bluuebunny/crossref_metadata_2025 huggingface dataset:
Paper 9: Unsteady Flow in Pipes with Gradual or Sudden Area Changes
Authors: Benson R. S. , Garg R. D. , Woods W. A.
Published: June 2010

The paper describes a theoretical and experimental investigation into unsteady flows in pipes with cross-sectional area changes. One-dimensional unsteady flow theory using the method of characteristics is used for analysing the wave action in the pipes. Both homentropic and non-homentropic flows are investigated.

For gradual area changes (effuser, diffuser) the generalized one-dimensional unsteady flow theories including friction are used. For sudden area changes quasi-steady flow theories at the area change are described to evaluate the boundary conditions. At a contraction the flow is assumed to be isentropic, whilst at an enlargement it is assumed that the flow is adiabatic but not isentropic. In the latter instance, it is assumed that there is a pressure recovery according to the conservation equations; this theory is equivalent to the sudden enlargement theory with pressure recovery at the plane of the area change.

Steady flow experiments are described to test the validity of the above assumptions. These show excellent agreement with the theory for the contraction. In the case of the enlargement the tests show that the plane of recovery is some distance downstream of the area change, the distance depending on the dimensions of the area change and the pressure ratio.

Extensive unsteady flow tests are described. Good agreement between the theoretical diagrams and experimental results is obtained from the gradual area changes and the sudden contraction. For the sudden enlargement the agreement is good at the pipe ends furthermost from the area change. In the region near the enlargement the flow is strongly three-dimensional. The plane of pressure recovery for unsteady flow is about half the distance downstream from the enlargement for steady flow. The results indicate that once one-dimensional flow is formed the agreement between the theoretical and experimental diagram is good.

It is therefore concluded that for gradual area changes the generalized one-dimensional unsteady flow theories may be used, for sudden enlargements quasi-steady flow theories may be used for predicting the flow in the regions some distance from the area change (about four diameters). For sudden contractions there is no limit to the region for consistent results to be obtained.
Paper 13: Experimental Investigation of Turbulent Heat Transfer in a Pipe Preceded by a 180° Bend
Authors: Lis J. , Thelwell M. J.
Published: June 2010

The local values of the heat-transfer coefficient to water flowing turbulently in a pipe were measured for the following entry conditions:

(1) A long hydrodynamic calming section. (2) One of three bends, having a radius 2, 3, or 4 times that of the pipe, and itself preceded by the calming section. The experiments covered a range of Reynolds numbers from 10 000 to 94 000 and heat fluxes from 5 to 50 W/cm2.

The dependence of the local and average values of the heat-transfer coefficient on the Reynolds number, length of the pipe, ratio of the bend to pipe radius and variation of physical properties of the fluid with temperature, is analysed and discussed. Correlations are proposed for the local and average values of heat transfer in the entrance region of the pipe and for the heat transfer under the fully developed flow conditions.
Paper 18: A New Graphical Representation of the Thermodynamic Properties of a Fluid in Motion, with Particular Reference to Air at High Velocities, Temperatures, and Altitudes
Authors: Cole E. H. , Spalding D. B.
Published: June 2010

Diagrams are described which represent the equilibrium thermodynamic properties of air, account being taken of dissociation. The ordinates are the logarithm of specific enthalpy in both cases; the two abscissae are the logarithm of specific volume in one case and that of velocity in the other. The specific enthalpy varies from 10 to 104 Btu/lb, the specific volume from 1 to 106 ft3/lb, and the velocity from 102 to 105 ft/s; the corresponding ranges of temperature and pressure are respectively 45°R to 11 700°R and 10-4 arm to 102 atm.

It is shown how constructions on the diagrams may be used for the representation and calculation of steady-flow processes involving compression and expansion, heating and cooling, shock waves, detonations, mixing, and combinations of these processes.
Paper 21: Some Aspects of Research at the National Gas Turbine Establishment on Internally Air-Cooled Turbine Blades
Authors: Barnes J. F. , Fray D. E.
Published: June 2010

This paper describes some of the results obtained from a series of experiments on internally air-cooled turbine nozzle and rotor blades. These were formed by an extrusion process and had, respectively, sixteen and thirteen cooling passages of approximately elliptical cross-section. The cooling characteristics of both types of blade were measured in an experimental high-temperature turbine and further experiments were conducted in cascade tunnels. Some of the cascade experiments on the rotor blade were conducted at comparatively high Reynolds numbers and showed, in accordance with predictions, the extent to which chordwise non-uniformities in blade temperature become larger as Reynolds number is increased.

Other experiments were conducted with the turbine to determine the effects on aerodynamic performance of discharging spent cooling air into the main gas stream. The results showed good agreement with predictions based on a simple flow model, and in particular indicated that flow separation, with its associated losses, did not occur. Finally the results of an endurance test are presented, together with a brief description of the way in which thermal plus centrifugal stress patterns can be redistributed by creep in non-uniformly cooled blades.

Brief mention is made of those fields of research which require further attention, namely an investigation of the factors governing the local values of heat-transfer coefficient on the external surface of turbine blades and the testing of the assumptions used in calculating stresses in cooled blades.
Paper 24: The Development of a Controlled Wet-Steam Generator
Authors: Ryley D. J. , Fallon J. B.
Published: June 2010

This paper describes what is believed to be the first attempt to make a wet-steam ‘wind’ tunnel. Saturated water is sprayed from a small high-speed rotating disc so that the globules are entrained by a stream of saturated steam at the same temperature in which the disc is immersed.

The tunnel is designed for a maximum steam speed of 30 ft/sec in a circular working section of 16-in diameter with steam pressures ranging from a full vacuum to 10 lb/in2 gauge. The entrained globules range in size from 5 to 100 micron, and the minimum nominal dryness fraction is 94 per cent.

A sampling technique was developed based on the impressions made by the globules on a prepared slide, and an attempt is made to relate the globule size to the disc size and speed, the injection water flow and the physical characteristics of the saturated liquid and vapour.

Globule trajectories were calculated by computer allowing for variation of drag coefficient and acceleration of the entraining steam.

In the paper the design of the equipment and the problems encountered both in generating the wet steam and in determining the size of the globules are discussed.
Paper 25: Two-Dimensional Subsonic Flow in a Parallel Diffuser
Authors: Martin B. W.
Published: June 2010

From the laws of conservation of mass, momentum and energy, predictions are made of subsonic flow conditions between parallel surfaces of infinite depth under the influence of a positive pressure gradient. The model employed presupposes a boundary layer outside a main stream across which the flow parameters are uniform. The theory suggests limitations on boundary-layer thickness, and indicates velocity profiles differing substantially from that of a conventional turbulent boundary layer. Owing to momentum exchange between the free stream and the boundary layer, limitations on the static pressure ratio and the length of the diffuser also appear to be implied.
Paper 4: Stresses in a Rotating Toroidal Shell
Authors: Webster J. J.
Published: June 2010

A method is given in this paper for calculating the mean hoop and meridional bending stresses in a rotating toroidal shell. The rotational stresses in a wheel, consisting of a portion of a toroidal shell, built in at one edge to the hub, have been calculated and are compared with the stresses determined experimentally with electrical resistance strain gauges.
Paper 13: Tests beyond Yield on a Spherical Pressure Vessel Containing a Series of Oblique Nozzles
Authors: Townley C. H. A. , Procter E. , Gadd B. W.
Published: June 2010

The paper describes the first of a series of three tests designed to obtain information about the nozzle assemblies on reactor pressure vessels under a variety of loading conditions, with a view to predicting their behaviour in service. This first test is concerned with the effect of loadings which cause yielding in the nozzle region, and while overloads as severe as those described cannot occur in practice, the results enable a quantitative assessment to be made of the margins between operating pressure and failure pressure as far as shortterm yielding is concerned. They also provide data which will be of interest when improved design methods, involving higher working stresses, are considered.

The test was carried out on a spherical vessel containing a small group of oblique nozzles, manufactured to represent a nozzle layout typical of reactor vessels, at scale size. The vessel was hydraulically pressurized up to 1670 1b/in2 gauge when failure occurred through the heat-affected zones of the nozzle to shell welds. The basic shell stress at failure was approximately equal to the ultimate tensile strength of the material.

Strain readings recorded during the tests, and the results of the metrological surveys, carried out on the vessel before and after testing, are discussed in the report.
Paper 1: Bend-Buckling of Pressurized Cylindrical Shells
Authors: Coutie M. G. , Maunder L.
Published: June 2010

Thin cylindrical shells subjected to high bending loads normally buckle by forming a number of diamond- shaped panels on part of their compressed surfaces. The values of the buckling loads show considerable scatter but are in general substantially less than those predicted by simple linear theory.

This paper describes an attempt made a few years ago to improve the buckling strength and to reduce the scatter in the buckling loads of such shells by means of internal pressure. It was expected and confirmed that internal pressure would increase the buckling loads, but little improvement was obtained in the amount of scatter. Considerable modifications of the buckling deformations were observed; at sufficiently high pressures the diamond pattern disappeared entirely and was replaced by a single ridge of deformation extending circumferentially around the compressed side of the shell.

An account is given of the experimental investigation together with some excerpts from the theoretical work. Most of the shells were formed from thin steel sheets bent into the shape of a cylinder then soldered down a generator. They were filled with water, plugged at their ends and put under pressure by means of a hand-pump. Observations made during bending included load, pressure, strain, deflections and mode of buckling. These are discussed and compared with the results of other investigations.
Paper 16: Effect of Thermal Cycling on Pre-Stressed Steam Pipelines
Authors: Jeal R. H. , Bindley D.
Published: June 2010

Investigations into the effect of temperature and pressure cycling on a pre-loaded model main steam line of 0·5% Cr-0·5% Mo-0·25% V steel have shown that a relatively large increase in length occurred over a few cycles at 100 per cent cold pull, and a decrease in length occurred at 50 per cent cold pull. Using high temperature platinum-tungsten strain gauges, it has been found that large changes in strain occur round an expansion loop in the model pipeline. It is suggested that large changes in the design stress distribution in a main steam line occur during the commissioning stages of a generating unit, making creep behaviour of the line during base loading difficult to predict. It is further suggested that failure in pipelines when a unit is working under a twoshift system is due to low cycle fatigue, as the strain changes occurring do not appear to approach an equilibrium minimum under cycling conditions.

It would appear that strain changes, and hence the effect of low cycle fatigue, can be minimized by choosing a level of cold pull between 50 and 100 per cent, the actual level depending upon the physical characteristics of the pipe material, the more important ones being thermal expansion and the change of yield stress with temperature.

Using the plastic strain range measured in the test a prediction can be made regarding the time to failure.
Paper 8: Excitation of Resonant Vibrations in Spur and Helical Gear Systems
Authors: Wood B. , Hunt T. M.
Published: June 2010

A back-to-back gear rig (12 000 ft/min maximum pitch-line velocity) was used to demonstrate various causes of high-speed gear vibrations with either straight spur or helical teeth, the transducers being four strain gauges mounted on the gear shaft. The primary cause of excitation is shown to be transmission errors in the straight spur case, but with helical teeth a variation in contact length is the prominent factor, with lateral movement of the resultant load as possibly the chief cause where the contact length is constant. Noticeable temperature effects were only experienced at the highest speeds; here the thickness of the oil film on the tooth face has a considerable effect on the tip relief, the modification becoming less as the temperature rose. Damping varied considerably (0·004 to 0·042 critical) between modes, and slightly with change in load, and therefore no overall damping factor could be taken for the rig; the average damping factor for the specific mode was used in each amplitude calculation. Calculation of the natural frequencies of the gear system was performed with the use of receptance theory with considerable success; the amplitude predictions were not quite so favourable but were generally of the right order.
Paper 2: Effect of Bending Moments on Nozzles with Forged Transition Pieces
Authors: Kitching R. , Jones N.
Published: June 2010

An experimental study has been made of the elastic stress distributions arising in the vicinity of two transition rings of the type used to connect cylindrical ducts with large spherical pressure vessels. The effect of bending moments on the duct was considered and theoretical estimates of the stresses were made by modifying certain well-known analyses. Two of these methods gave results close to the experimental values in a region which included the position of maximum stress. This occurred near the weld between the spherical shell and the transition ring.

In a further investigation it was found that, for the order of loads applied, the principle of superposition may be used to calculate the combined effect of a local bending moment and an internal pressure.

When allowable bending moments at design pressure are calculated using a limiting stress concentration factor, the heavier transition piece is slightly superior to the other.
Paper 3: The Napier Deltic Diesel Engine in Main-Line Locomotives
Authors: Chamberlin R. H.
Published: June 2010

This paper gives details of operating experience with the Deltic engine in railway service, the troubles and defects encountered, and the design changes introduced to overcome them, together with details of subsequent service experience.
Paper 7: Operating Experience of Installed Gas Turbines
Authors: Auer W. P.
Published: June 2010

Twenty-four years ago the first industrial gas-turbine unit, a Brown Boveri 4000 kW set installed by the City of Neuchâtel in Switzerland, started a new era of power generation. This new type of prime mover has since been widely introduced and generally accepted. It serves as base-load and as peaking plant. The fuels used range from natural and blast-furnace gases to diesel, crude, and heavy fuel oils. Extensive experience of running has accumulated in all applications which has permitted the analysis of the operating performance of the gas turbine.

The paper reports on the performance of some characteristic gas-turbine installations that are representative of the different applications and fuels.

In addition to providing interesting information on the general performance of the gas turbine, the experience gained under various conditions has also permitted the discovery, understanding, and control of special design problems not previously recognized. The more important of those discovered in recent years are discussed and corrective measures are explained.
Paper 29: A Theoretical Investigation of the Creep and Redistribution of Stress in Fabricated Aluminium Alloy Beams
Authors: Warren J. W. L.
Published: June 2010

The analysis of THE Creep and redistribution of stress in highly redundant fabricated structures both by the matrix force and matrix displacement methods is discussed. Application is considered to structures of the skin-stringer type and an analysis of a fabricated aluminium alloy box beam under constant load and temperature is presented. It is concluded that although the stepwise solution is cumbersome its use may well be justified for complex structures for which the effect of creep would be difficult to anticipate.
Paper 1: The Measurement of High-Speed Unlubricated Metallic Friction
Authors: Williams K.
Published: June 2010

There exists a likelihood of using, sometime in the near future, metals sliding together in a normal atmosphere at speeds above those normally encountered in engineering mechanisms today. This has led to the desirability of obtaining information about the properties of such materials under extreme conditions of sliding.

In this paper a survey is made of the experimental techniques and apparatus used by previous investigators working in this subject. The advantages and disadvantages of the different approaches adopted by them are discussed, and the reasons for the construction of a pin and disc type of apparatus, of the size described, are outlined.

The procedure adopted, for designing a suitable machine for use in the laboratory, capable of yielding the desired information under controlled experimental conditions, is outlined. The requirements of the necessary instrumentation are followed by details of the systems finally used.

The apparatus finally developed is fully described and details are given of the experiments conducted. A typical set of results are discussed and the experimental errors assessed.
Paper 6: A Study of the Friction Characteristics of Resin-Bonded Bearing Materials Lubricated by Water
Authors: Hurren D. E. , Midgley J. W. , Pritchard C.
Published: June 2010

An investigation has been made of the static friction of various resin-bonded fibre materials lubricated by water in a thrust-bearing rig.

The static friction of water-lubricated phenolic resin-bonded asbestos materials mated with steel is initially low, μ = 013–0·3. This low friction is consistent with the composition of the bearing surfaces as it lies between that of asbestos and that of resin, on clean steel.

On running-in, the static friction of these materials increases substantially to μ = 0·3–0·6. Evidence has been found that this is due to the formation of a surface layer on both the mating surfaces causing adhesion. It is concluded that the layer is thermoplastic in nature. Because of this behaviour static friction measurements in which the mating surfaces are not run-in give an unrealistically low value for the static friction.

The suggestion that water is held by surface fibres and hence provides boundary lubrication is not borne out by the present results.

Under the test conditions employed the static friction of phenolic resin-bonded materials in which polythene and graphite had been incorporated was not lower than that of the parent materials. This was probably because the friction of polythene itself can be high due to its adhesion to the mating steel, and it is evidently difficult to add sufficient graphite to reduce the friction and yet maintain the physical strength.

The static friction of silicone resin-bonded asbestos and polyester resin-bonded cellulosic materials can also be high, probably for the same reason that the phenolic resin materials develop a high friction.
Paper 3: The Effect of the Steelmaking Process on the Life of Rolling Contact Bearings
Authors: Scott D. , Blackwell J.
Published: June 2010

The rolling-four-ball test, which closely simulates the rolling and sliding experienced in angular contact ball-bearings, has been used to study the influence of the steelmaking process on the rolling contact fatigue properties of steels used for rolling bearings. Commercially available balls, as well as specimens made from conventional En-31 and various special high-speed tool-steels manufactured by different processes, have been compared. Methods of improving steel quality, such as vacuum induction melting, vacuum consumable arc melting and vacuum degassing have been assessed. The same types of steel manufactured by similar methods by different steelmakers have been tested.

Significant differences in performance have been found between different types of steel and between the same types of steel manufactured by different processes. Acid material was generally superior to basic material, and vacuum techniques were beneficial. Modifications in the steelmaking procedure which improved material properties gave increased resistance to rolling contact fatigue. The effect of the steelmaking process was found to be similar with all steelmakers.

Observations of significance in the study of the mechanism of failure have been made.
Paper 19: An Experimental Investigation of a Cylindrical Journal Bearing under Constant and Sinusoidal Loading
Authors: Carl Theodor E.
Published: June 2010

Simultaneous measurements were made of loading, film pressure and journal displacement of a journal bearing under the action of both constant and sinusoidal loading. The applicability of Reynolds' (I)† boundary conditions is confirmed. If the bending of the shaft results in a modification of the oil film profile, the location of maximum film pressure is shifted closer to the position of minimum film thickness. Calculation of pressure distribution assuming constant viscosity and infinite bearing stiffness results in a value for peak pressure which is too high. The contribution of the pressure attributable to the movement of the shaft centre to the total pressure within a bearing subject to variable load has been elucidated. Measurements of the displacement of the journal centre under sinusoidally fluctuating and alternating loads confirm Hahn's calculations.
Paper 16: Minimum Allowable Oil Film Thickness in Steadily Loaded Journal Bearings
Authors: Martin F. A.
Published: June 2010

There are various factors limiting the load carrying capacity of a steadily loaded journal bearing operating under hydrodynamic conditions. Two of these factors are considered.

(1) Surface finish criterion Bearing and journal surfaces are slightly grooved due to machining processes, and when initial contact is made between the surfaces, it is only made at local high peaks, leaving an idealized effective hydrodynamic oil film at the minimum film thickness position in the bearing. This minimum film thickness at metal-to-metal contact conditions is dependent on the surface finish of the two mating surfaces. (2) White-metal wiping criterion At high-speed operation, the oil film temperature in the region of the minimum oil film position will be high if the bearing is operating with a large eccentricity. A condition can arise where the oil film temperature is sufficiently high to cause local plastic flow of the bearing white metal. This criterion is known as ‘wiping’, and at high speeds it will predominate over the surface finish criterion.

These two criteria are used in an analysis which gives guidance to the minimum allowable oil film thickness for journals of various sizes running at various speeds. This gives the bearing designer, using conventional hydrodynamic theory (Ocvirk, Cameron and Wood, etc.), some yardstick to assess whether or not his calculated minimum oil film thickness figures are satisfactory.
Paper 8: Failure of Rolling Contact Bearings
Authors: Simpson F. F.
Published: June 2010

Illustrations of various faults and effects encountered on rolling contact bearings.
Paper 18: Non-Linear Modes of Vibration of a Rigid Rotor in Short Journal Bearings
Authors: Huggins N. J.
Published: June 2010

An unusual analytical approach to oil whirl is presented. Instead of using linearized equations for the oil forces all the non-linear terms are retained. The complex equations are solved on an analogue computer, and the more important results are given which show the unusual vibration characteristics of an oil film. It is shown that self-sustained oscillations can exist and, with an exciting force, sub-harmonics are likely. Also the frequency of response may be a sub- or super-multiple of the exciting force.

Ocvirk's short bearing approximation is used as the basis of the analysis. It is recognized that it has certain deficiencies, and the results are therefore treated as indications and not as accurate predictions. Comparison to other theoretical and experimental work supports the validity of the present analysis.
Paper 17: Dynamic Characteristics of a Hydrostatic Thrust Bearing
Authors: Hunt J. B.
Published: June 2010

An earlier comprehensive application of the Navier-Stokes equations to the problem of the oscillatory loading of hydrostatic thrust bearings has been linearized, and shown experimentally to be true for ratios of vibration amplitude to oil film thickness not exceeding 1/10. From the resulting expressions, the stiffness and damping constant of an oil film can be readily found.
Paper 4: Some Experiments upon the Behaviour of Hypoid Oils in Heavily Loaded Contacts
Authors: Archard J. F. , Hatcher B. G. , Kirk M. T.
Published: June 2010

Measurements have been made over a wide range of speed and temperature of the thickness of the oil film between rotating crossed-cylinders of hardened steel lubricated with a hypoid base oil and with the base oil compounded with a range of E.P. additives. These values of the film thickness agree well with those found in previous studies of elastohydrodynamic lubrication. It has been shown that the addition of the E.P. additives has no appreciable effect upon the thickness of the film.

It is deduced from these studies that an oil film of appreciable thickness must exist between the teeth of hypoid gears over a wide range of operating conditions; the major mechanism of lubrication in a hypoid gear is, therefore, elastohydrodynamic and the main function of E.P. additives is to prevent the initiation of catastrophic forms of failure by local penetration of this hydrodynamic film.
Paper 13: The Influence of an Intercalated Inorganic Salt on the Frictional Characteristics of Graphite
Authors: Hughes R. I. , Daniel S. G.
Published: June 2010

In recent years, various workers have attempted to improve the lubricating properties of solid lubricants, particularly at high temperatures, by mixing them with inorganic salts. Since graphite forms interlamellar compounds with a variety of inorganic salts, this presents a convenient means of producing evenly dispersed and reproducible combinations. Graphite reacts with ferric chloride vapour to form such a compound in which ferric chloride planes alternate with the carbon planes in the graphite lattice. Although formed from a hygroscopic salt, the compound is quite stable under normal conditions.

The frictional characteristics of this material have been assessed over a range of temperatures using a pin-and-disc-type friction rig. The results have been compared with those obtained using the parent graphite and molybdenum disulphide as reference lubricants.

It is concluded that the intercalation of an inorganic salt in the graphite structure can lead to certain improvements in lubricating properties, particularly with respect to the adhesion of lubricant to substrate in dry applications; salts other than ferric chloride may be more suitable for this purpose.
Paper 14: The Effect of Pressure and Temperature on Some Properties of Fluids of Importance in Elastohydrodynamic Lubrication
Authors: Galvin G. D. , Naylor H. , Wilson A. R.
Published: June 2010

Recent advances in the theory of elastohydrodynamic lubrication have greatly increased the demand for information on the physical properties of lubricants at high pressures. Specifically, the viscosity and density and their variation with temperature and pressure enter directly into calculations of the behaviour of lubricants in loaded contacts, whilst for some experimental techniques the dielectric constant at the appropriate conditions is also required.

This paper presents measured values of viscosity at pressures up to 15 000 lb/in2 at 30°, 60° and 100°C, and of density and dielectric constant at pressures up to 50 000 lb/in2 at 20° and 100°C for a series of lubricants including mineral, vegetable and synthetic oils.

The use of the Clausius-Mosotti relationship to predict dielectric constants at high pressures is shown to be unsatisfactory, and this is demonstrated by application to capacitance measurements obtained in a disc machine.
Paper 3: Some Properties and Applications of the Platinum Metals and Rhenium
Authors: Darling A. S.
Published: June 2010

The ability of platinum and certain of its alloys to function effectively as structural materials for long periods in air at temperatures above 1400°C ensures for these materials a remarkable position in a variety of industrial processes. The physical characteristics of the platinum metal group are reviewed in this paper and contrasted with those of the base metal rhenium which is similarly rare and expensive. Rhenium and the refractory platinum metals oxidize rapidly when heated in air and rhodium-platinum alloys are generally employed when prolonged resistance to high temperature creep is required. Dispersion strengthened platinum alloys provide even higher elevated temperature properties.

Economic justification for the industrial use of the platinum metal group is not difficult to provide because most processes centre on the unique ability of these elements to perform a specific function. In other instances their employment results in a cheaper and superior product. The applications of platinum in the glass industry are briefly described and an outline presented of the philosophy underlying the development of some new rhenium and platinum alloys. Consideration is given to the characteristics of hydrogen-palladium alloys and to their fuel cell and energy storage applications.
Paper 15: Pure Silicon
Authors: Vodden H. A. , Williams J. L.
Published: June 2010

The requirements of the semi-conductor industry for manufacturing devices such as transistors and rectifiers have resulted in new standards of purity for certain materials. Ultra-pure silicon is now produced commercially, with impurity levels lower than 1 part in 1010, in single crystal form of high structural perfection. This paper describes such a material, laying particular emphasis on the electrical properties, and describes methods by which it is manufactured commercially. The importance of electrically active impurities, such as boron and phosphorus, is discussed with reference to the p-type and n-type conductivities which are thereby introduced.

The necessity for strict control of physical parameters during manufacture is emphasized, and methods used for the evaluation of the essential physical properties such as electrical resistivity and crystal structure are described.

Some of the applications of pure silicon are introduced in this paper and the physical basis underlying the use of pure silicon in semi-conductor device manufacture is briefly reviewed.
Paper 12: Carbon
Authors: Adams J. M.
Published: June 2010

The nature of natural and industrial carbons is described, with some recommendations for designing components, in particular, methods which are available for processing final articles to size without machining. Typical applications are briefly reviewed subdivided under the following headings: mechanical applications; electrical applications; and other industrial applications (in this section the various commercial forms of carbon are also reviewed).

The paper concludes with a review of several new forms of carbon which have come into the market in the last few years.
Paper 8: Recent Developments in Engineering Ceramics
Authors: Popper P.
Published: June 2010

Ceramics in the context of this paper will be considered to be inorganic non-metallic materials which are shaped when in a finely divided form, followed by a high-temperature sintering treatment.

A better understanding of the properties of ceramics (e.g. alumina) can be gained by the study of the properties of the material in single crystal form (e.g. sapphire). The properties of different materials can be related to their crystal structure. This scientific pursuit has led to a number of new materials (silicon nitride, Si3N4, and boron nitride, BN).

Compared with metals ceramics compete favourably on account of their high strength at high temperatures, good wear and corrosion resistance. Their main drawbacks are brittleness and failure by thermal stresses. The application of new methods of fabrication has been aimed at producing ceramics of high density and to accurate dimensions.

The properties of the following materials will be discussed in some detail: alumina, Al2O3; silicon nitride, Si3N4; silicon carbide, SiC; and boron nitride, BN. It will be demonstrated that different methods of fabrication can result in widely differing properties of the same material. Small grain size and high density are essential for good mechanical strength.

Methods of joining ceramics to metal will be discussed. Some important applications will be reported and consideration will be given to problems facing the designers.
Paper 14: Developments in Refractory Castables
Authors: Robson T. D.
Published: June 2010

A short account, not intended for specialists, is presented of the constitution and general properties of refractory castable mixes. The basic factors affecting the performance of castable refractories are discussed and modern trends in the compounding of the mixes, and in the manufacture of the cement bond, are outlined. Attention is drawn to certain types of refractory castable mix which, it has been claimed, are specially suitable for specific duties or which have been used for new applications. After a survey of established usage, the emerging lines of future development are identified. The increasing construction of major refractory units entirely with castable mixes has necessitated some discussion of the methods of engineering design which are applicable to castable refractories, and emphasizes the need for more research in this field.
Paper 4: The Significance of Surge Diagrams
Authors: Marples E. I. B.
Published: June 2010

The aim of this paper is to show how surge diagrams follow logically from two simple principles: The propagation of pressure waves at the speed of sound, and Joukowsky's law expressing the relation between variations in pressure head and in velocity head.

Surge lines are a manner of plotting Joukowsky's law and of showing how energy which is being introduced into a pipe or is being drained from it can be converted from one form into another.

Complications can be avoided in drawing surge diagrams by recognizing the truly significant factors. If this is done, most practical problems can be studied with adequate accuracy by simple diagrams.

The methods used are illustrated by typical examples from the frequent problem of a power failure in a pumping station. Excessive surge pressures are usually avoided by providing an air vessel or a flywheel, the aim being to stop the column of water gradually and to dampen out the oscillations. Special care is needed in avoiding the formation of voids or air spaces anywhere in the system.
Paper 2: The Velocity of Water Hammer Waves
Authors: Pearsall I. S.
Published: June 2010

Sudden flow changes in a pipeline cause water hammer waves to be transmitted up the pipe. The magnitude of these pressure waves is directly proportioned to the acoustic velocity.

The value of the acoustic velocity depends on the bulk modulus or compressibility of the liquid. It is thus affected by pressure, temperature and gas content of the liquid, as well as by the elasticity of the pipe.

For water, considerable data are available on the variation of acoustic velocity with temperature and pressure. These are summarized and it is shown that, whereas temperature causes changes of the order of 1 per cent per 5 degC, the variation due to pressure is negligible except at very high pressures.

The presence of free gas causes a considerable increase in compressibility, and it is shown that even as little as 1 part of air in 104 parts of water by volume causes a 50 per cent reduction in acoustic velocity. The damping of the pressure waves, which has an overall beneficial effect, is also greatly increased by the presence of free gas, and data are given on these effects. Solids in liquid have a similar but less drastic influence.

Experimental results are given of some tests on two sewage pumping stations in which good agreement was obtained between theory and experiment.

The elasticity of the pipe also affects the acoustic velocity and a summary is given of the data available for steel, concrete, and rock-lined tunnels, with different types of pipe fixing.
Paper 6: Water Hammer Effects Due to Branched and Stepped Pipes
Authors: Pearsall I. S.
Published: June 2010

No direct general solution is possible of the water hammer equations. It is thus necessary to use either iterative techniques on a computer or a graphical method to obtain a solution. Most practical systems are not simple pipelines but have changes in section and branch pipes. The paper shows how it is possible to allow for changes in section and branches in the graphical method for the cases of a valve closure or a pump shut-down. The case of a surge tank with base throttle is also applied to a reservoir-turbine installation.

In many cases it is not necessary to carry out the exact calculation as the use of an equivalent system will be sufficiently accurate. For a pipeline with different diameters or wall thickness an equivalent simple pipeline can be used. The various suggestions are reviewed and compared for four valve closure cases.

For branch pipes or surge tanks some cases where the branches can be neglected are given. The method of allowing for friction in the graphical method, and the assumptions made, are also mentioned.

Two examples are included of comparison between the exact method and an equivalent system, with some experimental results.
Paper 3: Effects of Valve Operation
Authors: Livingston A. C. , Wilson J. N.
Published: June 2010

In modern pumping installations it is generally considered that the most common cause of water hammer is that due to inadvertent stoppage of the prime mover. However, mal-operation of pipeline valves is a further common source, and if danger from such units is to be avoided a knowledge of their operating characteristics is essential.

Valve characteristics can determine, to a great extent, the magnitude of the surges which will be initiated following opening or closing of a valve. By graphical representation it is shown how important proper valve selection and operation can become, when related to the system characteristics.

Terminal float valves, pressure reducing valves, etc., are prone to oscillation or ‘hunting’ and, if the valve movement enters into phase with certain multiples of the pipeline period (2 l/a), resonance occurs. The effect of such continuing valve oscillation is illustrated graphically.

Check valves are primarily installed in pumping systems to prevent the establishment of the reverse flow which could damage both pump and prime mover. For trouble-free operation it is important that the valve possesses inherent non-slam closing features. The effect of check valve operation with respect to surge is illustrated graphically.

If certain basic system parameters are known it is possible to predict how a check valve will perform in a given installation. The results of the application of one such analytical approach are presented, together with full experimental verification.
Paper 1: Computer Solution of Surge Problems
Authors: Streeter Victor L.
Published: June 2010

Methods for handling the transient flow equations are developed for application of the high-speed digital computer. For incompressible flow cases ordinary nonlinear differential equations occur which are solved simultaneously by established sub-routines on the computer, such as the Runge-Kutta method. For the partial differential equations of compressible water hammer with nonlinear terms such as friction, the method of characteristics and of specified time intervals are employed for those problems in which the flow changes from one steady-state to another steady-state. For steady-oscillatory flow, impedance methods have been adapted to the computer with harmonic analysis of the exciting disturbance. Experimental evidence is presented to confirm the accuracy of the procedures for single and series pipes, for pump failures, and for reciprocating pumps. Additionally the design problem of optimum operation of a valve to minimize transient pressure fluctuations has been introduced and applied to single and series pipes, including a pump failure situation.
Paper 5: A Method of Programming Graphical Surge Analysis for Medium-Speed Computers
Authors: Harding D. A.
Published: June 2010

The use of digital computers for the analysis of pressure surge effects in hydraulic systems is discussed and a method of writing programmes is described in which the sequence of the calculations is broadly similar to that used in conventional graphical analysis but a numerical solution of the conjugate water hammer equations replaces the graphical construction of a surge diagram. Time dependent variables are integrated by the Runge-Kutta method but the standard procedure has been modified so that the calculations can include pressure and flow at the pipe boundaries which are subject to the step changes given by the water hammer equations at each step. The method is illustrated by a programme for the analysis of pressure surge following the shutdown of a pump discharging through a single main to a reservoir.
Paper 8: Some Observations on Linear Theory of Railway Vehicle Instability
Authors: Bishop R. E. D.
Published: June 2010

During ‘bogie hunting’, motion takes place in a limit cycle, so that a description of the motion in terms of linear theory cannot be found. It does not follow, however, that linear theory is valueless. On the contrary, rapid progress is now being made towards an understanding of the phenomenon on the strength of it. An attempt is made in this paper to examine the implications of this fact in very general terms.
Paper 1: The Dynamics of Railway Vehicles on Straight Track: Fundamental Considerations of Lateral Stability
Authors: Wickens A. H.
Published: June 2010

The dynamics of existing railway vehicles on straight track is dominated by motions in the lateral plane commonly referred to as hunting. Hunting is a self-excited oscillation caused by the combined action of the conicity of the wheels and the creep forces acting in the contact plane between wheel and rail. In this paper existing and recently developed theories of the lateral motion of railway vehicles are discussed in relation to experimental work on both models and full-scale vehicles.

It is shown that a realistic theory taking into account flexibility between the wheelsets and the frame in the longitudinal, lateral, and vertical directions, and the influence of wheel and rail profiles, yield values for the critical speeds which are consistent with experimental results. The influence of various parameters on stability is discussed and it is explained how railway vehicles can be designed for stable running at high speeds. Examples of suitable choices of suspension and other parameters will be given and experiments carried out in order to verify these concepts will be described.
Paper 2: The Riding of Two Particular Designs of Four-Wheeled Railway Vehicle
Authors: Gilchrist A. O. , Hobbs A. E. W. , King B. L. , Washby V.
Published: June 2010

This paper discusses the dynamic behaviour of two designs of railway vehicle, taking into account the non-linear features of their suspensions and of the forces arising between rail and wheel. The parameters required for the theoretical analyses are obtained from measurements of the vehicles and from detailed studies of rail and tyre profiles. The vehicle behaviour is then predicted and these predictions are checked against running tests made on a special test track. The main features discussed are the lateral motion on plain track (hunting) and the response to an isolated vertical irregularity (a ‘dipped’ rail-joint). The effect of various parameters on this behaviour is described and some comments are made upon the problems of derailment.
Paper 5: Electronics Applied to Medium-Speed Engines
Authors: Bruffell W. K. , Williams D.
Published: June 2010

The use of electronic recording equipment now covers development, production, and service problems. Previously fuel injection characteristics and gas exchange pressures were the only parameters normally indicated. Today, however, owing to the demand for greater power outputs, a much wider range of parameters are studied electronically. The success of engine development and production relies upon the ease and accuracy with which engine performance can be measured. The historical development of engine indicating techniques used by the authors' company and the existing measuring accuracies are discussed. Various tables outline the individual and overall errors that were obtained using a wide range of transducers and associated equipment. The need for correct calibration procedures is emphasized throughout, and some of these procedures with their standardizing equipment are included in the paper.
Paper 6: The General Planning of a Department of Mechanical Engineering in Universities and Colleges of Technology
Authors: Tonkin C. W.
Published: June 2010

The author stresses and explains the need for the thought and care which must be given in the planning of departments of mechanical engineering in Colleges of Advanced Technology and universities. The need to use space and facilities as economically as possible is considered and the purposes of different forms of instruction are discussed. The provision of research and undergraduate facilities is mentioned and the need to provide rooms other than those designed for purely academic purposes is considered.
Paper 18: Flow in a Rectangular Cavity
Authors: Lewis W. E.
Published: June 2010

This paper briefly describes preliminary work in the investigation of the flow in a rectangular cavity formed in one wall of a square channel. The results of visual studies, carried out on a water tunnel and showing the flow pattern for various depths of a cavity of fixed chord, are described. Also wind tunnel data on pressure loss and noise generation are discussed.

The flow patterns found in an annular cavity are also described.
Paper 13: The Development of a Disc Local Heat Flux Meter for Use in Boiler Furnaces
Authors: Northover E. W. , Hitchcock J. A.
Published: June 2010

This paper describes the development of a meter, employing the radial disc principle, for measurements of the local heat flux to the water/steam tube surfaces of boiler furnaces. The design and material requirements are stated for the meter to operate successfully in the arduous conditions of a combustion chamber.

The development of the meter is followed from the initial prototype to the proving of the final design.