bluuebunny/crossref_metadata_2025 huggingface dataset:
Paper 9: A Rotating Cylinder Viscometer for Measurement at Elevated Temperature and Pressure
Authors: Wonham J.
Published: June 2010

This paper records some of the recent experimental methods used to determine the viscosity of water. In drawing attention to the many techniques used (most relying upon calibration of the instrument by a fluid of known viscosity), the conclusion may be drawn that an absolute instrument is required which will produce results over a wide range of temperature and pressure.

It has long been known that the rotating cylinder viscometer is capable of a high degree of accuracy, but technical considerations have, in the past, restrained most workers from pursuing this method at high pressures.

Progress in the development of the rotating cylinder instrument for these conditions is described and specific problems encountered with this method are discussed.

This work is a continuation of the design studies of Kjelland-Fosterud (1)† and Whitelaw (2) who both gave considerable thought to the problems associated with this type of instrument. The first instrument to be tested by the author was based on Whitelaw's design but it was found that certain aspects of this instrument required major alteration. A new instrument was set up and has been found suitable for accurate viscosity determination.
Paper 5: The Dynamic Behaviour of Mineral Insulated Thermocouples
Authors: Furber B. N. , Broderick R.
Published: June 2010

This paper deals with the experimental determination and correlation of the dynamic response of mineral insulated thermocouples. In a given installation the dynamic response is largely dependent on the resistance to heat transfer between the hot junction and the region of which the temperature is to be measured.

This thermal resistance is composed of

(1) the resistance from the sheath to the surroundings—usually a conduction or forced convection problem; at elevated temperatures radiation could be important. (2) the resistance from the thermocouple hot junction to the sheath—a conduction problem complicated by the difficulty of defining the physical properties of the thermocouple materials, the interface resistances, and the geometry.

In many applications the thermocouple is inserted into a pocket to provide protection or support. In this case there is an additional resistance from the sheath to the containing pocket which involves conduction and/or radiation across a gas film and resistance (1) becomes the resistance between the pocket and its surroundings.

The effects of all these resistances have been investigated, but for the application of particular interest to the authors, i.e. the dynamic response in gas flows at temperatures below 400°C, the dominant resistance was found to be resistance (1) above. Emphasis has therefore been placed on determining the influence on the time constant of the following parameters:

Reynolds number Temperature level Direction (heating or cooling) and magnitude of the transient.

A correlation of the data has been obtained which enables the time constant to be predicted for a range of thermocouple and pocket diameters and of gas conditions.
Paper 6: Effect of Vapour Drag on Laminar Film Condensation on a Vertical Surface
Authors: Mayhew Y. R. , Griffiths D. J. , Phillips J. W.
Published: June 2010

A simple theory is presented for laminar film condensation of a pure vapour on a vertical surface which takes account of the drag induced on the liquid film by the flow of the condensing vapour.

Experiments were carried out with steam at atmospheric pressure condensing inside a vertical 1.824 in diameter tube 8 in high. The downward vapour velocity was varied from 5 to 150 ft/s, the corresponding range of the film Reynolds number at the bottom of the tube being 200-500. Experimental results agreed well with the theory.
Paper 27: On the Two-Dimensional Unsteady Flow of Compressible Fluids
Authors: Daneshyar H. , Pearson R. D.
Published: June 2010

A numerical method which was developed in a previous report is applied to the prediction of two-dimensional non-steady homentropic flow of air in a specially shaped duct. Previous methods for performing such calculations have not been practical owing to their inherent lack of stability when applied to non-steady flow cases.

These methods have therefore only found application in problems concerning supersonic steady flow.

The present method is sufficiently rapid to allow of its use in the solution of real problems. It is also demonstrated to be free from instability, so that computation of non-steady flows is now possible. Only subsonic homentropic flow free from shock effects is considered, but these limitations are not fundamental.

The method relies on the finite difference relations along bicharacteristics and particle path lines.

A comparison with experiment is presented which appears to indicate that errors introduced by the assumptions are acceptable for practical application, at least to those shapes for which boundary layers do not separate.
Paper 7: An Investigation of Steady Compressible Flow through Thick Orifices
Authors: Deckker B. E. L. , Chang Y. F.
Published: June 2010

A thick orifice of a given diameter is one in which the length-diameter ratio exceeds that of a British Standard sharp-edge orifice of the same diameter. Thick orifices are important technically but little systematic work appears to have been performed on them. Sharp-edge orifices are treated as limiting cases of thick orifices.

This paper describes a carefully controlled investigation into the behaviour of the steady flow of air through thirty-eight orifices ranging in diameter from 3/32 to 1/2 in and of length-diameter ratios, l/d, of 2.0, 1.0, and 0.5 and of sharp-edge orifices. These orifices have been calibrated against a range of sharp-edge orifices according to the British Standards code. The maximum possible instrument error over the experimental range (maximum pressure 150 lb/in2 absolute, maximum temperature 940°R) is estimated to be less than 0.1 per cent. The greater part of the overall error is attributed to the use of the code and may be as high as 1.6 per cent in some cases. About seven hundred experimental measurements have been made during the course of this investigation from which new relationships between the geometrical and physical parameters have been derived. The existence of a hysteresis phenomenon in a compressible flow through an orifice has also been measured for the first time. The main conclusions are:

(1) When the ratio of the orifice diameter, d, to that of the cylinder cross-section is small the air expands from a state of virtual stagnation at a distance of one orifice-diameter from the plane of entry to the orifice. The ambient pressure is attained at the plane of exit only in the case of orifices for which l/d ≥ 2. (2) In the range of Reynolds numbers between 104 and 105 the dimensionless mass flow, G = m( T0)1/2 /d2 po, and the coefficient of discharge, Cd, are independent of the Reynolds number. (3) For a given l/d ratio G, or Cd, is a function only of the overall pressure ratio. (4) The l/d ratio is an important parameter in thick orifices because of the possibility of jet attachment. The observed behaviour of thick orifices may be explained on this basis. (5) For l/d = 0.5 there is a clearly delineated hysteresis in the flow near the threshold of choking, the lower branch corresponding roughly to the behaviour of a sharp-edge orifice and the upper branch attaining a value of Cd of nearly 0.9 for the choked regime. (6) Within the limits of accuracy of measurement, eccentric location of the orifice has no effect upon either G or Cd.

Finally, the experimental results are compared with published theoretical and experimental work on compressible steady flow through orifices.
Paper 13: Abrasive Wear of Journal Bearings by Particles in the Oil (Apparatus, Experiments, and Observations)
Authors: Broeder J. J. , Heijnekamp J. W.
Published: June 2010

Abrasion is generally defined as wear caused by fine solid particles. In this paper the term abrasion will refer only to wear caused by hard particles introduced into and entrained by a fluid flowing between two solid surfaces, the particles possibly becoming embedded in one of these surfaces.

For the study of this type of wear a plain journal bearing was considered suitable. Arguments for this choice and a description of the apparatus are given.

The use of an aerostatic bearing for the application of load to the plain journal bearing has made friction torque measurement feasible.

The abrasives used were silicon carbide particles of very narrow size distributions; the carrier fluid was a mixture of a straight mineral oil and n-hexadecane. The wear of the shaft was determined by measuring its surface profile, the wear of the bush by measuring its deviation from roundness.

Various combinations of materials were investigated. In most cases hardened steel shafts and soft bronze bushes were used. In addition, some plastic materials served for the bushes; steel, bronze, and aluminium were applied both as bush and as shaft material. Embedding of particles was observed at various places in the bushes, which were usually softer than the shaft.

Additional information on the wear processes was obtained by microscopical inspection of the worn surfaces. Results of the experiments are discussed.
Paper 7: Principles in Organization of Design Staff
Authors: Wearne S. H.
Published: June 2010

Organization of people at work has become a subject of increasing research and theory, but the main interest in industry has been organization for manufacturing. Few studies have been made of the organization of engineers. In this paper are set out ideas of how research and theory might apply to the organization of design departments.
Paper 4: Induction System Development for High-Performance Direct-Injection Diesel Engines
Authors: Jones P. E.
Published: June 2010

This paper describes some of the techniques employed by the author's company in the development of induction systems for direct-injection engines. Emphasis is placed upon those methods amenable to use during the day-to-day performance development of several engine types simultaneously.

The induction system has two functions to perform: ( a) to provide maximum gravimetric aspiration, and ( b) to generate optimum and consistent swirl. These requirements are investigated using digital computers, air flow and swirl rigs, and engine experimental results. The effects of port size, port shape, valve timing, engine speed, and heat transfer on volumetric efficiency are presented in simplified theoretical and experimental forms. The behaviour of ports is discussed and a method of correlation of air swirl rig and engine results is presented. Experimental data is included, demonstrating the importance of correct swirl match. Fully machined inlet ports are discussed together with reasons for their adoption. The principles of induction pulse tuning are briefly enumerated and typical results included. Iso-fuel consumption curves are included to show the present level of d.i. engine performance.

The paper concludes with a tentative hypothesis to explain engine swirl response, and suggests the general level of performance improvement likely during the next few years.
Paper 25: Size Sampling of Steam-Borne Water Droplets
Authors: Ryley D. J. , Fallon J. B.
Published: June 2010

The results are briefly reported of a detailed study undertaken to assess the most promising method of sampling steam-borne water droplets for size. The ‘impressions’ method based upon a standard microscope glass slide smoked with the aerosol magnesium oxide was chosen for experimental development. A supporting probe was designed which exposed the slide in novel manner that avoided the ‘cut-off’ of smaller droplet sizes associated with conventional impaction techniques, without the necessity of accelerating the steam. The assembly was tested in a steam tunnel in which the wet steam mixture is prepared by introducing water droplets from a spinning disc atomizer into dry steam. The droplet size is varied by adjusting the disc speed and the tests were conducted at steam conditions up to 6 per cent wet with velocities up to 30 ft/s at pressures from 17 inHg vacuum to atmospheric.

The paper explores the corrections which must be applied to the observed crater size frequency distribution to allow for the collection efficiency of the probe, penetration of the stagnant layer inside it, as well as sedimentation and transient phase changes. Results suggest that the sampling method can be employed successfully at relatively low velocities of flow, but the corrections and processing of data are tedious. The advantages and limitations of the method are discussed at some length and a numerical example is appended to illustrate the application of the corrections.
Paper 10: The Influence of Moisture on the Efficiency of a One-Third Scale Model Low Pressure Steam Turbine
Authors: Smith A.
Published: June 2010

The rapid increase in blade-tip diameters and peripheral speeds of low pressure turbines in large 3000 rev/min turbo-generators has presented the designer with many difficult mechanical and aerodynamic problems.

To assist in the aerodynamic development of such blading, design studies on an experimental low pressure (l.p.) turbine were started early in 1959. Economic and technical considerations limited the choice to a one-third scale model steam turbine capable of running at three times the normal rotational speed to preserve full-scale working Mach numbers on the blading. Overall output and steam consumption were measured on a hydraulic dynamometer and by volumetric tanking respectively. The inlet steam temperature was controlled by a direct injection desuperheater so that the expansion could be kept dry for traversing or reduced to design inlet temperatures for normal wet running.

Three multi-stage sets with last row blade diameters corresponding to 90-in, 120-in, and 136-in full-scale turbines have now been tested in the experimental turbine and the wet performance of the largest forms the subject of this paper.

The overall wetness losses on the model 136-in diameter turbine have been assessed from a series of seven tests in which the inlet superheat and rotational speed were varied whilst maintaining fixed inlet and outlet pressure levels. To isolate the stage moisture correction factor (α), however, where

a stage-by-stage approach was adopted, in which the dry stage efficiencies were initially established from interstage traverses under dry steam conditions.

Two wet steam analyses were made, the first assuming equilibrium and the second supersaturated expansion, but the choice seemed immaterial since the moisture correction factor was almost the same for both.

In the case of the supersaturated expansion calculation, it was necessary to establish the point of reversion from supersaturated to near equilibrium expansion (the Wilson point) and supplementary water extraction results were used to establish the maximum supersaturation ratio. These suggest that the maximum level is nearer to 3 in the model turbine than to the value of 4–6 quoted for convergent-divergent nozzles.
Paper 26: Erosion Control in the Wet Steam Turbine
Authors: Todd K. W. , Fallon J. B.
Published: June 2010

The general problem of erosion of turbine blading under wet steam operating conditions is reviewed and remedial methods available to the design engineer are considered. Of these, direct attack on the source of erosion, steam-borne water drops, is most attractive and is examined in some detail.

Five stages may be distinguished in the process culminating in erosion. They are: formation of droplets, their deposition on diaphragm blading, subsequent detachment, acceleration towards the moving blades and final impact with them.

The possibilities of interrupting this process at any stage are discussed and the paper primarily deals with the experimental investigation of these possibilities for the three intermediate stages using a full sized cascade of hollow last stage diaphragm blades. This enabled various configurations of extraction slots to be investigated as well as the effects of energizing the blade wakes and heating the blades. The construction and operation of the cascade and associated instrumentation are discussed and results are presented in terms of blading efficiencies for the various processes.
Paper 31: Measuring Steam Wetness and the Operation of Drainage in a 50 Mw Condensation Turbine
Authors: Christ A.
Published: June 2010

After a short recapitulation of the main problems in wet steam turbines, the goal of the measurements is outlined, namely to determine experimentally as accurately as possible the real expansion line in the wet steam region of a 50 MW condensation turbine.

These experiments embraced measurement of the steam and water flow withdrawn from the turbine in the water draining system and measurement of the steam wetness after the last runner stage. For this purpose a special probe was built in which a small amount of steam was tapped from the main flow and heated up to saturation. The probe was movable over the blade length of the last runner stage and results are given as local steam wetness as a function of the probe position.

A comparison of the results with the findings of modern theory gives some explanation of the experimental facts.
Paper 15: The Runner Outlet Vortex-Core Flow and Its Influence on Pressure Pulsations in Francis and Propeller Turbine Draught Tubes
Authors: Vuŝković Ivo , Velenŝek Boris
Published: June 2010

Through experimental researches it has been shown that pressure pulsations in partially loaded Francis turbines can be considerably diminished by centring the vortex core behind the runner. For this purpose a pulsation damper in the form of a coaxial diffuser has been installed at the draught-tube inlet. Comparative experiments on a turbine model with and without the coaxial diffuser have proved the advantage of such a damping arrangement.
Paper 3: Parametric Resonances in Umbrella-Type Generating Units
Authors: Benkö G. B. , Holmén E. K.
Published: June 2010

Whilst investigating a number of water-turbine umbrella-type generators with only two radial bearings manifesting troublesome whirlings the authors discovered that the whirlings were mainly attributable to parametric resonances. Parametric resonances occur in non-linear systems having many degrees of freedom in the vicinity of excitation frequencies where these are equal to the sums or differences of two of the system's natural frequencies. The occurrence of parametric resonances is thus primarily dependent only on the layout and the parameters of the rotating parts and bearings, and is not to be blamed on runner perturbations. The prediction of future risks for parametric resonances is possible, however, only with limited accuracy owing to uncertainties in machine data. Several possibilities for improving the whirling characteristics of a projected unit are discussed.
Paper 6: Notes on the Measurement of Vibrations on Rotating Systems
Authors: Benkö G. B.
Published: June 2010

In analysing the vibrations of rotating systems it is often advantageous to trace the path of the shaft centre from vibrograms taken by two instruments at 90 degrees, because the resulting patterns can yield valuable information about the mechanism of excitation. It is also shown that the same pattern can represent several types of vibration, but for a correct identification it is necessary to know in what sense the patterns have been described. Instrument deflections for some simple cases of transverse vibrations, whirlings, and two-component whirlings are analysed both in stationary and in synchronously rotating co-ordinates and a few typical patterns are shown. Some inherent characteristics of stationary instrumentation are discussed.
Paper 4: Synchronous Whirling of a Shaft within a Radially Flexible Annulus Having Small Radial Clearance
Authors: Black H. F.
Published: June 2010

Where it is intended to run the shaft at high speed—that is, above the first critical speed—contact between the shaft and annulus may take place in running up to speed just below the critical speed if the mass eccentricity is sufficient in relation to the damping. It is shown that such contact can radically alter the high-speed behaviour of the shaft over a speed range possibly extending to several times the critical speed. In this range, synchronous whirling can take place at a radius exceeding the annular clearance. The whirl radius in this condition may attain between ten and one hundred times the magnitude expected in normal high-speed running at the same speed. The dependence of magnitude and range of this type of whirling on annulus to shaft stiffness ratio, damping and surface friction is examined: the conditions for stability of equilibrium are theoretically examined. The essential features of the theory have been tested on a laboratory rig; some typical results are given. There is some evidence that this type of whirling can occur in centrifugal pumps, the cumulative effects leading to failure.
Vibration and Noise in Hydraulic Turbines and Pumps
Authors: Parmakian J.
Published: June 2010

This paper describes numerous examples where objectionable vibration due to various causes occurred at hydraulic turbines, pumps, and pump-turbines. It also includes an analysis of some noise levels in power plants with Kaplan and Francis type turbines.
Paper 2: Pressure Oscillations in Francis Turbines
Authors: Oftebro I. , Lønning A.
Published: June 2010

In this paper the theoretical investigation of five plants, and the results of measurements obtained during testing, are presented to explain and describe pressure oscillations in Francis turbines of the critical frequency fs = nrzr/60, where nr is the runner speed (rev/min) and zr is the number of runner vanes.

The oscillations, although causing no damage to the machinery or its foundations, are intolerable owing to the intense sound produced. This is an interference phenomenon, caused by the interaction of guide vanes, runner vanes, and the pressure propagating velocity in water, and may be avoided by careful construction.
Paper 10: Unsteady Incompressible Flow through Hydraulic Systems
Authors: Roberts B. W.
Published: June 2010

The unsteady Bernoulli equation applied to an incompressible fluid may be used to calculate the unsteady pressures and velocities in a hydraulic system involving pipework and hydraulic machines. The effects of changes in the dynamic pressure, fluid friction, and the quasi-steady pump or turbine characteristics can be included.

The results are applicable to situations in which the time describing the system disturbances is very much slower than the characteristic length of the system divided by the wave speed. In other words, the approach is similar to a rigid water-column theory used in water-hammer analysis. A worked example is also included.
Paper 7: Control of Variable-Discharge Pumps and Dangers of Pipeline Resonance
Authors: Cooper B. J. , Hartland D. , Lawson R. , Stone A. M. , Tyler R. D.
Published: June 2010

The discharge and power input of Deriaz mixed-flow pumps and pump turbines can be controlled over a wide range without significant loss in efficiency by movement of the blades. The attainment of the highest pump efficiency involves a small region of positive slope in the head discharge graph.

This paper examines the limitations of designing pumps which do not exhibit positive slope and the problems of governing if a positive-slope region is accepted.

It is shown that operation in the positive-slope region can introduce a serious organ-pipe resonant instability in the pipeline.

A simple criterion to determine whether or not such oscillations will occur is given. This stability criterion involves the dynamic characteristics of both the pump and the pipeline.

Finally, computer studies of a particular Deriaz pump installation are presented. These underline the severity of the situation should resonance develop and show how it can be avoided by the use of an air bottle of appropriate design.
Paper 7: An Investigation into the Performance of Dynamically Loaded Journal Bearings: Experiment
Authors: Middleton V. , Dudley B. R. , McCallion H.
Published: June 2010

The design of a rig to determine the load and attitude relationships of a hydrodynamically lubricated bearing under steady and dynamic loading is described.

The bearing is nominally of 3 in diameter with a diametral clearance of 0·0075 in. Two bearing lands of length-diameter ratio of 0·282 are fed by a central circumferential oil groove. It has been designed on these model conditions to minimize bearing distortion and temperature gradients in order to provide a basis for comparison with the results of the computer program reported in Paper 6.

Two perpendicular load components are applied mechanically through spring levers displaced by cams. The load components are measured by strain gauges and the displacement of the bearing is detected by four inductive pick-ups. The arrangement of these permits the relative linear and angular displacements of the journal and bearing axes to be determined. Inlet and outlet oil temperatures are measured for viscosity determination.

Both steady and dynamic loads are applied by the loading system. Load diagrams of approximately circular and elliptical form may be obtained directly by adjusting the magnitude and phase of the eccentrics serving as cams, while more complex load patterns may be obtained by special cams.

The polar load diagrams recorded are used as data for the computer program of Paper 6. Theoretical and practical results are then compared.
Paper 12: Hydrodynamic Theory of Dynamically Loaded Bearings and its Application to Engine Bearing Design
Authors: Hahn H. W. , Radermacher K.
Published: June 2010

In recent years the hydrodynamic theory of dynamically loaded engine bearings has been developed to such an extent that calculations of bearing behaviour under all kinds of loads can be made with good correlation to experimental results and field experience. In addition to these calculations, experiments have been performed to determine the influence of variables in practical bearings such as oil-inlet pressure or temperature, the shape of the oil inlet, and the quantity of the lubricant.

At the engine-design stage, engine-bearing behaviour can be predicted by using calculations based on hydrodynamic theory. Some examples are given to show that the load-carrying capacity and consequently the reliability of engine bearings can be increased by using these calculation methods on a digital computer and with a variation of bearing characteristics, such as dimensions, clearance, oil pressure, temperature, and viscosity, or with a variation of load characteristics such as magnitude or direction of counterweight-mass forces, gas pressure, and firing order.

Very good correlation is obtained between these predictions and real engine-bearing behaviour in fast-running diesel engines, as measured by radioactive tracer methods. Many German diesel-engine producers are using these calculations in an early stage of engine design.
Paper 5: The Effect of Journal Misalignment on the Performance of a Journal Bearing under Steady Running Conditions
Authors: Smalley A. J. , McCallion H.
Published: June 2010

A method of solution is described in which the governing equation is modified to account for variations in the oil-film thickness in the axial direction owing to journal misalignment. The position of the journal is specified by means of its eccentricity at its mid-length and by two parameters defining the extent and direction of the misalignment.

The pressure distribution is evaluated numerically, and the direct load, friction torque, oil flow, and couple arising from the misalignment of the journal are obtained by numerical integration.

A full range of journal misalignment conditions is examined for two length-diameter ratios. Results are presented in the form of non-dimensionalized graphs, showing the variation of direct load and misalignment couple with the journal misalignment parameters described. The angle between the line of action of the misalignment couple and the load line is evaluated in each instance, and graphs are presented to show the variation of the performance parameters for a particular degree of misalignment with the direction of application of the couple. Results for the particular instances in which the couple is in line with or at right angles to the load line are extracted, and these are compared with published experimental results of other workers. Good agreement is obtained, and moreover it is shown that, in general, these are not the two extremes of misalignment. For these two conditions design charts are presented, whereby, from knowledge of the applied couple and direct load, the degree of misalignment and the resultant peak pressure parameter may be determined. Charts which illustrate the reduction in load capacity for a particular journal misalignment in the plane of the load are also presented.

General validity is claimed for this method of exploring a relatively unexamined subject, and the results are considered by the authors to be a useful improvement on those obtained by previous analytical workers.
Paper 11: Anti-Vibration Journal Bearings
Authors: Pope A. W. , Healy S. P.
Published: June 2010

An experimental rig has been constructed to establish the vibration characteristics of plain, dammed groove, and tilting pad bearings having a variety of clearances.

The rig is perhaps unusual in not being a small piece of laboratory equipment, but consisting of a naval anti-submarine frigate turbo rotor (15 000 rev/min) running in two journal bearings each supported by an isotropic cantilever system of variable stiffness.

Two pairs of induction probes mounted close to the test bearing monitored the shaft movement and provided an oscilloscope display of the movement of the bearing centre. Detailed information about the shaft oscillations was obtained from a wave analyser and vibration meter.

The static rig natural frequencies with various bearing housing support stiffnesses were primarily determined. From preliminary running tests a fairly stiff bearing housing support, which gave a strong vibration of approxi-mately half rotational speed, was chosen for all subsequent work.

With the rotor wheel balanced the tilting pad bearing tested was found to be free from serious vibration. The dammed groove type of bearing tested was also stable at low speeds but was not capable of stable operation at 15 000 rev/min and above. The plain bearing tested produced serious vibration above 9000 rev/min. The frequencies and amplitudes of vibration which occurred in different bearings with a deliberate rotor unbalance were also measured. Increase of the clearance lowered the onset speed of serious vibration.

The locus of the mean position of the journal centre of the tilting pad bearing was almost a vertical straight line whereas all the other bearings showed the usual approximate semi-circle.

Instantaneous oil film pressures up to 900 lb/in2 were measured using a pressure transducer in the bearing.

As the design particulars of the bearings tested differed somewhat the results were not strictly comparable but nevertheless an approximate design rule has been suggested.

Practical data provided about the vibration behaviour of the different journal bearing designs can be used by the many theoretical investigators in this field. This is important in view of the lack of practical attested results to substantiate or otherwise the many theories advanced.
Research Report 3: Performance of Large Journal Bearings for Steam Turbo-Generators
Authors: Watson H. , Morton P. G.
Published: June 2010

the well-known Growth of turbo-generator size has meant using very large bearings, in which the flow is turbulent. To help in their development, two large bearing research rigs have been operated by the English Electric Company, one for 20 in diameter bearings at 3000 rev/ min which has been in use since 1959 and, more recently, one for 28 in bearings. This brief report gives some of our findings.

Most of the bearings in a modern steam turbine for power generation are turbulent. Sizes currently reach up to 20 in diameter at 3000 rev/min and are likely to grow further. Gradual increase in size through the years showed a marked increase in power loss as diameters of about 14 in were exceeded.
Summary 2: Elastic Deformations in a Journal Bearing Housing
Authors: Ibrahim S. M. , McCallion H.
Published: June 2010

the fluid film Thickness in conventional bearings will be influenced by the elastic distortions of their housings. This elastic distortion can arise from the oil film pressure and will in turn modify the pressure distribution. The present investigation is aimed at putting an order of magnitude on the modifications to the pressure distribution. At this preliminary stage only the mathematical methods to be used and one or two initial results will be presented.
Paper 1: Survey of Auditory Hazards in Power Stations and Their Evaluation in Terms of Hearing Conservation
Authors: Acton W. I. , Coles R. R. A.
Published: June 2010

Detailed noise surveys of twenty-one modern power stations indicated that the main sources were turbo-alternators and fuel pulverizing plant, with boiler feed pumps, fans of various types, and high-pressure steam valves and pipes as secondary sources. Furthermore, noise levels increased with increasing capacity of plant. The noise levels measured in certain locations in power stations exceeded recent hearing damage risk criteria and it is likely that, unless protected, exposed personnel will eventually suffer hearing damage. The exposed personnel may be divided into two groups: those such as fitters, cleaners, etc., who are only exposed intermittently and the unit control staff who are often exposed continuously for 8-hour periods for five days every week.

The principal features of noise-induced hearing loss and of a hearing conservation programme are outlined. The first steps are reduction of noise at source and in transmission; in the situations described, provision of acoustically isolated control rooms is indicated. Where noise levels exceed the damage risk criterion, even for short intermittent exposures, ear protection is required; different types of ear protector, their advantages and disadvantages, and their effects on communications and on the hearing of other important sounds will be reviewed. In addition, a programme of hearing tests (monitoring audiometry) may be desirable.
Paper 9: Acoustically Induced Vibration
Authors: Clarkson B. L.
Published: June 2010

High frequency, low-amplitude pressures in acoustic environments can cause significant vibration and there is the possibility of fatigue failures.

This paper outlines the general theory of the vibration of structures in acoustic environments and indicates appropriate simplifications which may be made in some special cases. Applications to aircraft structures, tall buildings in atmospheric turbulence, and aircraft cabins are outlined. As an example, an aircraft structure excited by jet noise is considered in some detail. A simplification of the general theory is given and the results compared with experiments on several types of aircraft structure. A tentative design procedure is suggested.
Paper 8: Noise from Fans in Power Generating Plant
Authors: White W. W. , Lawson R.
Published: June 2010

In the first part of this paper the question of fan noise in power generating plants is considered, concerning sound generation, propagation, attenuation, and measurement. Some examples of fan sound spectra from existing boiler plants are presented and the possible future trends are mentioned. The paper secondly deals with the design of nuclear plant gas circulators as a means of avoiding excessive sound power generation with its consequent possibility of structural damage.
Paper 2: Noise of Industrial Diesel Engines
Authors: Priede T. , Grover E. C.
Published: June 2010

The characteristics and level of the noise emitted by stationary diesel engines of the type used in power houses are considered. With gas sources adequately silenced the spectrum of the noise of the automotive engine has a pronounced peak in the frequency range 1000–2000 c/s whereas the larger stationary engine shows a peak at a much lower frequency. Most notable among the constructional differences are the exposed flywheel and in many cases panelled crankcase; the significance of these design features is discussed.

The authors have attempted to isolate the various noise sources: combustion and mechanical (particularly piston slap). The contributions to the total noise of the individual outer surfaces, such as crankcase frame, flywheel, cylinder head and various covers and panels, are also discussed in detail.
Paper 11: Origins of Rotary Positive Displacement Blower Noise
Authors: Priede T.
Published: June 2010

Rotary positive displacement blowers (Roots type) are widely used for two-stroke cycle diesel engines. The inlet noise varies from about 100 to 150 dB over its operating range and thus, even with the predominant source of noise from the engine, very little of the delivery noise is emitted.

An investigation into the origins of the inlet noise was carried out by the author on a number of commercially available blowers of different design and size, ranging from 0mD03 ft3 /rev swept volume to 3 ft3 /rev swept volume.

A detailed study of the origins of the noise was made on a small two-lobe experimental blower. The two end casings were fitted into circular locating grooves cut in the end plates. These side casings could be removed or their position varied.
Paper 5: Noise Reduction in the Circulating Water Pumphouse at Blyth ‘B’ Power Station
Authors: Acton W. I. , Bull T. W. , Hore R. A. , Schwarz K. K.
Published: June 2010

The noise produced by the circulating water pump motors at Blyth ‘B’ power station contained a pure tone and this led to complaints both from the public and from the plant attendants. It was established that the noise was principally magnetic in origin, attributable to an unfavourable combination of numbers of stator and rotor slots, and the noise level was reduced by modifying the design of the rotor to obtain a better slot ratio. The noise level was still undesirably high, however, and an experimental silencer for the cooling air inlets and outlets was designed and a mock-up constructed of timber, hardboard, and mineral wool slab. These combined measures reduced the noise inside the pumphouse to well within the ISO noise rating number 85, which has been taken as the hearing damage risk criterion, and abated the public annoyance outside the pumphouse.

This paper describes the basic origin of magnetic noise in squirrel-cage motors and methods for controlling noise levels both by design of motor and silencers within the limits set by electrical and economic design parameters.
Paper 3: Noise in Transformers
Authors: Wilkins J. T.
Published: June 2010

Transformer noise is caused almost entirely by vibrations of the iron circuit. The means by which vibrations are generated are discussed, together with factors affecting their magnitude. The transmission path from the iron circuit to the transformer tank wall is examined and modes of resonance and methods of increasing the attenuation along this path are discussed.

External devices for attenuating noise are described, together with methods for finding the required attenuation for particular site conditions.
Paper 1: A Sensitive Manikin for Evaluating Seat Comfort
Authors: Cooper F. D. , Hall L.
Published: June 2010

To supplement subjective appraisal to determine the degree of comfort provided by an automobile seat, there was an increasing need for an instrument capable of quantitatively measuring pressures between the occupant and the seat.

The method used to determine, initially, the optimum pressure distribution by subjective road tests on a specially constructed seat is described.

The S.A.E. manikin, being adjustable and possessing its own measuring devices in addition to simulating the human being for size, weight, and proportions, was the obvious choice for use as a basis for the new tool. Mechanical load cells fitted with strain gauges were used successfully for measuring pressures between the occupant and the seat and, therefore, proved acceptable for attachment to the relevant area of the manikin.

The display of the results was initially achieved by the construction of isograms, but although visually effective it was too time-consuming. By using results obtained in this manner from nearly thirty complete seat tests, it was possible to compile a computer programme, the output sheets of which conveyed to the seating engineer full information which enabled him to decide whether a seat was acceptable or not and, if not, in which particular areas to consider modifications.
Paper 6: Visibility from the Driver's Seat: The Conspicuousness of Vehicles, Lights and Signals
Authors: Moore R. L. , Smith H. P. Ruffell
Published: June 2010

The importance of good visibility of the road scene is discussed in relation to ( a) visibility from the driver's seat, and ( b) how clearly vehicles, rear lights, and signalling lights can be seen. Suggestions are made for additional arrangements of lights to assist in fog and in following in queue conditions. Methods by which direction indicator lamps could be made more efficient are noted.

It is concluded that, in the design of a vehicle, there is a need to study the conflicts that arise between good visibility and other safety factors.
Paper 2: Statutory Quantitative Control of Packaged Commodities
Authors: Metcalfe T. J.
Published: June 2010

The meaning of ‘trade’, i.e. transferring or rendering of money's worth in consideration of money, the entitlement of the purchaser of goods to receive true weight and just measure and consideration of the importance of quantity control to the packer are discussed. The legal responsibilities of packers of merchandise, historical and contemporary, are explained and the questions of whether the Weights and Measures Act 1963 oppresses the packer who appreciates the fundamentals of business economics, requires higher standards of quantitative accuracy than heretofore, and favours the consumer at the expense of the packer and/or the distributor are considered.

The performance factors of automatic weighing and measuring devices, measuring to determine weight and vice versa, weight representation dependent on the count per unit mass, checkweighing and the fundamentals of dependency are all discussed. The role of the Inspector of Weights and Measures with reference to the mechanics of commodity quantitative control is discussed: where to check, how often, and to what extent. Valuation is made of the results of checking. Consideration is also given to the liabilities of, and defences available to, traders and whether or not deficiency tolerances should be laid down.
Paper 5: Check Weighing: A Review of the Weight Control Problem and its Solution
Authors: Walton D.
Published: June 2010

Producers of consumer products are increasingly turning their attention to the use of automatic machinery for filling, wrapping, and packing operations under the stimulus of improving productivity and of planning for reduced availability of labour.

To an extent progress is hampered by demands made by the recent Weights and Measures legislation which has extended the area in which certain legal requirements regarding packed weight must be observed. One immediate effect has been to make packers more aware of limitations in present filling and checkweighing equipment and of the need, in some cases, for further development of more accurate high speed equipment if legislation is to be met economically. Such equipment takes time to develop, particularly when it must be of approved design. The development of automatic checkweighing machines has had a chequered career but a number of approved models are now available. Such machines can be used successfully in weight-control schemes designed to protect the packer from producing underweights and, where possible, to prevent excessive over-pack. However, the installation of a checkweighing machine does not automatically guarantee success.

The paper reviews some of the problems involved and discusses in some detail factors—such as weight distribution from filling machines—which have to be considered in determining where and how automatic checkweighers can be usefully applied. A brief review of some of the more recent developments is included.
Paper 7: Wrapping and Packaging by Machines
Authors: Sillett E. J.
Published: June 2010

The paper discusses optimum wrapping and packing speeds, including automatic feeding, collating and general handling of retail products and in particular plastic products similar to margarine. The necessity for tailoring the wrapping and packing section to meet production requirements without stopping is made plain, as are the limitations imposed by the nature of the product and the wrap on the machines. The problems of collation and the steps which have been taken to increase optimum speed are also described.
Paper 6: Development of Faster Net Weighing Techniques to Match Higher Packaging Machine Speeds
Authors: Plumbly R. H.
Published: June 2010

The paper covers the development of net weighing of granulated sugar for small packets during the last forty years. Reference is made to the weighing of icing sugar where it is relevant.

The main influences have been:

(1) Large increases in the proportion of prepacked sugar, compared with total sales to the domestic market. (2) Continual advances in the speeds of packing machines. (3) Company policy to maintain the highest possible weight standards.

In pre-war days, automatic net weighing machines were available which gave the required accuracy at a speed under 15 weighings per minute. During the next twenty years the advances in weigher speed were slight in comparison with the speeds obtainable on the packaging machines. The result was that larger and larger numbers of weighers were needed to feed one packaging machine, thus increasing the problems of putting the sugar into the packet.

The development of an electronic net weighing machine has restored the balance. In the late 1920's four compound beam weighers fed a 50 packets per minute filling and sealing machine; now four electronic weighers feed a 240 packets per minute unit, with similar weight accuracy.
Paper 9: History and Development of Flexible Packaging
Authors: Finnen A. M.
Published: June 2010

This paper deals essentially with flexible wrapping materials and their performance on packaging machinery. The emphasis throughout is on the packaging media but the demands made on them by machines are given prominence. The basic principles of the main types of machine are enunciated and illustrated with simple flow diagrams. These show the passage of the wrapping material through the machine and the text isolates the different sections and the wrapping problems involved. For example, the feeding, forming and closure sections of a machine are examined and such properties as slip, tensile strength, elongation and heat-sealability of wrapping materials are considered in relation to them.

The paper opens with an historical survey of packaging, packaging materials and packaging machinery. The economic trends which shaped the packaging industry are presented and general developments in packaging materials and machines are traced from the turn of the century. Some comments on the functions of packaging and its part in the industrial scene are made.

The packaging media covered include paper, cellulose films, aluminium foils, plastic films and the main forms and combinations of them. The production, properties and uses of these materials are outlined but the main emphasis, as stated above, is on their machinability.

Current developments in wrapping materials and machine principles are discussed and some effort is made to forecast trends in flexible packaging generally.