bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Measurements of Brake Usage in a High-Speed Saloon Car
Authors: Carpenter N. 
Published: June 2010

The paper describes equipment which has been developed to record the duties imposed upon automobile brakes in service under various normal conditions. The principal measurement required was the rate of energy dissipation at the brakes, and this was recorded, together with the drum speed and deceleration, on a roll-chart recorder. The principles involved in these measurements are discussed in some detail, together with an outline of the practical precautions necessary to preserve the accuracy of the readings. From the results it will be possible to develop improved testing cycles for the test machines used in the development of brake lining materials but, in addition, some points of fundamental interest have emerged from the investigation. The results quoted in the paper show that the energy dissipated at the brakes is directly related to the mean journey speed for a given journey when other factors are kept constant and that: Energy dissipated at the brakes = (mean journey speed) n where n has a value of about 3.4 for the conditions encountered in this investigation. The effect of mean journey speed is shown to be much greater than that of the other variables considered although it must, of course, be taken in conjunction with the characteristics of the road. Braking in hilly country is shown to be appreciably more severe than on corresponding roads through flat country.
The Riding Qualities of Wheeled Vehicles
Authors: Cox H. L. 
Published: June 2010

A wheeled vehicle traversing an irregular road surface is subjected to forced vibration. This vibration is analysed into heaving, pitching, and rolling modes, and means are described to compute or simulate the response of the vehicle both to continuous excitation at definite frequencies, and to isolated obstacles affecting one wheel at a time. It is shown that a simple model, comprising only rigid masses, linear springs, and velocity damping, suffices to represent the riding quality of the vehicle, and a procedure by which the model may be matched to the vehicle as closely as possible is described. The theory is illustrated by computation of the impact loads imposed on the wheels of a six-wheeled lorry when surmounting artificial obstacles, allowance being made for the effects both of the wheels leaving the road, and of interaction between the four wheels in the rear truck. Good agreement with experimental records of wheel load is shown, and it is suggested that similar computation or simulation applied to passenger-carrying vehicles would prove of value in the improvement of riding quality.
Recent Developments and Modern Techniques in the Use of Gaskets
Authors: Herrington M. G. 
Published: June 2010

The paper is concerned with a brief review of the history of the cylinder head gasket. It sets out some of the initial defects and the manner in which they are overcome. The author mentions some of the successive developments which have taken place in engine design and construction which have necessitated a reconsideration of gasket design. The various changes in gasket construction, including an analysis of the considerations governing the introduction of the corrugated-steel gasket are stated. The problems which are continually being met in the industry in relation to gasket troubles are considered, both from a design and production standpoint. The paper concludes with a short comment on the approach to gasket design in the future.
The Design and Development of Small Radial-Flow Turbo-Chargers
Authors: Judson C. A. , Kellett E. 
Published: June 2010

Turbo-chargers are already well established for Diesel engines of moderate and high outputs, and there is no reason why this should not also apply to Diesel engines of 100 h.p. and upwards. In the former case, axial-flow turbines are used, but these suffer from serious disadvantages in the smaller sizes, so that radial-flow turbo-chargers are more likely to be adopted. The range of applications on the smaller Diesel engine is very extensive compared with its larger counterpart, and in particular, automotive engines will have a serious influence on the design and development of the small turbo-charger. Owing to the rapidly and widely varying load conditions, the component efficiency must be high, and the rotating assembly as light as possible to give rapid response times. This involves intensive development of turbine and compressor, and the use of shaft speeds of 40,000–50,000 r.p.m., which until recently would have been regarded as impracticable for service conditions where a life of several thousand hours must be accepted. The automotive field is also highly competitive, and production quantities are large. Consequently, the design of the turbo-charger must be such that it can be made economically and in large numbers, and at the same time be as efficient as possible over a wide range of operational conditions. Although economic conditions may fix the minimum size of the turbo-charger, the limit does not yet appear to have been reached on an aerodynamic basis, and reasonably high component efficiencies are readily attainable with rotors of 4 inches diameter or less. The onset of exhaust smoke in some automotive service applications will not only dictate the matching conditions for the turbo-charger, but may also necessitate some further development to prevent it being a limitation on the power output from a given installation.
Air Suspension for Road Vehicles
Authors: Sainsbury J. H. 
Published: June 2010

This paper presents a résumé of the course of development of the air springs of the double-convoluted and rolling-lobe types. The theory of the air spring design is discussed and typical methods of installation are described. The present-day air springs are limited to a maximum pressure of 100 lb/in2 to cater for the maximum static load. There are no minimum pressure requirements for a double-convolution bellows, but in order to obtain good flexing life and maximum spring response the rolling-lobe type is generally limited to a minimum pressure of 40 lb/in2. The ancillary equipment for an air suspension system is described, this consisting of compressor, storage tank and levelling valves.
Petrol Injection in Germany
Authors: Heinrich H. , Stoll H. 
Published: June 2010

An account is given of the development of the petrol-injection system in Germany, a subdivision having been made according to piston aero-engine, two-stroke automobile engine and four-stroke automobile engine. The increase in performance achieved in the piston aero-engine by the injection system is described. Experiments carried out during the past 10 years on the two-stroke engine have shown that the demands made on the injection equipment in regard to injection accuracy and working life can be met forthwith, but that the injection system makes demands on scavenging which differ from those of the carburettor. The attraction of petrol injection in the four-stroke automobile engine is represented chiefly by the gain in performance, the wider controllable speed range and the faultless acceleration over the entire speed range irrespective of the driving conditions. As a rule, the authors' company supply for all these engines the fuel-injection systems known in connection with Diesel injection, making allowance for the slight variations called for and irrespective of whether direct injection or manifold injection is used. Manifold injection points to ways and means of effecting economy in the injection method (pump and nozzle). The control problem is the most difficult problem in petrol injection, no matter whether direct injection or manifold injection is used, and it calls for intensive development. The success of petrol injection is decisively governed by a faultlessly functioning mixture control.
Transient Temperatures in Brake Drums and Linings
Authors: Newcomb T. P. 
Published: June 2010

A solution is given to the problem of heat conduction in an infinite slab when one face is subjected to a thermal flux which decreases linearly with time, while at the other face there is no flow of heat. This solution can be used to determine the transient temperatures reached during braking with uniform deceleration. Typical curves showing the agreement between temperatures determined theoretically and experimentally at varying depths inside a brake lining during single brake applications are given. The problem of repetitive braking at regular intervals is also discussed and a comparison of theoretical and experimental temperature measurements is made. The effect of a nonuniform pressure distributed circumferentially along the lining is also considered in an appendix.
Vehicle Headlamp Beam Control
Authors: Jones K. J. 
Published: June 2010

The problem of obtaining reasonable night-time seeing conditions when meeting oncoming traffic demands the use of uniform meeting-beam intensities. Variations will exist, and can be tolerated provided they are not too great or too frequent. The sources of variation relevant to the problem have been examined and the necessary degree of control stated.At present lamp-aiming errors swamp all other variations. If these aiming errors can be reduced considerable improvement will be possible with existing equipment: by following the trends in aiming accuracy the need for lower lamp production variations and even better control of voltage may be established.The immediate objective is stated as an improvement in aiming followed by a movement towards a higher degree of control of aiming, lamp production and voltage variation.
Construction and Behaviour Characteristics of Tyres
Authors: French T. 
Published: June 2010

Development of automobile tyres over the past few years has led to certain improved performance characteristics and also to a wider choice of tyre behaviour patterns than has earlier been the case. To obtain optimum required performance characteristics for a particular vehicle design, attention must be paid both to individual tyre parameters and their interaction with particular features relating to the vehicle. Examples are given. The impact of new materials for making tyres and of constructional variations in the tyres is discussed in relation to improved tyre performance characteristics, including comfort, road adhesion, ease of control, high-speed running, tread pattern life, noise and tyre power consumption. Testing techniques which have assisted in assessment of some of these items are discussed, with illustrative results. The relative effects of mechanical and tyre variables are summarized. Reference is made to future trends in requirements of automobile tyre behaviour and possible consequent changes in tyre construction and form.
Some Problems in the Design of Crawler Tractors
Authors: Little L. F. 
Published: June 2010

Problems encountered in the design of crawler tractors used in the earthmoving industry are considered tinder two principal headings, those associated with performance and those which arise when attempting to improve life and reliability under arduous operating conditions.The characteristics of soils, their ability to sustain weight and tractive effort and the influence of track proportions are discussed, and problems in the application of conventional soil-mechanics concepts to the prediction of vehicle performance are illustrated by the results of field experiments.Of the factors affecting durability the most difficult to contend with is that of shock loads in the suspension and transmission resulting both from ground conditions and the high rotational inertia of the transmission train. A comparison of recorded loads under operating conditions with mechanical and hydraulic transmissions shows the advantage in favour of the latter type.The effect of a high average load factor and generally unfavourable atmospheric conditions on engine life are examined with particular reference to cooling and filtration.The importance of reducing operator fatigue is emphasized, and future trends of development having as their objective the reduction of stress in both man and machine are suggested.
Initiation and Some Controlling Parameters of Combustion in the Piston Engine
Authors: Clarke J. S. 
Published: June 2010

This paper reviews some of the research in combustion phenomena which has taken place during the past two decades. It is shown that much of the research carried out on gas-turbine development is of fundamental value and can be applied to other internal-combustion engines. The problem is discussed from the aspect of intake considerations, mixture formation, and ignition and then there is a detailed section on chemical kinetics. A table of the effect of heat loss and volumetric efficiency is given. The various sections are illustrated with the experimental results. It is concluded that the theoretical and practical approaches can be combined and that further quantitative study is required on heat loss and mixture processes.
Natural Ventilation of Buses
Authors: Culver R. , Hickin G. N. , Sag N. 
Published: June 2010

This paper describes the utilization of the pressure and flow pattern existing around a vehicle when it is in motion. Methods by which these flow patterns can be made visible are described and the results of visual observations are discussed. As a result of these observations most suitable air inlet and outlet positions are established and the results of airflow measurements indicate that a substantial increase in the volume of air entering the bus was achieved. In conclusion a design philosophy leading to optimum conditions is explained.
Application of the Flash Temperature Concept to Cam and Tappet Wear Problems
Authors: Dyson A. , Naylor H. 
Published: June 2010

In the lubrication of a modern automotive engine the cams and tappets are among the most sensitive parts and are expected to become more difficult to lubricate as engine speeds increase. This paper deals with the two types of cam and tappet distress that occur mainly at high engine speeds; scuffing and polishing (or burnishing). The occurrence of these phenomena is believed to be controlled by the temperatures in the contact zone, and in order to treat these in a quantitative manner the flash temperature theory of Blok has been applied to cam and tappet systems. For this purpose, some preliminary measurements have been made of the coefficient of friction between cam and tappet. The contact temperature reaches a maximum at three points in the valve operating cycle; at the cam nose and at the two points of zero tappet acceleration. The relative values of these maxima depend on the cam contour, spring forces, materials of construction, etc. If the temperatures at these points are excessive, either scuffing or polishing is liable to occur. A case of polishing wear is examined, and it is shown that most of the observed details may be explained on the flash temperature theory. It seems necessary to postulate that a steel surface with a low velocity relative to a rubbing contact will scuff if the contact temperatures are high enough, but that the surface will become more liable to fail by polishing wear as this relative velocity increases. This is related to some phenomena observed with steel spur gears. The theory may also be used to evaluate the relative scuffing properties of different cam profiles, with certain limitations which are explained in the paper, the metallurgy being constant. Some indications as to the design of a cam profile to avoid scuffing are also given, but there is no experimental backing for these.
A Comparison of the Wear of Small Gasoline and Diesel Laboratory Engines
Authors: Pike W. C. , Newman P. 
Published: June 2010

Differences in the top compression-ring wear characteristics of two single-cylinder engines are presented. Wear determinations were made using the radioactive tracer technique. It was found that a high-speed, 19/1 compression ratio (C.R.), indirect-injection diesel-engine displayed generally more severe wear than did a 5/1 C.R. gasoline engine and experiments made to investigate the observed differences are described. As part of these experiments the diesel engine was extensively modified to enable it to be run as a spark-ignition engine under comparable conditions to the gasoline engine. Comparative wear data are given for the two engine types under various controlled running conditions. The main test variables were: load, cooling-jacket temperature, fuel type and fuel sulphur content. Analysis and discussion of the results is based on general considerations of corrosive and abrasive conditions prevailing in the cylinders as influenced by the combustion process.
Instrumentation Problems of Internal-Combustion Engine Development
Authors: Hempson J. G. G. 
Published: June 2010

Some reasons for use of varied measurement techniques in internal-combustion engine development are given and the broad principles of transducers are discussed. It is emphasized that the treatment is based on the practice and experiences of one organization and does not claim to be a critical survey of all possible methods. Practical examples of pressure, movement, strain and vibration measuring systems are given with reasons for choice of the method used. Some experiences with strain gauges in special circumstances are mentioned. Normal temperature measurements are not discussed but certain particular cases, such as differential thermo-meters and probes for dynamic measurement, are mentioned. The many uses of scaling or counting equipment are outlined with some examples, such as accurate tachometry. The visual display units and photographic recording gear used to present the output from transducers are described, together with some mention of driver amplifiers and carrier systems which are also needed. The problems of time sweep generators and marker pulses are presented together with an outline of better solutions not yet achieved. The final section mentions some responsibilities of the instrument section outside the scope of the paper and refers to general principles guiding the operation and staffing of such a section and its position as a service to the basic purposes of the organization as a whole.
Integration of Heating, Ventilation and Refrigeration into Vehicle Design
Authors: Copley D. W. 
Published: June 2010

Current trends in car heating and cooling are reviewed. The need is stressed for close co-operation between the vehicle and heater manufacturers, in order to arrive at the most economical heating system to satisfy technical requirements within limited space. A standard of vehicle heating is suggested, and the heat quantities to achieve this indicated. While experience to date in heating has been almost entirely confined to liquid-cooled engine systems, the possibility of alternative heat sources are considered. To ensure consistently satisfactory distribution of heat and ventilation, the need for improved body-sealing, together with a built-in, suitably positioned air outlet, is discussed. While present heating systems satisfactorily condition the temperature of the air within the vehicle at low ambient and up to around 55°F, at higher temperatures there is a need to introduce into the vehicle, at high level, a large volume of fresh unheated air, this at present being achieved by opening windows. Ducting this air from the existing plenum chamber is suggested as a more elegant solution in which filtration could be included. Vehicle refrigeration is reviewed and a smaller and cheaper system of ‘spot cooling’ suggested, as an alternative to the American approach of full car cooling, for the volume production 1–1 1/2 litre British car.
Improving Temperature Control in Diesel Engine Vehicles
Authors: Bisiker J. G. , Benford J. L. 
Published: June 2010

The fitment of thermostats to water-cooled engines indicates the need for temperature control, but a thermostat is limited in maintaining adequate temperatures in diesel engine vehicles under many operating conditions. Inadequate temperatures result in high wear rates and other disadvantages of cool running are also discussed. Equipment designed to improve temperature control is described in Appendix II and graphs of engine temperatures are shown in the paper for road tanker operation. The effectiveness and limitations of fan control and automatic radiator shutters are discussed and known advantages of improved engine wear, reduced fuel consumption and better cab heater performance are illustrated from service experience.
Mechanics of Off-the-Road Locomotion
Authors: Bekker M. G. , Bekker M. G. 
Published: June 2010

Off-the-road locomotion has always been, an important part of technology and economics. Yet it has never been treated within a comprehensive theoretical approach. Space research, and in particular preparations for the exploration of the surface of the moon, have in a sense dramatized the issue. As the trial and error method is not applicable in the latter case, theoretical work and research in simulated lunar conditions have already started. New emphasis on off-road mobility on this planet, stressed from commercial and military viewpoints, has also contributed to the growing interest in this area.Early work on the mechanics of off-the-road locomotion started in 1913 in Germany and in 1943 in England, and laid the first cornerstones for a theoretical approach. The solid foundation for the development of the mechanics of soil-vehicle relationship, however, was first established between 1944 and 1950 in Canada. On that foundation the first general outline of a theory which covers all the physical phenomena pertaining to terrain-vehicle systems was completed in the United States around 1960. The results of this work were the main theme of the First International Conference on the Mechanics of Terrain-Vehicle Systems held in Italy in 1961. The theory is based on the Coulombian criterion of soil failure which relates to thrust, and on semi-empirical moduli of sinkage which relate to the motion resistance. It constitutes a working tool for engineers and planners and offers a general methodology for the further development of mathematical equations needed in the prediction of vehicle performance and design parameters. The accuracy of such predictions so far achieved is encouraging, although much improvement is necessary.These new methods enable the user and designer of motor vehicles to have a much better understanding of the relative merit of various types of locomotion in various environments. They have laid a foundation for the more rational planning of vehicle development and the evaluation of design trends, and the preliminary optimization of terrain-vehicle systems in randomly changing conditions due to climate and geography has been made possible.Long range evaluation of future trends in off-the-road locomotion indicate that the so-called articulated vehicles, composed of a number of self-propelled units linked together by free steerable joints, in a manner similar to a railroad train, offer great promise. Future progress is seen in terrain measurement, in the analysis of terrain-vehicle relations from the viewpoints of performance and design, and in research aiming at the improvement of the present theories.