bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paper 8: One-Year Post-Graduate Courses in Universities
Authors: Bannister F. K. 
Published: June 2010

After a short historical introduction, the various kinds of formal post-graduate courses in mechanical engineering are briefly surveyed. These range from the short course of one or two days to the full-scale graduate course of 12 months or thereabouts and assessment is made of their respective suitabilities for different purposes. The main emphasis in this paper is placed on the 12-month M.Sc. course and a variety of organizational and educational aspects of this type of course are considered. They include: (1) the problem of the initial assimilation into a common course of students of varying ages, industrial experience, and academic freshness; (2) the inclusion of project work in a basically formal course; (3) the possibility of subdividing the 12-month period into a number of shorter periods in order to facilitate the release of staff from industry; (4) the desirable proportion of overseas students in a course; (5) the relationship between a graduate course and the research activities of a department. Connections with, and support from, industry are considered, as is the influence of S.R.C. Studentships on recruitment. The Robbins Committee recommendations on advanced formal courses are reviewed, and their effect on the growth in numbers of such courses is considered. Comment is made on certain implications of the Arthur Report and the probable future development of one-year post-graduate courses is discussed.
Paper 10: Steam-Piping Installations
Authors: Dimmock D. 
Published: June 2010

This paper is intended to be of a practical nature and deals with the various aspects and problems which require to be considered and dealt with by a project engineer responsible for the layout, design, and engineering of a main steam piping system. Two types of installation are considered: (a) Main steam piping for power station plants operating within a temperature range of 482°C (900°F) and 568°C (1055°F), and (b) Long steam distribution lines operating up to a temperature of 468°C (875°F). Although many of the problems are common to both types of installation such as pressure drops, terminal reactions on plant, expansion, layout, etc., these in both cases are discussed and procedures proposed for the preliminary and final stages of design, in order to arrive at a reliable and economic installation. The necessity of preliminary and final detailed analysis is shown and the importance of considering the various types of supports, guides, and restraints in conjunction with this work. Other features dealt with are the drainage of steam lines, cleanliness during erection, clean service conditions, lagging, and their contribution to satisfactory operation of the piping systems.
Paper 8: Maintenance Planning Applied to Plant Auxiliaries in the Central Electricity Generating Board
Authors: Wright V. J. , Seymour R. E. , Norris N. D. 
Published: June 2010

The C.E.G.B. operates 230 power stations of various ages and output capacities representing a total capital investment of some £2400 million. The steam conditions, sizes of generating units, and complexity of the installed plant reflect the stage of technical development at the time of their construction. These factors influence the cost of production at individual stations as also do the nature and cost of fuel. The economic level of maintenance at each station is thus dependent upon a number of factors and must generally be established locally. This places an obligation on the maintenance engineer to collect and consider economic, in addition to technical, data. Also, service experience must be fed back to the design engineer so that future plant designs may be improved. Unless a simple and effective control system is employed paper work can become an intolerable burden. Power station maintenance can be broadly divided between: (1) work which can only be carried out while a generating unit is shut down; (2) work which can be carried out with the main plant on load. The first category has received the greatest attention, since the cost of keeping a modern generator out of service can be substantial. Planning of this work is based on Critical Path Analysis techniques which are now well known and widely practised. However, the day-to-day maintenance of a large variety of auxiliary plant also presents a heavy planning burden upon the maintenance department. The basic minimum requirements for the effective local control of this work have been examined, while the most economic methods of: (a) co-ordinating maintenance in a number of stations in the best national interest, and (b) ensuring that service experience is fed back to design engineers are also receiving attention.
Paper 17: Study of Sintered Carbides and Surface-Treated Materials for Unlubricated and Elevated Temperature Rolling Elements
Authors: Scott D. , Blackwell J. 
Published: June 2010

Materials and surface treatments potentially suitable for unlubricated and elevated temperature rolling bearings have been compared, wear resistance being assessed by loss of weight under unlubricated conditions. Tungsten carbide was superior to other materials tested. Grain size of the tungsten carbide and the amount of matrix material can have a considerable effect on performance. Use of solid film lubricants can eliminate or reduce wear. Soft nitriding can also be beneficial. Metallurgical investigations of some selected failed specimens have been carried out.
Paper 14: Hydrodynamic Lubrication of Lightly Loaded Finite Cylinders
Authors: Boness R. J. 
Published: June 2010

Theoretical results of the load-carrying capacity of lightly loaded finite cylinders indicate that the effect of side leakage can be secondary to upstream boundary condition considerations. Neglecting side leakage the calculations are extended to cover the experimental results of Crook into the régime where the fluid properties are pressure dependent. The results support the adoption of the new velocity and velocity gradient boundary conditions suggested by Lauder.
Paper 15: Thermal Aspects of Hydrodynamic Journal Bearing Performance at High Speeds
Authors: Woolacott R. G. , Cooke W. L. 
Published: June 2010

This paper describes a rig for testing journal bearings at high speeds under steady loads and reports on measurements of bearing and lubricant temperatures and lubricant flow-rates for hydrodynamic journal bearings operating at speeds up to 35 000 rev/min and mean bearing pressures up to 3333 lbf/in2. Variations of temperature and flow-rate with load, speed, oil-inlet temperature and pressure, clearance, and oil-inlet grooving are also described, and the effects of bearing and lubricant temperatures on bearing performance are discussed.
Paper 8: Side-Leakage Factors for a Rigid Cylinder Lubricated by an Isoviscous Fluid
Authors: Dowson D. , Whomes T. L. 
Published: June 2010

Many lubricated machine contacts can be represented by cylindrical surfaces, and some of these contacts such as gears and rolling contact bearings have been studied extensively in recent years within the developing subject of elastohydrodynamic lubrication. When high loads are carried by the contact, side leakage is of little importance, but there is little evidence to indicate the quantitative importance of side leakage when the loads are light. This question has assumed greater importance with the recent recognition that many nominally parallel surface thrust bearings rely upon thermal distortion for their effective load-carrying capacity, since the deformed shape can be approximated by a pad of cylindrical form. In this paper solutions of the Reynolds equation are presented for the geometry of a cylinder near a plane lubricated by an isoviscous fluid. The resulting pressure distribution has been integrated to yield normal and tangential surface force components and the results are presented in the form of side-leakage factors to be used with the Martin solution for an infinite cylinder. The approximate ‘short-cylinder’ theory is presented and compared with the full computer solutions. The results are applied to two lubricated contact situations.
Paper 3: The Assessment of Vehicle Ride and Handling
Authors: Hales F. D. , Barter N. F. , Oliver R. J. 
Published: June 2010

The paper deals primarily with MIRA's contribution in the areas of vehicle ride and handling. Vehicle ride and handling are defined in broad terms to delineate the areas under consideration, ride being concerned with passenger reaction, and handling with the driver-vehicle relationship. The most difficult problem of all ride and handling studies is considered to be the human subject since human variability, adaptability, sensitivity and absence of a fixed scale of values render study in the simpler engineering senses difficult. Instrumentation systems used in the measurement of vehicle ride and handling studies are considered in a general way. A typical ride instrumentation system is illustrated. Assessment of vehicle ride is considered under two headings, subjective and objective. The methods for subjective assessment of stimuli are discussed and as an illustration of the techniques involved the design of a subjective ride experiment is given. Brief details of the objective measurement technique and the ways of analysing the subsequent data are presented, and typical spectra obtained from the data analysis are shown. The correlation between the subjective and objective results is discussed. Objective assessment of vehicle handling is considered in some detail. The ways of determining steady state behaviour based on the under/over-steer concept are detailed. The use of a tethered testing technique to overcome difficulties of steady state testing while braking and under limiting adhesion conditions is outlined. Assessment of handling under transient conditions is investigated by means of step input and frequency response tests. Typical results are used to illustrate vehicle behaviour. Further ride work and subjective assessment of handling are briefly discussed, as are probable future techniques that may be used in the assessment of vehicle ride and handling.
Paper 9: Measurement of Vehicle Characteristics for Ride and Handling
Authors: Ellis J. R. , Sharp R. S. 
Published: June 2010

The paper describes some apparatus which has been developed to measure those characteristics which are of interest in vehicle ride and handling. These are: Vertical, lateral and fore-and-aft tyre stiffnesses and damper characteristics. Suspension spring rates and friction, suspension geometry and suspension roll stiffnesses. Steering gear geometry and dynamic characteristics, moments and products of inertia of the vehicle and vibration characteristics of the seats. Some relevant theory and sample results are included in the Appendices.
Paper 11: Testing Automobile Components
Authors: Love R. J. 
Published: June 2010

Test procedures on components fall generally into four categories: ( a) overcoming service troubles; (6) design studies; ( c) acceptance testing; ( d) quality control. Some tests may be undertaken in complete vehicles, but the use of special test rigs, in which components can be tested in isolation, offers a number of advantages. Rig tests are generally a compromise between simplicity and realism. It is important to be able to reproduce the type of deterioration which occurs in service, and the study of service failures is helpful. Measurements of service loadings and environmental influences are in many cases desirable, and where examples of service failure are not available, these measurements are essential. Most laboratory tests merely indicate, with some approximation, whether one component is better than another, and it is usually not possible to determine confidently whether a component is suitable for service. To maintain a high level of reliability in components in service, coupled with efficient design, it is necessary to introduce more realism, both in laboratory tests and proving ground tests. This is being done to a limited extent, and a method is also available for relating both proving ground performance and laboratory performance to behaviour in service. Much more needs to be done to establish the most suitable techniques.
Paper 13: The Magnetic Tape Control of Engine Test Beds
Authors: Harris W. J. 
Published: June 2010

A 4-channel magnetic tape recorder is used to collect data from the vehicle under test during actual test conditions. Recordings of engine speed, engine load and generator system load are transferred to a 14-channel tape recorder and used to automatically programme up to three engines mounted on test beds in the laboratory. The techniques of recording and replaying the engine test data are described.
Paper 16: The Performance of Annular Diffusers
Authors: Stevens S. J. 
Published: June 2010

Tests have been carried out to investigate the influence of inlet conditions on the performance of symmetrical annular diffusers having 4:1 area ratio and 2·5° and 5° wall angles. The conditions at inlet were varied by using either approach lengths or annular gauzes. Tests on the 2·5° diffuser showed that the ‘efficiency’ deteriorated with increase in outer wall momentum thickness. In addition to the overall performance characteristics a detailed study has been made of the boundary layer growth in the 5° diffuser. A theoretical analysis, based on the assumption of power law velocity profiles, of the flow in conical and annular diffusers operating with fully developed flow at inlet, has been carried out. While it is necessary to estimate the loss in stagnation pressure along the streamline of maximum velocity, the method does not require the use of an empirical auxiliary equation for the variation of the shape parameter. Comparison with experimental data shows good agreement for the point of separation and the axial static pressure distribution.
Paper 4: Controls for Low-Pressure Hot-Water Heating
Authors: Porges F. 
Published: June 2010

The paper describes modulating control for low-pressure hot-water systems. Compensators and mixing valves are described, and their advantages and disadvantages discussed. The use of time switches is described and typical programmes given. Frost-protection devices for overriding time switches are reviewed, and a strong plea is made for greater simplicity. Difficulties which can arise from faulty positioning of thermostats are discussed. Thermostats detecting lower temperatures than they are intended to can cause safety devices to shut the plant down unnecessarily, and examples are given of such occurrences. Heat retained in the boiler refractories can cause the water temperature to go on rising after the burner has shut off. A heat balance is drawn up and suggestions made for preventing this phenomenon from operating high-temperature safety devices. The difficulties of sequence control of two or more boilers in parallel are discussed. It is difficult to find a method of detecting part load which does not make the boilers hunt; this problem is discussed and a solution for one particular case is offered.
Report 9: Measurement of Transient Surface Temperatures in Metal Cutting
Authors: Braiden P. M. 
Published: June 2010

This report is concerned with measuring the varying thermal stresses in a metal-cutting tool, due to the temperature variations occurring at the tool-chip interface, in the course of intermittent cutting operations. During cutting, the tool is rapidly heated, developing compressive thermal stresses in addition to the mechanical stresses due to the cutting action, but during the non-cutting, or cooling, part of the cycle these latter stresses are absent, and a tensile stress develops on the tool surface. It is believed that these rapidly alternating stresses lead to tool failure by eventual chipping of the cutting edge. The temperature at the interface is measured by means of the tool-work thermocouple technique, in which a tungsten carbide cutting tool contacts a steel workpiece, thereby forming the hot junction of a thermocouple system. The technique is well established for temperature measurements during continuous cutting operations, but care must be taken if it is to provide reliable results. The extension of the technique to include intermittent processes is described, and results are shown for processes having a frequency of 15 c/s. Cutting times as small as 0·026 s have been used and temperature records for this, and greater cutting times, are presented. A disadvantage of this method is that a temperature record is obtained only whilst the tool and work are in contact, and a method to overcome this is outlined.
Report 25: Evaluation of Lubricity
Authors: Pannett D. J. , Cameron A. 
Published: June 2010

The effect of adding rape oil to mineral oil in a compounded axle-box lubricant was investigated, using critical temperature, friction, voltage discharge, and electrical resistance. The critical temperature was measured in a Bowden-Leben machine. The other quantities were determined by using a 1-in steel ball rubbing against 3 planes in a micro cup. All these methods gave compatible results.
Report 27: Some Rigs for Investigating the Properties of Self-Lubricated Bearing Materials with Reciprocating and Oscillating Motion
Authors: Sheppard P. F. , Crump W. J. J. 
Published: June 2010

Self-lubricated bearing materials find many of their applications in bearings with peculiar motions which will not support a hydrodynamic film. With motions other than continuous rotation or continuous sliding very little information is available. To provide these data for the designer and to investigate the suitability of these materials for specific duties several special test rigs have been developed. This report describes some of the rigs developed for this work and the relevance of the results to field experience. The rigs are capable of subjecting the test bearings to a wide range of speeds and load with reciprocating, oscillating and semi-rotary motions in atmospheres of controlled humidity. Results are usually based on attained life, but both wear and friction are measured.
Report 28: A Low-Shear-Rate Viscometer for Use at Pressures up to 120 000 Lb/In2
Authors: Galvin G. D. , Jones B. , Naylor H. 
Published: June 2010

As the first part of a programme in which the properties of lubricants under conditions encountered in the elastohydrodynamic régime will be measured, a low-shear-rate viscometer operating at pressures up to 120 000 lb/in2 has been constructed. It is of the falling body type in which the time of fall under gravity of a hemispherically ended cylindrical sinker through the test fluid is measured. The relationship between viscosity and fall time is of the form: A major correction is applied for the effect of pressure on the density of the fluid and a smaller one for the changes in dimensions of the viscometer under pressure. A means of measuring the change of density of the fluid is incorporated in the viscometer.
Paper 12: The Development of an Apparatus to Measure the Normal Emissivity of Small Plane Samples in a Controlled Atmosphere
Authors: Furber B. N. , Broderick R. 
Published: June 2010

The heat transfer from fuel elements in magnox reactors under all normal conditions is predominantly by forced convection. However, in safety assessments a burst in a bottom main coolant duct is postulated, a reversal of the carbon dioxide coolant flow takes place, and heat transfer from the fuel elements at this instant could be by radiation only. The effective emissivity of the fuel element or the normal emissivity of plane specimens of fuel element material and a geometrical factor are therefore required to enable the maximum fuel element temperature to be determined. The paper is mainly concerned with the development and calibration of an apparatus suitable for measuring the normal emissivity of small plane samples at temperatures up to 650°C. Though the design of the apparatus has been influenced by the special requirements involved in testing magnox specimens, the apparatus has a general application and the normal emissivities of other materials are also given.
Paper 21: A Quasi-Steady Flow Representation of Centrifugal Compressor Performance Characteristics in Non-Steady Flow Systems
Authors: Benson R. S. , Whitfield A. 
Published: June 2010

This paper describes a theoretical and experimental study of the non-steady flow performance of a centrifugal compressor. The experimental work was designed to study the effect of pulse frequency on the compressor performance, for a given delivery configuration, using a rotary valve pulse generator. The experimental rig was designed so that it was possible to study the reverse flow and the pressure pulsations in the suction side of the compressor. The objective of the investigation was to discover how the compressor performance deteriorated with pulse frequency, and also to determine the frequency at which reverse flow through the compressor first occurred. The objective of the theoretical work was to predict the onset of reverse flow through the compressor and the mean and transient delivery pressure ratio using the conventional stationary pipe non-steady solutions by the method of characteristics. The compressor unit was replaced by a boundary condition within the pipe system equal to the experimentally known steady flow characteristics of the compressor. The physical size of the compressor was replaced by an equivalent pipe length; this technique is described. The theoretical results are compared with an extensive series of experimental results. This work is a direct extension of that given in reference (3).
Paper 23: An Investigation of the Losses in the Rotor of a Radial Flow Gas Turbine at Zero Incidence under Conditions of Steady Flow
Authors: Benson R. S. , Cartwright W. G. , Das S. K. 
Published: June 2010

The performance of a radial flow turbine, operating on compressed air, is measured over a range of pressure ratio and speed. Separate tests on the nozzle assembly alone enable the rotor performance to be separated from the overall characteristics. In particular, the conditions at each pressure ratio for which the nozzle exit whirl velocity is equal to the rotor tip speed may be deduced. Also, it is possible to evaluate the enthalpy ‘loss’ in the rotor, that is, the difference between the specific enthalpy drop actually occurring in the rotor and its isentropic value. An attempt is then made to relate this loss with the relative velocities within the rotor passages as predicted by inviscid, two-dimensional analytical techniques. The method developed by Stanitz and co-workers has been programmed to analyse the rotor internal fluid flow properties in the blade-to-blade plane for the conditions of zero incidence. The region investigated does not include the whole rotor, but extends from a boundary upstream of the blade tip to a downstream boundary at a radius equal to 72 per cent of the tip radius. The analysis is performed for overall turbine static to static pressure ratios of 1·2 to 1·6. The result of the theoretical analysis is to show that the variable ratio of rotor outlet to inlet specific volume with changing pressure ratio is accommodated almost entirely without any change in the flow distribution; that is, over the region of the impeller investigated, and at overall turbine pressure ratios up to 1·6, the compressible flow through the rotor may be considered as being through stream tubes of fixed geometry. There is thus a sound basis for the correlation of rotor loss coefficient in terms of parameters which describe compressible flow with friction along variable area pipes. Consideration is given to the manner in which the zero incidence loss coefficient may be defined in order to remain constant at varying pressure ratios.