to avoid gas-liquid separation problems. The carbon dioxide reduction subsystem was based on batch-wise operation of two Bosch reactors to permit periodic shutdown for carbon removal. Experimental results are presented on operation of the Bosch reactor which include catalyst activation, recycle rate, recycle gas composition, reactor temperature, catalyst consumption, packing density of carbon and life of reactor materials during extended operation. Experimental data are presented on the solid-absorbent unit with silica gel and synthetic zeolites for removal of water vapor from the Bosch reaction and for water-vapor feed to an electrolysis unit.

Currently under investigation at the Langley Research Center in Hampton, Va., is a research test chamber to study and test life support subsystems for long-duration space missions. This system is designed to support four men for a period of 1 year in a near-earth circular orbit with resupply at a 90 day interval. Critical life support subsystems include the recovery of water from urine, waste management, and personal hygiene. Microbiological studies in support of the development and testing of a wick evaporator, water management subsystem are reported. The goal of this program is to produce water meeting the recommended standard of “essential sterility,” that is, no more than a sum total of 10 micro-organisms per ml. Modification of the wick evaporator system to permit the use of heat for sterilization will be described. Microbiological and chemical results obtained during research and development on a bench model and from two units inside the ILSS test chamber are presented.

This paper summarizes the results of a broad survey study of the influence on weight of future large launch vehicles through use of advanced materials. Interrelationships of results with other factors such as design criteria, design approach, types of wall construction and advanced analysis techniques are considered. Specific results are presented for both advanced metals and wall construction techniques. New, computerized techniques used in developing these results are described, and applicability to similar future studies is noted.

The early 1960's military airlift capability was inadequate to support a new national policy of flexible military response to aggressor action. An Air Force Specific Operational Requirement for an airlift vehicle of massive payload potential with extremely high operational reliability initiated development of the C-5 aircraft. Combat troop and cargo handling requirements for the C-5 are reviewed as they were originally defined. The eventual sequence of refinements to those requirements is characterized by continual change and improvement of requirement definition. Joint government and contractor C-5 development effort is traced through first aircraft flight, and a baseline of C-5 combat troop and cargo handling requirements is established for future comparison with the actual C-5 capabilities.