bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vaporizer Performance
Authors: Liu C H , Perez-Ortiz R M , Whitelaw J H 
Published: February 2007

Measured values of fuel droplet velocity, size and flux are presented for a vaporizer based on a T-shaped duct with upstream atomization by a single axial jet and by six radial jets. They were obtained for a practical range of kerosene and air flowrates and inlet air temperatures with the vaporizer in free air and in a sector of an annular combustor with combustion. Phase Doppler velocimetry was used to measure droplet velocity and size distributions and was complemented by photographic visualization of the flames within the combustor. The results obtained outside the combustor, and without combustion, showed that the Sauter mean diameter of the droplets ranged from 20 to 60 μm and the liquid-fuel flux from 0.2 to 30 per cent of the total fuel as the inlet air temperature was increased from that of ground-idle to that of full power. The droplet size and liquid-fuel flux also diminished with an increase in air flowrate, and an arrangement of six radial jets resulted in better atomization than an axial arrangement. The corresponding fluxes with combustion were in the range between 0.1 and 8 per cent as a consequence of heat transfer from combusting gases to the vaporizer tubes. Experience with the vaporizer operating within the combustor at fuel flowrates and inlet air temperatures representative of take-off showed that the vaporizer performance could deteriorate rapidly due to the formation of carbon deposits, particularly in the region where the flow impinged on the cross tube. The deposits led to reduced heat transfer and vaporization with a consequently larger proportion of larger droplets and a tendency for the region of intense combustion to move downstream.
The Minimum Film Thickness in Lubricated Line Contacts during a Reversal of Entrainment—Piezoviscous Behaviour
Authors: Hooke C J 
Published: February 2007

In many line contacts the operating conditions, such as load, entrainment velocity and contact radii, vary with time. Generally, the results from standard elastohydrodynamic lubrication theory, derived for constant conditions, can be used to obtain a quasi-steady prediction of film thickness that is sufficiently accurate for design purposes. An important exception to this is where the entrainment direction changes because, under those conditions, the quasi-steady approach predicts that there will be no clearance between the surfaces while in practice a residual film will persist. A previous paper showed that the minimum film thickness during entrainment reversal depends primarily on the rate of change of entrainment velocity. Limit expressions for the minimum clearance in the four regimes of lubrication were obtained. The present paper is part of a programme to develop a minimum film thickness chart for entrainment reversal and deals with the transition between the rigid-piezoviscous and the elastic-piezoviscous regimes.
Strategies to Meet US 1994/95 Diesel Engine Federal Emission Legislation for HSDI diesel Engine Powered Vehicles
Authors: Bürgler L , Herzog P L , Zelenka P 
Published: February 2007

The forthcoming US passenger car and light-duty truck emission limits are currently the most stringent ones worldwide. The paper discusses which type of diesel engine has the best chance of fulfilling those requirements and what development strategy has to be followed. A comparative analysis between IDI and DI diesel engines shows the potential of the HSDI diesel engine to meet NOx/particulates limits of 0.4/0.08 g/min while maintaining its fuel economy advantage. Appropriate technological strategies are outlined. Besides the well-known technologies such as central position of injector and piston bowl, multi-valve cylinder head, inlet port swirl control etc., main emphasis is placed on the optimization of mixture preparation using fuel systems with variable injection rates as well as oxidation and DENOX catalysts.
Vehicle Electrical Power Supply Systems and Their Impact on System Design
Authors: Williams G A , Holt M J 
Published: February 2007

The electrical power system is the vital lifeline to most of the control systems on modern automobiles. The following general trends are observed. (a) increased use of electrically actuated systems, (b) increased use of electronic control, (c) increasing requirements for high-integrity power supplies for safety critical systems, (d) increased average electrical power consumption (heating, actuation, control systems), (e) increased electrical demand at engine idle combined with reducing idling speeds, (f) increased interest in higher voltage systems, (g) electrical system problems a major cause of roadside breakdowns. These trends clearly indicate major changes in the requirements of vehicle electrical power supply systems and will demand considerable activity from the vehicle industry in the next decade. An important aim of this paper is to illustrate and promote a systems view of electrical power while considering existing and future problems and opportunities.
The Influence of Injection Rate Shaping on Diesel Fuel Sprays—An Experimental Study
Authors: Winklhofer E , Ahmadi-Befrui B , Wiesler B , Cresnoverh G 
Published: February 2007

A current strategy in the development of direct injection (DI) diesel engine combustion systems is the control and limitation of the initial ‘premixed’ combustion heat release ensuing from the auto-ignition of the injected fuel. This requires control of the amount of fuel vaporization and mixing taking place during the ignition delay time. Since the latter is determined by the fuel composition and the in-cylinder gas temperature, development efforts have focused on the injection of well-controlled, portioned fuel quantities prior to the ignition as a means of achieving the desired goal. This practice is becoming known as ‘fuel rate shaping’. Consequently, the fuel spray penetration during this period, fuel evaporation and mixture preparation, as well as the influence of in-cylinder air motion on mixture distribution, are main subjects of interest in affording insight into fuel rate shaping attempts. These have been addressed through a combined experimental and theoretical investigation of the spray characteristics associated with different injection practices. The experimental investigations have been performed in an optically accessed spray research engine. Basic aspects of fuel spray tip penetration, time and location of auto-ignition and flame propagation have been recorded with a high-speed line-scan camera. The results provide the space and time-scale characteristics for the propagation, ignition and combustion of a selection of diesel fuel sprays. Investigations have been carried out for a conventional fuel injection system equipped with a set of different single-hole injector nozzles, as well as for a dual-spring injector and an injector with a split injection device. The experimental results provide an insight into the propagation of the fuel spray front, yield qualitative information about its spatial and temporal distribution, and, in the case of split injection, show the interaction of the initial pilot fuel portion with the main injection.
A Model-Based Approach to the Automation of Failure Mode Effects Analysis for Design
Authors: Price C J , Hunt J E , Lee M H , Ormsby A R T 
Published: February 2007

This paper describes the application of model-based technology in the area of failure mode effects analysis (FMEA). FMEA involves the repetitive application of engineering expertise, and so would seem to be a promising target for automation through knowledge-based systems (KBS) technology. However, in order to decide what would be the effect of a failure in a sub-system, it is necessary to reason about the structure of the sub-system being investigated and to be able to represent and reason about different facets of the way in which the sub-system works. The difficulty of automating this analysis of failure effects for new designs has meant that, in general, automation of the FMEA task has concentrated on only the clerical aspects of FMEA—helping the human expert to keep track of which possible failures have been analysed. The work described in this paper automates the analysis phase of the FMEA process. This should enable the development of computerized aids for the FMEA engineer which will eliminate much of the tediousness of the task.
Systems Modelling and Control Applied to a Low-Pressure Gas Distribution Network
Authors: Parkinson J S , Wynne R J 
Published: February 2007

A control system has been designed and implemented to provide more effective energy management of low-pressure gas distribution networks. The key to this is the provision of a control scheme that maintains low pressures across a network. The work was approached from first principles and a modelling technique has been developed which provides reduced order models that adequately describe the characteristics of multi-feed gas networks. The models were then used for the control system design, which in this case also included the selection of the optimal measurement points for most effective control. Following extensive design studies a relatively straightforward control scheme resulted which has been implemented and proved to be effective.
The Role of Maintenance Management Deficiencies in Major Accident Causation
Authors: Smith E J , Harris M J 
Published: February 2007

There appears to be an increasing awareness that organizational and managerial factors play a critical role in ensuring plant safety. A detailed study is presented of one branch of industrial management, viz. maintenance management. It has highlighted the nature of some of the links between managerial practices and the reliability of plant equipment and personnel. The causes of several major accidents are analysed using a systems approach, with the aim of understanding how the maintenance function was involved. A key conclusion is that, prior to major accidents, there is often a lack of detailed safety objectives and long-term safety control. Without these it becomes very difficult to assess the adequacy or otherwise of other maintenance management elements such as maintenance strategy, resources or administrative structure. In the absence of tight safety and reliability control and consequent corrective actions a mismatch can develop between the perceptions of management and the actual condition of the plant.
Coverage of Non-Metals in the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code
Authors: Short II W E 
Published: February 2007

The chemical and petrochemical industries have decades of experience in specifying metallic piping lined with non-metals as a cost effective alternative to high-priced alloy materials of construction for piping in corrosive service. Early on, application of plastic piping was essentially limited to atmospheric chemical sewage service and to above-ground vents and drains. However, applications and usage of plastic piping continue to increase as engineers become more confident in specifying plastic materials and mechanical contractors gain experience with their installation. Non-metallic materials are being developed that are not only corrosion resistant but also have increasingly higher pressure and temperature capabilities. Plastic double-containment piping has experienced tremendous growth for handling hazards and toxic fluids. In the United States, recent dramatic growth of plastic double-containment piping applications has been, to a large extent, for compliance with the Environmental Protection Agency (EPA) regulations of the 1976 Resource Conservation and Recovery Act (RCRA). Related EPA regulatory efforts were accelerated in 1988 by more stringent amendments to this legislation. Industry in the United States must comply with these EPA regulations by December 1998. Plastic piping and metallic piping lined with non-metals have been covered to some extent by the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code for several years. The distinctive requirements of non-metallic piping and piping lined with non-metals were incorporated into the 1980 edition as a separate Chapter VII, which is dedicated to this growing area of interest in piping. This paper provides an overview of the present coverage of non-metallic piping lined with non-metals in the ASME B31.3 Chemical Plant and Petroleum Refinery Piping Code (1). Some topics that warrant further investigation are presented as well.
Conditioning Monitoring of Ethylene Main Pipeline Pumps
Authors: Lloyd S A , Ansley-Watson P 
Published: February 2007

The pumping of ethylene at supercritical conditions over long distances demands sophisticated pumping stations. One condition that must be avoided at all times anywhere in the line is the generation of temperature hot spots, as these can lead to thermal decomposition of the ethylene under pressure with potential catastrophic consequences. Both submerged motor driven pumps (canned pumps) and more conventional machines with mechanical seals have been used in this application: opinions are sharply divided as to which is the optimum design. The authors contend that no single answer exists but in either application the ability to safely disperse any leakage and to accurately diagnose machine conditions to detect any potential hot spots is of paramount importance. A sophisticated health monitoring is required for the pumps with temperature sensors as well as vibration monitors: the rate of temperature rise is an important parameter in these applications. This condition-monitoring installation should be linked back to the central control station via a SCADA (supervisory control and data acquisition) link. Innovative condition-monitoring features such as temperature-measuring devices installed between each pump stage are reviewed and their potential benefits assessed.
The Mk 4 and Mk 5 Coaches for British Rail InterCity Part 1: The Mk 4 Coach SpecifiCation and Procurement
Authors: Higton J A , Temple D R 
Published: February 2007

The story of the Mk 4 and Mk 5 coach developments from 1984 to 1991 is told by two members of the BR Project Team specially assembled to manage the procurement and entry into service of the new coaches. The paper is in two parts. Part 1 of the paper opens with a brief résumé of BR coach development from the Mk 1 in 1951 through to the Mk 3 of the early 1970s. The Mk 4 coach was specifically designed for the electrified East Coast Main Line and formed part of a push-pull train called InterCity 225. The coaches were purchased under a new set of competitive procurement rules and as such the project team had to learn to deal with some new problems along with a lot of old ones. Engineering developments were instigated in the areas of ride quality, braking and gangways and these are described. Interior mock-ups were also used to specify InterCity's requirements. The paper reviews preparation of the procurement specification, as well as the process of tendering and placing the contract. The design features of the Mk 4 coach are described, together with a brief description of the production and assembly process.
The Mk 4 and Mk 5 Coaches for British Rail InterCity Part 2: Testing, Commissioning and Service Experience with the Mk 4 Coach and Development of the Mk 5 Specification
Authors: Higton J A , Temple D R 
Published: February 2007

The story of the Mk 4 and Mk 5 coach developments from 1984 to 1991 is told by two members of the BR Project Team specially assembled to manage the procurement and entry into service of the new coaches. The paper is in two parts. Part 2 describes the testing, commissioning and service experience with the Mk 4 up to March 1991. Extensive ride development testing was necessary in order to enable the Mk 4 to meet its demanding ride specificiation. For the first time in nearly 20 years the ORE Climatic Testing Chamber in Vienna was used to test the complete coach at the specified extremes of temperature. Commissioning and service experience is discussed with details of some of the problems encountered and their solutions. The development of the Mk 5 coach engineering specification concludes the paper.
Recent Developments in Light Rail Systems
Authors: Ware D K , Jones R N H 
Published: February 2007

The 1980s saw a resurgence of interest in light rail systems throughout the world and particularly in Great Britain, where they had almost disappeared. Properly planned and executed they can effectively cater for a significant segment of city transport, using nonproprietary technology which is non-polluting and which can make use of a variety of energy sources. This paper outlines some recent trends in the technology of light rail vehicles and control systems, and goes on to describe four new systems of different characteristics or stage of development.
Hong Kong Metro's Traction Equipment: The Drive for Efficiency
Authors: Moyes A D 
Published: February 2007

This paper describes the evolution of the electric multiple unit traction equipment of the Hong Kong Mass Transit Railway Corporation (MTRC). Traction energy efficiency is particularly important to the MTRC and has been improved by 46 per cent on the most recently supplied cars. The justification for the conversion of the existing camshaft cars to chopper control and the relative merits of different types of drives in MTRC's application are discussed. The utilization of energy, the method used to optimize coasting for energy saving, life-cycle costs and the design features of the gate turn-off thyristor chopper cars are described.
Brakes along the Line
Authors: Leigh M J 
Published: February 2007

The Railway Division Chairman reviews his career in railway braking with Davies and Metcalfe, including his apprenticeship in the automobile industry. He outlines his involvement with various multiple units in the United Kingdom and Australia, discussing the brake blending with its possibilities. The outcome of locomotive brake competition in the direct release market is described and the advantages of two-pipe brake systems for both direct and graduable braking are highlighted. He concludes by mentioning training and the engineering profession.
Acceptable Noise Levels for New Railways
Authors: Shield B M , Roberts J P 
Published: February 2007

There is, at present, no UK legislation controlling the noise that may be emitted by railways. The widespread concern over noise likely to be radiated from the Channel Tunnel Rail Link has highlighted this deficiency and in March 1990 the Government established the Mitchell Committee to recommend guidelines for a national noise insulation standard for new railways. The results of previous studies of railway noise annoyance and the acceptability criteria that have been derived are examined with reference to recent research, and more effective criteria for social acceptability are suggested where new rail lines are concerned.
The Suppression of Single-Fin Buffeting Using Tangential Leading Edge Blowing on a Delta Wing
Authors: Bean D E , Wood N J , Mabey D G 
Published: February 2007

The application of tangential leading edge blowing to reduce levels of single-fin buffeting has been studied. The tests were performed at the University of Bath in the 2.1 m × 1.5 m wind tunnel using two cropped 60° delta wings. To measure the buffet excitation, a rigid fin instrumented with miniature differential pressure transducers was used. A flexible fin of similar planform and size was used to measure the buffeting response. Steady state static pressure data and laser light sheet flow visualization were employed to aid interpretation of the vortical flow over the wings, and hence identify the causes of the buffeting. The profiles of the buffet excitation and response were found to match each other very closely. It was observed that the leading edge blowing modified the leading edge vortices by reducing the ‘effective angle of attack’ of the vortex. Blowing at a constant rate shifted the buffet excitation and response to higher angles of attack. Flow visualization confirmed that the mechanism at peak buffeting had not changed, but had been merely shifted. It has been shown that the use of an optimum blowing programme could completely suppress the buffeting response.
Development of a Large Deployable Space Reflector Structure
Authors: Russell A G 
Published: February 2007

This paper describes the selection, configuration, design and development of the 5 m diameter deployable reflector structure currently being undertaken jointly by British Aerospace Space Systems Limited and the University of Surrey. Large reflectors represent the most likely, near-term application of a large deployable space structure and offer the most promising opportunity for the development and qualification of the hardware required. Such a large, deployable reflector has to compete against other reflector designs which are not suitable for development into larger space structures but are optimized solely as reflector backing structures. These competitors provide a useful measurement of performance against which the development reflector may be compared in terms of mass, stiffness, cost and reliability. The proposed reflector comprises a radio frequency reflective surface of gold-plated molybdenum knitted wire mesh supported from the nodes of a tetrahedral truss. The development 5 m diameter reflector is made from six deployable tetrahedrons configured symmetrically around a central node. Larger reflectors are possible using the same concept with longer struts or by using an extension of this concept with extra rings of tetrahedrons. The solution is dependent upon the required reflector size and stowage volume restrictions. This design has brought together two critical items of hardware for a large deployable space structure: a simple, light, reliable self-latching hinge (developed by the Ministry of Defence and the University of Surrey) and a long, light, stiff, inexpensive carbon fibre tube (manufactured by the pultrusion technique).
Reconstruction of the Anterior Cruciate Ligament
Authors: Seedhom B B 
Published: February 2007

Ligaments are strong collagenous structures that act as constraints on joint motion, thus confining the articular surfaces to more or less the same paths. In so doing they prevent arbitrary apposition of these surfaces from occurring and resulting in abnormal stresses which may damage the joint surfaces. Ligaments rupture due to excessive loads, particularly those resulting from trauma occurring during sporting events or motor vehicle accidents. Knee and ankle joints have the highest frequency of ligamentous injuries. This paper is a brief review of the current approaches to the reconstruction of the knee ligaments with specific reference to the anterior cruciate ligament (ACL) being the most frequently reconstructed. This is not only because it is frequently injured but also because of the debilitating consequences of such an injury. Approaches ranging from the conservative to those that advocate the use of frank prosthetic replacement have been adopted by surgeons at both ends of the spectrum. Following a discussion of the rationale for reconstruction of the ACL, the mechanical and biological considerations of the reconstructive procedure are discussed. The different methods of ACL reconstruction are reviewed. These include: (a) primary repair, (b) reconstruction with different tissues, including autogenous allografts and xenografts, (c) reconstruction employing different synthetic devices. A brief discussion of the procedures used for reconstruction with different types of tissue and of the surviving examples of the synthetic devices will follow.