bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Photogrammetry in Piping Design
Authors: Bracewell P A , Klement U R
Published: February 2007

Piping design for ‘revamp’ projects in the process industry requires the retrieval of large amounts of ‘as-built’ data from existing process plant installations. Positional data with a high degree of accuracy are required. Photogrammetry, the science of measurement from photographs, was identified in Imperial Chemical Industries plc (ICI) as a suitable tool for information retrieval.

The mathematical formulation enabling the definition of three-dimensional positions from photographic information is described. The process of using ICI's photogrammetric system for the definition of complete objects such as structures and pipes is illustrated. The need for specialized photogrammetric software for design purposes is explained. A case study describing how the photogrammetric system has been applied is described and graphical outputs from this exercise are shown. It is concluded that this particular photogrammetric system has proved to be a cost effective and accurate tool for the retrieval of ‘as-built’ information.
On Propagating Buckles and their Arrest in Sub-Sea Pipelines
Authors: Steel W J M , Spence J
Published: February 2007

Damaged sub-sea pipelines may experience propagating buckling provided the water depth is sufficient. Theoretical results are given for propagation pressures and arrestor capacities with strain hardened material.
No Smoke with Fire
Authors: Desty D H
Published: February 2007

This paper describes the origination, development and exploitation of Indair, Mardair and Stedair waste gas flares over the period 1967–82. The devices use the Coanda effect to entrain air and produce smokeless premixed flames.
Current Concepts in Centrifugal Pump Hydraulic Design
Authors: Salisbury A G
Published: February 2007

The principal objectives of centrifugal pump hydraulic design are defined. A review of methods presently used to attain these objectives is then given, together with brief descriptions of the theoretical basis for some of the techniques. References are given for the more important concepts to enable in-depth consideration.
Coal-Fired Stirling Engines for Railway Locomotive and Stationary Power Applications
Authors: Walker G , Kentfield J A C , Johnson E W , Fauvel R , Srinivasan V
Published: February 2007

Increase in the price of oil has stimulated interest in coal-burning engines including the Stirling engines. Applications for large (> 1 MW) coal-burning Stirling engines are foreseen for marine propulsion, stationary power, railway locomotive and the heavy off-highway rubber-tyred equipment used in mining, agriculture, construction and forestry.

This paper is directed principally to speculations about large coal-fired Stirling air engines with water lubrication for railway locomotive application, but similar philosophy is applicable in the other applications for large slow running engines.

A brief discussion is included about mechanical arrangements and the use of air as a working fluid with water as the lubricant in Stirling engines combined with fluidized bed coal combustors and sodium vapour heat transport systems. The possibilities for railway locomotive application are explored in terms of a large unit designed from the start to utilize Stirling engines and the conversion of existing steam locomotives. Related studies have considered the conversion of diesel-electric locomotives and the designing of a free-piston Stirling engine hydrostatic drive yard locomotive.
The Evaluation of Load and Torque in Hot Flat Rolling from Slip Line Fields
Authors: Sparling L G M
Published: February 2007

This paper presents a computer evaluation of slip line fields for rolling with medium arc of contact to thickness ratios for conditions of sticking throughout the arc of contact.

The results of load and torque evaluations using a computer version of the Prager geometrical method are combined with the results obtained by Dewhurst, Collins and Johnson for the classes of slip line fields with shorter arc of contact to thickness ratios. The two methods of slip line field evaluation by the Prager and the matrix methods are shown to give load and torque functions which give a smooth transition over the boundary. The load and torque functions are presented in the form suitable for use with the yield stress functions of Cook and McCrum (BISRA method).

The computer evaluation of slip line fields by the Prager method lacks elegance by comparison with the matrix method, but is the only method at present available for the evaluation of slip line fields for rolling where two rigid metal zones occur on the surface of the rolls.

It is also believed that the computerized Prager method for slip line field evaluation is more readily adapted to the evaluation of slip line fields for conditions of mixed sticking and sliding friction.
A Comparison of US, West European, UK and Japanese Performance 1977–80
Authors: Jacobson M A
Published: February 2007

Many reasons have been advanced for the apparent lack of competitiveness of several West European car manufacturers when comparing them with those of Japan. The underlying facts are more basic than robots replacing men, union versus management conflicts, low productivity, lack of investment in new plant and reluctance to adopt new processes. Many manufacturers in Western Europe are wasteful in the use of energy at several critical stages of car production, starting with energy use in the manufacture of the primary materials, ferrous and non-ferrous, plastics and tyres, proper utilization of process heat, insulation of buildings, dispersal of facilities, leading to extra transhipment costs and holding of contingency stocks for work in progress. Up to one-third extra energy is needlessly spent in many plants built or refurbished in the past two decades—much of it being lost to the atmosphere. Over half the production cost of a modern European motor car is accounted for by materials and around 30 per cent by manufacture. With Japanese cars requiring 20–30 per cent less energy during manufacture than their European counterparts, many of the old established manufacturers of cars and major components have a difficult future ahead, for the cost of energy is likely to rise year by year. A radical re-assessment of energy utilization during all phases of production is urgently called for.
Plant Floor Information Systems Via Programmable Controller/Computer Networks
Authors: Lesner W T , Hughes K G
Published: February 2007

Plant floor information systems are gaining popularity and importance in nearly every production environment. Current competitive and economic considerations demand that manufacturers be more concerned with obtaining the highest levels of efficiency and quality. In order to attain these goals, many manufacturers are implementing—or considering implementation of—computerized information systems. This paper examines the design of a plant floor information system for monitoring engine manufacture at the Cadillac engine plant.
Operational Requirements of Light Rail Vehicles
Authors: Hellewell D S
Published: February 2007

The paper begins with a brief historical resume of railcar development and then continues by outlining the three main types of service upon which light rail vehicles could be used with advantage. Passenger, marketing and operating requirements are identified. The paper outlines various technical considerations before concluding by discussing future options.
The Ford Cargo
Authors: Marshall P H
Published: February 2007

During 1981 and 1982 the fifteen year old Ford ‘D’ Series was replaced by the distinctively designed Cargo range. This is intended to meet road transport needs in the 1980s and beyond for vehicles from 6 to 32.5 tonnes gross mass and up to 150 kW. This segment covers about 50 per cent of the total Western European market for commercial vehicles above 3.5 tonnes.

This paper gives a glimpse of how the objectives for such a programme were defined and how they were met by careful attention to planning, initial design, development and testing with the close co-operation of manufacturing engineers at all stages.
A Complete Steel Shelf from Fifteen Tonne Coils Every Three Seconds
Authors: Challis E G , Lee R W , Perry A J , Turner J L
Published: February 2007

Shelves with improved selling features which use steel more effectively are produced on a continuous flow line. The process nearly doubles capacity, copes with greater variety and reduces unit costs.
Driving Axles into the Eighties
Authors: Davies A J , Harrop S , Rufus D , Thompson J M
Published: February 2007

GKN Axles Limited, Heavy Division manufactures a range of forgings and heavy axles for domestic and international markets. It constitutes approximately 50 per cent of GKN Axles Limited, who employ 2800 employees, contributing in 1981 £60 million turnover to the automotive sector of GK N.

This paper shows how the Company, formally Kirkstall Forge Engineering Limited, revised its marketing, product engineering and investment strategies in order to implement a coordinated programme to ensure realization of progressive product and financial objectives.
Vehicle Build Sequence Control for Metro Production
Authors: Harries G M , bill K W Cock , Lewis R G H
Published: February 2007

The introduction of the Austin Metro was the result of massive investment in product design, facilities and computer systems. This paper describes one of many significant systems to support vehicle production. The product range and volume, the facilities involved and the system design criteria are reviewed. The system is detailed in terms of the computer configuration used, and the major sub-systems involved in controlling the sequence of final vehicle build. The impact of the system on the plant is discussed together with a review of the benefits experienced. The overall aim of the paper is to demonstrate the advantages of a strategic approach to the problems of computer integrated manufacturing.
Integrating an Advanced CAD/CAM System with Shipbuilding Technology
Authors: Cloke D W , Metcalfe R
Published: February 2007

In 1981 Appledore Shipbuilders implemented a Computervision CAD/CAM system to evaluate its application to shipbuilding and to use it for production work. This paper describes how the system's facilities have been used, what has been achieved to date and how it interfaces with shipbuilding technology.
Valid Human Operator Control Models for Closed Loop Design
Authors: Sutton Lt Cdr R
Published: February 2007

The Sea Harrier VTOL (vertical take-off and landing) aircraft is an example of a complex man–machine system. During the development of such systems it is essential that financial costs and modifications are kept to a minimum. At the computer aided design stage it is necessary for the system designer to have available valid models of the various sub-systems in order to optimize the closed loop performance. The formulation of reliable models of the hardware components is relatively easy to obtain. However, this is not the case for the human operators who close the loop and control the system. Therefore the designer requires valid human operator models. Herein valid human operator models that have been developed in recent years are discussed. Although most of the models discussed have been developed for aerospace applications they may be adapted and used in other areas of study.
The Measurement of the Fluid Borne Pressure Ripple Characteristics of Hydraulic Components
Authors: Edge K A , Wing T J
Published: February 2007

Pressure pulsations generated by pumps and motors can often be a major source of noise in hydraulic systems. In this paper two test methods for the determination of the pressure ripple characteristics of pumps are described. The first method enables a pump to be characterized by a frequency spectrum or a single figure or merit, enabling simple comparisons to be drawn between units. Typical results are presented and discussed. The second test method enables pump characteristics to be defined in more detail. This provides useful information for designers. The method also has the ability to provide information on the pressure ripple characteristics of valves. Typical results are again presented.
Selecting Advanced Machine Tools by a Systems Approach Based on Key Machined Components
Authors: Kilmartin B R , Leonard R
Published: February 2007

The previous paper (1) described how computer-assisted modelling techniques were used to identify ‘key’ components from a sales forecast encompassing a wide range of products. In this second paper a methodology for formulating the specification for the new investments is described, together with a procedure for making the final selection.
An Experimental Investigation into the Effect of Changes in the Geometry of a Slot Nozzle on the Heat Transfer Characteristics of an Impinging Air Jet
Authors: Hardisty H , Can M
Published: February 2007

High velocity, impinging, air jets are commonly used for heating, cooling, drying etc., because of the high heat transfer coefficients which occur in the impingement region. To provide data for design, a variety of slot nozzles has been tested to determine the effect on heat transfer of both nozzle shape and slot width. A small heat flux meter was used to measure local values of the heat transfer coefficient in the impingement zone, and these local values were integrated to yield space average values.

As a necessary preliminary to the heat transfer investigation, the discharge coefficients of the nozzles were measured. From the first test series it was found that heat transfer results from differently shaped nozzles could be satisfactorily correlated provided that the effective slot width was used to characterize nozzle shape. From the second test series it was found that for geometrically similar arrangements, narrower slots gave higher heat transfer coefficients.
A Theory of Non-Linear Anisotropic Hardening
Authors: Rees D W A
Published: February 2007

A yield function is derived which accounts for translation, contraction and rotation of the yield surface in the progress of plastic deformation for non-linear work-hardening materials. The present theory removes the restrictive condition of a rigid translation implicit in linear work-hardening by the kinematic hardening rule. The function proposed is shown to be in good agreement with experimentally determined yield loci for 2 1/4 per cent Cr, 1 per cent Mo alloy steel at room temperature in a principal biaxial stress subspace and those for aluminium 1100 at room and elevated temperatures in a combined tension-torsion stress subspace. Parameters pertaining to translation are determined, in confirmation of the theory, from reversed yielding torsion tests on tubes of En 3B steel.
The Interaction of Pantograph and Overhead Equipment: Practical Applications of a New Theoretical Method
Authors: Gostling R J , Hobbs A E W
Published: February 2007

Theoretical predictions of pantograph/overhead interaction are described, together with associated validation experiments and consequent hardware developments. The concept of a combined pantograph overhead ‘system’ is introduced.
Stresses in an Internally Pressurized thin Rectangular Prismatic Duct
Authors: Holland M
Published: February 2007

An elastic analysis is developed which results in equations for the prediction of stresses at principal positions in the duct. These equations express the stress as a function of the aspect ratio and the ratio of the thickness of adjacent sides (opposite sides are taken to be of the same thickness). It is shown that for a fixed ‘longest side’ length, an optimum stress condition is achieved when the aspect ratio is two-to-one and the four sides have the same wall thickness.
Structural High Temperature Materials—A View with a Future
Authors: Alexander J D
Published: February 2007

High temperature structural materials are used to contain or extract power from furnaces—the jet engine being considered as one of these. To improve efficiency of operation and life, materials have been strengthened by various metallurgical mechanisms and each has required a better production control. The parameters of casting have been understood and developed to the extent where the orientation of single crystal turbine blades is now controlled on a semi-automated production basis. High strength disc materials are made to precise structures and defect levels to optimize properties.

In the future this understanding will lead to more novel melting techniques, for cleaner material and even more precise and automated production control. The detailed material understanding gained from metallic materials gives an immediate opportunity to review the traditional approach to ceramics and to take a major and physics-based step to their more general acceptance.

This understanding and precision of manufacture with its associated automation gives an opportunity for the wider use of these high temperature materials in other areas such as modern diesels.
Static Axial Characteristics of Aerostatic Annular Porous Thrust Bearings with Tilt
Authors: Singh K C , Rao N S , Majumdar B C
Published: February 2007

A theoretical analysis is presented to predict the static axial performance characteristics of a porous circular thrust bearing with a central hole for both open and sealed ends, taking into consideration the tilt of the runner pad. The flow in the bearing matrix is considered to be three-dimensional. The governing equations of gas flow through the porous pad and the bearing clearance are solved simultaneously using the finite difference technique to obtain pressure distribution in the bearing clearance. The load capacity, mass rate of flow and static axial stiffness are calculated numerically for various bearing dimensions and supply conditions and presented in graphical form. The bearings with sealed ends have comparatively better load capacity over those with unsealed ends. The effect of tilt is to decrease the load capacity and increase the mass flowrate.
Triple Epicyclic Four-Clutch Six-Ratio Change-Speed Systems
Authors: Lloyd R A
Published: February 2007

Orthodox epicyclic change-speed gearboxes are not optimized to produce the maximum number of ratios from a given number of clutches and gear-sets. A class of triple epicyclic mechanism has been derived which meets this goal, and 2692 structural variants have been elucidated, grouped in 28 families. The topology of epicyclic systems has been studied to ensure that these variants may be constructed, and a systematic procedure has been set out to determine which of them will suit any particular purpose. Two examples are given.
Experimental Verification and Measurement of Recompaction Waves Induced by Bulk Cavitation
Authors: Driels M R
Published: February 2007

A brief review of an existing theory is given for the fluid motion following reflection of an underwater shock wave from a free surface. This one-dimensional theory is tested against experimental data obtained from simple apparatus designed for laboratory simulation of underwater shock. Correlation between theory and experiment is good.
Heat Losses from a Divided-Chamber Diesel Engine
Authors: Alkidas A C , Cole R M
Published: February 2007

The various components of heat loss were investigated in a single-cylinder divided-chamber diesel engine. The effects of engine speed, air/fuel ratio, injection timing, intake air temperature and coolant temperature on the heat rejection to the coolant were examined. The magnitudes of heat rejections to the coolant and to the individual cooling zones (cylinder liner, intake port, exhaust port and antechamber) were found to be related primarily to the rate of fuel consumption. The contributions of piston friction and exhaust port heat transfer to heat rejection to the coolant and the magnitude of heat loss from the exterior surfaces of the engine to the surroundings were also evaluated.
Static and Dynamic Properties of Oil Films in Displaced Centres Elliptical Bearings
Authors: Singh A , Gupta B K
Published: February 2007

The possibility of improving the stability of elliptical bearings by displacing the lobe centres has not received much attention so far. The present paper examines in some detail the effect of displacing the lobe centres on the load capacity, attitude angle and on elastic and damping coefficients. Ellipticity and horizontal displacement ratios have profound influence on bearing characteristics. An increase in ellipticity ratio increases vertical stiffness without much effect on horizontal stiffness; similarly an increase in horizontal displacement ratio increases horizontal stiffness. The numerical results given in the paper will help the designer to select suitable ellipticity and horizontal displacement ratio to have a bearing of desired static and dynamic properties.
Non-Uniform Flows in Axial Compressors Due to Tip Clearance Variation
Authors: Horlock J H , Greitzer E M
Published: February 2007

An approximate analysis is presented for the asymmetric velocity non-uniformities that can exist in an axial compressor due to variations in tip clearance around the circumference. Calculations have been carried out for several different compressor configurations, as well as for both rotating (fixed to rotor) and stationary clearance variations. The numerical results show that, for a given compressor, the ratio of (per cent) variation in axial velocity to (per cent) variation in pressure rise coefficient due to asymmetric clearance increases as flow decreases, although this trend in not necessarily true for the magnitude of actual velocity non-uniformity. In addition, the velocity non-uniformity due to a rotating clearance can be substantially larger than that due to a stationary clearance.
Identification of Linearized Squeeze-Film Dynamics Using Synchronous Excitation
Authors: Stanway R
Published: February 2007

This note demonstrates how the four damping coefficients associated with a squeeze-film isolator can be identified from time-series records of the displacement responses to synchronous excitation.
Analysis of Elastohydrodynamic Lubrication of Elliptical Contacts with Rolling along the Major Axis
Authors: Evans H P , Snidle R W
Published: February 2007

Describes results of the elastohydrodynamic lubrication analysis of the type of elliptical contact which occurs in high conformity gears.
The Effects of Non-Flatness on the Performance of Slippers in Axial Piston Pumps
Authors: Hooke C J , Kakoullis Y P
Published: February 2007

All previous analyses of slippers in axial piston pumps have assumed that the slipper running surface was perfectly flat and have all failed to explain the satisfactory performance of these bearings. It has been suggested, however, that slippers in axial piston pumps may depend, for their successful operation, on the small deviations from a perfect flat of the slipper surface. This paper examines the relationship between such a non-flatness and the minimum film thickness produced under steady operating conditions. It is shown that a very wide range of slipper non-flatnesses can lead to satisfactory slipper performance and that the minimum film thickness predicted is remarkably insensitive to the actual amount of deviation from flat.
Comparison between Analytical and Vectorial Methods of the Synthesis of Equations of Motion
Authors: Goraj Z J
Published: February 2007

In this paper the advantages and weak points of the analytical and vectorial methods of the derivation of equations of motion for discrete systems are considered. The analytical method is discussed especially with respect to Boltzmann-Hamel equations, as generalized Lagrange equations. The vectorial method is analysed with respect to the momentum equation and to the generalized angular momentum equation about an arbitrary reference point, moving in an arbitrary manner. It is concluded that, for the systems with complicated geometry of motion and a large number of degrees of freedom, the vectorial method can be more effective than the analytical method. The combination of the analytical and vectorial methods helps to verify the equations of motion and to avoid errors, especially in the case of systems with rather complicated geometry.
Determination of Bearing Deflections
Authors: Kilicay O
Published: February 2007

The availability of new spindle units which have hydraulically controlled variable preload bearings, means that the radial and axial deflection of bearings can be calculated more accurately than was possible when bearings had a preload set when cold and liable to change at working temperature. The present study gives the method of calculation for combined loading (i.e. axial and radial together), typical results are illustrated and the extreme cases of radial load only and of axial load only are compared with SKF's empirical formulae.
A Plan to Reduce Forced Outages in Power Stations
Authors: Kelly A G
Published: February 2007

The amount of plant needed to meet the load in an electric utility is very dependent on the forced outage rates. In a utility that presently experiences high forced outage rates, there is a danger that future plans will use such high figures. The correct approach is to launch an attack on present forced outages, reduce them to figures comparable with best world figures and plan the forward plant programme on that assumption. This paper describes such a programme in some detail.
Modernization of Control Systems to Maintain Plant Reliability and Economy in a Flexible Operating Regime
Authors: Wronski G , Wilson R G
Published: February 2007

The bulk of the electricity generated within the Central Electricity Generating Board (CEGB) is produced from units with a capacity of 500 MW and above. A further 10.2 GW of generation is due to be commissioned in the next few years. Hence those 500 MW units with the highest generating costs now need to develop a flexible operating capability.

An attempt is made to define the effect on plant performance of improving the plant automatic controls systems and enhancing the amount and presentation of information to operating staff. The consequences on plant performance of providing minute to minute regulation against grid frequency are given.

The economic consequences of running at off design conditions are evaluated and related to the benefits of modernizing the control and display systems on the 500 MW units.

Examples are given of the improvements being made in instrumentation and data handling systems.
The Effect of Large-Scale Structures on the Stability of Coal-Face Steering
Authors: Edwards J B
Published: February 2007

Simplified models of piecewise rigid support structures for power-loaders operating on longwall coal-faces are shown to be amenable to analysis by z-transform methods. Such analysis predicts that increasing sufficiently the length of the sub-sections of the structure (compared to the inherent delay within the vertical steering system of the machine) should stabilize the vertical steering of the entire coalface. Increasing the width of the structure to embrace more than two consecutive cut floors is shown analytically to eliminate the need for electronic tilt-feedback in control systems.

In general terms, these analytical predictions are shown to hold good in detailed simulations of the system that eliminate the simplifications demanded by the analytical method. The general conclusion of the work is therefore that an increase in the size of support structure segments can potentially reduce the complexity of steering control systems. The size-increase must be substantial, e.g. to four to five times the size of conventional structures.
The Preservation and Starting from Cold of Large Oil-Fired Generating Plant
Authors: Lang A , Piatt A , Senior C H
Published: February 2007

The rise in oil prices in the late 1970s and the down-turn in the economy have reduced the demand for load from oil-fired generating plant. As a result of this a modified operating regime has been instituted for the three 676 MW units at the Inverkip Power Station of the South of Scotland Electricity Board. A single unit is maintained in service, the other two being held at one week's and one month's readiness. The paper describes the methods used to prevent deterioration of the plant in the cold, shut-down condition. The quickest possible starting from cold of the service unit is essential and the methods adopted, which enable full-load to be attained within eight hours, are also described.
Thermally Insulated Diesel Engines
Authors: Wallace F J , Kao T K , Tarabad M , Alexander W D , Cole A
Published: February 2007

The paper first reviews the current state of development of ‘adiabatic’ diesel engines in Europe and the US. This review section is followed by a brief description of the experimental programme on thermal barrier components for single cylinder engines in the University of Bath, England, and finally by a theoretical section dealing with the performance potential of compound engine schemes based on ‘adiabatic’ engine operation.
Evolution and Design Principles of Low Noise, Lightweight Engines
Authors: Priede T , Anderton D , Dixon J , Grover E C , Lalor N
Published: February 2007

The relationship between combustion and inertia excitation as a function of engine size and rated speed is illustrated, and design concepts for low noise, including reduced structure response, are discussed.
The Design, Construction and Installation of a Continuous Casting Plant for the Production of Special Steel Billets at Stocksbridge Works
Authors: Murray J D
Published: February 2007

The decision to install a continuous casting plant for the production of special steels was taken by the British Steel Corporation in January 1979. In October 1983, the plant installed at their Stocksbridge Works operated for the full month at rated capacity. In this paper an attempt has been made to give an appreciation of the project from concept to customer acceptance of the product produced.

Increasing economic pressures demanded that new technological processes be adopted to reduce the conversion costs from raw materials to sold billet products, and maintain or improve the product quality. Early in the modern history of steel-making it was realized that the continuous casting process would reduce costs by the considerable energy savings and improved yields which could be achieved. However, it was not until recent years that certain aspects of the process were developed such that continuous casting could be considered acceptable for the high demands of special steels.

The metallurgical parameters for the machine and the translation to machine hardware have been discussed, together with some of the problems encountered in the construction and commissioning.

The finished plant introduces contemporary technology to the steel-making process and Stocksbridge are justifiably proud of the enviable position now occupied with a plant which places it at the forefront of continuous casting technology, producing a product which is at least as good as that produced by the conventional ingot route but with enhanced productivity and profitability. All metallurgical requirements have been satisfied and the course is set for developing the route for steels used in even more demanding applications and markets.
The Parsons Centenary—a Hundred Years of Steam Turbines
Authors: Harris F R
Published: February 2007

The first practical multi-stage turbine in the form in which we know it today was built by the Hon C. A. Parsons in 1884. After referring briefly to other pioneers of early turbine development, and outlining the essential differences between impulse and reaction turbines, the main part of the lecture is devoted to a historical survey of steam turbines as applied to the generation of electricity in central power stations, over the intervening one hundred years. Progress in many areas of interest is described: these include considerations of blading design, steam conditions, single- and double-reheat, and many mechanical features, as well as condensing and feed heating plant. Specialized applications of turbines for use with nuclear reactors, for district heating, for use with dry cooling systems where water is scarce, and for rapid starting are also described. Where possible, significant milestones in development are identified by year and by builder; progress up to the present day is reported. Some of the problems which sometimes arise with turbine plant in service are briefly mentioned, and the prospects of developments over the next few years, including the possibility of significant increases in steam pressure and temperature, are outlined.
The Use of Limp Porous Blanket Baffles to Control Acoustic Vibration in Crossflow Tubular Heat Exchangers
Authors: Byrne K P
Published: February 2007

It has been found that a single rigid dissipative baffle can be used to prevent the development of acoustic vibration in a crossflow tubular heat exchanger which has an in-line tube arrangement. This paper presents the results of an investigation of the possibility of using a limp porous blanket as a dissipative baffle. The blanket could be woven from ceramic or glass fibre and could be installed in either in-line or staggered tube arrangements. Recommendations are given for the mass per unit area and the specific flow resistance of the blanket.
Duct Inspection and Repair Programme for Magnox Nuclear Power Reactors
Authors: Giblin J
Published: February 2007

Details are presented of the inspection, repair, and replacement programmes that were necessary after welding defects had been discovered in primary circuit attachments at three of the Central Electricity Generating Board's (CEGB) steel pressure vesselled stations. These were at Bradwell and Dungeness ‘A’ power stations in the South Eastern Region of the CEGB and at Berkeley power station in the South Western Region. The refurbishment programme required both nuclear reactors at each station to be shut down for periods of two to three years.
A History of the Dowty Marshalling Yard Wagon Control System
Authors: Bick D E
Published: February 2007

During the passage of wagons through marshalling yards accurate speed control is essential for high throughput and zero damage to rolling stock and freight. This paper deals with certain aspects of the history of the Dowty system, now installed in fourteen countries and five continents. It describes the novel concept, introduced in the 1960s, of power-operated oil-hydraulic units fitted at intervals to the rail track and operating upon the wheel flanges. Details are also given as to how it developed into the present form, which has the advantages of reduced capital, running and maintenance costs, being worked by the force of gravity alone. For his contribution to the project the author was awarded the Institution's Bramah Medal for 1980.
Computer Aided Design of Split Power Hydrostatic Transmission Systems
Authors: Dorey R E , Vaughan N D
Published: February 2007

Split power hydrostatic transmission systems have been proposed in applications ranging from machine tool drives to military tanks. So far only quite simple arrangements have been considered and the full potential of the transmission remains to be exploited.

This paper investigates the design of the split power transmission for a vehicle drive and shows how the transmission characteristics can be matched to the particular requirements of the vehicle duty. The number of design alternatives makes a computer investigation an ideal approach to assess the most appropriate solution in a given application. To enable computer programs describing behaviour of complex transmissions to be easily constructed and altered requires a unified approach to the modelling procedure. The paper describes how such an approach can be used for the evaluation of transmission performance and emphasizes the importance of the computer model in determining the efficiency and fuel economy of the vehicle transmission system.
A Technique of Introducing the Characteristics of Interface Joints in the Computer Aided Design of Drop Hammers
Authors: Ismail H S , Sadek M M
Published: February 2007

A technique, based on both the finite element and receptance methods, is developed by which the characteristics of interface joint inserts are introduced in the computer aided design of machine structures in general and specifically the case of drop hammers. The hammer frame, under investigation, is that of a one-third scale replica of an industrial drop hammer where the characteristics of the anvil/column interface joint are studied. The effect of both the experimental and theoretical properties of damping materials on the dynamic response of the hammer frame is also investigated.
The Search for Good Solutions—What Skills are Required of the Designer?
Authors: Sheldon D F , Gill H
Published: February 2007

The ‘economic imperative’ for good design is outlined and some of the issues involved in improving design performance are discussed. Positive proposals are made to this end and the question is raised immediately: is genius essential? If so, are we wasting our time in educating and training designers? Clearly such genius would be welcomed but is unlikely to be available in large measure. Thus we have to achieve an improved performance with what is available and so the emphasis is on the individual designer; the development of his creative skills and sensibilities; his ‘fitness’ for the task. The development and nurturing of such fitness can be facilitated by imaginative collaboration between industry and education but its sustenance has to be maintained by continual intellectual and creative challenge. Industry must provide the stimulus and the creative environment for this new potential to grow and be given the constant challenge necessary if it is to be fully exploited. Industry's role in this undertaking has to be taken much more seriously than hitherto.
On Machine Perception of the Relative Position of Two Objects Using Bilateral Tactile Sensing Systems
Authors: McCallion H , Pham D T
Published: February 2007

>New systems for measuring the relative location of two contacting bodies using tactile signals generated by the contacts are presented and discussed. Kinematic models of the systems are given to aid their visualization, and the Kutzbach formula is used to test the uniqueness of the relative location vector inferred from the tactile signals.

Using the Kutzbach formula it has been shown that, in general, bilateral systems involve measurements of more than one state of contact, that is they are multinary in character.

In the Appendix mathematical procedures have been described for evaluating the relative location from the tactile signals.
Preparing the Offer
Authors: Warby D J
Published: February 2007

The activities connected with the preparation of an engineering tender are considered in the context of a notional entrepreneurial company, Entaprize Limited, which does not have a rigid product base. Commencing with the corporate plan, which identifies the basic decision to seek an area of business, the succeeding steps are followed through to the preparation and submission of a tender.

The treatment of the process is in the context of the type of inquiry specification customary for purpose made goods for a major purchasing organization. The emphasis is on the relationship of Entaprize Limited as supplier to their purchaser clients, but of course, Entaprize are also purchasers from their own suppliers and subcontractors.
Study of Drift in an Asymmetric Linear Hydraulic Motor
Authors: Datta B N , Murty A S R , Sinha G L
Published: February 2007

It is well known that in a hydraulic servomechanism the ram exhibits in the open-loop a linear motion in addition to its usual oscillatory motion for a sinusoidal input. This phenomenon, called drift, gives rise to an apparent instability of the system and the study of the dynamic behaviour becomes difficult. A theoretical investigation into the causes and remedy of this phenomenon is made on a loaded system with an asymmetric linear hydraulic motor controlled by an open-centre three-way spool valve. The original non-linear system equation in dimensionless form is derived taking into account the effects of leakage, compressibility (both fixed and varying) and area ratio, and solved numerically by the fourth-order Runge–Kutta method. It is shown that the determination of the reverse flow boundary is essential prior to the study of drift, since the rate of drift will be maximum near the boundary frequency. It is also shown that while the effect of compressibility due to the change in initial volume is mainly responsible for drift for an area ratio of 1 : 2, the effect of area ratio itself is predominant for an area ratio not equal to 1 : 2. It is observed that in most of the cases the drift can be removed by giving a proper input shift to the valve. A method of calculating the input shift required is suggested and the effects of different system parameters on its magnitude are studied.
A Comparison of Oil and Water as Grinding Fluids in the Creep Feed Grinding Process
Authors: Ye N E , Pearce T R A
Published: February 2007

This paper contains a comparison of water-based and neat oil grinding fluids when used in the creep feed grinding of a nickel-base alloy with an induced porosity wheel. Grinding with oil resulted in less wheel profile wear and improved surface finish but higher forces in the direction normal to the workpiece travel were obtained and workpiece burn occurred at lower stock removal rates. The implications of these findings for the creep feed grinding of nickel-base alloys are discussed.
Industrial Robots: A Human Factors Perspective
Authors: Edwards M
Published: February 2007

Industrial robots have been increasingly used in industry to perform a variety of tasks. A study was carried out of the implications for the workforce of this new technology. Two categories of human task were found to be associated with the use of robots: one, common to all applications, concerned maintenance and programming while the other comprised the residual tasks which varied with different robot applications.
The Bolted Joint: Economy of Design Through Improved Analysis and Assembly Methods
Authors: Junker G H , Wallace P W
Published: February 2007

The design of bolted joints has been based on the assumption that joint behaviour is linear; it has also been assumed that the magnitude of the bolt clamping loads within a broad range do not effect the transfer of loading between the bolt and the clamped parts. Recent research has shown that most joints have eccentricity and that this causes the joint behaviour to be very sensitive to bolt clamp loads; further research has shown that clamp load can be increased and its scatter reduced by new controlled tightening methods. Applying the new design knowledge and tightening techniques can increase the load-carrying capacity of existing structures and permit lower weight and lower cost in new designs.
Modelling the Characteristics of Interface Surfaces by the Finite Element Method
Authors: Villanueva-Leal A , Hinduja S
Published: February 2007

This paper describes the development of a finite element model to simulate the behaviour of an interface which is formed between two contacting bodies. The normal behaviour is modelled using well-known equations. From available experimental data, the shear behaviour of the interface during loading, reloading and unloading is approximated by third-degree polynomials. The model approximates this non-linear behaviour using an incremental method. During each iteration, a portion of the external load is applied and the shear and normal stiffnesses are calculated using the tangent-stiffness method. Three examples, including a bolted cantilever, are analysed and the predicted results are compared with experimental results.
The Dynamical Behaviour of Externally Pressurized Gas-Lubricated Unloaded Porous Journal Bearings
Authors: Malik M , Rodkiewicz C M
Published: February 2007

In many practical applications, such as with vertical rotors, journal bearings operate with nearly zero eccentricities. In such situations the externally pressurized gas-lubricated porous bearings can offer a viable alternative to the self-acting gas and oil bearings which are generally prone to film induced instabilities under lightly loaded conditions.

This paper presents a thorough investigation of the dynamical behaviour of unloaded externally pressurized gas porous bearings. Expensive computations and a large number of design variables involved with the overall performance analysis make it difficult to carry out a comprehensive study of these bearings. However, an attempt has been made to bring out clearly the effect of the more important design variables on the dynamic performance of the bearings.
Structural Error Synthesis of a Four-Bar Function Generator Using the Reliability Concept
Authors: Khare A K , Rao A C
Published: February 2007

Structural error synthesis of mechanisms is usually carried out either by the precision point approach or by using optimization techniques. A new approach for such problems using the reliability concept is presented in this paper. Besides being simple, this approach leads to a closed form solution and the mechanism can be designed to perform with any desired reliability. Its application is illustrated by means of a numerical example and the results are compared with those available.
Estimation of Flash Temperatures in Dry Sliding
Authors: Lingard S
Published: February 2007

The paper develops expressions for the flash temperatures experienced by contacting surface asperities during dry sliding. The analysis is based on the heat transfer equations of the Jaeger—Archard theory but additional terms are introduced to allow for the effects of junction growth and cold work in plastic conjunctions.

Results of direct measurements of surface temperature in metallic contacts are also given which are in approximate accord with the theory.
Stamping Rectangular Plates into Doubly-Curved Dies
Authors: Yu T X , Johnson W , Stronge W J
Published: February 2007

Shallow spheroidal shell segments have been press formed from rectangular plates by stamping between a die and matching punch that have two degrees of curvature. Experiments on mild steel, copper and aluminium plates that were not clamped in the die have measured the punch force, contact regions and final curvature distribution; and have observed plate buckling for a range of die curvature ratios and plate sizes. An analysis based on a rigid/plastic material idealization and decoupled in-plane forces and bending moments has been correlated with these experiments. The sequence of deformation modes has been identified; initially these are bending but in later stages, in-plane forces predominate.
Arbitrary Motions in Long Cylindrical Squeeze Films: Numerical Model and Experimental Validation
Authors: Rogers R J , Sousa A C M , Qureshi T B
Published: February 2007

Dynamically loaded cylindrical squeeze films are analysed by a finite difference technique for predicting the transient fluid velocity and pressure fields, as well as the resulting squeeze force, given any specified motion of the internal cylinder. Apart from neglecting axial flow, no assumptions are made with respect to the relative magnitudes of the terms in the flow equations. Experimental results were obtained using a test apparatus in which quasi-elliptical orbits were generated using spinning eccentric masses. The squeeze force data show reasonable agreement with numerical results obtained for five orbit cases.