bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reducing the Vibrations Caused by a Marine Diesel Generator Set
Authors: Day M J , Randall R J , Ratcliffe C P , Rider E 
Published: February 2007

This paper details work undertaken to investigate the use of pneumatically controlled vibration absorbers to reduce the vibrations caused by a G&M/Perkins six-cylinder diesel generator (DG) set. The DG set had a mass of approximately 1 tonne and reductions in vibration levels near the engine mounts of about 10 dB were achieved using four absorbers with a total active mass of 18 kg. The absorbers incorporated air springs which have the advantage of a variable stiffness depending on the contained air pressure within the springs. The ability to continuously tune to a target frequency was offset by the non-linear stiffness of the air springs, which makes control of the absorbers more complicated. For the work reported in this paper, the absorbers were manually tuned to the desired operating frequencies. Sensitivity trials for absorbers detuned from the optimum frequency are also reported.
Factors Affecting Car Fuel Consumption
Authors: Redsell M , Lucas G G , Ashford N J 
Published: February 2007

This paper describes a programme of statistical analyses on test data conducted to investigate the effects of a number of factors on car fuel consumption. The data used for the analyses were obtained from a comparative study of the fuel economy of petrol and diesel cars, conducted at the Department of Transport Technology, Loughborough University, on behalf of the Transport and Road Research Laboratory (TRRL). Three Vauxhall Cavalier cars (1300 cc, 1600 cc petrol and 1600 cc diesel models) and six drivers, categorized by sex and age, participated in the tests. Each test was completed over an extensive test route on public roads encompassing all types of driving environments. Factor analysis was used to determine the underlying relationships between a number of measured variables and fuel consumption. Under the ‘free-flowing’ environment of the motorway route section, fuel consumption was primarily influenced by ambient pressure, vehicle speed and frequency of gear change. In suburban conditions, only throttle velocity made any significant contribution to fuel consumption. In the tests over urban sections, the significant variables were found to be vehicle speed and deceleration, frequency of gear change and ambient pressure. Of the ambient factors examined, only pressure had any significant independent effect. The associations derived from factor analyses point the way to realistic correction techniques for vehicle test data. Regression models were constructed to fit the measured fuel consumption data to an expression derived to give fuel consumption as a function of engine, vehicle and environmental parameters. For purely urban, suburban and motorway travel and an overall journey based on a 50/40/10 per cent split of urban, suburban and motorway road types, 93.8, 92.4, 88.2 and 95 per cent of fuel consumption variance was explained by the respective regression models. Regression variables based on engine power correction factors for ambient temperature and humidity showed a degree of statistical significance in all models.
Hybrid Solid State Fluidic Technique in Engine Fuel Injection Systems
Authors: Huang Q , Jones B , Leighton N J 
Published: February 2007

This paper describes a multi-point fuel injection system utilizing fiuidic devices as fuel injector stages for spark ignition engines. The novel fuel injector unit consists of no-moving-part fluidic devices controlled by a solenoid valve interface and unique air/fuel mixing nozzles for good fuel atomization. The results of laboratory tests show that the fluidic device stage has a fast dynamic response and its on/off switching delay to the control flow signal is within 1 ms. A balanced fuel distribution at the four fluidic injector stages (for a four-cylinder engine) and well-atomized air/fuel mixture at the mixing nozzles were obtained from this injection system. The engine tests show that this fuel injection system provides an extended lean limit of the air/fuel mixture, 7 per cent improvement in fuel economy and 10 per cent reduction in hydrocarbon (HC) emissions compared with a base-line carburetted fuelling system due to the improved fuel distribution and air/fuel mixing quality by the multi-point fluidic injection system.
The Evolution of Bus Design—a European Perspective
Authors: McKnight J 
Published: February 2007

For the 1992 SAE/IMechE exchange lecture, the Chairman of the Automobile Division of the Institution of Mechanical Engineers reviews the background to the major evolutions in bus design in Europe over the past decade or so. This includes a review of the bus and its environment, together with the effect of legislation. An overview of European bus operations is included, with comments on the climate of change within the industry in Great Britain. Trends in bus production levels in Europe are also examined. Considered in the bus design evolution are: the changing nature of vehicle configurations with a movement towards low floor one-step entry products, changes in engine design to achieve diesel exhaust emission standards and innovations in transmission design yielding benefits in fuel economy and improved foundation brake life. Views are expressed on future design needs, including alternative fuels and vehicle electrics. The progress towards a European bus is reviewed.
The Influence of Automotive Diesel Back End Volatility and New Fuel Additive Technology on Regulated Emissions
Authors: Bertoli C , Del Giacomo N , Caprotti R , Smith A K 
Published: February 2007

Public concern over diesel emissions and air quality has provided the focus for testing the effects of changes to diesel fuel back end volatility using test fuels obtained by closely following real refinery practice and new fuel additive technology. On a typical European city bus engine, the increase in 95 per cent distillation temperature has no overall effects on regulated emissions; conversely, particulate emissions can be controlled by new fuel additive technology.
A Review of Internal Combustion Engine Losses Part 2: Studies for Global Evaluations
Authors: Ciulli E 
Published: February 2007

The global evaluation of losses is important in providing information about the behaviour of an engine. This may be used, for instance, in design and development of new models, where one with inherently the lowest friction may be chosen with a consequent potential gain in fuel economy. This paper reviews studies on the determination of total engine losses. Experimental works are reported from which, sometimes with theoretical support, empirical formulae are obtained that allow an extension of the results to engines similar to those investigated. Besides formulae in which losses are expressed as an equivalent pressure averaged in the complete cycle, more detailed formulae for the determination of instantaneous loss torques are reported, which are also useful in obtaining a better evaluation of the engine speed trend in fault diagnosis. All formulae can be used in computer programs for the numerical simulation of engine performance, a use that can reduce the time needed for experimental work.
Effect of Reduction of Payload on Stability During Tipping of Granular Materials
Authors: Fessler H , Hyde T H , Sun W 
Published: February 2007

Experiments have been carried out with an open-ended box representing the body of a tipping truck during emptying of dry sand while standing on sideways-sloping ground. The mass that had flowed out and the shape of the remaining sand were measured after tilting the box to different inclinations. After measuring the angle of repose of the sand and making simplifying assumptions, the shape of the remaining payload could be defined using coordinate geometry. Excellent agreement between calculated and measured values allowed the method of calculation to be used confidently to determine the roll-over couples at different sideways slopes and tipping angles when emptying granular materials with different repose angles. The reductions of the roll-over couples due to allowing for the material that has flowed out are shown to be significant. A simple relationship between maximum roll-over couple, sideways slope and repose angle is established.
The Design and Development of the LotusSport Pursuit Bicycle
Authors: Hill R D 
Published: February 2007

Aerodynamic drag constitutes over 96 per cent of the overall resistance to motion for a typical rider and bicycle combination. Although the rider of a typical track pursuit bicycle constitutes approximately two-thirds of the overall aerodynamic drag, the bicycle itself still contributes one-third. Any reduction in the drag generated by the bicycle can therefore have a significant effect on the maximum attainable speed for a given power input, and thus the time to cover a given race distance. At the same time it is important to optimize the riding position so as to minimize both the rider drag and any interference effects between the rider and bicycle. Cross-wind conditions are also of vital importance to cyclists. For most conventional tubular framed bicycles any wind on a velodrome will result in significantly slower times due to the increased drag. For a properly designed monocoque aero bicycle, however, a cross-wind can mean faster times on a velodrome due to a ‘sail’ effect being generated. The LotusSport monocoque pursuit cycle has been designed and developed to gain maximum benefit from aerodynamic drag reduction and sail effects. It was produced for, and used at, the 1992 Barcelona Olympic Games where it was ridden to the gold medal in the 4000 metre individual pursuit event.
Transverse Vibration of Buried Pipelines Due to Internal Excitation at a Point
Authors: Köpke U G 
Published: February 2007

This paper is concerned with the dynamic response of buried pipelines due to excitation located inside the pipe. This work is important for application to techniques that employ vibration to investigate pipeline support conditions using a vibrating pipe inspection device. It also has application to the detection of spanning in off-shore pipelines. Three different theoretical models are developed and investigated. The first model employs the theory of elasticity, the second is a finite element model and the third is a beam-on-elastic Pasternak foundation. Good agreement between these models is demonstrated. The beam-on-elastic Pasternak foundation model is successfully used to predict ‘signatures’ of the pipe-soil response that characterize soil support features, such as hard and soft supports.
Servo Actuated Railway Pantograph for High-Speed Running with Constant Contact Force
Authors: Galeotti G , Galanti M , Magrini S , Toni P 
Published: February 2007

High-speed running on the Italian railway has been recently developed. One of the main problems to be solved for good high-speed running is the current pick-up with a pantograph from an overhead contact line. This problem can be solved by biasing, at very high values, the stiffness of the springs acting on pantograph arms. Unfortunately, in this way the pantographs developed up to now, based on previous experience, gave bad results due to excessive contact force (that is, after 2000 km it is necessary to change the worn contact shoe). A simple approach to easily and quickly solve this problem is the use of a servo actuated pantograph able to maintain the contact force at a given value. In this way the main problem to be solved is the right choice of the force actuator kind. Starting from the existing pantograph the authors show how it should be possible to have an almost constant contact force using an optimized servo actuated pantograph.
Pressurization of Bone Cement under Standard, Flanged and Custom Acetabular Components for Total Hip Replacement
Authors: Beverland D E , Kernohan W G , Nixon J R , Orr J F , Watson P 
Published: February 2007

Custom acetabular components are proposed to achieve uniform cement mantles, even in irregular acetabula presented at revision, in order to enhance fixation. One aim of developing custom components was to permit pressurization of bone cement by the components at insertion and maintain the pressure during polymerization. A model acetabulum was set up for the insertion of standard, flanged and custom components under constant force. Cement pressure was measured at the floor of the acetabulum by means of a piezoelectric diaphragm transducer. Polythene tubes were inserted in the model acetabular walls to estimate penetration of cement into cancellous bone. Insertion of the standard and flanged components caused cement pressures up to 106 kPa which decayed to less than 21 kPa as cement escaped at the rim and the components came into contact with the acetabulum. The custom component maintained a pressure of over 60 kPa during polymerization from an initial pressure of 105 kPa and examination of cement mantles on removal showed no evidence of contact. The custom component also showed enhanced penetration of cement, especially around the rim of the acetabulum. It is concluded that the custom component design achieves higher cement pressures and that better fixation will result.
LNG Power Recovery
Authors: Wong W 
Published: February 2007

The thermal efficiency of a Carnot cycle is limited by the maximum and minimum temperatures available. The construction of LNG (liquid natural gas) terminals and the need to vaporize LNG offers a cooling source at a very much lower temperature than sea water. By using the cold sink and by adapting the waste heat available from a combined cycle plant, it is possible to recover power from the vaporization of LNG. This is done by the use of a reverse cascade refrigeration process where energy is extracted by expanders instead of energy input by compressors. The paper explains how the hot and cold processes can be integrated to produce a compound cycle with an overall efficiency of some 55 per cent or more depending on the quantity of LNG to be vaporized. Special reference is given to the features needed for the rotating equipment and how equipment selection is critical to the realization of a practical working power station.
The Turbine Performance of Centrifugal Pumps: A Comparison of Prediction Methods
Authors: Williams A A 
Published: February 2007

Standard centrifugal Dumps may be operated in reverse as water turbines, and for hydroelectric plums of less than 100 kW (micro- hydro) they are often cheaper than specifically designed turbines. However, in order to use a pump in a micro-hydro scheme, the turbine performance-must be found either by testing or by calculation. Several methods have been suggested for predicting the turbine performance based on the data for pump performance at best efficiency, but they produce a wide range of results. In this paper, eight such methods are compared using an analysis of the effects of poor turbine prediction on the operation of a pump as turbine at a typical micro hydro site. The comparison uses the results of turbine tests on 35 pumps of various types and sizes, some of which have come from the author's own tests. None of the eight methods gives an accurate prediction for all of the pumps but one of the methods can be recommended as a first estimate of the turbine performance.
Sir Charles Parsons and Electrical Power Generation—a Turbine Designer's Perspective
Authors: Bolter J R 
Published: February 2007

Sir Charles Parsons died some three years after the author was born. In this paper the author looks back at the pioneering work of Parsons in the field of power generation. It shows how he was able to increase output of the steam turbine generator from 7.5 kW in 1884 to 50000 kW in 1930 while increasing efficiency from 1.6 to 36 per cent, and relates these achievements to the current state of the art. Blading design, rotor construction and other aspects of turbine engineering are considered. The conclusion is that Parsons and his associates charted the course which manufacturers and utilities throughout the world have continued to follow, although increasingly sophisticated design and analytical methods have succeeded the intuitive approach of Parsons. His constant search for improved efficiency was and is highly relevant to today's concern for the environment. Finally, although it did not become a practical proposition in his lifetime, the paper reviews Parsons' vision of, and continuing interest in, the gas turbine, first mentioned in his 1884 patents.
Design and Performance of Vaneless Volutes for Radial Inflow Turbines: Part 1: Non-Dimensional Conceptual Design Considerations
Authors: Whitfield A , Noor A B Mohd 
Published: February 2007

The requirements for the volute of a radial inflow turbine are that it should collect the working fluid, deliver it to the turbine rotor as efficiently as possible and provide the desired rotor inlet conditions. The design requirements of the turbine leads to the rotor design and the identification of the desired flow conditions at rotor inlet in terms of the magnitude and direction of the absolute Mach number. The volute must then be designed to ensure that the desired rotor inlet conditions are attained. A non-dimensional design procedure for a vaneless turbine volute is described. Based on a knowledge of the flow direction and magnitude of the absolute Mach number at rotor inlet the overall dimensions of the volute in terms of the radius ratio and flow area ratio are first established. The overall design is then developed to provide the variation of the volute centroid radius and area ratio with azimuth angle. A trapezoidal cross-sectional shape is then used to establish the outer dimensions of the volute. The non-dimensional procedure assumes a one-dimensional compressible flow and as such relies on the empirical specification of the dissipation of angular momentum, the dissipation of energy and the deviation of the swirling flow from that of a free vortex. The effect of the uncertainties associated with the empirical data on the volute design geometry is assessed. A complementary experimental investigation to develop and substantiate the required empiricism is presented in Part 2, which follows. As the design procedure is essentially one-dimensional it must be interpreted with a knowledge of the actual three-dimensional flow within a volute passage. Supportive experimental studies will be presented in Part 3 in the next issue.
Positional Accuracy of Holes When Drilling in Inclined Workpiece Surfaces Part 1: Experimental Results
Authors: Kaminski J , Crafoord R 
Published: February 2007

The influence of cutting forces on hole positional deviation when drilling with twist drills in workpiece surfaces of 5° inclination and horizontal surfaces has been investigated. An approach to explain the drill tip wandering phenomena is presented. Variations in cutting forces were also investigated when drilling in workpieces of different materials and different feedrates with standard as well as short drills. Results of this investigation show that hole positional deviation has an obvious connection to cutting forces. The standard and the short drills show different wandering paths during the penetration process. Standard drills wander down the slope, while the short ones first move downwards and later begin a motion upwards.
A Generalized Approach to the Modelling of Modular Machines
Authors: Yan X T , Case K , Weston R H 
Published: February 2007

This paper describes a method of graphically simulating modular machines within a computer aided design environment. This forms part of a much larger Science and Engineering Research Council (SERC) funded programme aimed at advancing modern practices when designing and building manufacturing machines. A generalized approach to the synthesis of the generic features of various kinematic motion pairs is presented and prismatic and revolute motion primitives generalized in their functional and geometric aspects. A hierarchical ring and tree data structure has been designed and implemented to comprehensively represent these motion pairs and to simulate their performance. More complex modular manufacturing machines can be represented using information from a library of up to three degree of freedom motion modules. Seven two degree of freedom motion primitives and twelve three degree of freedom motion primitives with articulation configurations have been analysed and included in the motion primitive library. The configuration of modular machines comprised of physically separate but logically connected distributed motion primitives are described. Examples of a two-finger industrial robot gripper and a three-finger industrial robot hand are used to demonstrate the general principles.
Functional Interaction Management: A Requirement for Software Interoperability
Authors: Singh V , Welz F , Weston R H 
Published: February 2007

There is a much increased demand for a degree of interworking between software packages as it is no longer reasonable to expect a single application to be able to do its job without support or reference to data and events that are handled by other closely related application systems. In practice, it is essential to help ensure and maintain discipline and harmony to enable graceful co-operation among interoperating software components. Functional interaction management is identified as a vital service requirement necessary to help address this issue of software interoperability. Current manufacturing control systems (MCS) exhibit deficiencies and constraints that inhibit or complicate their interaction. This paper reports on ongoing research work where the main thrust is to derive a new generation of reconfigurable and modular forms of MCS, the components of which can ‘functionally interact’ and share common information through accessing distributed data repositories in an efficient, changeable and standardized manner. The emphasis is on: (a) development of an effective framework to manage functional interaction between MCS components, which typically may comprise software packages that facilitate production planning, product design, finite capacity scheduling and cell control; (b) ‘soft’ integration of these MCS components over the CIM-BIOSYS integrating infrastructure.
Finite Element Modal Analysis of the Engine Front End Accessory Drive Systems
Authors: Zhu H 
Published: February 2007

The objectives of the study were to create finite element (FE) models for the engine front end accessory drive (FEAD) systems, to carry out normal mode analyses on the systems and to make a comparison of the predicted frequencies with those of measurement. The analytical results of three FEAD systems showed that more accurate frequencies were calculated using the complete accessory model than the concentrated mass model. Therefore the complete accessory model should be created for structural analysis of the FEAD systems. It was also pointed out that great care should be taken in the creation of FE models.
Automotive Materials Recycling for the Future
Authors: Shergold M 
Published: February 2007

Environmental issues are occupying an increasingly high profile in all our lives. For many years, the motor industry has been conscious of the need to reduce the impact of our products on the environment, particularly in terms of tailpipe emissions. In recent years, the disposal of end-of-life vehicles has also gained a measure of public visibility. This paper examines the current disposal situation for end-of-life vehicles and considers the impact of developments in vehicle design on the existing infrastructure from both a technical and a commercial perspective. An industry-proposed improvement strategy is briefly described and the technical and infrastructural issues arising are considered.