bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paper 2: Some Effects of Lubricant and Temperature on Failure in Rolling Contact
Authors: Scott D. , Blackwell J. 
Published: June 2010

The rolling-four-ball test has been used to carry out an exploratory investigation on materials for unlubricated and elevated-temperature rolling bearings. Besides high-speed tool and stainless steels, other hard, wearresistant materials have been compared under unlubricated conditions at ambient and elevated temperatures. A solid material, molybdenum disulphide, has been assessed as an elevated temperature lubricant. Significant differences in performance have been found between different materials. The failure mechanism varied with environmental conditions. With liquid lubrication, plastic deformation and fatigue occur. The amount of deformation, the resistance to fatigue, and the mode of failure are affected by the type of lubricant and the nature of the additives. In the absence of lubricant there was no pitting, the useful life of rolling elements being limited by wear assessed by loss of weight. The term ‘wear’, in this paper, means grooving by removal of material evenly from the surface without pitting or deformation. Use of a solid lubricant reduced the wear rate. Material combination and compatibility of mating material surfaces are particularly significant in resistance to pitting and wear. An examination of failed specimens has been carried out to obtain a better understanding of the failure processes.
Paper 5: Some Factors Affecting the Whirl Instability of a Journal Bearing (Part 2)
Authors: Bowman R. M. , Collingwood L. C. , Midgley J. W. 
Published: June 2010

Experiments have been carried out on a simple unloaded shaft-bearing system to provide values for the onset conditions of oil whirl which can be readily compared with theoretical estimates making the minimum assumptions. Further evidence has been found to support the previous conclusion (Part 1) that, contrary to current theories, the ratio of elastic to hydrodynamic forces has a significant effect on the stability in the laminar flow region, and has a similar effect in the Taylor vortex region. It is suggested that this is because the axis of a journal rotating above its critical speed is not stationary, as assumed in current theories, but is rotating at shaft speed about its mean position. The extension of this work to include an investigation of the influence of clearance ratio, length to diameter ratio, journal mass and shaft diameter has confirmed that there is a substantial increase in stability with reduction of B. With Taylor vortex flow, the results are consistent with the onset of whirl occurring at twice an effective natural frequency, which is determined by the shaft stiffness and an oil film stiffness acting together. On this basis estimates are made of the effective oil film stiffness in the Taylor vortex region. In the laminar flow region, there is a similar variation of stability with B. The transition from laminar to Taylor vortex flow has a pronounced effect on the stability.
Paper 16: Copper and its Alloys
Authors: West E. G. 
Published: June 2010

There have been many developments in the copper-base alloys during the past few years, but the full properties now available to the engineer are not being fully utilized in many instances. This paper discusses the newer ranges of alloys with indications of the fields of use: electrical alloys covering both alloys of high conductivity and medium conductivity with mechanical properties, including those at raised temperatures, superior to high-conductivity copper itself; high-strength alloys for mechanical engineering applications, including information on the effects of raised and very low temperatures on mechanical and physical properties; copper alloys for castings—discussed in groups based on gunmetals (for example with additions of nickel), aluminium bronzes (including those with high nickel and other alloying additions), and the manganese-containing alloys. Parallel with the development of new alloys, there have been important advances in the fabricating processes applied to copper-base alloys, and these are briefly discussed in relation to the older as well as the newer materials.
Paper 4: Dynamics of Railway Vehicles on Curved Track
Authors: Müller C. Th. 
Published: June 2010

With the laws governing the statics of a bogie in a curved track as the starting point, the system of interdependent differential equations describing the impact process for a four-axle bogie vehicle running into a non-superelevated rail curve (points) at constant speed was drawn-up and solved on an analogue computer. The following quantities were varied: angle of impact; guide spring rate; lateral stiffness of coupling between bogies and vehicle body (length of cradle pendulums); damping constant of cradle dampers. The results of the calculation are illustrated with reference to practical measures with the aid of figures.
Paper 5: Track Parameters, Static and Dynamic
Authors: Birmann F. 
Published: June 2010

In the first part a static investigation is made of the total elasticity of the track on soft sub-soil and loose ballast, and for rock and consolidated bedding. The oscillating mass of the permanent way will differ in behaviour, depending on construction, rail profile, sleeper spacing, etc. The damping and the phase shift can be determined by modern measuring techniques and a few limit values are given. In the second part the dynamic behaviour of the track is investigated for velocities up to 200 km/h. New methods of measuring the wheel loading on the rail are briefly described. Elements of permanent way calculation, based on new methods of computation, are briefly considered. The role of the lateral elasticity of the rail is shown in the third part, theoretically and according to measurements.
Paper 9: A New Method of Dynamically Stabilizing Railway Bogies, Four-Wheel Wagons, and Road-Railers against Undesirable Lateral Oscillations
Authors: Williams D. 
Published: June 2010

A new method is described of dynamically stabilizing railway bogies, four-wheel wagons, and road-railers so as to be proof against undesirable lateral oscillations. It is generally accepted that the root cause of all such oscillations is the inherent instability of the ordinary axle-set, i.e. the integral unit of live axle and two wheels. By seeking to eliminate this instability, the new method tackles the problem at its source. It puts a stop to the mild, though ever-present, snaking action to which the conventionally mounted axle is prone, and ipso facto cuts out the possibility of such action developing into the more violent unstable motions that are usually referred to as ‘hunting’. The principle relied upon in the method is that of the inertia-guided axle, i.e. an axle with a leading guiding arm that is integral with it in yaw and that is connected at its forward end, by means of a velocity damper, to a floating mass (provided by, and identified with, the mass of the vehicle body itself) whose lateral inertia provides the necessary guidance. Alternate guiding arms come into action wherever the direction of travel is reversed.
Paper 1: Measurement and Recording of Transient Pressures in Unsteady Flow
Authors: Davies P. O. A. L. 
Published: June 2010

The problems in developing satisfactory measuring techniques for studying pressure transients can best be considered under three headings. First, there are the problems concerned with obtaining a continuous electrical signal which represents the value of the pressure at any instant. Suitable devices include diaphragm-type instruments and piezo-electric types and these may have quite different characteristics. The former are generally more suitable for low pressure and low frequency applications, while the latter can be used for very short time transient measurements at higher pressures. The types of error which are most likely depend both on the application and the characteristics of the primary transducer unit chosen. A second group of problems is concerned with the recording or analysis of the electrical signals from the pressure transducer. These include errors associated with chart-type recordings, cathode-ray oscillograph recording, statistical sampling and filters, and for frequency analysis. The importance of various transient and steady-state recording errors and the type of application will again determine which is the most suitable equipment to choose. A final group of problems is associated with the calibration of the measuring system finally selected and the interpretation of the measurements. There are several difficulties and sources of error here since it is not always possible to perform basic calibration under the same conditions as the experimental measurements.
Paper 2: Accuracy in Cylinder Pressure Measurement
Authors: Lyn W. T. , Stockwell A. J. , Wang C. H. T. 
Published: June 2010

The paper commences with a definition of the requirements of cylinder pressure measurements for (1) general engine development work, (2) frequency spectrum analysis in engine noise investigation, and (3) thermodynamics and combustion analysis. Methods for the determination of the frequency response of cylinder pressure transducers are then treated both theoretically and experimentally. For the continuous recording type of transducer a shock chamber technique is used. For the balanced pressure type of pick-up a comparison with a continuous recording type, of known frequency response, is made. These techniques do not completely simulate engine conditions and comparisons of the two types of pressure transducers were made dynamically under engine conditions. The results showed that all the continuous recording types of pressure transducer so far tested were sensitive to transient heat transfer owing to combustion. A rig was therefore developed to simulate such conditions outside the engine. Detailed descriptions are given of examples of both types of pressure transducer as developed at C.A.V. The method of recording timing marks is presented in some detail and the advantage of the ‘closed circuit’ magnetic type of degree pick-up is described.
Paper 7: Accuracy of and Representative Results Obtained with an Infra-Red Pyrometer Measuring Compression Temperatures
Authors: Myers P. S. , Uyehara O. A. 
Published: June 2010

In a spark-ignited internal combustion engine there are two zones of interest ( a) the burnt mixture and ( b) the unburnt mixture. Of interest to the authors and to many of their colleagues are the pre-reactions which occur in the unburnt zone. To follow the extent of these pre-reactions both the pressure and the temperature of the unburnt mixture are required. Pressure transducers can be obtained from many commercial establishments, but a temperature pyrometer that can follow the temperature of the unburnt mixture is not commercially available. The current technique uses the absorption, emission characteristic of the water vapour in the cylinder. The use of water vapour as the sensing element is desirable since water vapour is normally in the air which the internal combustion (i.c.) engine breathes. Radiation of a known intensity (known black-body temperature) is passed through the engine, through a band pass filter (H2O water vapour band at 2.6 μ) to an infra-red detector. The output from the detector, after amplification, is fed to a cathode-ray oscilloscope. By suitable means, it is possible to compare the undisturbed radiation from the black body with the black-body radiation after it has experienced absorption emission events during the compression process. The reversal point can be visually observed on the oscillogram. At this reversal point the temperature of the gas and the black body are equal and the crank angle at which this occurs can be determined. Other temperatures and crank angles at which reversal occurs can be observed to obtain the unburnt mixture temperature versus crank angle curve. The authors' experiences with different infra-red detectors and other temperature-measuring techniques, as well as comparison between the velocity of sound method and the infra-red technique, are discussed. Data obtained with the instrument are presented.
Paper 9: Velocity and Rate of Flow Measurements in Internal Combustion Engines
Authors: Kastner L. J. , Tindal M. J. , Williams T. J. 
Published: June 2010

Measurement of both the mean and instantaneous values of gas velocity in internal combustion (i.c.) engines presents problems of considerable difficulty and the application of electronic methods of measurement has made important contributions in this field. The problems encountered in metering pulsating flows are briefly discussed with special reference to the advantages of two metering devices which employ electronic circuits. Whilst pressure transducers enable the variation in instantaneous gas velocities to be inferred in certain circumstances there are many other cases where a direct indication of velocity variation is desirable. The hot wire anemometer (h.w.a.) has been highly developed for aeronautical engineering applications but special problems arise in the reciprocating engine where velocity variations can be large. This paper describes a constant temperature h.w.a. using a d.c. circuit which has proved stable and relatively easy to operate. If velocity measurements in the engine cylinder are required the problem becomes a three-dimensional one, and the response of the h.w.a. to variation in flow direction is discussed. Consideration is given to materials suitable for probe wires.
Paper 5: The Complete Transfer of an Existing Mechanical Engineering Department to a New Site
Authors: Till A. J. , Smith H. J. 
Published: June 2010

An account is given of the planning, construction and occupation of the Department of Mechanical Engineering at Brighton College of Technology. This College took over all the advanced studies of the Brighton Technical College and the paper describes the transfer of the old department and its establishment in a new building. The organization of planning consultation between architects and College is explained and the position of the Department in relation to the whole College is shown. Schedules of accommodation indicate the floor areas available and the expected student capacity. Description is given of the detailed design of individual laboratories involving work by all members of the teaching staff grouped in three sections dealing with Thermodynamics, Mechanics and Materials and Production Engineering respectively. The preparation and finance of the schedule of equipment and the purchasing, supply and installation arrangements are explained. Economy made necessary the transfer of some existing equipment and the organization of removal and reinstallation is described. A short description of the main features of construction of the building is given followed by details of services and furnishings. The final layout of the laboratories is discussed and criticized in the light of eighteen months' use. The paper concludes with general comments which may prove of value to others undertaking similar tasks.
Paper 16: An Analysis of the Losses in a Radial Gas Turbine
Authors: Benson R. S. 
Published: June 2010

A discussion of the flow pattern in the rotor passages of a radial gas turbine showed that loss data for predicting turbine performance could only be adequately obtained from rotating cascades or turbine tests. The details are given of an analysis of the radial gas turbine tests described by Hiett and Johnston. The analysis showed that the deviation in the nozzle gas leaving angle was dependent not only on the nozzle geometry and gas leaving angle but also on the rotor speed and geometry. Two rotor loss coefficients were obtained, one, ζ RA, was similar in form to the conventional axial turbine type loss coefficient, the other, ζ RB, could be used with Wallace's theory for predicting the off-design characteristics of the turbine. The two loss coefficients are shown to be related. The results showed that ζ RB could be expressed as a function of the gas incident angle and the relative velocity at the rotor tip for each turbine. The conventional loss coefficient ζ RA had a minimum value at negative incidence to the blade but was nearly constant over a wide incidence range. At high positive and negative incidence the coefficient was strongly dependent on the overall pressure ratio across the turbine. At zero incidence the two loss coefficients were equal. The tests showed that for this condition the rotor loss coefficients decreased with increase in flow coefficient and with increase in mean acceleration across the rotor. For low mass flow rates there was a rapid increase in the loss coefficient. Finally, it was observed that there was a correlation between the deviation in the nozzle gas leaving angle and the optimum incident gas angle to the rotor.
Paper 19: An Investigation of the Flow through Tandem Cascades
Authors: Railly J. W. , El-Sarha M. E. 
Published: June 2010

An experimental investigation of the slow speed performance of a tandem cascade of aerofoils is described. The theoretical criteria on which the cascade was designed are discussed; the method of Ackeret, described elsewhere, was used to obtain the geometry of the aerofoils. Tests were carried out on the effect of the magnitude of the gap between each tandem pair and of the effect of varying, independently, the stagger of each aerofoil. Tests were carried out over a wide range of inlet angle for the range of staggers adopted and optimum deflections for the cascade were determined.
Paper 24: The Decay of Turbulent Velocity Profiles
Authors: Livesey J. L. , Turner J. T. , Glasspoole W. F. 
Published: June 2010

The importance of rapidly changing velocity profiles in turbulent ducted flow systems is discussed. A review of the available experimental data is then made. Various methods of generating an artificial velocity profile are described and, where possible, comparison is made between experiment and theory. It is shown that two velocity profiles which apparently have similar characteristics, namely peakiness and shape, may have widely differing decay rates. This is determined by the turbulence introduced into the flow at the time of profile generation. A correlation is discussed which relates the decay rate of a particular velocity profile to the profile peakiness and the loss coefficient of the generating spoiler. Some evidence is produced which gives a physical foundation for the correlation. A method of calculating the maximum pressure rise associated with changes in velocity profile shape is described. It is then shown that this maximum pressure rise will be significantly reduced by turbulent mixing and wall skin friction. The changes are discussed in relation to pipe velocity profiles of the power law type. Estimates are obtained for the mean transverse velocities leading to the decay. These are compared with some recent experimental jet flow data. Finally, the paper discusses the effect which velocity profile decay may have on turbulent ducted flow. In particular, the improvement in performance of a diffuser and the changes in the drag on a cylindrical strut when the upstream flow is in a state of decay are commented upon.
Paper 14: On the Reflection of Shock Waves from Deflector Plates
Authors: Woods W. A. 
Published: June 2010

The paper first explains the importance of the reflection of shock waves in the design of certain chemical plant. The theory of the reflection of shock waves is also discussed in the first part of the paper. It is shown that when a shock wave travelling along a pipe containing stationary gas reaches the outlet end of the pipe there may be ( a) a reflected expansion wave, ( b) a reflected shock wave, ( c) a reflected sound wave, ( d) no reflected wave at all, ( e) a standing shock wave situated at the end of the pipe, depending upon the strength of the incident shock wave and the amount of blockage present at the outlet end of the pipe. The conditions for each kind of reflection are determined, and in the case of the reflected shock wave region the strengths and speeds of the reflected shock waves are established throughout the region and the results are presented graphically. In the second part of the paper the results are given of experiments carried out on a shock tube fitted with various kinds of deflector plates. The experiments were performed to study the reflection of shock waves from the deflector plates by measuring pressure/time indicator diagrams near the outlet end of the pipe. The indicator diagrams revealed the approximate pressure amplitudes of the incident and reflected shock waves and also the wave travel times for the shock waves. This information was used in conjunction with the charts given in the first part of the paper to establish the deflector geometry and spacing needed in order to avoid the occurrence of a reflected shock wave.
Paper 17: The Action of the Parallel-Surface Thrust Bearing
Authors: Ettles C. M. M. , Cameron A. 
Published: June 2010

The pressure generation of parallel-surface bearings has been investigated experimentally using dynamic instrumentation mounted in the moving surface. It was found that when the pads were truly flat and parallel a negative pressure was generated which was approximately proportional to the inverse square of film thickness. A complete reversal of pressure generation was shown as the film thickness was successively decreased. This is shown to be due to increasing thermal distortion of the pads. It is shown that useful loads are carried on a wedge-shaped film produced by thermal distortion. Appropriate theory has been developed for the infinitely wide case which includes the density and viscosity wedge effects, variations of film shape, frictional generation and conduction to the bearing solids. Fair agreement was obtained between theory and experiment after suitable treatment for side leakage.
Paper 3: Film Thicknesses in Elastohydrodynamic Lubrication by Silicone Fluids
Authors: Dyson A. , Wilson A. R. 
Published: June 2010

In an earlier paper it was shown that the thicknesses of lubricant films in elastohydrodynamic contacts, as deduced from the measured electrical capacities between two heavily loaded rotating discs, agreed well with theoretical values. Exceptions to this result were observed for a polymer solution and a silicone fluid; the discrepancy between experimental and theoretical film thicknesses with these fluids was tentatively attributed to non-Newtonian behaviour. This paper describes further work carried out with the object of investigating this point more closely. Polydimethylsiloxanes (silicone fluids) covering a wide range of nominal viscosities were used, and the thicknesses of the films formed by these fluids in a disc machine were measured over a wide range of rolling and sliding speeds and of temperatures. Since continuous shear viscometry of these materials is impossible under the conditions encountered in the disc machine, use was made of the relation between the behaviour of visco-elastic substances in oscillatory and in continuous shear. There is a good experimental and theoretical basis for this relation. Published information on the properties of silicones in oscillatory shear was used to predict their behaviour in continuous shear, under the conditions of interest in elastohydrodynamic lubrication. This information has been used to predict the film thicknesses in elastohydrodynamic lubrication, and to compare these predictions with experimental results. Although there were differences in detail, experiment and theory were in approximate agreement over most of the range covered. The reasons for some of the discrepancies are discussed.