bluuebunny/crossref_metadata_2025 huggingface dataset:
The Measurement of Tractor Performance
Authors: Manby T. C. D.
Published: June 2010

Methods of testing to B.S.I, and International Codes are reviewed and some examples given. Test results include details of performance with hydrostatic and hydrokinetic transmissions. Additional testing under oversea conditions including altitude testing, simulated tests in dusty conditions, and air cleaner tests are examined in some detail.
Design and Operation of Motorway Coaches
Authors: Pearson J.
Published: June 2010

The opening of the Birmingham to London motorway, on 2nd November 1959, freed the British coach operators from the archaic law which governed their vehicles down to a maximum speed of 30 mile/h. To make full use of the motorways the construction of a high-speed coach was undertaken by the ‘Midland Red’.
The Design History of a V8 Engine
Authors: Phillips A. J.
Published: June 2010

The author describes the design of a modern high-quality car engine and gives details of special problems encountered with the use of light alloys, and how they were successfully overcome. The principal engine components are described and illustrated and details of balancing calculations are given in the Appendix.
Crossed Helical Gears for High Speed Automotive Applications: Some Observations on the Problem of Failures, the Effects of the Changes of Design and Manufacturing Processes
Authors: Jacobson M. A. I.
Published: June 2010

The paper indicates that the problem has arisen in the last 10 years and is related to the increase in speed and output of automotive petrol and diesel engines. Failure incidence is furthermore associated with the change over from gear type to the cheaper multi-lobe constant displacement type lubricating oil pump. The latter have a very pronounced cycle of high torque pulses. A similar severe cyclic loading of the gear teeth is experienced when driving a distributor type diesel fuel injection pump.

Changes of component design leading to reduced gear tooth loading are beneficial but cannot compensate for insufficient quality of surface finish of the tooth flanks.

Failures of four distinctly different types of drives are illustrated and cause of failure analysed in detail.

The part played by lubrication and oil additives is discussed. The author suggests that no drive will be successful unless the surface finish roughness of the tooth flanks is equal to or less than the oil film thickness generated. This film thickness diminishes rapidly with increase in sliding velocity and/or lubricating oil temperature. A relationship between tooth surface finish roughness and maximum safe tooth sliding velocity is demonstrated, based on the analysis of success and failure of 14 different engine types. The importance of obtaining a consistent quality of tooth flank surface finish is stressed and manufacturing methods of obtaining this are compared. The information on hobbing, shaving, grinding, lapping, buffing, phosphating, cutter blunting, shaving techniques for difficult abrasive and hard materials, detailed floor to floor production times etc. can be safely applied to gears of automotive proportions generally. The author gives a summary of his findings concerning successful and unsuccessful combinations of materials for worm-wormwheel as well as crossed-helical-gear drives.

The stage by stage tooth flank surface finish improvement of an extremely successful crossed-helical-gear drive is followed through its different phases of production and demonstrated by photographic records.
Car Brake Usage and Test Schedules
Authors: Mackenzie D. K. , Newcomb T. P. , Watton B.
Published: June 2010

An investigation of car brake usage has been made on different routes and also on hills of various slopes. From the results obtained on a number of cars it has been found possible to define two parameters V0 and M, which describe the type of route and the manner of driving over the route respectively. V0 is the speed at which it would be theoretically possible to drive over a route without applying the brakes. The range of values of V0 was measured over short sections of four routes each approximately 100 miles in length. M was found to relate the average journey speed to V0 and the maximum speed of the vehicle. The range of M was obtained by observing the behaviour of a large number of private cars over part of two routes.

The brake application and release speeds, the brake line pressure and the deceleration were measured at every brake application. The drag losses at given speeds were also obtained and the amount of energy dissipated at the brakes calculated. On any journey on a flat road the energy dissipated at the brakes per unit weight of vehicle is shown to be related to V0, M and the journey speed. The work done by the brakes per unit weight of vehicle has also been measured when motoring down hills and shown to be dependent on the slope of the hill.

The results of the brake usage study have been used to formulate test schedules to simulate normal, fast overload driving, and conditions encountered when motoring down hills and Alpine passes. These tests are given in tabular form for cars of maximum speed in the range 70 to 120 mile/h.
Some More Light on Diesel Combustion
Authors: Alcock J. F. , Scott W. M.
Published: June 2010

This paper discusses the process of combustion, as revealed by high speed cinematography, in a small high speed diesel. Two direct injection types and one prechamber type were examined, and combustion sequences are shown. The phenomena are complex, but the main features are:

(1) In small engines much of the fuel strikes the chamber wall and moves along it. (2) Swirl is greater than has hitherto been supposed, squish much less. (3) Most of the flame is of the carbon-rich diffusion type. (4) Soot from very rich mixture is always formed at high loads, but can burn later leaving a clean exhaust. (5) Combustion knock does not seem to be related to the total fuel in the chamber on ignition, but rather to the amount of fast burning mixture present.
Third Paper: The Development and Test Data of the Lucas Direct Flame After-Burner
Authors: Clarke J. S. , Soltau J. P.
Published: June 2010

In designing an after-burner it was decided to use the California emission test cycle since this was the only recognized test standard. It also gave a fair coverage result, but for British conditions a modified cycle with longer idling and 15 mile/h cruising periods was used.

Experience in gas turbine design was invaluable in tackling this design problem. Modern American automobiles have carbon monoxide emissions of 1·5–4 per cent when measured over the standard test cycle, but on some European vehicles 3–5·5 per cent has been observed.

The dimensions of the after-burner had to be restricted to the available space in cars, and designed as simply as possible. Prototypes were made and extensive testing carried out. Eventually a satisfactory unit was produced with good performance on the road. The reduction in pollution was very satisfactory and values for the Californian cold test procedure were 1·5 per cent carbon monoxide and 100 parts per million hydrocarbons.
The Use of Fuel Cells in Automobiles: Examination of the Problems Involved in the Motor and Transmission
Authors: Watson E. A.
Published: June 2010

This paper examines the limitations that are imposed by the characteristics of an electric motor employed in a vehicle powered by fuel cells and having a performance comparable with a petrol- or diesel-engined vehicle of present-day design. It is not, in the first instance, intended to deal with the substitution of fuel cells for the storage battery on an electric truck. As a result of certain desirable characteristics, such as absence of fire risk, silence in operation, manoeuvrability, and ease of control, the battery-operated electric truck has already found a special market despite its relatively high cost of operation when due allowance is made for battery replacements. It cannot compete in any way, however, with the ordinary internal-combustion-engined vehicle for rapid transport over distances of 20 miles and more.

The object of the paper is to consider what limitations may arise that are due to the characteristics of the electric motor even if the fuel cell is developed to the extent of becoming an extremely light and efficient unit.
Some Experiences with a Differentially Supercharged Diesel Engine
Authors: Dawson J. G. , Hayward W. J. , Glamann P. W.
Published: June 2010

The ideal output characteristic required from an internal combustion engine for vehicle propulsion is constant power output over the working speed range, and the present conventional engine falls very far short of this. The paper describes the development of a diesel engine which is supercharged by a compressor driven by a differential gear in such a way that the boost, and therefore the output torque, increases with decrease in engine speed and which goes some way towards giving the desired output characteristic. The further step is described of including a hydraulic torque converter in the system so that automatic operation by a single pedal control can be achieved over the practical operating range of normal road vehicles. It is shown that the full operating range required by all normal vehicles can be obtained with a gearbox with two speeds only. The results of road tests on a truck with varying payloads are given and the fuel consumptions achieved are shown in comparison with the same engine in both its naturally aspirated and turbocharged forms. Notes are given on the component development and mechanical development of the engine necessary to achieve these results in a reliable way. Details are shown of possible production arrangements of differential gears and drive trains, one of which incorporates a hydraulic retarder which can be done cheaply and effectively. The paper concludes with a note on future developments and a summary of possible advantages.
A Theoretical Analysis of the Lateral Properties of Suspension Systems
Authors: Hales F. D.
Published: June 2010

The suspension system of a vehicle interconnects its wheels and body and provides the means by which forces and movements are transferred from one to the other. The lateral properties of suspension systems are required for lateral handling and other suspension studies, and this paper contains a theoretical analysis of such properties for a range of suspension systems: viz. double wishbone, Macpherson strut, swing axle, beam axle, and beam axle-Panhard rod. The lateral motions of a wheel on a road, resulting from prescribed motions of the vehicle body, are derived for the range of suspension systems considered. Attention is concentrated on the two principal body motions of vertical and rolling velocity, and the resulting suspension movements are determined in terms of these suspension derivatives.

In the case of the double wishbone suspension, the various types, each with differing characteristics, are distinguished. Regions are defined within which suspension systems will have certain properties, and the boundaries of these regions are determined. By a suitable choice of defining parameters, the Macpherson strut suspension is shown to be equivalent to a double wishbone suspension, and therefore the analysis of the double wishbone suspension is applicable to the Macpherson strut. By comparison with the double wishbone suspensions the remaining suspensions considered have only limited ability to vary their suspension characteristics.

The effects of suspension design on the steady state roll angle, suspension jacking, and load transfer are investigated. A single end suspension is first considered, and the dependence of the roll angle and suspension jacking on the suspension derivatives is demonstrated. This dependence enables the significance of the various regions derived earlier to be stated. For the complete vehicle, the suspension derivatives again determine the roll angle, and in this case the wheel load transfers are also dependent, via the body transferred rolling moment, on the suspension derivatives.

The suspension derivatives are required in handling studies and the method of analysis is capable of giving considerable insight into the general behaviour of suspension systems.
An Introduction to the Dynamic Properties of Vehicle Suspensions
Authors: Ellis J. R.
Published: June 2010

While the general outline of vehicle suspension behaviour is fairly well known little interest has been shown in the detailed dynamic performance of the various designs. From such a study it is possible to predict the natural frequencies of the suspension systems and their response to various disturbances whether these are due to cornering forces, wind gusts or road disturbances.

Initially some typical suspensions are considered using the equation of Lagrange. Body movements are considered to consist of vertical and lateral displacements together with rotation about a geometrically defined point, the instantaneous centre of roll. Wheel movements are controlled by the geometry of the particular suspension. The suspensions considered do not exhaust the subject but serve as a guide for the analysis of particular systems which may be required from time to time.

The linearized equations of motion are given in matrix form, from which the natural frequencies of the system may be derived. No attempt is made to produce formulae for the natural frequencies since in practice it is more satisfactory to substitute numerical values for the symbols at this stage.

Some of the differences between the tyre behaviour in static and rolling states are mentioned. This is of particular relevance in view of the development of extensive vehicle vibration test rigs.
Internal Combustion Engine Poppet Valves: A Study of Mechanical and Metallurgical Requirements
Authors: Cowley W. E. , Robinson P. J. , Flack J.
Published: June 2010

Some factors affecting the performance of exhaust valves are considered and the importance of improving engine design to give minimum valve operating temperature is stressed. Strength requirements are reviewed and it is shown that the advantages of higher mechanical strength and better corrosion resistance of austenitic compared with ferritic steels may be lost due to the valves operating at higher temperatures and hoop stresses. The corrosion conditions inside the cylinder head are considered and a new test is described in which lead monoxide coated specimens are exposed to atmospheres which produce valve corrosion similar to that which occurs in an engine. The order of merit established by this test agreed fairly well with the known behaviour of valve alloys when the effect of operating temperature was taken into account. Valve head corrosion has been shown to be due to surface carburization-oxidation and internal oxidation; by applying a suitable surface coating, valve life can be appreciably increased.
Discussion in the United States of America on Some Experiences with a Differentially Supercharged Diesel Engine
Authors: Dawson J. G. , Hayward W. J. , Glamann P. W.
Published: June 2010

The paper* Was first presented at an Ordinary Meeting of the Automobile Division of The Institution of Mechanical Engineers, at Headquarters, 1 Birdcage Walk, Westminster, London, S.W.I, on Tuesday, 14th April 1964. It was again presented at the S.A.E. National Powerplant Meeting, Baltimore, Maryland, U.S.A., on 20th October 1964, under the Chairmanship of Professor Philip S. Myers†.

The discussion papers and the authors' reply which followed this second presentation of the paper were forwarded to the Institution by Professor P. S. Myers on 16th December 1964 and were approved for publication in this volume
An Engine Designer's Scrapbook
Authors: Moult E. S.
Published: June 2010

‘Half the marvels of my morning, Triumph over Time and Space, Staled by frequence, shrunk by usage, Into commonest commonplace’
Torsional Stiffness Analysis of Car Bodies
Authors: Cooke C. J.
Published: June 2010

Expressions are provided for calculating the torsional stiffness of a car body passenger compartment.

The two main reaction systems which contribute towards the torsional stiffness, i.e. the couple due to shear forces in the roof and floor and the rectangular frame formed by the sill torque boxes and the end bulkheads of the passenger compartment, are considered separately. This enables the behaviour to be studied qualitatively as well as quantitatively. It is shown theoretically and diagrammatically that the first system is dependent on the bend stiffness of the members forming the door apertures.

Simplifying assumptions permit the expressions developed to be sufficiently straightforward for them to be acceptable for repeated use in the design office to optimize the distribution of material. Alternative approaches are suggested for cases where greater accuracy is necessary. The basic expressions relate to a simplified structure but a technique is supplied for assessing the contribution of extra members.

The effect of the horizontal offset of the wheel centres from the ends of the passenger compartment is discussed and the influence of suspension and structure geometries on the effective offset is mentioned. Ways in which the deflections of the passenger compartment affect the front and rear end structures are discussed qualitatively.
Second Paper: Studies on the Skidding Resistance of Passenger-Car Tyres on Wet Surfaces
Authors: Maycock G.
Published: June 2010

This paper reports investigations into the effect of tread pattern, pattern modifications, tread material and tyre casing construction, on the skidding resistance of passenger-car tyres at speeds between 25 and 80 mile/h on a range of wet road surfaces.

The technique used was to brake the front wheels of a car until these wheels locked, and to record the resulting deceleration of the vehicle. From the deceleration record, both the peak and locked-wheel values of the braking force coefficients were obtained. The method is described and an assessment of the errors involved is given.

The experiments showed the importance of adequate drainage of the region of contact between tyre and road, particularly at the higher speeds, in order to remove the lubricating film of water. Such drainage can be provided either by a tread pattern or a coarse road surface, and the present results indicate the importance of each and their inter-relation.

The results of various modifications to a standard tread pattern are given; these show that on smooth surfaces worth-while increases in wet road adhesion at high speeds can be obtained by suitable design of tyre tread patterns. The magnitude of the increases in friction due to changes in tread material are given for both peak and locked-wheel coefficients. Ratios of peak to locked-wheel coefficients have been calculated over a wide range of surface and tyre combinations, and they show the potential value of devices enabling a vehicle to make use of these high coefficients.
Cooling Rates of Brake Drums and Discs
Authors: Newcomb T.P. , Millner N.
Published: June 2010

An investigation has been made of the rates of cooling of vehicle brake drums and discs. Thermocouples were inserted in the drums and discs and in the wheel hubs and their outputs fed via slip ring units to meters mounted inside the vehicle. The drums or discs were heated to a uniform temperature of 300°-400°C by drag braking and the rate at which they cooled measured while the vehicle was driven at constant speed. Measurements were made at various speeds in the range 0 to 90 mile/h.

From the log (temperature) against time plot a cooling coefficient bv was determined. It is shown that at a vehicle speed v the quantity bv can be expressed in the form bv = b0 +Kv0·8 where b0 represents the loss of heat to the hub and K is a constant depending on the size and shape of the drum or disc. Values of these constants have been determined on a variety of cars having discs and drums varying from 7 in to 11 in diameter and on a lorry fitted with 16·75 in diameter drums. Cooling rates are shown to depend on shape and size of the disc or drum. Results show that the cooling rates of front brakes are about 20 per cent higher than the rear brakes and that front discs cool about 25 per cent more quickly than the corresponding drum size recommended for the same vehicle. The cooling rate of front discs did not change when wire wheels were fitted instead of solid wheels. Ventilated discs and solid discs were also compared. The effect of fitting dust shields on disc brakes is shown to reduce the cooling rates by about 30 per cent. The effect of otherwise disturbing the air flow was studied.
The Analysis by Computer of a Motor Car Underbody Structure
Authors: Allwood R. J. , Norville C. C.
Published: June 2010

Structural analysis techniques developed since the introduction of digital computers now allow the analysis of any three-dimensional, elastic structure made up from straight uniform beams and flat panels. A motor car underbody is not composed of these elements but by breaking it down into a large number of small elements, the complex components from which an underbody is assembled may be approximated to by these types of elements. In this paper we report the results of an analysis of a Ford Classic underbody and compare these with the results obtained from experimental tests made on an actual underbody removed from the production line.
Engine Cooling System Design and Development
Authors: Stratton D. G. , Stringer R. E. , Taylor S. R. G.
Published: June 2010

Engine cooling is a complex multi-stage process of which only the latter stages, that of heat exchange between water and air, are considered.

Cooling system performance targets as air temperature to boil values are indicated. The relationship between engine heat rejection to the coolant, radiator matrix specific dissipation and air temperature to boil is established in a form suitable for simple calculations.

Measurement of cooling system quantities and performances of individual components requires suitable test rigs and a full size vehicle wind tunnel. Data acquired from such measurements provides the basis for the application of an analytical approach to the design and development of cooling systems to achieve given cooling performance targets in the most economical manner.

A computer programme, capable of embracing the wide range of cooling system parameters, is seen as the most effective way of fully examining both new and alternative designs.
Second Paper: The Effects of Physical Factors on Ignition Delay
Authors: Lyn W-T. , Valdmanis E.
Published: June 2010

The effects of physical factors on ignition delay have been studied on a motored research engine using a single injection technique. The fuels used included a high cetane number reference fuel, gas oil and M.T. 80 petrol.

The primary factors investigated are those pertaining to the fuel spray, such as injection timing, quantity, and pressure (affecting drop size, velocity and injection rate); hole diameter (affecting drop size and injection rate) and spray form (nozzle type); and those pertaining to the engine, such as temperature, pressure and air velocity.

Engine operating variables such as speed and load affect the ignition delay because they change the primary factors such as injection pressure, compression temperature, pressure and air velocity.

It has been found that under normal running conditions, compression temperature and pressure are the major factors. All other factors have only secondary effects.

Under starting conditions, when ignition is marginal, mixture formation becomes as important as compression temperature and pressure. Such factors as air velocity and spray form which affect the mixing pattern can have a very pronounced effect on ignition delay.

Published data on ignition delay are compared with those obtained in the present investigation and a generalization of the data is recommended for engine design and computational work.
First Paper: Full-Scale Studies of the Performance of Plant in the Compaction of Soils and Granular Base Materials
Authors: Lewis W. A.
Published: June 2010

The installation and test procedure employed at the Road Research Laboratory for studying the performance of compaction plant is described. The results of tests on a wide range of equipment are summarized and an outline is given of some investigations of more fundamental factors likely to affect the performance of compaction plant.

The author would like to acknowledge the help given by his colleagues and particularly Mr A. W. Parsons of the Laboratory who assisted in much of the work described in the paper.

The work described in this paper was carried out as part of the programme of research of the Road Research Laboratory and is contributed by permission of the Director of Road Research. Reproduced by permission of the Controller of H.M. Stationery Office, Crown copyright.
Experimental Studies of Force Systems on Steered Agricultural Tyres
Authors: Taylor P. A. , Birtwistle R.
Published: June 2010

The paper reports the experimental determination of the force systems acting on free-rolling 7–50 times 16 agricultural tyres, measured with a six-component suspension of the test wheel. Multivariate experimentation techniques were used involving five variables: slip angle, camber, vertical load, tyre pattern and land or furrow operation. The results are presented as three force and three moment components; other methods of representation are discussed briefly. Although the side or cornering force depends on many factors, particularly the soil surface, and is therefore difficult to predict, it is suggested that the draught force (i.e. resistance in the direction of motion) can be expressed as a function of slip for all surfaces.
Second Paper: Meeting the Spark Plug Requirements of European Engines
Authors: Robson J. V. B.
Published: June 2010

Modern engines and driving conditions have imposed serious problems on the spark plug designer. Colder or ‘harder’ spark plugs are now required yet they must resist cold fouling in city driving. These conditions are largely being met by spark plugs in which the insulator core nose protrudes beyond the steel shell.

Design features are discussed and techniques for engine evaluation of spark plugs are described.

If the spark plug temperature exceeds 950°C it is liable to become a source of pre-ignition though the actual pre-ignition temperature will depend on the fuel used. Transient pre-ignition from hot areas and deposits in the combustion chamber will increase the temperature of even very cold spark plugs and may force them into run-away pre-ignition.

Detonation and the relationship of the spark plug to run-on are discussed.

Improper installation and operation of ignition systems will precipitate apparent spark plug problems. Variations between identical engines may require careful investigation.

Two-stroke engines have their own problems of pre-ignition and fouling and some are now operating on surface discharge spark plugs. Some require small size spark plugs.

Racing engines and Wankel engines have particular requirements which do not necessarily relate to other engines.
The Use of Alternators on British Passenger Cars
Authors: Edwards L. E. , Winkley A. W.
Published: June 2010

The need for generators of higher output ratings and improved performance at low engine speeds has resulted in the development and growing employment of alternators for battery charging systems on British passenger cars. This paper discusses some theoretical and practical problems in the specification, design and application of such alternators.

Part 1 covers the method of assessing the ‘Effective Output’ of an alternator by means of engine time-speed histograms, and shows the way in which this effective output is influenced by the drive ratio of the alternator. Empirical rules are put forward for deciding the effective output needed for a car with given electrical loading, and correlation is shown to exist between the empirical assessment and the results of practical vehicle running tests. The manner in which the alternator characteristics can be modified by the designer within a given overall size of machine, and the influence upon the effective output of such changes, are discussed.

Part 2 surveys the practical experience gained to date by the authors' company in the use of alternators on British passenger cars. The reasons leading to the present standard fixing arrangements for alternators arc described, together with suggested designs for the alternator mounting bracket which forms part of the engine. The different forms of noise emanating from an alternator are discussed.

The practical implications of achieving the desirable drive ratios lead to the conclusion that improved performance of the conventional belt drive arrangement will become necessary.

The paper concludes with some remarks on the philosophy of warning light indication, and describes some systems which meet the present requirements.
Optimum Stiffness-Weight Design of Peripheral and Ladder Frames
Authors: Sharman P. W.
Published: June 2010

The equation for the torsional stiffness of a rigid jointed rectangular plane frame is given and non-dimensionalized to provide simple comparative criteria. The effect of extreme variation in member properties is discussed. Design charts for certain cases are given.

It is shown that the equation may be modified for ladder frames of uniform spacing, under certain simplifying assumptions. The equations have been applied to model frames giving good agreement with experimentally determined values.

The members are analysed in terms of their stiffness-weight ratios and the weight parameter is calculated for families of peripheral and ladder frames. For frames of the same torsional stiffness the optimum designs are then discussed. The effect of a constraint on minimum flexural stiffness on the optimum design of a ladder frame is discussed.
Run-on in Gasoline Engines
Authors: Affleck W. S.
Published: June 2010

When the ignition of a car engine is switched off, the engine normally comes to rest within a few revolutions but, occasionally, it may continue to fire erratically for a few seconds or longer. This phenomenon is known as run-on and, for the majority of European engines, is the result of spontaneous ignition of the fuel-air mixture in the combustion chamber.

Part 1 of this paper describes experiments in a single-cylinder research engine which have been made to establish the principles controlling run-on. In particular the effects of air/fuel ratio, the nature of the fuel and the pressure-temperature-time history of the fuel-air mixture in the combustion chamber have been studied, as it is known that these factors play an important part in spontaneous ignition in experiments in laboratory vessels. From these observations it has been possible to formulate a theoretical model of the run-on process which explains the salient features of the phenomenon. In particular, it shows how the gradual cooling of the engine limits the duration of run-on and also how the duration of run-on may be considered as a measure of the extent to which fuel or engine factors must be altered to eliminate run-on.

Part 2 describes the application of these principles to car engines using normal commercial-type fuels. It is concluded that the following are important features in the control of run-on: the use of fuel of sufficiently high Research octane number, minimum opening of throttle at idle, sufficient time for cooling of the combustion chamber before the ignition is switched off, efficient engine cooling, and small valve overlap. Current devices for reducing exhaust emissions are likely, through their effects on these features, to increase the tendency of an engine run-on. Combustion chamber deposits, though, appear to have little influence.
A Rational Approach to the Aerodynamics of Engine Cooling System Design
Authors: Paish M. G.
Published: June 2010

The aerodynamic inefficiencies of motor vehicle cooling systems are generally of secondary importance to their production costs. However, the advent of the inexpensive moulded fan has meant that an improvement in cooling system aerodynamics can be more readily achieved which could reduce costs and radiator sizes, with the additional benefits of predictable performance and improved economy.

In the investigation described, the design objective was to meet the top gear cooling targets entirely with ram-induced airflow, and to design the engine driven fan so that it consumed negligible power for top gear conditions, whilst being capable of meeting the cooling targets in the intermediate gear ratios. The work divided itself into the following three sections:

(1) The prediction and achievement of the maximum ram-induced airflows. (2) Designing the cooling fan to be effectively free-wheeling and, therefore, consuming negligible power during top gear motoring, and to measure the performance of the resulting fan throughout the ram and fan assisted airflow regimes. (3) Designing and predicting the performance of a cooling system which was subsequently built and installed in a test vehicle in order to check its performance and making an overall comparison with regard to the original system.

The paper shows that the design objectives were closely achieved. The 1·7 litre test vehicle was cooled satisfactorily with a one foot square radiator with the expenditure of only 0·9 hp in the cooling system when travelling at 70 mile/h.
Transverse Engines—The First Decade
Authors: Bareham E. G.
Published: June 2010

To justify the title of the paper, mention is made of the B.M.C. Mini and Leyland Atlantean bus, both having transverse power units and being introduced slightly over ten years ago. Although these were not the first vehicles to embody the principle, they are claimed to have exploited it in modern production quantities. A survey is made of the development of the fore-and-aft engine position used in the majority of vehicles today and the reasons for changing this well-established arrangement are discussed. A short account is given of the B.M.C. Mini design history, including some development problems and their solutions. This is followed by descriptions of larger versions based on the original 850 cm3 concept. Descriptions are given of competitive transverse power units with some comments on their technical merits. Turning to public service vehicles, details are presented of the Leyland Atlantean and other rear-engined power unit layouts. Pros and cons of the various design approaches seen in the various car applications already described are discussed. Attention is drawn to certain critical design areas, such as power unit mountings, gear control, drive line flexibility, etc. In conclusion it is shown that there is no overall ideal design solution to the problems already mentioned and compromise is inevitable in the creation of any new design. The transverse engine, although still regarded as unorthodox, has established itself as a sound engineering proposition for both private cars and bus applications and its future appears to be assured.
An Exercise in Steam Car Design
Authors: Palmer R. M.
Published: June 2010

In recent years atmospheric pollution by the exhaust emissions of vehicles has become of increasing concern, particularly in America. One consequence of this has been a review of alternative power sources to the petrol engine, with the object of finding a suitable system with significantly lower quantities of toxic emission products. The merits of various possible systems have been amply discussed elsewhere and are not covered in this paper.

Among others, the Rankine cycle engine using steam or other vapour has been put forward and indeed has many ardent supporters. It has been the subject of considerable publicity in the technical and popular press, for the most part extolling its virtues but seldom mentioning any vices.
Measurement of Vehicle Handling by Tethered Testing
Authors: Barter N. F.
Published: June 2010

The technique of tethered testing is introduced as a method of measurement of vehicle steady state handling, where the vehicle under test is attached to a large parent vehicle by means of an arm attached at its centre of gravity, and the tyre forces, which in the normal free vehicle situation produce a centrifugal acceleration, are simply reacted by this arm. The tethered testing rig built at M.I.R.A. is described.

It is shown that the concept of tethered testing leads naturally to the idea of describing vehicle steady state handling by means of a quantity which depends only on lateral acceleration, and suitable quantities are shown to be static margin and the slope of a curve of mean front wheel steer angle against vehicle slip angle. These quantities are defined and their derivation in terms of vehicle stability derivatives is outlined in an appendix. Some examples of tethered test measurements are given in the form of plots of static margin against lateral acceleration, and a tentative set of criteria for good steady state handling is given in terms of the behaviour of static margin with lateral acceleration.
Vehicle Handling Qualities
Authors: Hales F. D.
Published: June 2010

The paper is concerned in general with quantitative methods of analysis for the general steady-state motion of an automobile and, in particular, for methods that are able to assess the non-linear characteristics of vehicles. In this context it is observed that any quantity used must satisfy three requirements; it must have a physical significance and be capable of prediction and measurement.

For this purpose three basic handling concepts are considered, understeer, static margin and slip/steer gradient. Following the analysis of the perturbation motion about steady circular motion, the concepts are rationalized and related to the theoretical vehicle behaviour. In a discussion of this analysis the relationship between the three concepts are investigated and subsidiary vehicle parameters highlighted.

The final stage of the quantitative method outlined is dealt with in a section on experimental procedures. Three procedures, response mapping, tethered testing and steering pad tests, are examined, and the required measurements and analysis processes needed to obtain measurements of the handling qualities are derived. Finally a typical set of experimental results from a response mapping experiment is included as an example of processes described.

It is concluded that the concepts of understeer, static margin and slip/steer gradient can be successfully applied theoretically to the general non-linear cornering motion of an automobile, and that experimental techniques exist that yield measurements from which quantities defined by the theoretical analysis can be obtained, with the exception that measurement of static margin in the general non-linear motion condition is not satisfactory because of experimental problems. The tethered test technique and the steering pad test are also able to provide measures of the most important associated vehicle stability parameter.
The Italian Way to Safety
Authors: Bencini M.
Published: June 2010

Confronted with the high accident rate on Italian roads the automotive engineers in Italy feel that active or primary safety is of basic importance, namely, those features that provide the automobile with the highest possible degree of controllability in any circumstances. Of course, passive or secondary safety is not neglected as it reduces the consequences of the first collision (against another vehicle or obstacle), namely, the injuries which occupants suffer during the second collision from impacts against the passenger compartment interior. Exhaustive design and testing development work is going on. Other factors involving limitations in the specific performance of engines are discussed.
Paper 6: Experiments on the Performance of Slow-Speed Hydraulic Motors for Use in Agricultural Tractors
Authors: Howson D. F.
Published: June 2010

Two series of experiments were carried out. In the first series, drawbar performance tests were conducted with a tractor fitted with slow-speed hydraulic wheel motors of different capacities. The advantage to be gained from the use of dual-capacity motors may be assessed from the results of these tests.

An experimental dual-capacity motor is described and details of its performance are given.

In the second series of experiments, an attempt was made to isolate and analyse sources of output torque loss in a slow-speed motor of the radial piston type.
Paper 7: Hydraulic Powered Steering for Heavy Vehicles
Authors: Bowers E. H.
Published: June 2010

The paper deals briefly with the factors affecting the matching of powered steering to the vehicle performance, the basic requirements of the hydraulic pumps, valves, and actuators, and the current design trends.
Paper 1: Paper 2: A Standard-Triumph Family Car Engine-its Design History during a Decade
Authors: Eley D. C.
Published: June 2010

The paper gives the history of the conception and design details of a mass-produced four-cylinder 803 cm3 engine, its redesign to 948 cm3 and the design of a twin-carburettor version. Finally a further redesign to increase the capacity to 1147 cm3 for both single- and twin-carburettor versions.

An initial appraisal was made of the type of unit required to power a small family saloon car.

Engine performance requirements were established from a performance curve of the vehicle obtained from frontal area aerodynamic coefficient, estimated weight, etc.

The configuration of the unit was fully investigated, the number and disposition of the cylinders, type of cooling, position of valves and type of valve gear were all explored, bearing in mind technical requirements, cost and ease of production and production plant requirements.

Having decided upon a four-cylinder in-line liquid-cooled unit, a detailed description is given of the reasons for the design configuration of the major components and the disposition of the ancillary equipment.

The need to extend the range of models of this vehicle brought about the first increase in capacity to 948 cm3 and design modifications are enumerated. A twin-carburettor version was a further requirement and design and development details are discussed.

With the introduction of a completely new design of motor car using this power unit, the road holding and general handling characteristics of the vehicle were so outstanding that improved engine performance became a necessity to match the above qualities.

The methods of increasing performance are discussed and the reasons given for the necessity to increase capacity. In view of already established transfer machinery for all major components, the minimum of change was essential and a history of the design and development of the unit is given. It is shown that careful study of existing equipment is vitally necessary when making extensive design changes. First designs made the minimum of change and only when test work showed shortcomings were further changes made. A series of designs and tests finally achieved a sound design giving excellent results from extended tests. This process established that all the modifications were vitally necessary to achieve the performance and reliability necessary for the engine to have a further period of production and enable progressive development to be successful.
Paper 2: Adhesion in Railway Braking
Authors: Hatch D. , Law J. , Parker R. C.
Published: June 2010

Reasons are advanced why the processes of adhesion in braking may differ from those in traction, and limitations of adhesion-measuring machines are discussed.

It is shown how the nature of the variation of braking torque with velocity may affect the driver's manner of applying the brakes.

Incidence of pick-up from 2000 brake applications on three different types of brake (cast-iron tread, non-metallic tread, and disc) are studied to investigate the effect of load, the effect of moisture, and the effect of speed on adhesion. The incidence of pick-up is found to be less for a loaded than for an empty train and greater for wet than for dry rails, so confirming known facts and justifying the particular method of approach.

A complex adhesion/speed characteristic with a minimum value in the range 40–50 miles/h for dry tare conditions is shown to exist, which demonstrates that relations generally accepted to be applicable to braking are invalid. On wet rails incidence of pick-up is higher on the leading bogie and the suggestion is made that brake forces to this bogie could be reduced. Off-tread braking increases vulnerability to wheel sliding but with wheel-slide protection the exacting demands of dense suburban traffic are adequately met.
Paper 8: Effect of Suspension Characteristics on Adhesion
Authors: Koffman J. L. , Batchelor G. H.
Published: June 2010

Work so far carried out confirms that the dynamic variations of axle load are similar in magnitude to the changes of axle load due to quasi-static weight transfer. The dynamic responses of the suspension, particularly the primary stage, are therefore considered to be of appreciable significance so far as adhesion is concerned. Road test results obtained with Bo-Bo electric locomotives having spring and kinematic drives as well as axle-hung motors are presented and these indicate the effect of specific suspension arrangements on variations of axle load.
Paper 4: Steelworks Maintenance Organization
Authors: Roberts J. D.
Published: June 2010

The paper describes Redbourn Works approach to the problem of organization for effective and economic maintenance. The procedure is typical of that needed to maintain any large process plant in continuous operation.
Paper 3: Forced Convection Heat Transfer in Passages with Varying Roughness and Heat Flux around the Perimeter
Authors: Rapier A. C.
Published: June 2010

An approximate theoretical expression is derived for the ratio by which heat-transfer data, obtained from simple symmetrical flow passages, must be ‘transformed’ when applied to passages with varying roughness and heat flux around the perimeter. It is shown to be in good agreement with more elaborate theoretical treatments of special cases and with experiment.
Paper 7: Experiments Concerning the Aerodynamic Performance of Inward Flow Radial Turbines
Authors: Hiett G. F. , Johnston I. H.
Published: June 2010

For some years, a programme of research into the aerodynamic performance of inward flow radial turbines has been conducted by Ricardo & Co. under the sponsorship of the Ministry of Aviation.

The paper describes this experimental work and presents an edited version of the principal test results. The sensitivity of turbine performance to changes in the major design variables such as nozzle angle, rotor size, and rotor shape is illustrated and the effects of practical variables such as tip clearance and leakage flows are recorded.
Paper 8: Studies of Flow through Centrifugal Pump Impellers
Authors: Simpson H. C. , Cinnamond C.
Published: June 2010

A photographic technique is used here to give quantitative measurements of the three-dimensional flow pattern in pump impellers operating at conditions of practical interest. This technique is used to study the flow through a series of impellers of outlet angle varying between 20° and 35° and inlet angles constant at 20°, operating over a range of throughflows. Attention is here focused on the flow patterns at, and below, the best efficiency point.

Experimental results show that standing vortices can appear at both the leading surface near the impeller eye and at the trailing surface near the impeller tip, with the latter becoming more important as the throughflow is reduced. A qualitative explanation for the appearance of these vortices is given in terms of boundary-layer theory and the effect of the trailing surface vortex on the pump performance is discussed. Estimates are made of the internal slip coefficient and a study of the losses in the volute close to the impeller tip is made. The data are again analysed in terms of the Busemann potential flow theory. It is concluded that impeller design, by influencing the impeller flow pattern and introducing separation regions, can have an important effect on pump performance, particularly with reference to stability.