bluuebunny/crossref_metadata_2025 huggingface dataset:
Paper 15: Flow Studies in a Low-Speed Radial-Bladed Impeller
Authors: Benson R. S. , Cartwright W. G. , Jackson D. C.
Published: June 2010

Measurements of the static pressure distribution along a vane are compared with the predictions of potential flow theory for a straight radially bladed rotor revolving in a large water tank. At very large angles of incidence, the observed pressures depart from the ideal values by a factor several times greater than the local pressure difference across the blade. Under conditions of radial outflow, however, the pressure difference integrated over the area of the blade has a moment about the axis which is within 16 per cent of the torque calculated from potential flow over a wide range of flow rate. For inflow, the correlation of blade pressures with potential flow is greatly improved by imparting pre-swirl to reduce the tangential component of the inlet relative velocity.
Paper 17: Stage Matching, Stall, and Surge in Multi-Stage Axial Flow Compressors
Authors: Gray S.
Published: June 2010

Despite major advances in axial compressor theory and practice, the lack of a rational method of predicting surge limits remains as an outstanding deficiency. Accumulating experience suggests the association of surge initiation with local stalling phenomena, within the compressor, which are inadequately represented by conventional assumptions. A simple, revised model of stage matching under local stalling conditions is shown to provide a rational and consistent qualitative description of observed compressor off-design and surge initiation characteristics, and the effects on these of a variety of factors. Improved local stall criteria could provide the key to quantitative predictions of multi-stage compressor surge limits.
Paper 20: Detailed Flow Measurements in an Experimental Two-Stage Transonic Compressor
Authors: Oldham R. K.
Published: June 2010

A high duty research compressor has been manufactured which is large enough (34-in first rotor tip diameter) to yield valid results from traverses between the blade rows. The compressor is designed to operate at a first rotor tip speed of 1390 ft/s, produce a pressure ratio of 1·88, and pass a flow of 42·3 lb/s ft2 annulus area. A brief outline of the design method is given and the measured overall performance characteristics are presented. The results from the inter-blade row traverses are compared with the design profiles as predicted by axisymmetric flow calculations. Analysis of the traverse data has produced information on blockage factors, incidence, deviation, and pressure loss which will be useful in the design of other transonic compressors.
Paper 27: Calculation of the Flow past Turbomachine Blades
Authors: Smith D. J. L. , Frost D. H.
Published: June 2010

This paper considers the problem of determining the inviscid, subsonic compressible (or incompressible) blade-to-blade flow field through a turbomachine blade row, and presents two computer solutions, known as the ‘matrix’ and ‘streamline curvature’ methods, for solving this elliptic problem. In the former method the equations of motion are formulated in terms of a stream function and the numerical solution is based on finite difference approximations; in the latter, the equations of motion are solved in conjunction with the equation of continuity by an iterative process starting from a guess for the streamline pattern. Solutions for several blade profiles, giving flow patterns and blade surface velocity distributions, are included.
Paper 7: Mass Flow Prediction in Natural Circulation Boilers
Authors: Thomson A. S. T. , Scott A. W. , Rooney D. H. , Bradford A. M.
Published: June 2010

This paper presents results from a programme of steady-state natural circulation tests carried out on a two-tube experimental boiler. The circuit was constructed using normal commercial tubes and the tests covered the following range of variables:

During the tests, measurements were taken of pressure, pressure difference, circulation rate, and density or void fraction at the top of the riser tube. The void fraction data are presented for use. A theoretical analysis was carried out using an annular type flow model in the riser tube with a simple two-phase friction pressure drop expression which required only void fraction data.

A comparison was made between the theoretical results and the experimental data and the comparison was extended to include ( a) homogeneous flow, ( b) Martinelli–Nelson correlation, and ( c) Thom correlation. The results indicate that the analysis used, which requires only void fraction data, gave the best correlation over the range of natural circulation conditions covered.
Paper 9: Theoretical and Experimental Studies of Wet Steam Erosion in a Counter-Rotating Radial Steam Turbine
Authors: Söderberg E. O. , Widell K-E.
Published: June 2010

Erosion test in a model counter-rotating radial flow turbine has been performed to assist in the design of a 460-MW radial flow turbine. Three rows of erosion specimens were inserted at different radial locations in the last blade ring upstream of the blades to investigate the influence of the radial distance between the stages. Results showed that small droplets were formed and that erosion diminished with increased radial spacing up to a certain distance.

A theoretical model for calculating droplet trajectories, sizes, and impact velocities has been derived, taking full account of wake velocity, variable droplet drag coefficient, and atomization. The calculations explained all the experimental facts and made it possible to convert the model test results to the full-size turbine showing no risk of erosion in the latter.
Paper 12: Fog Droplet Observations in Laval Nozzles and in an Experimental Turbine
Authors: Gyarmathy G. , Lesch F.
Published: June 2010

By measuring the extinction coefficient of visible light, the mean droplet size in steam fog of known dryness may be determined on the basis of light-scattering theory. A device comprising a continuous gas laser as the light source and a photomultiplier tube as the sensor is described together with experimental results obtained in low-pressure steam fogs. These were produced in Laval nozzles in one experiment, while in another experiment the fog in the exhaust casing of a model low-pressure steam turbine has been studied.
Paper 19: Conditions Producing Concentrated Erosion in Large Steam Turbines
Authors: Moore M. J. , Sculpher P.
Published: June 2010

The paper presents the results of intrascope observations and instrument traverses in the final stages of three large steam turbines and describes the processes controlling the distribution of erosion on the moving blades. Concentrations of eroding water are shown to be produced by complex steam flows in the final stage which redistribute the water depositing on the surfaces of fixed blades. Of the three turbines considered, each has a different redistribution process, two leading to concentrated erosion, the third to a more uniform distribution of damage. In the former two turbines, it was found that the concentrations of water could be dispersed by small fences fitted to the fixed blade trailing edge, this simple modification promising to extend significantly the operating life of the moving blades.
Paper 30: A Theory for the Prediction of Local Phase Velocity, Static Pressure and Amount Condensed for Condensing Annular Flow in Tubes
Authors: Porteous A.
Published: June 2010

This paper presents a theory for condensing fluid flow in pipes. The theory incorporates the Reynolds flux concepts, advanced by Silver and Silver and Wallis, to account for the modification of interfacial shear when a phase change occurs across an interface. The basic theory is applicable to any fluid condensing in the annular two-phase flow régime and enables good predictions to be made for the local values of phase velocity, static pressure, and amount condensed. A comparison has been made with published experimental data for steam condensing with velocities in the range 380–730 ft/s, i.e. turbulent vapour core and a laminar/turbulent condensate film. A further outcome of the comparison with experimental data is a rationalization of the Reynolds flux concept with less empirical modification.
Paper 33: Liquid Phase Movement in the Last Stages of Large Condensing Steam Turbines
Authors: Valha J.
Published: June 2010

This paper deals with the generation and the movement of the liquid phase in the last stages of large condensing steam turbines. Considering thermodynamic instability, the primary droplet size resulting from spontaneous condensation is dependent on radial position, the flow, and inlet parameters. The analysis of the liquid phase transport to the blade surface is given, and the stability and disintegration of the liquid films on the blade surface is discussed.
Session 1(a): Basic Techniques—Mechanical: Stacking and Destacking of Letters
Authors: Copping G. P.
Published: June 2010

The mechanized movement of letter mail essentially involves the processing of individual items. The extraction of single items from a reservoir and the later regrouping of the items are therefore the primary and ultimate treatments to which mail must be subjected. The problems involved and the techniques of reliably effecting these basic actions are studied and explained.
Re-Orientation of Moving Letters
Authors: Gubbay D. M. , Wiles J. R.
Published: June 2010

Several areas of every item must be examined in any automatic mail processing system. This introduces the necessity for mechanisms to turn and twist items so that the appropriate areas are brought into view of the various scanning devices. This paper studies the basic movements and offers solutions.
Assessment of the Performance of Phosphor Postal Items
Authors: Agate M. S.
Published: June 2010

This paper describes the work carried out to date to establish a relationship between the amount of phosphor, in a given form, to be applied to a postal item, and the efficiency in terms of the number of correct operations interpreted therefrom by the machine reader. The investigation leads to the specification of the phosphor density for stamps which will provide a known performance margin for the automatic letter facing system. Related problems in the address code sorting system are also discussed.
Automatic Letter Facing
Authors: Copping G. P.
Published: June 2010

The evolution of automatic letter facing is traced from the original machines of the 1930s to the present-day equipment. Mechanical engineering problems are discussed and the course of future design considered.
Control Systems for Automatic Letter Facing Machines
Authors: Wicken C. S.
Published: June 2010

Techniques for controlling the routing and processing of letters flowing through automatic letter facing machines are considered, current U.K. practice being discussed in some detail.
Letter Facing Machine: Development and Design of Production Machine
Authors: Adams G. F.
Published: June 2010

The paper briefly describes the purpose and operation of the letter facing machine and sets out certain basic considerations for the design of production machines for British Post Office use. The design of the letter facing machine Mk 1 is then described by reference to specific aspects and, in addition, by outlining the problems encountered. Further developments following on from the first machines are then discussed and more specific detail given on the Mk 3 machine. Finally, an indication of the possible work still to be done is considered.
Session 5: Letter Sorting: The High-Speed Letter Sorting Machine
Authors: Smith M. G. , Tottey S. T.
Published: June 2010

The paper describes the development of the machine to meet operational requirements and discusses the steps taken to standardize on components for use on this and other associated postal machines. The techniques of sorting mail at high speed, the machine's relationship with the translator, and the features introduced to deal with ‘Post Office Preferred’ items are dealt with in the paper.
Mechanical Sorting of Coded and Uncoded Mail
Authors: Giles B. E.
Published: June 2010

The stages in the development of British operator-controlled sorting machines are described, together with an outline description of the functioning of these machines. The natural progression to the production of a multi-selection automatic sorting machine, which included principles proven in the operator-controlled machine, is covered. The latest development, the convertible letter sorting machine, and the reasons for it are briefly explained.
Session 6: Vending Machines and Pillar Boxes: ‘G’ Type Stamp-Vending Machine
Authors: Bath R. J. , Taylor M.
Published: June 2010

A new stamp-vending machine designed and developed for the British Post Office is described. A brief outline of stamp machine history is followed by a review of the reasons for the adoption of the particular design. A description of the mechanism shows how the design specification has been met, despite the limitation of size imposed by existing mountings. The stamps are issued from a roll by the user operating a lift flap after insertion of a valid coin, and no additional source of power is required. The machine may be readily set to issue any predetermined stamp combination.
Development of the Pillar Letter Box 1852–1969
Authors: Cutmore N.
Published: June 2010

The introduction deals with early posting methods—the post receiving office, which became inadequate as postal traffic increased, leading to the design of the first type of pillar letter box in 1852. A brief history follows of the different types of pillar letter boxes (illustrated) until the introduction of the type F (new square type) in 1968. A description is given of the new-type box, dealing in detail with the concept of unit construction and the rapid emptying methods used.
Session 7: Translators and Computers: Optical and Magnetic Drum Translators
Authors: Soar A. , Phillips K. H. C.
Published: June 2010

A requirement was foreseen for a translator capable of providing translation facilities in smaller sorting offices. The design philosophy adopted was one which gave insurance against a major breakdown by providing a number of inexpensive independent units in place of a centralized translation equipment. The paper describes a novel data storage device comprising a Perspex drum fitted with a special binary data code film on its periphery, and employing optical scanning techniques for data retrieval. The principles of operation and manufacturing aspects of a code sorting translator incorporating both optical and magnetic storage drums are described.
A Proposal for the Use of a General Purpose Computer as a Translator
Authors: Ibbetson D. N. I.
Published: June 2010

The requirements to be fulfilled by the equipment used to control letter coding and sorting equipment in a modern sorting office are summarized and a method of using a general purpose computer for these purposes is described. Emphasis is given to the use of a magnetic drum to reduce the cost of core store and to the method of organizing the computer program. The ability of the computer to undertake secondary tasks and the constraints imposed by the requirement of high reliability are mentioned.
Storage Problems in the Parcel Post
Authors: Beardmore A. F.
Published: June 2010

This paper discusses problems concerned with bulk-handling storage devices used in the parcel post. These storage devices, which are used to absorb the traffic peaks, include glacis, containers, band conveyors, concentrators, and chain conveyors. They require automatic feed or discharge, or sometimes both, depending on their functions in the office. The main problems stem from the space needed to provide the required storage capacity and the site limitations.
Air-Bag Vertical Rising Conveyor
Authors: Sauvée R. L.
Published: June 2010

The need to elevate items of widely varying characteristics under random load conditions presents an unusual engineering problem. The riser described provides a means of handling packets, parcels, or mailbags in a vertical path. Two belts contained in a trunking are normally held in close contact with each other against the back plate by means of an air bag providing constant pressure but allowing rapid variation in volume. Articles are introduced between these two bands on the horizontal plane, enveloped by the belts, and carried positively into the heel of the trunking where, after transition into the vertical plane, the articles are conveyed to the point of discharge.
The Langton Riser
Authors: Whittington K. W. H.
Published: June 2010

The paper commences with an explanation of the need for reliable bulk-mail elevators in multi-storey sorting offices; it continues with a brief description of the Langton riser. There follows an historical review of Post Office experience with such machines, including references to the first scale model, early operational experience, and the design changes subsequently introduced. Mention is then made of the improved reliability of the redesigned risers. In conclusion, brief descriptions are given of the steps being taken to overcome the remaining shortcomings.
Installation and Acceptance of Postal Engineering Plant
Authors: Cummings F. G.
Published: June 2010

The paper covers primarily the period between the placing of a contract for postal engineering plant and the introduction of this plant into live service following acceptance testing and ‘confidence’ trials. There is, in addition, some reference to the immediate post-commissioning period. The procedures described relate, in the main, to the traditional method of equipment and building provision whereby the two aspects are dealt with under separate auspices. However, reference is made to an alternative approach, known as a ‘package deal’, whereby building and mechanization are provided under a common contract.
Croydon Sorting Office
Authors: Davey D. V. , Barrow R. V.
Published: June 2010

The paper describes the general mechanization of this new office, which is adjacent to East Croydon railway station. The office was brought into operational use in mid-1969. The first part of the paper is concerned with the general mechanization features of the office and the method of operation. In the second part of the paper, details of the letter code sorting installation are given. An account follows of the procedures for commissioning this installation, and some of the problems encountered are discussed.
Session 11: Some Research Projects: Application of Automatic Speech Recognition to Parcel Sorting
Authors: Scarr R. W. A. , Bezdel W.
Published: June 2010

The ‘state of the art’ in speech recognition is reviewed with particular reference to the kind of problems that are likely to arise in a parcel sorting environment. Speech recognition equipment developed by the authors is described. To justify a speech recognition equipment for parcel sorting it must be shown to increase productivity. Simulations relevant to voice control of parcel sorting have been carried out to try to assess what this improvement might be, and the results are discussed.
Paper 9. Manual Gearboxes in Cars
Authors: Looman Johannes
Published: June 2010

The paper describes the type of gear, produced in millions every year, which can be found in most modern cars. Manual gears having now reached a high stage of development, improvements can be made only in construction details, in fitting the gears into the cars, and in the technique of finishing. Five manual gears are discussed and ten details of construction are explained. Finally, two examples of semi-automatic gears are given.
Paper 10. Manual Gearboxes—Cross-Country Vehicles
Authors: Adshead H.
Published: June 2010

The aspects of design peculiar to the transmission unit of the cross-country vehicle are dealt with in this paper. General problems associated with four-wheel-drive vehicles, inasmuch as they affect the transmission unit, are considered together with the effect of gear ratio range and controls on clutch life, related to operator usage. Consideration is also given to requirements of casings, transmission brakes, lubrication, sealing, and breathing. The provision for power takeoff drives together with their power requirements are covered and the basic design of the transmission unit is considered in relation to service experience.
Paper 12. The Inverted Tooth Chain as an Automotive Transmission Medium
Authors: Hoar M. S.
Published: June 2010

Throughout the world's automotive industry, a great deal of thought is currently being directed towards achieving power transmission layouts which are both compact and weight-saving and which achieve the desired distribution of vehicle weight. This trend is particularly noticeable in Europe, where success in the market place depends to a large extent on giving greatest passenger space for the customer's money.

However, it was on a very non-European passenger car that a product was introduced which is now helping designers obtain maximum transmission compactness at minimum cost. The car was the Oldsmobile Toronado, and the product the Morse Hy-Vo® inverted tooth chain.
Paper 13. Automatic Gearboxes, Hydrokinetic (Cars)
Authors: Ivey J. S. , Davis E. J.
Published: June 2010

This paper reviews the installation of automatic transmissions into vehicles, and the matching calibration of the transmission and converters to various types of engines and vehicles. Bench and field acceptance testing, with some reference to transmission manufacturers' approval of fluid and materials, are also discussed, and unorthodox automatic transmissions such as transaxle in-line and transverse, are reviewed. The paper finally examines volume production techniques of today's automatic transmissions and presents some remarks on future trends and requirements.
Paper 17. Overdrives
Authors: Abbott R. L.
Published: June 2010

Overdrive is defined as gearing which provides a higher ratio than that given by the final drive crown wheel and pinion. The ratio requirements of the modern car are discussed. All types of overdrive gearing are reviewed and the Laycock unit, being the only separate unit now produced in the U.K., is considered in detail. This unit is of particular interest since ratio changes are made under torque. It is, therefore, necessary to consider the changes in rotational energy which result. The paper analyses the factors involved and presents equations relating clutch torque, time, and inertias. Expressions are given for energy transfer to the output shaft and the rate of energy dissipation at the clutch. Some details of the epicyclic gearing and planet bearing loads and life factors are given. Control systems are briefly discussed.
Paper 20. Cold Forming of Gears
Authors: Egan P. F. , Connell G. , Jones B.
Published: June 2010

It is ever-increasingly important to find and develop new techniques for the manipulation of metal such that the utilization of metal is improved and subsequent machining operations are either substantially reduced or eliminated. When metal rolling as a process is utilized, more often than not substantial advantages such as improvement of physical characteristics and metallurgical properties are apparent. One of the main objectives of this paper is to bring to delegates' attention presently available processes and current developments in the field of cold gear rolling. The paper also outlines the interrelationship of warm and hot rolling to cold rolling, particularly with consideration to the present state of the art where limitations on cold rolling are imposed due to material plasticity and physical geometry considerations. The effects of current rolling processes and proposed development processes represent a radical departure from traditional manufacturing techniques.
Paper 26. Synchromesh Mechanisms: Experience of Heavy Truck Gearboxes
Authors: Rosen I. , Kruk S. , Eker P. O. , Mellgren H.
Published: June 2010

The design characteristics of different synchronizers with comparisons of designs, performance, and dependability in operation are discussed. The theory of operation is dealt with in detail. The influence of experience in practice on design from the effects of clash, hard gear changing, wear, clutch and oil drag are included. Suitable materials, machinery processes, and interdependence of dimensions are described. The paper concludes with notes on practical and laboratory tests and future development.
Paper 27. Strength of Transmission Shafting
Authors: Russell J. E.
Published: June 2010

The design theory for transmission shafting, both in the elastic and plastic states, is reviewed, with consideration of the effects of splines, fillets, and similar stress-raisers. Data are presented on the actual strengths of such shafts for various steels under static and fatigue loading, and the nature of the fatigue phenomenon briefly discussed. Some typical shafting failures are described, and the appropriate lessons drawn.
Paper 29. Propeller Shafts and Universal Joints—Characteristics and Methods of Selection
Authors: Macielinski J. W.
Published: June 2010

In this paper, both Hooke's joint and the modern ball type constant velocity unit are considered. Methods by which the specific capacity and life endurance of a joint may be estimated are described. A method of calculation to select a suitable joint for automotive purposes is discussed.
The Spectrum of Diesel Combustion Research
Authors: Lyn W-T.
Published: June 2010

This review attempts to thread a unified theme through the whole spectrum of diesel combustion and its related studies—from basic research on a single droplet to the development of a specific combustion chamber—and endeavours to demonstrate how, as a whole, they contribute to provide the quantitative link between design and performance.
Rate of Heat Release in Diesel Engines and Its Correlation with Fuel Injection Data
Authors: Whitehouse N. D. , Way R.
Published: June 2010

Basic heat release data have been obtained by analysis of cylinder pressure diagrams from a variety of engines, two-stroke and four-stroke, small (3·4-in bore) to medium size (12-in bore) over ranges of power, speed, and air supply conditions. The paper gives an account of early attempts to obtain a simple formula for heat release suitable for performance calculations by computer, using the simple and widely used single-zone model for conditions in the cylinder. The conclusion is reached that although it is possible to obtain useful calculations in this way, more sophisticated models are necessary for better understanding of conditions in the engine.
Rate of Heat Release in High-Speed Indirect Injection Diesel Engines
Authors: Bowden C. M. , Samaga B. S. , Lyn W-T.
Published: June 2010

The rates of injection and heat release of two designs of indirect-injection diesel engines have been studied over a range of speed, load, and timing. The relationship between these two quantities is significantly different from that previously found for open-chamber engines. It is suggested that only part of the air is available for mixing in a divided-chamber engine, and the movement of the piston controls to some extent the availability of the remaining part of the air. A semi-empirical scheme is proposed for relating the rate of injection to the rate of heat release for this type of engine.
Penetration and Vaporization of Diesel Fuel Sprays
Authors: Burt R. , Troth K. A.
Published: June 2010

In the diesel engine, fuel is injected into the hot, compressed air in the combustion chamber. Thus the process of diesel combustion is essentially inhomogeneous, and the mixing of the fuel and air in the combustion chamber dominates the whole combustion process. Since fuel–air mixing is so important the distribution of the injected fuel has a major effect on combustion performance. This is particularly true of direct-injection diesel engines which have relatively low rates of air movement.

In all diesel engines, fuel is injected into the combustion chamber at high pressure through small nozzles. The high-velocity liquid jet atomizes, after emerging from the nozzle, into a spray of liquid droplets. The penetration, distribution, and vaporization of the sprays, together with the air movement, govern the mixing of fuel and air.

The penetration of fuel sprays is dealt with in Part 1 of the paper; Part 2 describes a study of the vaporization of fuel sprays.
Air Motion and Fuel Distribution Requirements in High-Speed Direct Injection Diesel Engines
Authors: Watts R. , Scott W. M.
Published: June 2010

This paper deals with the requirements for good combustion in the smaller high-speed direct-injection engines. Reference is made to the poor fuel distribution with current injection systems, and to the necessity of supplementary air movement. The level of air movement and the importance of squish motion are reviewed, and typical responses of the performance to swirl levels illustrated. From experimental evidence, including combustion photography, the mode of mixing is described, and its dependence upon the mass distribution of the fuel, and the influence of the chamber wall, discussed. The measurement of cylinder swirl under steady flow rig conditions is presented, and the correlation with chamber proportions and engine performance given. Recommendations are made on chamber requirements for wide speed operation and on inlet port configurations for optimizing flow and swirl conditions.
Some Contributions to Experimental Combustion Research
Authors: Rödig J. , Žalud F.
Published: June 2010

Techniques of measuring air flow through inlet ducts of diesel engines and tangential air velocities in the cylinder are investigated. An impulse wheel anemometer and conical pressure pick-up are used to measure steady flow velocities. Air velocities in the combustion chamber are evaluated from dynamic pressure variations indicated by tensometric pick-ups. Chemical changes of the fuel during combustion in the cylinder are studied with the help of spectrographic analysis. The evaporation rate of fuel injected into the cylinder is measured by analysis of fuel luminescence.
Influence of Some Particular Fuel Injection Phenomena on Diesel Engine Performances
Authors: Becchi G. , Guglielmotti A.
Published: June 2010

This paper deals with some anomalies of the fuel injection system (cavitation, needle reopenings, gas entry into the injector) and their effects on the engine and fuel injection system behaviour. Particular attention is paid to the initial and final stages of the fuel injection, where irregularities have been recognized as one of the most frequent causes of abnormal behaviour of the combustion.
Predicting the Performance of Diesel Engine Combustion Chambers
Authors: Spalding D. B.
Published: June 2010

The availability of large digital computers, the recent development of adequate techniques of numerical analysis, and the growth of knowledge about the laws of turbulence, have combined to make possible the development of a comprehensive prediction procedure for the fluid-dynamic, heat transfer and combustion phenomena which take place in diesel engine combustion chambers. The difficulties, and means of surmounting them, are discussed in the lecture; it is argued that a very useful first stage would be a procedure applicable to axisymmetrical chambers; this could be constructed by extending already established techniques and knowledge. The procedure would be of the finite difference variety, and would employ a grid which expanded and contracted to accord with the piston motion.
Paper 1: Glandless Pumps in C.E.G.B. Power Stations
Authors: Barker B. , Blackmore R. H.
Published: June 2010

This paper describes the reasons for the selection and use of glandless pump motor units on certain hot water applications in C.E.G.B. power stations. For the duties concerned, high reliability with freedom from routine maintenance is of the utmost importance. In these instances the use of glandless pump units overcomes certain problems encountered which otherwise could detract from this aim, particularly with regard to pump glands where high pressures and temperatures are involved or where the exclusion of air ingress via the pump is desired. Applications are discussed in detail, followed by consideration of design requirements, features, and problems. A section is included on development and testing. Operating experiences are examined and reference is made to probable future trends.
Paper 6: Submerged Motor Drives for Glandless Pumps
Authors: Henden W. J. , Rix G. R. , Limmer R.
Published: June 2010

In view of the environmental operating conditions, special techniques have to be used to permit the manufacture of the submerged type of motor as an industrial proposition. The first choice to be made is that of stator winding conductor insulation, which must be impervious to water, flexible to wind, and have good thermal stability. A thorough survey of the limited materials available for such an application determined that high density polythene, extruded on to a flexible stranded cable, would best meet these requirements. Polythene has a relatively low flow temperature, which may be increased, and the mechanical stability of the cable improved, if it is subjected to irradiation dosage. The cable and the necessary seal termination are subjected to accelerated life testing at operating conditions in static pressure vessels before commitment to production. The concept of the mechanical design calls for the use of small rotating diameters consistent with sound engineering practices. Where possible, rotating surfaces must be smoothed to minimize water turbulence losses.
Paper 7: Computer Analysis of Externally Pressurized Journal Bearings
Authors: O'Donoghue J. P. , Rowe W. B. , Hooke C. J.
Published: June 2010

Several procedures for designing externally pressurized journal bearings have been presented. These vary from simple approximate solutions based on the bearing stiffness in the concentric position to full relaxation programs. In this paper the authors compare the predicted performance of bearings with experimental results. In addition to the static results obtained by the authors on a typical four-pocket grinding spindle bearing, the dynamic results of Patrick and Chen are also treated.
Paper 9: A Theoretical Analysis of the Floating-Pad Journal Bearing
Authors: Howarth R. B.
Published: June 2010

Limited applications and investigations have shown that the floating-pad journal bearing is a practical form of bearing which can be used to advantage. The operational complexities make a rigorous analysis exceedingly difficult if not impossible, and a simplified approach is adopted. The results of the analysis suggest that the floating-pad journal bearing is most suitable for high-speed, low-load applications where advantage can be taken of its desirable properties, in particular low energy dissipation and the high lubricant flow that can be accommodated for cooling purposes. The analysis also predicts the occurrence of a self-excited vibration becoming more pronounced as the eccentricity increases.
Paper 11: Hot Oil Carry-Over in Thrust Bearings
Authors: Ettles C.
Published: June 2010

Six sets of experimental results concerning 14 different thrust bearing assemblies of varying type and size are analysed to find the extent of hot oil carry-over. Temperature readings from 729 pads are used in the analysis. The percentage of exit heat carried over k is shown to vary between 80 and 60 per cent, depending on sliding speed and bearing type. The temperature at entry to the pad is shown to be higher than the housing supply temperature by a simple multiple of k applied to the temperature rise along the pad. Since no formal method exists at present for the calculation of operating viscosity in thrust bearings, it is hoped that this work will form a contribution in the design procedures for thrust bearings.
Paper 12: A Design Method for Radially Grooved Thrust Washers
Authors: Brockwell K. , Ettles C. , Stokes M.
Published: June 2010

A range of tests on simple radially grooved thrust washers is reported in which the number of grooves is varied from two to six. The mode of action by free thermal distortion is confirmed, the minimum film thickness occurring at 0·6–0·8 of the pad length. A degree of random waviness is shown to be beneficial, although it is likely that only half of the bearing circumferential length contributes to load carrying. The optimum number of pads appears to be four. The authors explore the use of multiple regression analysis in the design of such bearings. If several effects interact in the usual design process, it is shown that this technique can often give the direct influence of each design parameter separately without the need for iteration.
Paper 13: Tilting Pad Thrust Bearings: Factors Affecting Performance and Improvements with Directed Lubrication
Authors: Bielec M. K. , Leopard A. J.
Published: June 2010

The effect on flooded tilting pad thrust bearing performance of a number of external variables is examined. At sliding speeds between 10 and 100 m/s, and for specific pressure between 15 bar and 55 bar, measurements were made of oil film thickness, bearing temperature, and power loss for various oil inlet systems, oil quantities, housing pressures, and degrees of misalignment. Power consumption in high-speed thrust bearings can be safely reduced by the use of directed lubrication with a drained casing, bearing temperature being reduced and oil film thickness increased.
Paper 15: Determination and Application of the Dynamic Properties of a Turbo-Rotor Bearing Oil Film
Authors: Woodcock J. S. , Holmes R.
Published: June 2010

This paper presents a theoretical and experimental assessment of the eight coefficients which describe the stiffness and damping properties of journal bearing oil films, together with their subsequent use in predicting the performance of a real rotor. The performance is checked experimentally.
Paper 18: A Three-Disc Machine for Examining Elastohydrodynamic Oil Films
Authors: Gupta S. K. , Hamilton G. M. , Hirst W.
Published: June 2010

This paper describes a new disc machine which has three discs, the central one supported by air bearings. This configuration lends itself to simple manufacture and easy inspection of the disc surfaces. It is chiefly intended for very accurate friction measurements near the rolling point, but film thickness and other measurements can also be made. Two sets of results obtained with the machine are reported. The first, on mineral oils, shows that as the temperature is raised the effective viscosity becomes less dependent on speed. It is thought that this may be associated with the relaxation time. The second, on a silicone fluid, shows that the same power law which explains the poor film thickness can also explain the apparent loss of viscosity at the centre of the contact.
Paper 20: The Effect of Temperature on the Fretting Wear of Mild Steel
Authors: Hurricks P. L. , Ashford K. S.
Published: June 2010

This paper describes an apparatus used to investigate the temperature variable in fretting. Observations have been made on the nature of the wear, its appearance, and its extent in two atmospheres—air and argon. In argon, the wear is adhesive in nature and has been shown to be influenced by a change of material properties with temperature. With an air environment, the adherence and stability of the oxide product is temperature-dependent, thus affecting the wear rate. From a consideration of wear scar parameters it is shown that abrasion by α-Fe2O3 debris is not the main cause of fretting wear.
Review Paper 1: Gas Bearing Developments
Authors: Munday A. J.
Published: June 2010

This paper presents some of the developments in gas bearing technology since 1967, and considers the state of the art. The place of gas bearings in tribology is discussed, and the future development of gas bearings is suggested.
Report Paper 3: Elastohydrodynamic Lubrication of ‘O’ Ring Seals
Authors: Gibson I. A. , Hooke C. J. , O'Donoghue J. P.
Published: June 2010

This report gives details of a theoretical analysis of the lubrication of ‘O’ ring seals. Under dry contact conditions the pressure gradient at inlet to the contact zone is infinite, and an iterative solution has been developed to determine the inlet sweep of pressure under conditions of elastohydrodynamic lubrication. The exit film thickness and pressures have also been determined for conditions of variable outlet viscosity and pressure gradient. Typical results for an ‘O’ ring are given for a standard seal section.
Report Paper 4: Determination of Bonds between Metal Ions and Additives by Means of Surface Pressure and Infrared Spectra
Authors: Friberg S. , Müller H.
Published: June 2010

A surface balance of the Langmuir type was used to determine the effect of different metal ion specia in an aqueous solution on the surface pressure of monomolecular layers of additives. To gain more specific information about the bond properties, the monolayers were collected and the infrared spectra recorded. It is suggested that the results can be used as data when the bonds between the additives and the atom groups on a metal surface are being considered.
Paper 5: Windscreens of the Future
Authors: Kay S. E.
Published: June 2010

Some suggestions are made on the technological changes which may occur during the next 30 years or so to make available windscreens with improved safety and optical performance and to give a better environment within the car.
Paper 2: The Design Principles for Boiler Feed Pumps for C.E.G.B. 660-Mw Units
Authors: Otway F. O. J.
Published: June 2010

When the Central Electricity Generating Board increased the unit rating of their turbo-generators from 500 MW to 660 MW, the design basis of the boiler feed pumps was completely reviewed. The prime requirement was that the pumps should be made less sensitive to mechanical fault and capable of surviving disturbed suction conditions without failure. At the same time they were to be capable of rapid replacement. This paper explains the reasoning from these requirements that led to the decisions that the pumps should have only two or three stages with stiff shafts. The selection of suction stage pumps for use with the main pressure stages is considered. Gland security and light-load protection are discussed.
Paper 3: Boiler Feed Pump Design for Maximum Availability
Authors: Weldon R.
Published: June 2010

With increasing size of turbo-generator sets, the criterion of maximum availability for boiler feed pumps has assumed even greater importance. Capital cost, power consumption, and availability are all necessary considerations in the economic optimization of power-generation equipment design. The capital and running costs of the boiler feed pump are relatively small compared to the plant for which it is an auxiliary. However, such plant depends implicitly for its revenue-earning capacity on the reliability of the boiler feed pump. Awareness of these overall economic considerations has led to the maximum availability design concept for large boiler feed pumps.

To achieve these ends, a high-speed, rigid-rotor design concept has been evolved which permits the machine to continue in satisfactory mechanical operation under vapour-locked conditions. A new cartridge principle of pump construction has been introduced, wherein the complete internal assembly, incorporating end covers and bearings, is withdrawn as a single unit leaving the casing in situ.

The extensive research and development carried out to prove the individual features of the design are fully described, together with particulars of the complete prototype machine, which at the time of writing is believed to be the highest stage pressure boiler feed pump in commercial operation in any power station throughout the world.
Paper 4: Advanced-Class Boiler Feed Pumps for 660-Mw Generators
Authors: Leith T. O. , McColl J. R. , Ryall M. L.
Published: June 2010

The need for totally reliable boiler feed pumps for modern large generating sets has led to the specification of pumps capable of surviving dry run and thermal shock conditions. Special design features, introduced with the object of improving reliability with minimum effect on performance, are described. The development work leading to the adoption of these features and the reasons for the choice of materials and methods of manufacture are reviewed. Details of construction to accommodate rapid dismantling and replacement of the internal pump assembly are given. A comparison is made between glandless and geared suction booster pumps, and the relative advantages are discussed. Recent developments are described, which include the use of a suction inducer to improve the performance of the suction stage pump and the possibility of an integrated turbo-feed pump running at high speed without a separate booster pump.
Paper 5: Development of a Single-Stage Boiler Feed Pump for Nuclear Power Stations
Authors: Gasiunas A. A.
Published: June 2010

An unparalleled increase in the output of power-generating units in the last decade has made it necessary to reconsider the established boiler feed pump design philosophy. This paper deals with a number of design aspects which are of vital importance for the future development of a modern high head per stage boiler feed pump. The paper discusses the pressure and depression pulses that are generated when impeller vanes travel past the stationary vanes of guide equipment. It is considered that these pressure fluctuations can cause cavitational damage in the impeller and other parts, and also the uneven running of a pump. The influence of geometrical and hydraulic non-symmetry on radial forces in a double volute casing is dealt with. Test results of a double suction model boiler feed pump are presented, including descriptions of durability runs with paint-coated hydraulic surfaces.
Paper 6: Development of Boiler Feed Pumps in Czechoslovakia
Authors: Hladiš V. , Kupa J.
Published: June 2010

The paper outlines the main features of the development of boiler feed pumps in Czechoslovakia, which took place in parallel with the development of Czechoslovak power engineering. The basic design arrangement of boiler feed pumps as separate sets and their design execution are described. The development of material selection is also reviewed.

Some problems of rotor dynamics are referred to relative to the choice of speed and the influence of impeller packing ring design is emphasized.

The cavitation qualities of the boiler feed pump are considered and new aspects concerning the evaluation of cavitation tests are discussed. The determining by visual observation of so-called evaporating curves, which explicitly limit the cavitationless operation of the pump, is explained.
Paper 7: The Single-Stage High-Speed Nuclear Feed Pump
Authors: Bush A. R. , Valentin J. E. C.
Published: June 2010

Feed pumps applied to early large-size light water moderated nuclear reactors in the United States were modifications of existing split-casing volute type pipeline pumps or multi-stage pumps. An increase in unit ratings from 500 to 800–1100 MW showed the inadequacy of these pumps for the high flows required. Accordingly, the authors' company undertook a study to arrive at a suitable design. Various concepts were considered: number of stages, casing configuration, materials, etc. Reliability was the key consideration, along with flexibility of application and ease of manufacture. The final selection was a single-stage solid casing with an integral diffuser and condensate injection seals. The manufacturing problems which develop are discussed, together with performance tests run on the first machines of this type.