bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance, emissions and wear characteristics of an indirect injection diesel engine using coconut oil blended fuel
Authors: Masjuki H. H. , Kalam M. A. , Maleque M. A. , Kubo A. , Nonaka T. 
Published: October 2002

Dynamometer tests have been carried out to evaluate the performance, emissions and wear characteristics of an indirect injection diesel engine when fuelled by 10, 20, 30, 40 and 50 per cent blends of ordinary coconut oil (COCO) with ordinary diesel fuel (OD). The test was conducted for 100 h using each of the test fuels to monitor the effect of COCO blends on the wear and lubricating oil performance. OD fuel was also used for comparison purposes. The operating performance of the engine and the emission characteristics of exhaust gases were compared. The effect of blended fuel on the engin's wear and lubrication characteristics in terms of wear metal (Fe), water concentration, oxidation, viscosity, total base number and additive depletion was analysed. The performance and emissions characteristics results showed that 10-30 per cent coconut oil blends produced slightly higher performance in terms of brake power than OD. All the COCO blends produced lower exhaust emissions including polycyclic aromatic hydrocarbons and particulate matter. The wear and lubrication oil characteristics results showed that COCO blends up to 30 per cent produced similar results to OD. This programme will give useful information for further research and development in the future if COCO is used as an alternative to OD.
Implicit regulation for automotive variators
Authors: Beccari A , Cammalleri M 
Published: October 2002

A well-known practice uses mechanical variators to realize the so-called continuously variable transmissions (CVTs) for automotive application. A remarkable problem for one of the most used CVTs is given by the hydraulic control of the axial thrust on the half-pulleys that is necessary for torque transmission. It involves a heavy decrease in transmission efficiency. In the present paper, the possible production of the required axial thrust by a simple spring to eliminate hydraulic losses is analysed. It is shown that the power capacity of such a regulated variator is near to the maximum possible, and the belt torque loss is always considerably lower than the sum of the belt and pump losses of a standard controlled CVT. Moreover, it is not much greater than a slip limit controlled CVT for medium-low vehicle speeds, and slightly lower for higher speeds. Finally, the power capacity by the spring thrust is evaluated when the variator is used in split power transmissions, considering several configurations and steady ideal operation.
Three-point seatbelt maternal comfort and fetal safety
Authors: Thackray L A , Blackketter D M 
Published: October 2002

This paper presents the results of a study that evaluated the comfort and safety of three-point seatbelt use by pregnant women. Comfort was assessed by developing and administering a survey. Two hundred responses revealed high levels of discomfort due to the lap belt riding up onto the abdomen (64.5 per cent), the edges of the lap belt rubbing on the abdomen and thighs (61.5 per cent), compression of breasts by the torso belt (48 per cent) and the lap belt being too tight or too short (50 per cent). Evaluating seatbelt safety for the fetus was accomplished by reviewing case studies involving pregnant crash victims as well as baboon crash test results. Additionally, computer simulations, modelling a 35 mile/h collision with a pregnant woman in a three-point restraint, were developed. The simulations were used to predict fetal movement and acceleration behaviour relative to the mother. Fetal acceleration was found to reach values nearly 3 times greater than maternal acceleration, offering justification as to why a fetus might die as a result of abruptio placentae or skull injury.
Experimental and theoretical study of particulate re-entrainment from the combustion chamber walls of a diesel engine
Authors: Abu-Qudais M , Kittelson D. B. 
Published: October 2002

The purpose of this research was to investigate the influence of the in-cylinder surfaces on the net emission of the particulate matter in the exhaust of a single cylinder, diesel engine. In order to obtain this information, time-resolved sampling was done to characterize the particulate matter emitted in the engine exhaust. A rotating probe sampled the free exhaust plume once each engine cycle. The rotation of the probe was synchronized with the engine cycle in such a way that the samples could be taken at any predetermined crank angle degree window. The sampling probe was designed for isokinetic sampling in order to obtain reliable results. To characterize the exhaust particulate in real time, a filter for mass concentration measurements was used. The results showed about 45 per cent higher mass concentrations as well as particles of larger diameter emitted during blowdown than late in the displacement phase of the exhaust stroke. This suggests that high in-cylinder shear rates and velocities which are associated with the blowdown process, cause the deposited soot to be re-entrained from the surfaces of the combustion chamber, where re-entrainment is favoured by conditions of high surface shear. A mathematical model to predict the amount of soot re-entrained from the cylinder walls is presented. This model is based on information presented in the literature along with the results of the time-resolved measurements of mass concentration. This model supported the hypothesis of soot deposition during the combustion process, with subsequent re-entrainment during the blowdown process of the exhaust stroke.
Can increasing expenditure on research and development really be justified?
Authors: Bryson R. A. 
Published: October 2002

Economists since Adam Smith have recognized the contribution of innovation to profitability and growth. The relationship between corporate research and development and subsequent sales growth, both across and within industries, has been examined by many authors. Results have been varied showing at best no more than the suggestion of a causal relationship between research and development input and growth. These results are reviewed together with the various theories which have been developed in an attempt to explain the connection between technical innovation and growth. Starting with an examination of various national economies, the rate of commercial research and development expenditure has been compared to the rate of national growth. A number of industries in the United Kingdom, Germany, Japan and the United States of America were also examined, taking the automotive industry as a particular case. In addition to using published data a survey of smaller vehicle manufacturers in the United Kingdom was conducted. Although positive correlation was found at an international and industry level, no association between research and development expenditure and sales growth was found at a company or project level in the United Kingdom.
Optimizing local charge stratification in a lean-burn spark ignition engine
Authors: Arcoumanis C , Hull D. R. , Whitelaw J. H. 
Published: October 2002

Gas pressure and local gas velocities have been measured in a single-cylinder spark ignition engine operating at low load and 1000 r/min and the results have characterized the extent to which combustion was enhanced by the injection of a small quantity of a mixture of propane vapour and air towards the spark plug in an otherwise quiescent chamber filled with a homogeneous lean propane/air charge. The effects of the locally generated mean flow/turbulence and equivalence ratio on combustion were examined separately by first injecting a mixture of equivalence ratio identical to that of the homogeneous charge and then a slightly rich mixture into homogeneous charges of lower equivalence ratios. The results show the advantageous effect of jet-induced local turbulence for overall air—fuel ratios between 17 and 24 with a maximum gain in peak pressure of 55 per cent at an air—fuel ratio of 20. The local injection of a rich mixture, in addition to increasing the gain in peak pressure from 30 to 50 per cent at an air—fuel ratio of 24, has extended the lean limit of the engine to 29. The timing of ignition relative to the end of injection, which varied as a function of the injection pressure, was found to have a strong effect on the peak combustion pressure so that, for example, a reduction of 8°(CA) in the time between the spark and the end of injection resulted in a 25 per cent reduction in combustion pressure at an air—fuel ratio of 22. The average flame speed was increased by local injection at all equivalence ratios; for example, a value of 7 m/s was obtained with local injection at an equivalence ratio of 0.7 which is equivalent to the flame speed measured with a homogeneous charge at the much higher equivalence ratio of 0.9.
Stresses and deformations in overlapped diesel engine crankshafts, Part 1: Experimental results
Authors: Bickley I , D'Olier V , Fessler H , Hyde T. H. , Warrior N. A. 
Published: October 2002

Single-throw, epoxy resin models of five overlapped crankshafts with side-by-side connecting rods have been loaded in pure torsion or bending. Bending loads considered are those due to the radial or tangential components of the connecting rod force and those due to pure radial bending or radial bending due to journal displacement. After the photoelastic frozen-stress cycle, deformations and stresses in the crankpin and journal fillets were measured. The principal stresses were determined over the whole highly stressed (toroidal) fillet surfaces. At each angular position around the crankpin and journal the magnitude, meridional position and direction of the greatest principal stress were obtained. In torsion these maxima were fairly constant with angular position, whereas in bending they varied linearly, as in a simple beam in bending. The results were expressed as stress concentration factors based on nominal stresses in a bar of the same diameter as the crankpin.
A centralized hydraulic system for passenger cars
Authors: Darling J , Tilley D. G. , Hickson L. R. 
Published: October 2002

The majority of passenger vehicles use separate hydraulic circuits to drive and control high-power components such as the braking and steering systems. While this approach is acceptable, it is possible for significant improvements in effficiency to be achieved using a centralized system. In order to establish the advantages and disadvantages of the distributed and centralized approaches, a simulation-based feasibility study of the pressure, flow and power requirements of the individual engine cooling, anti-lock braking system (ABS), semi-automatic transmission, active roll control and power assisted steering subsystems was carried out. Using a realistic drive and load cycle together with simulation models accounting for component non-linearities and dynamics, the flow requirements of an integrated hydraulic system were established. It was shown that the steering and roll control suspension requirements were complementary. The steering system requires high flow at low forward speeds, while the suspension requires high flow during conditions of high speed. In addition it was shown that, although the peak flow requirements of an integrated system were high, the mean flow was moderate and the high demands could be met using small accumulator units, suggesting that the system would be feasible for use in passenger cars. Finally, an energy efficient integrated hydraulic circuit including some degree of safety back-up is proposed.
Scale, order and complexity in polymer processing
Authors: Bush S F 
Published: October 2002

From slow beginnings in the 1860s, the evolution of the polymer industry has been marked in the second half of the twentieth century by rapid increases in the scales of production, by increasing power to control order at the molecular level, and by the variety and complexity γ of the resultant processes and products. The paper reviews some of the key developments over the last 100 years or so with a view to identifying themes likely to be of continuing importance in the new century. A general model for the cost of a processing technology is proposed in terms of the factors Q and γ involved in producing a given artefact. Particular technologies are discussed in terms of the order in which basic processing functions are carried out. A major trend likely to continue into the twenty-first century is the way in which the supramolecular organization of the polymer chains is increasingly being brought under control, either directly by processing or indirectly by self-ordering properties of the polymers themselves. Self-organization of reinforcing fibres during processing to produce optimal performance of polymer composites is a parallel trend also likely to develop further into the next century. To illustrate these ideas the paper draws on examples from major polymer processes: extrusion, injection moulding, film blowing, reaction moulding, thermoforming, fibre making and coating.
Offshore technology—advances at the dawn of the new millennium reviewed from a UK perspective
Authors: Lyons G J 
Published: October 2002

This paper considers the technologies that have enabled offshore hydrocarbons production to reach the existing limits, and what may be required realistically to extend these limits further at the beginning of the new millennium. Advances are considered which relate to many parts of the world. Each has its own particular challenges. The viewpoint presented here is, however, from the United Kingdom.
It's not what you do, it's why you do it that makes the difference between engineering and science: The strategy and structure of process engineering in the United States
Authors: Axon C J , Howell J A 
Published: October 2002

The dramatic changes to academic process engineering by the UK's largest competitor, the USA, has led them to be stronger, more successful and more vibrant. It is advocated here that unless the UK also makes appropriate changes, it will not survive in the global process engineering marketplace. This paper reports on some of the conclusions of a study carried out last year by a group of young academics who visited the USA in late 1998. The report's findings have significance beyond chemical process engineering and touch all areas of engineering research in the UK (and further afield). It is concluded that universities must change the way that they develop the careers of younger staff, train students (under- and postgraduate) and promote collaboration between the different pure sciences and engineering. In addition, ideas are presented for both the Funding Councils and industry for ways in which they might change to meet the challenges just around the corner.
Monitoring the lubricant condition in a low-speed rolling element bearing using high frequency stress waves
Authors: Jamaludin N , Mba D , Bannister R H 
Published: October 2002

This paper presents the results of an investigation into the development of a reliable, nonintrusive and effective technique capable of accessing the lubrication condition within a low-speed rotating bearing. This unique monitoring system is known as pulse injection technique (PIT) and involves transmitting a Dirac pulse through a bearing via a stress waves (SW) sensor. Analysis of measured stress wave signatures differentiated between a properly and poorly lubricated bearing. This method was found to be effective as stress wave propagation is sensitive to the transmission path, which in turn is affected significantly by the type and amount of grease present in the vicinity of the working elements of a bearing. The ability of this technique to monitor the lubrication condition within a bearing whilst in operation could be utilised to determine the appropriate time for grease replenishment or addition.
Submicrometre particle separation via high-speed gas centrifuges
Authors: Hitchings A , O'Doherty T , Syred N 
Published: October 2002

The separation of submicrometre particulate matter from gases is a problem that has attracted much interest over the years. Filter systems require low face velocities and hence tend to be of large size, while also requiring sophisticated, bulky, regeneration systems. A high-speed centrifuge which can be linked with a turbocharger has been developed which can remove particulates well into the submicrometre range in diameter. The centrifuge operates at speeds of up to 60 000 r/min, with the assistance of both axial thrust air bearings and radial foil bearings. Experimental analysis of the centrifuge using particle sizing techniques etc. has shown the effectiveness of the system operating at a range of different flowrates. This has been done by comparing the relative effectiveness of the system for the different flowrates. The paper discusses the analysis of the separative efficiency (i.e. the ability to concentrate particles into a small proportion of the gas) of the present system and the predicted efficiencies of future systems.
Local flow characteristics and its effect on cowled finned systems
Authors: Lin S , Griffiths A J 
Published: October 2002

An experimental study of local flow characteristics within cowled finned systems has been carried out using laser Doppler anemometry (LDA). Such systems are used to control axial temperature profiles within the barrel of an extrusion process. During the experiments, a perspex model was used to simulate the actual system. The inlet Reynolds number within the air cowl was 1.72 × 104. The local flow between fins was characterized by the flow in the curved duct formed by the fin base tube, fin surfaces and air cowl around the outer diameter of the fins. The flow pattern between the fins was measured at the sight windows on the air cowl wall. The local flow characteristics and its effect on heat transfer behaviour on fin surfaces were discussed. It was highlighted that the heat transfer through fin surfaces can be greatly influenced by the local flow characteristics. The mean heat transfer coefficient in the curved duct was estimated using both empirical equations and experimental results. The mean coefficient was also predicted using a computational fluid dynamics (CFD) package, and was underestimated by 12 per cent when compared with that found using the empirical relationships.
Application of risk-based inspection for pressurized HC production systems in a Brunei petroleum company
Authors: Hagemeijer P M , Kerkveld G 
Published: October 2002

A large number of ageing oil and gas production and evacuation facilities are owned and operated by BSP (Brunei Shell Petroleum). The company is facing the challenge of optimizing the return on inspection efforts in a period of time when more production is required and operating costs have to be minimized. Over recent years significant improvements have been made to BSP's system of planning and performing offshore inspection, in particular concerning the management of hydrocarbon process containment integrity, via a change from a periodic return inspection approach to a risk-based inspection (RBI) approach. This article presents the quantified benefits achieved to date, and the way this process of change has been/is being managed, firstly, to yield the major savings today, and secondly to sustain these gains by setting up processes and systems to support the new way of working. The value of the RBI approach, in terms of its contribution to the company's business drivers, is summarized thus. Cost optimization—the implementation of RBI principles in BSP has reduced the inspection effort (per platform) significantly to a level, which only involves the ‘minimum required’. The move has been to invest more in planning, thereby reducing (eliminating some) offshore execution of work. These benefits have been quantified in Section 3.1. In addition, increased production availability—the approach has assisted in reducing planned shut down times and minimizing unexpected shut downs due to failures. The move has been from shutdown inspection to onstream inspection. These benefits have been quantified in Section 3.2. Finally, safety—has been improved primarily by reducing the likelihood of failures and having fewer inspectors commuting to and working offshore. The move has been to perform focused inspection on hot spots in the system to reduce HC losses. These benefits have been quantified in Section 3.3.
Ultra light rail developments
Authors: Griffin T 
Published: October 2002

Ultra light rail systems are small-scale tramways that utilize energy storage rather than continuous electrification. They have excited considerable interest because potentially they are a very cost-effective way of providing attractive urban public transport. This paper describes latest technical advances and service experience of the two principal developers. These are the Parry-Clayton range of vehicles, which are concentrating on mechanical and mechanical/hydrostatic transmission systems, and the EROS vehicle, which will have electric transmission. The paper also considers longer-term traction options and developments in related fields that should allow some transfer of technology to accelerate the process of achieving market-ready products.
Watershed UK accidents—lesson learned
Authors: Rasaiah W. G. 
Published: October 2002

Rail vehicle crashworthiness in the United Kingdom has developed over the past 15 years or so and is based on lessons learned from accident statistics and specific multifatality accidents. Recent UK accidents and developments in rolling stock design and operation require a review of current specifications and consideration of practicable changes to enhance crashworthiness in the future. This paper reviews ‘watershed’ UK accidents which have shaped vehicle crashworthiness design so far and the recent accidents which are likely to do so in the future. It begins with an overview of crashworthiness principles and accident statistics.
Hypervelocity impact on spacecraft carbon fibre reinforced plastic/aluminium honeycomb
Authors: Taylor E A , Herbert M K , Gardner D J , Kay L , Thomson R , Burchell M J 
Published: October 2002

Samples of a spacecraft primary external wall structure, as used in a low earth orbit remote sensing platform, have been tested to determine the response to the hypervelocity impact and ballistic limit (for mm-sized impactors) of the 47 mm thick structure at 5 km/s. A strong dependence of the ballistic limit on projectile density was identified. This programme was carried out using the two-stage light gas gun at the University of Kent at Canterbury. The equivalent diameters of the front and rear holes for each impact were analysed as a function of the impactor parameters. Damage equations derived by other experimenters were compared to the experimental results. X-ray non-destructive testing was used to determine the level of internal honeycomb damage for a sample. The dependence of the witness plate damage (placed behind the target to capture any ejecta from the rear surface) on the impactor parameters was recorded. It was found that the use of ‘equivalent thicknesses’ of aluminium may not be appropriate as a general conversion factor for carbon fibre reinforced plastic (CFRP) facesheets. A simple damage equation is presented, based on the total hole size as a function of the impact energy. The ballistic limit cannot be defined solely in terms of impact energy and shows an additional dependence with projectile density. The amount and type of ejecta produced is a strong function of density and a less strong function of projectile diameter, and its production cannot be linked with the rear hole diameter.