bluuebunny/crossref_metadata_2025 huggingface dataset:
Report 16: Photoelastic Analysis of Journal Bearings: Preliminary Investigations
Authors: Preater R. W. T.
Published: June 2010

Determination of the stress distributions associated with composite shell bearings under static and dynamic loading conditions is discussed briefly.

Experimental work recently started at The City University, using the three-dimensional ‘frozen stress’ photoelastic technique, is described.

Preliminary static loading tests have been carried out over a range of low temperatures, prior to stress freezing, on a simple bearing and shaft assembly made in Araldite.

One successful stress freezing cycle has been completed and the pressure distribution at the point of stress freezing is shown compared with low temperature distributions for a constant duty parameter.

It is anticipated that, at the time of presentation of this report, the stress distribution at the lubrication surface, as determined by analysis, may be shown compared with the recorded pressure distribution.
Report 17: Design of a Test Rig to Assess the Effect of Three Loading Parameters on Rolling-Bearing Performance
Authors: Jones D. B. , Yardley E. D.
Published: June 2010

In order to obtain information on the performance of certain types of 70 mm bore roller bearing for use in motors of advanced construction, a test rig which will reproduce the load and speed parameters expected to be encountered in service has been designed. The rig can apply steady axial and radial loads and an axial impact to give service conditions considerably more arduous than those which would be recommended by the bearing manufacturers. The programme of work is especially concerned with the effect of various axial impact loads on the performance of roller bearings which are already subjected to steady axial and radial loads.

This report covers in detail the design of the test rig and outlines the range of test conditions available, and the types of bearing that can be tested.
Report 20: Developments in the Measurement of Oil-Film Thickness in Dynamically Loaded Bearings
Authors: Butcher A. E.
Published: June 2010

This report describes the development of a capacitive system for the measurement of oil-film thickness in big-end and centre main bearings of a 600 h.p., 600 rev/min, diesel engine. The object of this work was to compare the theoretical prediction of bearing behaviour with the practical case. Engineering aspects of these measurements are given in the 1967 Institution of Mechanical Engineers Review Paper on dynamically loaded bearings.

Reasons for the development of this system are given, along with a description of measurement techniques, including transmission of signals from the moving big-end to the measuring instruments. Data recording, analysis, and presentation of results are also described.

One of the most significant features of this work was the manner in which the bearing distorted during an engine cycle. This has shown the need for further experimental measurements, which in turn have made it necessary for further development or partial automation of the measuring system.
Report 24: Evaluation of Lubricity
Authors: Lovell A. C. , Cameron A.
Published: June 2010

A new machine to measure friction at various temperatures between a ball rotating at 1 rev/min and various types of holder is described. The types of holder are a washer, a micro 3-ball cup and a micro 3-plane cup. The transition temperature of lubricants is determined in this machine.
Paper 3: Transient Heat Flow Investigations Using an on-Line Computer
Authors: Smyth R.
Published: June 2010

This paper describes some experiences using an on-line computer for transient heat flow investigations. It has been possible to link the experimental equipment to the core of a small high-speed digital computer by way of a multiplexer arrangement which enabled the output of several sensors attached to the experimental equipment to be monitored, sampled, and stored in the computer core at an exceptionally fast rate.

It has been shown that, provided access can be had to such a computer installation, it is possible to accurately investigate the output of thermocouples which have a time constant of less than 0·25 μs. The sampling rate ensures that frequency components above 10 kc/s in the transient heat flow phenomena can be accounted for.

The use of on-line data sampling, described in this paper, ensures that the laborious and time-consuming task of retrieving data from, say, film records or ultra-violet records, can be rejected as well as the effort of transferring such data to a medium suitable for input to a high-speed digital data-processing computer with the possibility of accompanying errors involved owing to manual handling of the data.

The use of multi-channel inputs to the control computer set-up ensures that a maximum of 64 signals can be accommodated simultaneously (although only five are described), and with the sample rates resulting from the use of the on-line equipment, it provides a means of monitoring phenomena such as shock propagations, flame propagations, etc., which might otherwise have been impossible within the accuracy range desirable.

A full description is given of the requirements of the auxiliary equipment necessary for the investigation of transient heat flow using the control computer.
Paper 7: The Measurement of Skin Friction in Pressure Gradients Using a Static Hole Pair
Authors: Duffy J. , Norbury J. F.
Published: June 2010

Two wall static holes of different sizes will give different readings of static pressure and the observed pressure difference is a function of the local skin friction. The static hole pair has, therefore, been proposed as a skin friction measurement device. This paper describes experiments which have been carried out to assess the accuracy of the static hole pair for the measurement of skin friction in favourable pressure gradients. The holes were formed in the wall of a pipe so that the device could easily be calibrated, and the favourable pressure gradient was then generated by inserting a central fairing. The skin friction values obtained from the device were compared with those measured by a Preston tube.

Results showed that the static hole pair is capable of measuring skin friction within about 2 per cent, but a number of practical difficulties are involved, including the necessity to measure very small pressure differences.

Brief consideration is given to the use of the static hole pair in adverse pressure gradients.
Paper 8: Measurement of Pulsating Air Flow by Means of a Bi-Directional Orifice Meter
Authors: Waters T. F. , Imrie B. W. , Cole B. N.
Published: June 2010

This paper discusses experiments carried out to investigate the errors involved when applying the steady flow methods of air measurement to air flows which are pulsating at frequencies between 30 and 130 cycles per second (Hz).

The mass flow measurements for steady and pulsating flow conditions are obtained by using four different sizes of bi-directional square-edged orifice plates with D and D/2 pressure tappings and a comparison of discharge coefficients for the subsonic flow of air in a 1-in diameter pipe, and the measurements cover a range of mass flows up to 0·03 lb/s.

Attempts are made to determine suitable correction factors and thus establish a commercially satisfactory means of air flow measurement from the delivery side of a two-lobed, Roots-type positive displacement blower. The following effects are discussed: (1) the significance of the non-dimensional parameters involved, and (2) the effect of pulse shape.
Paper 9: The Removal of Water from Low-Pressure Steam Turbine Blades by Trailing-Edge Suction Slots
Authors: Ryley D. J. , Parker G. J.
Published: June 2010

This paper reports an experimental research undertaken to explore the performance of a suction slot located in the trailing edge of a representative low-pressure steam turbine fixed blade.

Tests have been made on a 1-in wide section of a full-size hollow blade mounted in a single-blade test section. Typical turbine pressures were reproduced down to 3 inHg (abs.), and blade exit Mach numbers varied in the range 0·57–1·10. With round entry lips, the slot operated satisfactorily in any blade orientation, as it completely removed quantities of water that were in excess of the amount expected under operating conditions. Square entry lips gave somewhat poorer performance.
Paper 14: Discharge from a Cylinder through a Poppet Valve to an Exhaust Pipe
Authors: Woods W. A. , Khan S. R.
Published: June 2010

This paper is concerned with the gas exchange processes which occur in an engine. Previous work has been concerned with unsteady flow within the exhaust pipework; the present investigation provides a link between the cylinder and the pipe.

The modifications to the pulse generator machine which was used to simulate an engine are described, and an account is given of the tests carried out with the machine. The previous steady flow tests are briefly summarized and the unsteady flow tests which were carried out are summarized with the aid of a table.

The paper also presents a discussion of the test results and of calculations carried out to compare with the experiments.

The main conclusion from the results is that a very satisfactory method has been devised for calculating the gas exchange processes occurring in an engine model.

The main detailed conclusions are:

(1) The dependence upon pressure ratio of the effective area of a poppet valve need not be taken into account for the analysis of unsteady flow tests. (2) Calculations on unsteady flow and gas exchange should be made on a theoretical model which has an exhaust pipe equal in length to the actual external exhaust pipe plus the length of the ‘exhaust bend’. (3) The method of calculation using the cylinder boundary conditions is an improvement on the previous type of calculations, which used a ‘pressure input’ as a boundary condition.

Finally, the present work on a pulse generator with fixed piston using cold air, has provided a means of calculating the gas exchange processes from a knowledge of the release and supercharge pressures and the engine geometry. It has, therefore, provided an important link between the engine cylinder and the exhaust pipe system.
Paper 15: Critical Conditions during the Flow of Two-Phase Mixtures through Nozzles
Authors: Chisholm D.
Published: June 2010

Equations are developed for the flow of gas-liquid mixtures through nozzles under conditions of critical or ‘choking’ flow. The equations are compared with experimental data obtained during air-water flow through nozzles and pipes at almost atmospheric pressures. Comparison is also made with data on the sonic velocity in mixtures. Additional problems arising with vapour-liquid mixtures are also discussed.
Paper 19: Slow Transient Compressible Flow through Orifices
Authors: Deckker B. E. L. , Chang Y. F.
Published: June 2010

The discharge of compressed air from a cylinder has been studied experimentally. The effect of initial pressure and of orifice geometry on the expansion in the cylinder and on the transient flow through the orifice has been examined in detail.

During expansion, radial and axial temperature gradients are established which result in departures from isentropic behaviour. The state can be reproduced analytically only by using a variable polytropic index whose values are dependent on the history of the expansion.

From dimensional considerations the effects of fluid dynamical variables and of heat transfer on the transient flow have been isolated.
Paper 25: Unsteady Compressible Flow in a Pipe with a Non-Return Disc Valve
Authors: Kaddah K. S. M. I. , Woollatt D.
Published: June 2010

A simple non-return disc valve was tested in a pipe in which an unsteady flow was produced. The valve was tested with its disc fixed in position and was also tested with the disc controlled by a spring. Records were taken of the unsteady pressure diagrams at various points in the pipe and the disc displacement diagram.

To obtain the boundary conditions required for the unsteady flow calculation, it was first necessary to examine the flow in the valve under steady flow condition. The results of this investigation are briefly described.

It was found that the disc displacement diagram in unsteady flow can be calculated with reasonable accuracy from the pressure drop across the valve by integrating the equation of motion of the disc numerically. The equation of motion contains terms for the inertia of the disc, the spring force, and the gas force. Viscous friction damping forces were negligible for this valve.

Once the disc displacement is known, the pressure diagram can be calculated using the steady flow values for the pressure loss across the valve and the normal methods for one-dimensional unsteady flow calculations.
Paper 38: Water Drainage from a Cascade of Hollow Slotted Low-Pressure Turbine Blades
Authors: McAllister D. H. , Moore C. T.
Published: June 2010

To prevent or minimize the erosion of the last row rotor blades in large high-speed steam turbines it has been proposed to remove the film of water on the surfaces of the last row stator blades before it reaches the trailing edges and is swept off by the steam drag into the path of the rotor blades.

The paper describes experiments with a cascade of hollow stator blades with various dispositions of slots providing communication from the blade surfaces to the hollow cavity. The same cascade was used in turn with three different wet air tunnels, the experiments thus covering a wide range of Mach number and Reynolds number.

With suitably disposed slots, and bleeding a very small proportion of the working fluid, about 90 per cent of the deleterious water can be removed, thus preventing it from striking the moving blades.
Paper 39: The Flow of Wet Steam in a Turbine
Authors: Kirillov I. I. , Yablonik R. M.
Published: June 2010

This article considers methods of calculating condensation processes in wet steam turbines. Equations are given for determining the rate of nucleation, the growth of droplets, and the wet steam parameters. The condensation processes within the blade ring of a steam turbine are used by way of example. It is made clear that the condensation process is continuous at large enthalpy gradients. Under these conditions the theory of discontinuous condensation will not represent the actual process. Calculations based on the kinetic theory of phase change agree well with experimental findings.

The constructional features of the blading which operates within the Wilson zone can have a considerable effect on the extent of the undercooling and on the size of the droplets.

The trajectories of the droplets in the space between blade rings can be determined using standard approximate equations. The Coriolis force has a considerable influence on the motion of the entrained liquid within the moving blades. Under the influence of this force the liquid may move either with the flow or against it.
Paper 41: The Spontaneous Ignition and Ignition Delay of Liquid Fuel Droplets Impinging on a Hot Surface
Authors: Satcunanathan S. , Zaczek B. J.
Published: June 2010

The spontaneous ignition and ignition delays of liquid fuel droplets impinging on a hot surface are investigated. It is shown that the ignition delay–temperature curves follow closely the pattern of lifetime–temperature curves and that for the commercially important fuels, such as kerosine and diesel fuel, the ignition delays have a minimum value at some particular temperature. Zones of non-ignition are isolated and a hypothesis presented for their occurrence. It is further shown that within the temperature range investigated, the ignition delays of droplets impinging on a hot surface are much shorter than those of similar droplets undergoing spontaneous ignition when suspended in a stagnant atmosphere.
Paper 42: A Simple Theory for the Prediction of Losses in the Rotors of Inward Radial Flow Turbines
Authors: Bridle E. A. , Boulter R. A.
Published: June 2010

The results of tests on a series of small inward radial flow turbines, reported by Hiett and Johnston, are analysed. Stagnation type pressure loss coefficients are established for the rotors, enabling their performance to be predicted with fair accuracy over a wide range of operating conditions in both directions of rotation. In particular, secondary losses are related to the forces acting on the vanes, using a similar method to that of Ainley and Mathieson for axial flow turbines. Additional losses occurring during reverse rotation are related to the variation of lift coefficient with radius in the exducer.
Paper 8: Heat Transfer from a Wire in the Critical Region
Authors: Grigull U. , Abadzic E.
Published: June 2010

This work deals with experimental results on boiling from a horizontal platinum wire, 0·1 mm in diameter, submerged in saturated liquids as carbon dioxide (CO2) and Freon 13 (CF3Cl) in the critical region. Three discrete regimes without steady transition could be observed: natural convection, nucleate boiling, and film boiling. Near the critical point particular flow patterns appeared in the rising vapour in film boiling: regular bubbles, vapour columns, and vapour hazes with garland-like boundaries. These flow patterns could be simulated in model experiments with liquids and were also photographed with a high-speed camera.
Paper 8: Corrosion Problems in Motor Vehicles
Authors: Enrico F. , Ferraro I. , Marciante A. , Natale T.
Published: June 2010

Purely chemical or electrochemical corrosion is covered by this survey, which does not deal with damage due to combined effects of wear and chemical agents.

Two main classes of corrosion—‘internal’ and ‘external’—may be considered.

In the section headed ‘Internal corrosion’, the following topics will be discussed: exhaust valves corroded by combustion gases; silencers subject to corrosion due to the acid condensates collecting in the colder regions; cooling systems subject to corrosion due to chlorinated water and unsuitable additives; and cylinder liners corroded even when inoperative.

In the section headed ‘External corrosion’, in view of the environmental conditions to which a vehicle is exposed in service—meteorological agents, contaminated atmospheres, abrasion and dents caused by sand and gravel, chemical action of the salts used for ice removal from roads—protective treatments have been classified as follows: ( a) electrochemical; ( b) by paints.

In class ( a), after discussing the typical case of damage to fuel tanks, the various galvanic treatments recommended for carbon and stainless steel, brass, and alloys of aluminium, zinc, and magnesium have been described. In class (b), where protection by paints is dealt with, problems related to car bodies have been particularly emphasized.
Paper 4: Surface Integrity—A New Requirement for Surfaces Generated by Material-Removal Methods
Authors: Kahles J. F. , Field M.
Published: June 2010

The design of structures for modern industry has created stringent service, reliability, and safety requirements. Present manufacturing specifications for surfaces are concerned primarily with geometry, which includes surface roughness and accuracy. The need is growing to consider not only surface geometry per se, but also the nature of alterations in the surface layer. Typical surface layer modifications, as a result of temperature, stress, and environment during material removal, include phase transformations, plastic deformation and fracture, and chemical changes.

These various changes in the surface layer become increasingly significant with the more extensive application of materials such as high-temperature alloys, high-strength steels (including the maraging steels), refractory alloys, titanium, and beryllium. Some of the non-conventional machining methods, such as electrical discharge machining and grinding, electrochemical machining and grinding, and laser beam machining, can generate surface layer characteristics quite different from those produced by conventional methods. Surface alterations may also affect the residual stress, and with it the accuracy of thin section hardware, as well as decrease some of the significant mechanical and physical properties, such as fatigue strength, stress corrosion resistance, and fracture propagation rate. Control of surface layer characteristics, consistent with design requirements, develops ‘surface integrity’ which, in turn, leads to reliable service performance.

A general review of previous work on the subject of surface integrity is presented. Typical microstructural surface alterations are illustrated, and the residual stress induced in the surface and its correlation with dimensional accuracy is demonstrated. A survey is presented relating machining methods to fatigue strength and stress corrosion characteristics. Finally, some guidelines are suggested for the practical implementation of surface integrity by means of processing specifications. Some consideration is given to the cost of implementing surface integrity requirements and their effect on production rates, including precautions concerning needless over-emphasis for certain manufacturing requirements.

The data presented in this paper manifest that the metrologist's technical jurisdiction should be extended in depth from the Ångström range to the millimetre subsurface level.
Paper 43: Connection between Surface Quality and Processing
Authors: Gribovszki L.
Published: June 2010

This paper gives the modern general view of surface quality, and briefly reviews the most important methods of testing the characteristics of the surface layers produced by machining or processing. Methods of determining the remanent stresses are described in detail. After having demonstrated a newly developed method of test, the author discusses the magnitude and distribution of the remanent stresses brought about by the more important variants of heat treatment, surface compaction, machining, and grinding. In conclusion, an effective method is described for the complex investigation of the surface quality of gear teeth.
Paper 7: Surface Studies in the Investigation of Failure Mechanisms
Authors: Scott D.
Published: June 2010

Surface effects can influence the friction and wear characteristics and the fatigue behaviour of materials, so that any investigation of these phenomena necessitates careful study of the surfaces involved. Changes in topography, chemical nature, structure, and physical properties of surfaces subjected to sliding, rolling, abrasion, corrosion, deformation and repeated stressing have been studied using optical and electron microscopy and micro-probe analysis to obtain information of use in the elucidation of failure mechanisms and their controlling factors. Specific information from each technique enables comprehensive data to be accumulated. The paper reviews work which has been carried out in recent years, mainly from the technological viewpoint.
Paper 5: Preparation and Properties of Molecularly Flat Surfaces
Authors: Winterton R. H. S.
Published: June 2010

Very smooth surfaces may be prepared by cleaving suitable crystals of mica and other lamellar solids. Large areas of these surfaces are free from steps, even 1 molecule high, as may be shown by multiple beam interference techniques.

In this paper the nature of contact between mica surfaces has been investigated and strong adhesion has been found. The application of tangential loads to cause sliding results in severe surface damage—Amonton's law is not obeyed. If a monolayer of calcium stearate is spread on the surfaces, damage is eliminated and the shear strength of the interface falls to one-fortieth of its previous value.

Surface energies of mica, and mica coated with monolayers, have been measured and, in addition, these very well-defined surfaces are suitable for measuring the range of action of surface forces.
Paper 6: Assessment of Face Seal Performance Based on the Parameters of a Statistical Representation of Surface Roughness
Authors: Mitchell L. A. , Rowe M. D.
Published: June 2010

Most methods commonly used to describe real surface roughness do not provide adequate information to enable predictions to be made of fluid leakage between two surfaces. To carry out such an analysis it is essential to know the depths of the remaining valleys at all stages of compression.

It is shown that, when the distributions of peak and valley levels are defined, load-compression and load-leakage relationships can be derived if wedge-shaped asperities of constant apex semi-angle are assumed. The results suggest that a convenient quantity for specifying the form of a surface profile is the ratio of the distance between the mean peak and mean valley levels to the standard deviation of the distributions ( d/σ). For the best sealing performance d/σ should be as large as possible, whilst the centre-line average (c.l.a.), which provides a measure of the scale of the roughness, should be as small as possible.
Paper 24: New Developments in Surface Characterization and Measurements by Means of Random Process Analysis
Authors: Peklenik J.
Published: June 2010

New developments in engineering and science in systems involving surfaces (friction, wear, contact deformation, reflection, electrical conductivity and resistance, heat transfer, tolerances and fits, etc.) require more comprehensive characterization of their micro- and macro-geometrical texture. Previous experience exhibits the fact that a statistical description of a surface by means of the first and second moment of the ordinate probability density distribution such as c.l.a. or r.m.s. and other parameters is not adequate.

This paper discusses the more recent developments of surface characterization, considering a two- and/or three-dimensional random process by means' of the auto- and cross-correlation functions, power spectra, and the slope probability distribution parameters. A representative number of surfaces manufactured by a variety of metal-removal processes have been investigated in order to achieve, first, the differentiation of the surfaces with the same c.l.a. and r.m.s. values, and second, the separation of the periodic and random components in the surfaces. It is shown that the new techniques may disclose the differences in the internal structure of the surfaces.

The elementary correlation functions, which may describe analytically the types of real surface profiles, are employed for the design of the surface topography system based on the correlation lengths and correlation wavelengths. On a number of practical examples there is shown the applicability of the proposed surface classification which is independent of the surface generation process.

The theoretical approach and the experimental confirmation of the conclusions represent basically a new tool for comprehensive surface characterization. However, it should be considered that such a description requires a data requisition and processing by means of digital or special statistical computers. This circumstance does not affect the basic research work, but it is impractical for workshop application. Therefore new parameters and measuring methods have been developed to make the use of more comprehensive surface characterization methods possible in practice.
Paper 15: Today's Need—Functional Surface Roughness Control
Authors: Hydell R. R.
Published: June 2010

A working system of peak-to-valley surface roughness control, similar to the Swedish H system, has been developed and is in use on selected Aerospace hardware. A test of seven participating companies proved the compatibility of the system.
Paper 26: Survey of Factors Affecting Surface Finish
Authors: Dickinson G. R.
Published: June 2010

This paper discusses tool geometry, the reliability of surface measuring equipment in respect to feed/cutoff ratios and the relationship of fatigue and surface finish and other aspects of a surface which are not defined by B.S. 1134.
Paper 27: Effects of Machining on Ultra High Strength Steels
Authors: Dickinson G. R.
Published: June 2010

This paper describes the work carried out on ultra high strength steels with regard to the metallurgical damage to the surface that can be brought about by worn tools or poor grinding techniques.
Paper 13: Surface Roughness and Lubrication in Sheet Metal Working
Authors: Butler R. D. , Pope R. J.
Published: June 2010

The importance of surface roughness and lubrication in the manufacture of autobodies is discussed with particular reference to consistency, methods of measurement, and the need for overall optimization.
Paper 8: Study of the Finish Produced in Surface Grinding
Authors: Farmer D. A. , Brecker J. N. , Shaw M. C. , Nakayama K. , Shaw M. C.
Published: June 2010

The finish produced in reciprocating surface grinding was studied experimentally and analytically. The 2 n factorial design of experiments technique was applied to determine the relative importance of a large number of variables on the centre-line average (c.l.a.) surface roughness produced without spark-out. The most important variable was found to be table speed which should be low for best finish. The following variables were but one-half to one-third as important as table speed and should be adjusted in the direction indicated for good finish.

The peak-to-valley roughness was found to be from four to six times the arithmetic roughness over the entire range of grinding conditions investigated.
Paper 21: Topography and Mechanical Properties of Ground Metal Surfaces
Authors: Barker K. , Kaliszer H. , Rowe G. W.
Published: June 2010

The purpose of the paper is to investigate the significance of periodic removal of metal particles deposited during cutting in the pores of the grinding wheel. A measuring technique is described, and experimental results are given, which indicate that wheel life, topography, chatter vibration, workpiece skin hardness, and metallographic structure can be improved considerably by applying a special process of debris removal from the working periphery of the grinding wheel.

In other experiments using lubricants it is found that simple mechanical removal of debris may also be advantageous. A new technique of intermittent application of a lubricant is described. This is shown also to be effective when grinding a heated workpiece.

A new technique for examining the ground surface is described. This utilizes ¾-in inserts, which are heat-treated and then ground with the main body of the selected workpiece material. These inserts are subsequently removed and examined by metallographic sectioning. Microhardness traverses across the surface and in depth show marked variations due to the rapid heating of the surface during grinding and the immediate very rapid quenching. A 0·45 % C steel of general hardness 700 K.d.n. was, for example, increased to 1100 near the surface. At greater depths, the diffusion of heat tempers the quenched material, and the hardness falls again with further increase in depth. This excessive skin hardening can be avoided by ultrasonic treatment of the wheel at regular intervals during grinding.
Paper 9: Limits of Application of the Interference Methods for Surface Measurements
Authors: Trumpold H.
Published: June 2010

Owing to the increasing demands for surface quality, the determination of surface roughness values below 1 micron is of increasing importance. The different interference methods are described and applications, advantages, and disadvantages are examined.
Paper 20: New Optical Method of Assessing Surface Quality
Authors: Tipton H. , Roberts J. I.
Published: June 2010

A new method of assessing surface quality is described in which the light scattered from the surface is scanned by the edges of a chopper disc. The electrical output from the photocell is differentiated twice to give a signal which is a measure of the maximum rate at which the intensity of the reflected light falls off. It allows a simple, cheap, and robust instrument to be made which is insensitive to ambient illumination and can be used as a surface comparator either ‘on-line’ or as a bench instrument.
Paper 19: Surface Testing Using the Hommel Tester Type T
Authors: Wolff H.
Published: June 2010

This paper is based on test, results and shows how the characteristics of a measured profile—depth of roughness, ripple, and outliers—can be recognized individually and expressed numerically by varying the measuring conditions with respect to the test probe, the length measured, the cut-off, and the nominal parameter.
Paper 34: Calibration of Surface Texture Measuring Instruments
Authors: Sharman H. B.
Published: June 2010

Continuously lined surface texture calibration specimens are used to determine the transmission characteristics of surface texture measuring instruments.

The lines, deposited at 001 in pitch, are basically sinusoidal in shape with amplitudes ranging from 30 to 1000 μin. Rotating the axis of the specimen relative to the direction of the pick-up head traverse generates waves with pitches ranging from 0·01 to 0·5 in. The transmission characteristics, using 0·01-, 0·03-, and 0·1-in cut-off, of a surface-texture measuring instrument are compared with the requirements of British Standard 1134:1961.
Paper 1: Peak Counter for Surface Texture Measurement
Authors: Russell A.
Published: June 2010

The counter described counts the number and amplitude of peaks present in the waveforms generated by surface texture measuring apparatus. Two blocks of tunnel diodes are used to form two interlaced thresholds which determine the ‘rising’ and ‘falling’ switch points. The input waveform can be ranged and scaled to match the total excursion of the waveform and the minimum amplitude peak to be counted.
Paper 31: Surface Finish Assessment by an Electrical Capacitance Technique
Authors: Sherwood K. F. , Crookall J. R.
Published: June 2010

This paper gives a general theoretical treatment of roughness as a function of observed capacitance, and presents the implications and difficulty of obtaining a generalized solution. Some progress is made using certain stylized surfaces. Characteristics of possible instruments are discussed, outlining the practical feasibility of the technique.
Paper 3: Non-Contact Surface Contour Analyser
Authors: Keller B. E.
Published: June 2010

This paper describes the development of an accurate and rapid non-contact technique for numerically defining three-dimensional surface contour. Because the basic technique uses a diffusely reflected spot of light on the test surface to define surface position, considerable attention is given to surface condition variables which influence the ability and effectiveness of following a moving light spot on a test surface. Methods for transforming data points representative of surface contour into a practical form satisfying engineering and inspection requirements are also discussed.
Paper 32: Accurate Calibration of Surface Texture and Roundness Measuring Instruments
Authors: Spragg R. C.
Published: June 2010

Some of the finer points to be taken into consideration when accurately calibrating surface texture and roundness measuring instruments are discussed. Consideration is given to such things as stylus condition, linearity, range switching accuracy, frequency response, and overall sensitivity. The paper concludes with a brief account of an experiment to determine roundness errors to better than ¼ μin (0·006 μm).
Paper 36: Specimens Used for Checking Contact Profile Recording Instruments and M-System Profile Meters and Certification of Specimens
Authors: Lukjanov V. S.
Published: June 2010

This paper describes the results of experimental investigations of a visual interference method of certifying simple profile specimens and the basic expressions for calculating a photoelectric scanning system for interference fringes employed in certifying specimens of regular complex shape.
Paper 35: Some Aspects of Measurement of Roundness
Authors: Avdulov A. N. , Polunov Y. L. , Tabenkin A. N. , Faradjev I. A. , Shuster V. G.
Published: June 2010

This paper deals with the analysis of the extent to which the results obtained from the measurements of the same graph may vary while using different reference circles. The statistical characteristics of the graph were obtained experimentally, and the algorithms for circles were worked out. The analysis was carried out by the Monte-Carlo method on a digital computer.
Paper 39: In Situ Out-of-Roundness Measurement
Authors: Witzke F. W.
Published: June 2010

A new method is described for measurement of out-of-roundness characteristics of parts under conditions that are now considered extremely difficult or impossible.

For example, it is now possible to measure very large parts while they are still mounted in the machine tool, on a makeshift inspection fixture, or even in an assembly. Typical of parts now being measured by this method are crankshaft journals and throw surfaces, piston pins, machine tool spindle shafts, mill rolls, and reactor fuel rods. No expensive masters, precision spindles, or special skills are required. Results are plotted and measured on polar charts such as used on the more conventional roundness gauge. Accuracy of the out-of-roundness measurement is within ±10 per cent for most parts.
Paper 29: Waviness Measurement-An Instrument for Quality Control in Rolling Bearing Industry
Authors: Yhland E. M.
Published: June 2010

Waviness measurement by means of electrodynamic pick-up of rolling bearing elements is discussed from the point of view of a bearing manufacturer. Correlation with bearing vibration measurement is also considered.
Paper 44: Education for Surface Texture Assessment
Authors: Broadston J. A.
Published: June 2010

Limitations in the ability of surface texture assessment methods to evaluate truly the probable performance of surfaces under operating conditions are widely known. As the micro-geometric asperities of surface texture are very complex in character and as the conditions under which surfaces must operate are so varied, direct correlation of the two by means of simple indices is relatively impossible. While investigation of methods of assessment might provide consuming scientific and academic interest, as well as an intriguing diversion for those in metrology, such effort is of little avail unless it can be useful in enabling industry to produce better products at lower cost.

International effort is under way to reach world-wide agreement on standards for assessment devices, methods of evaluation, reference specimens and drafting room standards for designation.

Precise and accurate control of surface texture is increasingly important to product performance in advancing technology. Success depends upon personnel who have a thorough knowledge of the limitations of existing methodology as well as the broad perspective necessary to evaluate factors in terms of company goals.

Credos for engineers, manufacturers and quality personnel are given to assist in the human factors that play such an important part in the successful use of any assessment system.
Paper 2: The Application of a Small Scientific Computer to Calculations for Prototype Engines
Authors: Monaghan M. L.
Published: June 2010

It is often assumed that a large computer, because of its great speed and large core size, will invariably provide a cheaper result than a smaller computer. There are many problems in the internal combustion engine field, however, which can be tackled economically using a small scientific computer.

Among these are design calculations for prototype engines where program utilization is not very high. The cost of developing these programs for a small machine is low and, providing the required output is matched to the speed of the machine, actual operating costs can be kept low.

Many prototype designs give rise to problems where the solution warrants a computer, but time and money are such that a full scale study using a large machine is not possible. Here the small computer can be used to give a rapid economical answer to the problem while the relatively low cost of manual intervention on such a machine often allows a very flexible approach.

Calculations for prototype engines described in this paper cover cam ordinates and their analysis and the determination of big-end bearing loads. Research problems include the effect of Poisson's ratio on thermal stress, a check on the motion of an unusual type of shock absorber and calculations to assist in the development of a small Stirling cycle engine.
Paper 1: Pump Intake Design Investigations
Authors: Paterson I. S. , Campbell G.
Published: June 2010

Centrifugal pump design has reached the stage where to improve efficiency much research is necessary for limited returns, whereas the application of model techniques to the design of pumping systems in general and pump intakes in particular can yield immediate and manifold savings.

Test rig requirements and test techniques applicable to pump intake models are described, and limitations regarding model size and flow velocities are discussed in relation to scale effects.

Cumulative results to date on typical intakes for large circulating water pumps are summarized and design trends are assessed.
Paper 2: Integrated Design of Pump and Adjacent System
Authors: Paterson I. S. , McConnell T. A.
Published: June 2010

Owing to the incompatibility of free surface and closed conduit scaling requirements, pump intake investigations are often carried out in two stages.

Stage 1 covers pump intake design investigations, which establish the hydraulic acceptability of the main approach works, whilst Stage 2 deals with pump and adjacent inlet investigations, which are used to study in detail flow immediately upstream of the pump and its relation with pump performance.

Correlation of Stage 1 and Stage 2 is discussed and test rig and testing requirements for the latter are described. Results of model investigations and the ensuing suction duct designs for typical large circulating water pumps are summarized. The discussion is extended to more general comments on the effect of installation on pump performance and its measurement.
Paper 5: Model Testing of High Head Pumps
Authors: Nixon R. A. , Spencer E. A.
Published: June 2010

After a world-wide survey of possible sites, the National Engineering Laboratory was chosen as the independent laboratory best fitted to carry out acceptance tests on the bidder's model pumps for the Tehachapi Crossing Scheme.

Model test conditions corresponding as nearly as possible to the full prototype head of 1970 ft were required, involving powers of between 3000 and 4000 hp, comparative repeatabilities of the order of ±0·15 per cent, and overall accuracies better than ± 0·3 per cent, the whole test programme to be completed within a tight time schedule. The paper describes the preparation, specification, and general aspects of the execution of the test programme. Its relevance to model testing of pumps in general is also discussed.
Paper 6: Thermodynamic Scale Effects on Pump Suction Performance
Authors: Ward T.
Published: June 2010

An attempt has been made to account for the scale effects observed when comparing the suction performance of a pump with that predicted from model tests by considering the thermodynamic aspects of cavitation. However, although improvements in the prediction of performance may be obtained in some cases by using the equation developed, these aspects do not account for all the scale effects observed.
Paper 7: Sump for Tilbury Dock Extensions
Authors: Fellerman L.
Published: June 2010

This paper describes the study, by use of models, of two sumps for the installation of impounding pumps at the Tilbury Dock extension.

The first design studied indicated that there would be excessive random velocity fluctuations in the area of the impeller. Modifications reduced the fluctuations to more reasonable proportions. Problems of locating the impeller in a plane of low-velocity fluctuation led to a study of a second design of sump.

The second design, with the aid of flow straightening diaphragms, produced improved flow conditions in the plane of the impellers.
Paper 8: Some Hydraulic Modelling Techniques
Authors: Zanker K. J.
Published: June 2010

A general discussion is given of modelling techniques based on dimensional analysis and similarity. Particular attention is focused on the modelling of two-phase effects, where it is neither always obvious which are the predominant forces nor whether considering only two forces will give reasonable similarity. Three examples—air-entraining flows, high, siphons, and bubbly flows—are considered and some suggestions of suitable model scaling laws are made. These include We/Re for air entrainment and the cavitation number for high siphons. The results of model tests on air-entraining vortices at the Kariba Hydroelectric Scheme are presented as an application of the discussion.
Paper 9: Flow Patterns and the Affinity Laws for Model Testing of Impeller Pumps
Authors: Lupton H. R.
Published: June 2010

The accuracy of model testing rests on the applicability of the affinity laws interrelating the behaviour of geometrically similar machines running at various speeds. To be confident of this applicability it is necessary to ensure, with sufficient accuracy, the similarity of the flow patterns within the prototype and model.

With a perfect liquid considerable guidance as to the flow regime in a pump or turbine can be gained from partial streamline maps based purely on hydrodynamics. Approximate maps are given for the relative flow within an idealized centrifugal impeller, and the respects in which these fall short of representing the regime throughout a complete pump, even with perfect liquid, are discussed.

The actual flow patterns, both in model and prototype, will differ from the flow regime ruling in the case of a perfect liquid, and in general from one another, mainly by reason of viscosity. If cavitation occurs, further differences in behaviour will be caused, notably by reason of gas content and surface tension and by the downward limit of absolute pressure.

The nature, location, and extent of these relative departures, and their effect on the applicability of the affinity laws, are examined in the light on the flow pattern afforded by the streamline maps.
Paper 16: Friction in Wet Clutches
Authors: Evans E. M. , Whittle J.
Published: June 2010

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants.

A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.