CoA. ASAE Memos (1963-1968)
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Item Open Access Human factors problems in the design of vibration isolation systems: a contribution to the evaluation problem of passenger car suspension systems(College of Aeronautics, 1968-02) Fox, J. G.; Whitehead, G. D.1.0 Introduction In Appendix 1 of this report general procedures for the design and evaluation of vibration isolation, systems. are reviewed. It is shown that in general., a: vibration isolation system is adequate only when it enables a human operator to meet the objectives of some system by performing a task well enough and for long enough. If the vibration intrudes too far upon the operator's performance and endurance the system of which he is a part will not meet its objectives. There still remain examples today where inadequate vibration isolators limit the performance of a system. The agricultural tractor is one of these. It is not uncommon to see a tractor driver supplementing the tractor tyre spring by using his own vibration isolators - his legs.Item Open Access Research on the effect of mixture quality on the exhaust gas emissions of a petrol engine(College of Aeronautics, 1968) College of Aeronautics, (Cranfield)To meet the existing and proposed legislation for the control of air pollution by the exhaust emissions of petrol engines, a major research effort is required within the next five years. Not only are the regulations expected to become more stringent as the number of motor vehicles increases, but improvements will show a diminishing; return in terms of the percentage reduction of emissions when primary factors have been treated. A fundamental problem that is not well understood is the effect of the quality of the fuel-air mixture on combustion in the spark ignition engine. Knowledge of this factor could be important when the emissions are at a low level as a consequence of the employment of devices that treat factors such as mixture strength or the distribution of the fuel. Although the devices are effective in the reduction of the concentrations of hydrocarbons it is thought that many have an undesirable effect on the concentrations of the oxides of nitrogen. To improve the knowledge of these problems, it is the proposal that the research at the Advanced School of Automobile Engineering should be extended to a comprehensive study of the effects of mixture quality on the concentrations of carbon monoxide, hydrocarbons and oxides of nitrogen in the exhaust gas of a spark ignition engine. The facilities at the School are comprehensive and no financial assistance is requested for equipment. To allow the study to be completed within a time that is relevant to the urgency of the problem, a grant is requested for the employment of a Senior Technical Officer and a Laboratory Technician for a period of three years.Item Open Access A review of data analysis systems(College of Aeronautics, 1965-09) Whitehead, G. D.This review gives an appraisal of 8 Automatic Time history reocrd analysis systems. The appraisal indicates the analytical capabilities, analysis flexibility and the cost involved in performing the analysis. It is suggested that in choosing such a system for an educational institution, some analysis speed and automation should be sacrificed for computational flexibility and operational adaptability. The review does not indicate that a specific machine be considered, but rather that an analysis system be built from a number of manufacturing sources.Item Open Access A proposed integral land rover structure(College of Aeronautics, 1966-03) Tidbury, G. H.This note summarises the methods available for the analysis of vehicle structures and points out the advantages of each method. Reasons are given for the choice of the matrix force method in the analysis of a proposed integral Land Rover structure. Some results of the analysis are given and the design of the structure described.Item Open Access Stress analysis of vehicle structures(College of Aeronautics, 1964-07) Tidbury, G. H.A historical review is made of the methods adopted in vehicle design. This is divided into two sections, vehicles with chassis frames and integral structures. Complete solutions have been obtained for all types of chassis frames by Erz and the results of this work are given. The simple frame structural analysis has been extended for buses, with semi-integral and integral construction. Private car structural analysis has been very approximate using pencil and paper method4 various approaches have been tried with little success. The advent of the digital computer has made the analysis of such complex structures possible and the two basic methods of ‘displacements’ and 'force’ are described. The matrix force method due to Argyris is treated in detail with a complete analysis of a simplified box van structure under idealised loading. This method has been chosen for economy in computer space and its application to a more complex structure, an integral Land Rover, is indicated. With the advent of very large computers it is probable that displacement methods will, take precedence as less work in 'choosing' the idealisation and redundant systems is involved.Item Open Access Handling track requirements(College of Aeronautics, 1963-09) Ellis, J. R.Handling track requirements When the handling qualities of a vehicle are to be assessed, it is desirable that the test procedure enables the effects of the main vehicle parameters to be determined separately. The tests will consist of steady state and transient response determination. Modern instrumentation techniques which enable the vehicle accelerations, roll angle, and rate of turn to be recorded provide a means of measuring both steady state and transient responses. A portable 'handling' unit with lateral accelerometer, fore and aft accelerometer, roll position gyroscope, and yaw velocity gyroscope, together with a film or tape recorder, is a perfectly practical proposition.Item Open Access Submission to Science Research Council(College of Aeronautics, 1968) College of Aeronautics (Cranfield)Support is requested from the Science Research Council for an extension of the research facilities available for the investigation of flexural vibrations of crankshafts at the Advanced School of Automobile Engineering. Sufficient evidence exists to indicate that flexural vibrations of crankshafts are significant at certain running conditions and critical speeds of an engine. It is also possible that unaccountable failures of crankshafts in service may be explained by fatigue as a consequence of large vibrating stresses due to resonance of the bending mode. Lack of knowledge of these vibrations is such that the criteria used for the design of devices that reduce the amplitudes of vibration and noise at the critical speeds are not well founded. The results of the theoretical and experimental studies already carried out at the school are promising but they are restricted to a particular crankshaft. To fully establish the methods of analysis, to extend the analyses and to test a significant number of crankshafts of various types, it is the proposal that a Senior Research Fellow and a Research Engineer will be employed for three years. Additional test facilities and instrumentation are requested for the extension of the work in progress.