bluuebunny/crossref_metadata_2025 huggingface dataset:
Paper 8: Forces Transmitted by Joints in the Human Body
Authors: Paul J. P.
Published: June 2010

A technique has been developed which allows the assessment of the variation with time of the magnitude and direction of the resultant forces transmitted at joints in the human body during normal activity. Tests have been performed on joints in the lower limb and typical patterns of variation of force with time and leg position are shown for normal test subjects walking on level surfaces. The test procedure involves the measurement of external force actions transmitted to the leg and their correlation with photographic records. This information is processed to obtain the resultant force and moment actions at the joint, taking account of the effect of gravity and accelerations. The moment actions are transmitted by the development of tension in muscular or ligamentous connections crossing the joint and the corresponding reaction at the joint. Generally, the number of muscular or ligamentous connections exceeds the number of available equilibrium equations. A guide to the muscles which are acting at any instant is obtained by the myoelectric signals picked up by electrodes secured to the skin over the muscles. Even with this information, an explicit solution is generally not possible and the information is presented as curves of upper and lower limits of joint force corresponding to the use of muscles having the greatest or least moment arm.
Paper 6: Physical Characteristics of Articular Cartilage
Authors: Edwards J.
Published: June 2010

Since articular cartilage is the principal wear resisting tissue in animal joints, an understanding of its physical behaviour is of particular importance in studies of animal joint lubrication.

This review is concerned with the physical factors involved in rheology of cartilage. Particular attention is paid to the physico-chemical properties of its matrix and to the nature of forces acting between its liquid and solid components.

The experimental work reviewed includes studies of the interrelations between stress, strain, fluid flow, and time during compression and swelling of the tissue, and of transport of liquid through the matrix. The mechanism which controls the behaviour of cartilage during compression and swelling is discussed.
Paper 11: Friction and Wear, Detection and Measurement
Authors: Barwell F. T.
Published: June 2010

Wear is a complex process which may take many forms and this paper describes some methods for its study which have been used in engineering research in the hope that the principles involved may be suitable for more general application.

Measurement of change in size or shape is usually the most profitable but, in view of the small changes in dimension often involved, great care is necessary. The principles of engineering metrology are introduced and the advantages of ‘air gauging’ are outlined.

Estimation of the amount of wear is difficult because the changes are often very small compared with the total weight of the component subjected to a wearing process. Particular care is necessary to avoid false conclusions attributable to changes in weight caused by water absorption, etc.

Another fruitful method relies on providing some form of witness; for example, a diamond pyramid hardness impression may be made in the unworn surface so that its change in size can be used to estimate the extent of wear.

Stylus instruments have much application in wear studies, providing the simplest means for quantifying the texture of a surface.

The optical microscope is an invaluable tool for wear studies, particularly if adapted for microhardness testing and interference methods.

The paper concludes with a reference to electronic methods of surface study, particularly the electron microscope and the electron probe analyser.
Paper 1: Physiological Lubrication
Authors: McCutchen C. W.
Published: June 2010

Physiological lubrication differs from normal engineering practice in the materials used, and in the type of service to which the bearings are subjected. These permit or require—it is dangerous to specify which—at least two mechanisms which are outside conventional engineering.

The first is weeping, or self-pressurized hydrostatic lubrication. This occurs because the bearing material is microporous and easily deformed, and because the service is always intermittent. The second is a form of boundary lubrication which can support only very small unit loading. Unlike the boundary lubricants of industry which adsorb as close-packed layers upon the bearing surfaces, the synovial mucin molecules are inherently dilute, each extending through a large volume of solution, and any adsorbed layer is likely also to be dilute. Such a swollen layer should, nevertheless, be able to support small loadings, because any attempt to compress it will be resisted by a pressure which is, broadly, of osmotic origin.
Paper 10: Total Human Hip Joint Prostheses—A Laboratory Study of Friction and Wear
Authors: Duff-Barclay I. , Spillman D. T.
Published: June 2010

The design of artificial joints is determined by anatomical surgical, and physical considerations. A review of previous work has shown the need for data on the lubrication, wear, and friction characteristics of suitable biologically acceptable bearing materials. To obtain this information special equipment has been designed which can simulate the motions and loadings that occur in the hip joint during walking. The results of the investigations are presented.
Paper 2: Factors in the Design of an Artificial Hip Joint
Authors: Charnley J.
Published: June 2010

The design of an artificial hip joint is influenced by the problems of surgical technique in making the implant. Encouraging results have already attended the use of an elementary design of ball and socket joint with the rubbing surfaces exposed to tissue fluids. When the surfaces are of identical metals (chrome–cobalt alloy) the tissue fluids appear to lubricate in some measure; when the ball is of metal and the socket of high molecular weight polyethylene there appears to be some degree of self-lubrication in the plastic.

The essential problem is whether particles abraded from the rubbing surfaces will cause harmful tissue reactions over a long period of time. The more resistant the materials are to wear, the less will be the amount of the abraded material to cause harm. The success of the exposed joint is such that it seems desirable to explore to the limit this simple solution before seeking new and more complex designs. The exposed bearing has an additional advantage in permitting subluxation as a safeguard if the hip is violently forced beyond its designed range; this protects from avulsion the cement bond between the living bone and the implant.

General factors in design are discussed which have developed from practical experience with different types of total prosthesis used in clinical practice. The attempt has been made to concentrate on information obtained from surgical experience rather than to report laboratory tests which are readily repeatable in engineering laboratories.
Research Report 3: Are Synovial Joints Squeeze-Film Lubricated?
Authors: Fein R. S.
Published: June 2010

A simple analysis of squeeze films between compliant surfaces is presented and supported experimentally. Application of this analysis to synovial joints strongly indicates that a squeeze film of synovial fluid is readily maintained; further, the film appears to be hydrodynamically replenished through entrainment of fluid when the joint is moved. Joint failures due to ageing or injury and the failure of prostheses are rationalizable in terms of reduced film thickness and increased stress resulting from reduction of conformity and compliance of joint surfaces.
Opening Contribution 5: Collaborative Approach to Weld Quality by Designer and Inspector
Authors: Atkinson C.
Published: June 2010

Most engineering components are subject to inspection at some stage, particularly those incorporating welded joints. Often the task of the welder and inspector is hampered by the location of joints in positions difficult of access. This is just one aspect of poor design which could be eliminated by collaboration between designer and inspector at the outset. Up to the present, insufficient attention has been paid by designers to important features such as the weldability of materials, joint geometry, siting of welds, feasibility of heat treatment, and surface finish. The increasing use of non-destructive testing, particularly ultrasonics and radiography, has highlighted inspection problems, and as a result, designers are becoming more aware of their ultimate influence on inspection.

Although the aims of the designer and inspector are the same—adequate service performance at lowest cost without danger of shutdown—the designer's interest appears to wane as the inspector's functions become more significant.

A prolific cause of weld failure is fatigue cracking caused by stress-concentration at welded joints, yet how many designers realize that the external contour of a weld cannot approach the neat appearance indicated on drawings unless expensive grinding or machining is done?

The paper will attempt to explore, with the aid of examples, the avenues where more co-operation is needed between designer and inspector.

In addition the paper will present a new concept in the designer/inspector relationship in the form of a ‘failure index’ calculated from a number of variables known at the outset. This is a scheme to enable the designer to anticipate the relative amounts of inspection to be applied to various parts of complicated welded fabrications like those in conventional and nuclear power stations. The index system was devised specially as a collaborative link between designer and inspector in a field where the cost of failure in service can be enormous.
Paper 2: Aspects of the Wear of Spinning Travellers: The Division of Heat at Rubbing Surfaces
Authors: Grosberg P. , Mølgaard J.
Published: June 2010

The wear of ring travellers is important because it prevents the use of higher production speeds in ring spinning. This wear is probably affected by the body temperature of the traveller and an analysis is quoted which shows that a factor which has a very large effect on the body temperature is the division of heat between the traveller and the ring. To investigate this an experimental apparatus has been constructed which effectively rotates the ring and keeps the traveller fixed. It is thereby possible to estimate the division of heat between the two surfaces and to estimate its effect on the rate of wear.

The results of the experiments are still not conclusive but it has been shown that the pressure has a much more important effect on wear rate than does speed. The pressure also has a cumulative effect since it very drastically affects the division of heat between the two rubbing bodies so that high pressures and high temperatures are produced simultaneously.
Paper 4: The Chartered Engineer in the Process Industry
Authors: Haigh R. D.
Published: June 2010

The paper outlines training requirements for engineers in the process industries and discusses how they can be achieved. Attention is drawn to changes in the educational routes which are available now compared with 25 years ago.

Methods of recruitment direct from school or from the universities are compared, and the need to select candidates with both technical and managerial ability is emphasized. Opportunities exist for the trained engineer in the following three main spheres: (1) As a design and project engineer whose prime responsibility is to organize new capital projects and, by his skill, influence future plant efficiency and operating costs. (2) As a maintenance engineer who, whilst primarily concerned with the introduction of novel and improved maintenance techniques, is also able to make a contribution to the design of new plant by suggesting modifications to reduce maintenance. (3) As a machinery development engineer in industries where automatic machinery is extensively used for processing and packaging, and where frequently suitable equipment may not be available commercially.

The paper indicates the need for well-qualified people in each of these spheres and demonstrates that the scope and responsibility attached to the work are such as to provide adequate job satisfaction.

Emphasis is laid on the need for the engineer to work as part of a team with development and production personnel and also with other service departments such as accounts and management services.
Paper 7: Training in Engineering Practice in the Process Industry
Authors: Willetts J. R.
Published: June 2010

The author, who is responsible for technical training in IMI (K), discusses the work of professional engineers in the process industry and describes how they may be trained. The schemes in his own company for the training of graduate mechanical engineers and sandwich students are given and their evolution is discussed. The value of practical experience in the process industry is emphasized and the author shows how this can be given whilst maintaining interest and intellectual challenge by including some training with foreign companies.

The paper discusses the relative merits of the tutorial and project methods and shows how some of the advantages of each may be used. The author recommends some practical experience prior to entering full-time University courses for engineers in particular and applied scientists in general and considers, therefore, that ‘thin’ sandwich courses offer certain advantages over full-time University courses followed by practical training.

The author considers that the successful training of graduates requires careful thought and attention, and close liaison with the trainees to ensure that their wishes and the needs of the company are considered.
Paper 10: Sandwich Courses
Authors: Tait James S.
Published: June 2010

The Colleges of Advanced Technology exerted powerful influence on the Diploma in Technology Sandwich Courses. The effect of recent important developments should be investigated. The technological universities now offer degrees and have added to their range of interests. The National Council for Technological Awards has been replaced by the Council for National Academic Awards, and the Dip. Tech. by a degree.

Industry was free to select A-level students and, with the agreement of the College, to enter them on a sandwich course. All entrants to a technological university must now apply through the Universities Central Council on Admissions in September, nine months before entering A-level examinations. This restriction does not apply to C.N.A.A. Colleges.

The Industrial Training Act spreads the cost of industrial training and has other important repercussions. Government policy is restricting the numbers entering university to Robbins' figures.

All these matters raise questions. Other important questions concern integration, liberal studies, the five-semester course and, in a fluid situation, others will arise over the next few months. There is much to discuss!
Paper 5: Valves for High Steam Pressures and Temperatures
Authors: Fuller J. A.
Published: June 2010

The paper deals with steam valves as installed at large modern power stations. The types of valves dealt with are stop valves and safety valves.

In considering the former category, reference is made to design principles and applicability as well as to mechanical and metallurgical factors affecting component design. The influence of quality control techniques and commissioning hazards are discussed.

Safety valve design considerations are referred to, as are aspects of performance and noise, and also possible design trends.
Paper 18: Effect of Interface Geometry on the Wear of Graphite Sliding against Stainless Steel
Authors: Houghton J. E. , Mitchell L. A. , Crawford T. S.
Published: June 2010

The specific wear rate of reactor-grade graphite discs, sliding against En 58B stainless-steel cylinders, was determined for a range of theoretical contact pressures for unidirectional, constant-speed sliding in laboratory air. In many instances, wear was found to be discontinuous and associated with blistering of the graphite surface; the severity of blistering increased with increasing maximum contact pressure, but became negligible at low contact pressures, when the specific wear rate tended to a constant value—the microscopic component. At very high contact pressures, wear resulted predominantly from ploughing, i.e. instantaneous brittle fracture.
Paper 21: Variations in Friction and Wear between Unlubricated Steel Surfaces
Authors: Earles S. W. E. , Powell D. G.
Published: June 2010

Experiments have been conducted in a normal atmosphere using a 0·25-in diameter mild-steel pin specimen sliding on a 10-in diameter mild-steel disc. The ranges of normal force and speed are 0·5–10·4 lbf and 20–190 ft/s respectively.

Initially the coefficient of friction is comparatively large, and the wear is of the severe metallic form. However, frictional heating causes rapid oxidation of the surfaces and, if the sliding distance is sufficient, the eventual retention of an oxide layer causes a rapid decrease in the coefficient of friction and the wear rate decreases by 3–4 orders of magnitude. At speeds above about 75 ft/s and loads below about 5 lbf the formation, after several hours' sliding, of a continuous oxide layer on the track causes a further reduction in the pin wear rate. At higher loads and/or lower speeds this track condition is not attained.

At speeds of 75 ft/s and above there exists a critical load (the magnitude of which depends on speed) above which periodic removals of the surface film(s) occur producing metallic wear and high friction. However, the subsequent increase in oxidation allows conditions of mild wear to be re-established generally within a few seconds.

The steady-state coefficient of friction has been observed to be a function of load1/2 × speed, and periodic surface breakdowns found to occur when load1/2 × speed exceeds 170 lbf1/2 ft/s, the frequency decreasing with increasing load or speed.
Paper 22: Control of Fretting Wear of Sintered Aluminium Powder
Authors: Commissaris C. P. L. , de Gee A. W. J.
Published: June 2010

For the development of a new type of nuclear reactor to be built with light metals (Al, Zr, Be, Mg) as the main construction materials, equipment was designed for the study of wear under fretting conditions. With this equipment experiments can be performed in various gaseous and liquid environments, including the organic coolant terphenyl at temperatures up to 450°C. Two different vibrational motions can be applied: a torsional vibration in the plane of contact (pure fretting), and a vibration normal to the plane of contact (hammering motion). In the first phase of research attention was focused primarily on the wear behaviour of sintered aluminium powder (SAP). It was found that the wear of SAP against SAP, SAP against stainless steel, SAP against zirconium, and SAP against beryllium, strongly exceeds that of stainless steel against stainless steel, zirconium against zirconium, and beryllium against beryllium. Nevertheless, it was found possible to protect the SAP completely against fretting damage by using carbon-based bearing materials as mating components, or by coating the contacting surface with a plasma sprayed layer of antimony-tellurium alloy. After 400 h vibrating at 50 c/s in terphenyl of 400°C against a relevant layer, the SAP specimens proved to be virtually unattacked. Quantitative data on the wear of the sprayed layer itself are also presented. The wear rate of this layer is so small that application in practice can be seriously considered.
Paper 16: Recent Developments in Polytetrafluorethylene-Based Dry Bearing Materials and Treatments
Authors: Pratt G. C.
Published: June 2010

The addition of bronze or certain phosphates to lead/polytetrafluorethylene (p.t.f.e.) mouldings can produce a high degree of wear resistance. Similar performance can be obtained from porous bronze or phosphated steel surfaces impregnated with lead/p.t.f.e. The effectiveness of lead or lead oxides in these ternary compositions is related to an exothermic reaction with p.t.f.e. It is postulated that during rubbing the reaction takes place at local hot spots and results in the formation of a chemically bonded p.t.f.e. layer on the mating surface.

Polyethylene compositions have similar wear properties to p.t.f.e. compositions, but the response of polymers to the bronze+lead type of addition decreases as the molecular structure of the polymer deviates from the simple CF2 or CH2 type.

The optimum bronze/lead ratio for maximum wear resistance depends on the rubbing conditions. For instance, it is not possible to combine in a homogeneous composition maximum dry wear resistance, when a low bronze content is required, and maximum wet wear resistance, which requires a higher bronze content.
Paper 12: Study of the Effects of Elevated-Temperature Lubricants on Materials for Rolling Elements
Authors: Scott D. , Blackwell J.
Published: June 2010

Using a simple laboratory test rig, the effects of different lubricants on elevated-temperature rolling elements have been investigated. The lives of various materials have been compared when lubricated with currently used elevated-temperature lubricants such as diesters and silicones and potentially suitable lubricants such as polyphenyl ethers. Rolling contact fatigue lives with different polyphenyl ether type lubricants have been assessed, and the effect of composition and purity of the lubricant on the wear experienced has been investigated.

The nature of the lubricant has a dominant effect on the incidence of failure in rolling contact, and the deleterious effects of different lubricants vary with different materials.

Examination of failed steel specimens revealed the influence of the lubricant on surface changes caused by rolling action, and afforded some insight into the mechanisms of failure.
Paper 9: Effect of Work Hardening during Rolling Contact on Pitting of Gear Materials
Authors: Hirano F. , Kuwano N. , Ichimaru K.
Published: June 2010

In order to find the best combination of materials for reduction gears of marine turbines, the authors carried out an investigation on pitting using a disc machine. The resistance to pitting of wheel material was considerably affected by the work-hardening effect owing to rolling contact. Hard pinion material raised the resistance of wheel material to a great extent. The best result was attained by the combination of materials showing both the greatest work-hardening tendencies. The work-hardening tendency estimated by measuring the Meyer index served to predict the pitting life. The test results were discussed further based upon the theory of elastohydrodynamic lubrication.
Paper 1: Theory of Lubrication Applied to Pressure Nozzle Design in Wire Drawing
Authors: Chu P. S. Y.
Published: June 2010

Using the idea that a tube or nozzle placed in front of a die is capable of generating sufficient pressure to cause a thick hydrodynamic film to be formed during wire drawing, the equations of Tattersall were developed to facilitate the design of such nozzles. Design graphs are presented to correlate the geometrical factors of the nozzle with parameters of lubricant properties, speed, die angle, and film thickness. A preliminary experiment shows how the properties of the stearate soap lubricant under high pressure may be found.
Paper 11: Experiments in the Aerosol Lubrication of Power Gearing
Authors: Howell P. G.
Published: June 2010

Aerosol lubrication has been most fully exploited in the field of rolling element bearings, notably for rolling mills but also in other machinery. The paper describes the application of an aerosol system to a power-transmission gearbox.

The aerosol equipment was fitted to one gearbox of a 5-in-centres back-to-back rig so that either conventional sprays or the aerosol could be used. Involute test gears were made in through-hardened and nitrided case-hardened steels.

Under aerosol lubrication the following points were noted: (1) because of the lower cooling capacity of the aerosol, operating temperatures were much higher than under spray lubrication; (2) the through-hardened gears failed by scuffing when their bulk temperature reached 90°C; (3) for the same temperature rise the nitrided gears transmitted 2·3 times the power, and operated at higher temperatures and powers without damage; and (4) no reduction could be detected in losses, suggesting that the losses attributable to churning of excess sprayed lubricant are balanced by an increase in tooth friction with aerosol.

The experiments showed that power transmission gearing can be successfully lubricated by an aerosol, especially if the tooth surfaces are protected by nitriding.
Paper 20: Wire-Wool Type Bearing Failures: The Effect of Steel
Authors: Dawson P. H. , Fidler F.
Published: June 2010

As part of an investigation into wire-wool type bearing failures 21 steels of different compositions and structures have been tested for susceptibility to failure at one moderate rubbing speed and with one turbine oil containing no extreme-pressure (e.p.) additives.

It is shown that composition and, in particular, the chromium and manganese contents are the important factors. Heat treatment and metallurgical structure are of little importance. The critical chromium content would seem to lie between 1·3 and 2 per cent. The critical manganese content has not yet been determined, but it lies between 0·8 and 14 per cent.

Some early results from a study of the failure initiation process suggest that the susceptibility of the chromium and manganese steels may be associated with their transfer characteristics in high-speed lubricated rubbing.
Paper 24: Influence of the Hardness of Abrasives on the Abrasive Wear of Metals
Authors: Nathan G. K. , Jones W. J. D.
Published: June 2010

Abrasive wear tests were carried out using the abrasives carborundum, corundum, garnet, flint, and glass on a wide range of metals and alloys.

The results obtained show that the abrasives each have an effective hardness which defines the maximum hardness of a metal which it will abrade; this value is different from its measured hardness.

Further, a relationship has been derived of the form V = KWL log Ha/Hm which enables the volume V of abrasive wear of a metal to be calculated from a knowledge of its hardness Hm, the effective hardness of the abrasive Ha, the abrasive load W, and the length L of the abrasive path; the expression also involves a constant which is evaluated by experiment.
Paper 3: Recent Developments in Fluid Film Lubrication Theory
Authors: Lloyd T. , McCallion H.
Published: June 2010

Developments in high-speed electronic computers have greatly influenced the progress in fluid film lubrication over the past ten years. Static and dynamic oil film parameters have been computed for a wide range of finite geometries, for hydrostatic and hydrodynamic bearings lubricated by compressible and incompressible lubricants. These are either sufficient in themselves or else act as a yardstick against which approximate formulas may be tested. Much use has been made of iterative finite difference schemes, which are particularly well suited to digital computers, and these methods are now more fully understood. Other methods of solution include direct inversion of finite difference matrices and solution by expression of the pressure by some infinite series, a finite number of terms of which give adequate representation.

Besides the increase in design data available, there has been substantial progress through a re-examination of the effects of modifying some of the assumptions inherent in most of the available solutions of the Reynolds equation. These include the assumption of constant lubricant viscosity, of rigid surfaces and of laminar flow.

Major progress has been witnessed in two fields. The interaction of the lubricant film with elastic boundaries has been shown to be of prime importance in highly loaded contacts such as gears. This has led to the development of the special topic of elastohydrodynamic lubrication theory. The applicability of gas bearings in such growing industries as computers, space vehicles and nuclear reactors has resulted in great activity and progress in this field.
Paper 4: Bearings for Reciprocating Machinery: A Review of the Present State of Theoretical, Experimental and Service Knowledge
Authors: Campbell J. , Love P. P. , Martin F. A. , Rafique S. O.
Published: June 2010

The paper reviews the present state of knowledge and design techniques and attempts to provide a physical appreciation of the characteristics of bearing performance. The work which has been carried out recently in the United Kingdom, the United States, The Netherlands and Germany is examined and the paper attempts to relate this to experimental results and the practical engine. The possible relationships of components within the engine which affect the conditions of operation and parameters which could lead to improvement of these conditions are suggested and examined, and the possibilities of future work in exploring this area are indicated.
Paper 7: Rotor Stability
Authors: Sternlicht B. , Rieger N. F.
Published: June 2010

The theoretical and experimental work of several investigators in rotor-bearing stability is summarized. Incompressible fluid-film bearings under laminar and turbulent flow conditions and compressible fluid-film bearings of the self-acting and externally pressurized type under laminar flow conditions are described. Design charts are given for calculation of the threshold of instability under laminar and turbulent, compressible and incompressible flow conditions. The effect of rotor flexibility and non-linear effects are discussed. In addition, the author makes several recommendations for further studies.
Paper 8: Pressure Pad Bearings
Authors: Opitz H.
Published: June 2010

The principles, calculation methods and problems which have to be taken into account when designing pressure pad or hydrostatic bearings are discussed. A brief review of the current applications in machine tools is presented.
Paper 20: Solid Lubricants
Authors: Devine M. J. , Lamson E. R. , Cerini J. P. , Carroll R. J.
Published: June 2010

This paper describes a research investigation encompassing a study of the combination of lubricant materials, bearings, and design criteria for the long-term operation of mechanical systems with self-contained non-fluid lubricants. The feasibility of providing an oil-free lubricated internal-combustion engine was established.
Paper 25S: Sliding Noble Metal Electric Contacts
Authors: Antler Morton
Published: June 2010

Sliding electric contacts have the unique requirement of low and stable resistance without high friction and wear. Electrical breakdown of surface films, which can establish metallic contact between touching members, occurs only with appreciable circuit voltages. Consequently, noble metals alone are suitable for contacts that serve the low energy circuits of modern computer, communications and aerospace equipment. Approaches used by the engineer to reduce the friction and wear of noble contact metals include: design with low normal loads, careful selection of contact materials and lubrication. Gold coatings, generally as thin electrodeposits, have become the most widely used contact material for separable connector contacts, instrument slip rings and similar devices.

The ‘prow formation’ wear mechanism dominates the dry sliding of most noble contact metals, particularly during the early stages of sliding where break-in phenomena occur. Recent work shows that there is a critical load-dependent roughness for prow formation. The wear mechanisms of gold electrodeposits may differ from those of the wrought metal because of their characteristic topographic and crystallographic orientations.

Lubricants are often used for sliding noble metal contacts. Solid lubricants are effective only on rough surfaces. When contacts become burnished through use the lubricant reservoirs disappear and high wear commences. Thin films of lubricants having a fluid component, however, do not have this limitation, for they demonstrate hydrodynamic lift and self-healing qualities. Above a certain velocity, characteristic of the system, wear may be negligible with fluid-containing lubricants. Their ability to function on smooth surfaces is important, for the as-plated porosity of electrodeposited metals (which leads to deleterious contact corrosion) is directly related to roughness. Finally, coatings for thin gold-plated contacts have been developed which combine corrosion inhibitors and lubricants.
Paper 27: Protection against Dirty Environments: Filtration
Authors: Wells R. M.
Published: June 2010

The sources and types of environmental contamination, and the methods of removal by filtration, centrifugation, etc., are reviewed, with methods of test, filter media, and filter element and case designs.
Paper 7: Hydraulic Vibrators in Automobile Testing with Special Reference to the Rootes Suspension Parameter Rig
Authors: Hodkin R. K.
Published: June 2010

The principles of the conventional high performance hydraulic vibrator and its operating characteristics are described. An examination is made of the limitations involved and compared to the limitations of electro-magnetic and mechanical vibrators to show significant areas where the hydraulic vibrator has worthwhile advantages.

Mention is made of typical applications of hydraulic vibrators to vehicle testing and development. However, a substantial part of the paper is devoted to a specific installation, being a rig primarily designed for the measurement and study of vehicle suspension. This suspension parameter rig essentially consists of four long stroke hydraulic vibrators set in substantial pedestals so that the tyre contact patches of a vehicle may be individually supported and fed vertical inputs.

The rig and its associated instrumentation is described in some detail as are its various modes of use from static to dynamic testing up to around 100 Hz. Much of the work carried out on the rig is directly or indirectly associated with vehicle ride. In addition to the ability to feed in single and repetitive waveforms at different phase relationships, road inputs may be simulated.
Paper 12: Product Development Aspects of Motor Vehicle Testing
Authors: Stratton D. G. , Gallantree J.
Published: June 2010

Vehicle testing is seen to have the dual purpose of ensuring customer satisfaction and increasing engineering design experience and knowledge.

The techniques used vary in accordance with the objectives of the investigation. Research and development test methods are designed to assess the achievement of product performance objectives and to provide information to guide engineering design.

Specific examples of tests, instrumentation and analysis used in relation to vehicle durability, noise, ride and handling, heating and ventilating systems, and engine cooling systems are included. Importance of overseas testing to evaluate vehicle behaviour in various environments is stressed.

Production validation testing of vehicles built by production methods, prior to new model introduction date, is designed to ensure that performance specifications, vehicle reliability and quality targets are satisfied.

Quality control testing is designed to ensure that product objectives are maintained. Test methods are simple and results are interpreted on a ‘Go/No-Go’ basis.

Testing continues throughout the model life to assist in correlating warranty claims and customer complaints with the test methods used in product evaluation.
Paper 15: A Study of the Flow at Inlet to Gas Circulators for Nuclear Reactors
Authors: Lewis W. E. , Holmes M. J.
Published: June 2010

This paper describes experimental work on scale models of the intakes to gas circulators for gas-cooled reactors. One model was of a geometry suitable for the older type of reactor in which the boilers were outside the main pressure vessel while the other was associated with the more recent concrete pressure vessel concept.

In both models the flow was through a complex annular bend into the blade annulus in which the flow distribution was measured. In one case the bend was axisymmetric and turned the flow through 180° from one annulus into a concentric inner one. In the other model the geometry was much more complex with flow from a near hemispherical chamber being diverted into the blade annulus by a bend of more than 90° at the top of the intake and 180° at the bottom.

The tests showed that the original design of the first model gave a satisfactory performance but the other model required considerable development work.
Paper 14: The Working Environment
Authors: Billington Neville S.
Published: June 2010

It is pointed out that suitable thermal environments for people at work have not been accurately established. Although the broad characteristics are known, the data available to the system designer are incomplete. This is due, at least in part, to changes in architectural practice and in methods of heating and air conditioning which have occurred in the last 20–30 years. A literature review of the effect of the environment on work output, health, and accidents shows that large departures from good conditions provoke significant drops in production; the effect of small departures is not clearly defined. Points requiring further study are listed, and it is shown that such a study might well be economically rewarding.
Paper 5: Services in Relation to Building Design and Environment
Authors: Wise A. F. E.
Published: June 2010

Engineering services nowadays account for between 20 and 60 per cent of the cost of construction, and are a major factor in operating costs of buildings. They must be provided as economically as possible and in proper relation to the design of the building and the needs of the users. The paper explores this theme from two aspects (1) thermal conditions, and plant sizing in relation to building design and (2) standardization of services for specific building types.

The general effects of structural mass and window design are first discussed briefly and it is shown how these factors affect the temperature within naturally ventilated buildings in summer. Nominally sealed buildings are then considered and the size of refrigeration plant required for an office is discussed in terms of similar factors and in relation to the design conditions. Such relationships should be taken into account during sketch plan design.

The paper considers service cores in multi-storey buildings, where the plan of the building lends itself to a measure of standardization in the services. This theme is developed with particular reference to mechanical ventilation for the service cores in a 17-storey block of flats. Some details of this installation are given and used as a basis for discussing standardized services. Greater use of such systems, designed on a once-for-all basis and catalogued, would reduce the effort devoted year by year to similar design situations.

The examples used are drawn from current work of the Building Research Station.
Paper 12: Implications of Flexibility on Maintaining an Internal Environment
Authors: Shave R. E. J. , Vincent G. S.
Published: June 2010

In the application of heating and ventilating systems to building projects widely varying performance and installation demands can be created by the needs of flexibility in the use of a building. Planning flexibility may require space that can be divided by various methods on a linear basis or, alternatively, on a two-dimensional basis, which lead to various forms of modular system design. The planning requirement may be further complicated by a range of performance requirements to meet a range of different uses.

The paper deals with the evaluation of the problem and discusses the various approaches to service distribution, and how the problems of flexibility influence the distribution systems and the controllability required. The problem is particularly relevant to university buildings, and the paper describes how consideration of the same basic problem has led to two very different solutions with respect to two universities that have been designed, and indicates other factors which have influenced the resultant decisions.
Britain's Climate, its Variability and Some of its Extremes
Authors: Lamb H. H.
Published: June 2010

Britain's climate is considered first in relation to the factors, especially radiation, wind circulation and terrain, which produce and control climate. This leads to a brief review of how these things operate in the artificial environments and conditions created by buildings, towns and industry. The review of the natural climate of these islands, more particularly the temperature conditions which follows treats the matter in the setting of the wind and weather systems which bring the variations. Some insight is given into the present state of knowledge of the influences that bring about the more extreme anomalies and longer-lasting climatic changes. There are practical implications in this and other sections of the lecture regarding the climatic assessments required for planning and designs for the future.
Paper 1: Practices in the Domestic Field
Authors: Doherty C. H.
Published: June 2010

The paper briefly sketches the background to domestic heating in Britain from Roman times to contemporary awareness of the desirability of better heating. The extent of the domestic market now awaiting satisfaction, and the influences of fuel policy are discussed. The effect of contemporary building methods on the choice of heating systems is considered, and the available systems discussed. Present practices in both public and private sectors of housing are noted, together with comments on the reasons for past and prevailing techniques. Topics leading to considerations of the fuel suppliers' interest in the capital goods market in central heating systems are given, and, finally, some remarks on the potential role of district heating in the domestic central heating field are presented.
Paper 6: Some Basic Considerations in the Practice of Heating, Ventilating and Air-Conditioning
Authors: Eccleston W. H.
Published: June 2010

This paper covers some of the basic considerations associated with the practice of heating, ventilating and air-conditioning in temperate climates.

A diagrammatic representation of heat loss and gain for a room appears to provide a key to more accurate forecasting of fuel consumption for whole buildings.

Further, the smaller the thermal capacity of the system and, therefore, the quicker the response rate, the larger is the possible scope for fuel savings.

As far as space heating is concerned water systems are classified and there is reference to the more commonly used heat emitters and some of their characteristics. There is some reference to boiler power both for hot-water heating and steam generation.

Ventilation is discussed in the context of terminal points; there is also a brief reference to noise attenuation in ducts and to balancing of systems.

Air-conditioning is defined and the better known distribution methods are classified. Packaged water chillers are briefly examined and there are some suggestions regarding ‘mixing-units’. In addition there are some comments on cooling towers.

In conclusion there is a plea for standardization and in this particular instance reference is made to specifications for mechanical services works.
Paper 7: Selection and Testing of Automobile Heating and Ventilating Systems
Authors: Taylor S. R. G.
Published: June 2010

The aims of automobile heating and ventilating are summarized qualitatively. Objective acceptance tests for these aspects are outlined and quantitative targets stated as far as possible.

Possible means of achieving the aims are discussed under the headings of heat supply, heat transfer, control, air movement and air distribution.

Certain research and development tests used to supplement the objective acceptance tests are discussed including rig tests, velocity surveys and cold-room and hot-room tests.

Mention is made of tests in territory and of quality control tests.

It is concluded that the conventional system, using the engine waste heat rejected to a liquid coolant as the heat source, forced convection as the mode of heat transfer and ram plus an electrically driven fan to propel the fully fresh air for both heating and ventilating, has proved best able to meet most of the conditions encountered.
Review Paper 2: Basic Principles of Dry Friction Testing
Authors: Childs T. H. C. , Tabor D.
Published: June 2010

Friction is the force resisting relative motion between surfaces in contact. The coefficient of friction is the ratio of the frictional force to the normal load. Consequently the measurement of friction involves measurement of a normal load, movement of a surface, and measurement of a tangential force.

The first part of this review paper deals with the basic principles of the friction process. The second part is concerned with experimental methods of measuring the friction.
Report 1: A Ball-and-Plate Machine for Measuring Elastohydrodynamic Oil Films
Authors: Gohar R.
Published: June 2010

A lubricated steel ball is loaded and rolled against the underface of a flat plate of transparent material. Interferometry is used for measuring the shape and thickness of the oil film.
Report 2: Investigation of Cavitation Erosion in Non-Aqueous Liquids
Authors: Hobbs J. M.
Published: June 2010

Wear due to cavitation in non-aqueous liquids can be serious, leading to premature failures of valves, bearings, and even pumps. Although it can be shown that the collapse of vapour cavities will cause more damage than those containing some gas it is not possible to predict theoretically and with any certainty the stresses produced in materials. Thus, at present, laboratory erosion tests offer the best means of determining the relative behaviour of materials in a single liquid. However, previous experimental investigations using the vibratory cavitation test with different liquids have also been inadequate because of the many variables in the process and the lack of control over the test liquid conditions. An improved test device of the same type has been built at NEL in which temperature, pressure, and gas content can be varied independently. This has eliminated many of the disadvantages of former equipment and permitted a study of the effects of fluid properties to be started.
Report 4: A Comparison of Some Instrumentation Methods for Hydrodynamic Bearings
Authors: Ettles C. M. M.
Published: June 2010

The type of data required to check the operation of hydrodynamic bearings is discussed together with some of the more common instrumentation methods. Attention is drawn to the following methods of film thickness measurement: measurement of the operation of whole bearing parts; the capacitance and inductance methods, their characteristics, advantages and disadvantages; optical methods.

The measurement of local film pressure is discussed as also is individual pressure tapping, the installation of thermocouples, and the requirements for zero conduction error. The advantages of mounting instrumentation in the moving surface are given together with some design points for this type of dynamic transducer.
Report 8: Determination of Coefficients of Friction during Compressive Deformation
Authors: Male A. T.
Published: June 2010

A technique is described for determining coefficients of friction in a simple forging operation involving the deformation of a flat ring-shaped specimen between flat dies. This technique involves only the measurement of the change in shape of the ring upon compression and does not require a knowledge of the mechanical properties of the metal under the conditions of testing. It is therefore applicable over a wide range of testing conditions with respect to temperature, amount and rate of deformation, lubrication, etc. This technique has been used to study the limiting conditions of several lubricants for hot and cold working.

The possible application of frictional data obtained by this technique to mechanical working operations is discussed.