bluuebunny/crossref_metadata_2025 huggingface dataset:
A Fuzzy Logic Approach to Deadbeat Control
Authors: Shashishekhar N , Srinivasa Y G
Published: February 2007

A fuzzy logic approach to the ripple-free, finite settling time output control (or deadbeat control) of simple plants is presented. The approach is implemented by a fuzzy learning system which ‘learns’ the appropriate sequence of manipulated values required for dead-beat control of the plant. It is demonstrated how this learnt manipulated value sequence, together with the corresponding output value sequence, can be put to use in three distinct ways: firstly, for the open-loop control of the plant; secondly, for the parameter estimation of a conventional deadbeat controller; and, thirdly, for plant parameter estimation. A simulation study on a second-order plant model and an application case study with a pneumatic process were used to test and illustrate the fuzzy logic approach. Deadbeat control for minimum, and for one sampling period greater than minimum, output settling times was implemented with the fuzzy learning system. A comparative performance study of the fuzzy estimated deadbeat controllers with other conventional controllers is presented. The results of the conducted studies indicate the effectiveness and flexibility of the fuzzy logic approach to deadbeat control.
Robust Reference Models for Delayed Systems
Authors: Aguirre L A
Published: February 2007

This note is concerned with the design of open-loop reference models which lead to robust closed-loop control systems. A simple criterion is used to find the reference models in the frequency domain. The search is greatly facilitated by considering low-order reference models which are appropriate in approximate model matching problems. Numerical examples are provided.
An Uncertainty-Attenuating Controller for Mechanical Manipulators with Electromechanical Dynamics: Part 2
Authors: Teo C L , Zhu H A , Hong G S
Published: February 2007

Decoupling control of robotic manipulators, based on a dynamic model that includes both the mechanical dynamics of the links and the electrical dynamics of the joint motors, is studied in this paper. By using an algorithm of feedback linearization developed in this paper, the highly non-linear and strongly cross-coupled electromechanical system is decoupled and linearizd into a set of decoupled linear subsystems. Then, disturbance decoupling is further conducted for disturbance and uncertainty attenuation. It is shown that, by using the proposed control scheme, both modelling difficulty and control complexity of the manipulator system can be significantly reduced.
Parallel Adaptive Neural Network Control of Robots
Authors: Ge S S , Lee T H
Published: February 2007

In this paper, a parallel adaptive neural network (NN) control design for robots motivated by the work by Lee and Tan is presented. The controller is based on direct adaptive techniques and an approach of using an additional parallel NN to provide adaptive enhancements to a basic fixed controller, which can be either a NN-based non-linear controller or a model-based non-linear controller. It is shown that, if Gaussian radial basis function networks are used for the additional parallel NN, uniformly stable adaptation is assured and asymptotic tracking of the position reference signal is achieved.
Fuzzy Control of a Closed-Die Hot-Forging Machine
Authors: Pham D T , Wu M H
Published: February 2007

The development of a fuzzy control system for a closed-die hot-forging machine is described. Details of the input and output fuzzy variables and the fuzzy inference procedure are given. Results obtained using the fuzzy control system are presented. These demonstrate the ability of the system accurately to control the amount of energy delivered to the workpiece to keep it within narrow tolerances without overloading the die.
Microtribology of Magnetic Media
Authors: Bhushan B , Koinkar V N , Ruan J-A
Published: February 2007

Scanning tunnelling microscopy (STM), atomic force microscopy (AFM) and the modifications of AFM [such as friction force microscopy (FFM)] are becoming increasingly important in the understanding of fundamental mechanisms of friction, wear and lubrication and in studying the interfacial phenomena in micro- and nanostructures used in magnetic storage devices and microelectromechanical systems (MEMS). This paper describes modified AFM and FFM techniques and presents data on microtribological studies of magnetic media-magnetic tapes and disks. Local variation in microscale friction is found to correspond to the local slope, suggesting that a ratchet mechanism is responsible for this variation. Wear rates for magnetic tapes are approximately constant for various loads and test duration. However, for magnetic disks, the wear of the diamond-like carbon overcoat is catastrophic. Evolution of the wear has also been studied using AFM. AFM has been modified for nanoindentation hardness measurements. It has been shown that hardness of ultra-thin films can be measured using AFM. AFM has also been shown to be useful for nanofabrication.
Elastohydrodynamic Lubrication of Soft-Layered Solids at Elliptical Contacts: Part 2: Film Thickness Analysis
Authors: Dowson D , Yao J Q
Published: February 2007

This paper reports on the use of the Newton successive overrelaxation method to solve problems of elastohydrodynamic lubrication of soft-layered solids at elliptical contacts. Solutions have been obtained for a range of load, speed, elastic layer thickness and conjunction ellipticity, enabling the film thickness to be determined. The empirical formula thus derived is used to estimate the effective film thickness in the major load-carrying synovial joints in the body.
The Minimum Film Thickness in Lubricated Line Contacts during a Reversal of Entrainment—General Solution and the Development of a Design Chart
Authors: Hooke C J
Published: February 2007

In most line contacts the load, effective radius of curvature and entraining velocity change with time. Generally this is ignored when calculating the film thickness and a quasi-steady solution is obtained. Under most conditions the errors introduced by this are either small or are not critical. However, when the entraining velocity reverses, as, for example, in some designs of cams, the quasi-steady approach predicts that the film thickness will be zero. In practice a residual film persists and can provide adequate surface separation. Previous papers by the author have shown that the minimum film thickness at entrainment reversal depends on the rate of change of the entraining velocity. Expressions for the film thickness in the four regimes of lubrication—rigid isoviscous, rigid piezoviscous, elastic isoviscous and elastic piezoviscous—were obtained and the variations of the film thickness in the transitions between adjacent regimes examined. The present paper examines the region where more than two regimes overlap. The values of film thickness obtained are then used to develop an interpolation procedure for the accurate calculation of the minimumfilm thickness under all operating conditions.
Dynamic Performance of Oil-Lubricated Helical Groove Journal Bearings
Authors: Khan M Z , Stolarski T A
Published: February 2007

The provision of helical grooves on the surface of a plain journal bearing can, in principle, improve the stability of a rotor-bearing system. The improvement, however, depends on the arrangement of the grooves along the axial length of the bearing. In order to verify this, three types of helical groove bearing with different groove arrangements and a reference plain journal bearing were studied. The bearings were studied in a specially designed test rig. A computer model was also developed to predict the performance of the bearings studied. The experimental and theoretical results produced during the course of the studies show that at the expense of a reduced load capacity the helical groove bearings are more stable, particularly at low eccentricity ratios. For a given eccentricity ratio and speed the symmetrical bearing operates at higher temperature and with greater power losses than the other three bearings tested. At the same eccentricity ratio and speed, the asymmetrical bearing runs at about the same temperature as the plain journal bearing.
Lubrication Analysis of a Rolling Piston Rotary Compressor: Part 1: Mathematical Modelling
Authors: Padhy S K
Published: February 2007

This paper describes a mathematical model for the lubrication system of a single-vane rolling piston type rotary compressor. The lubricant flow in the compressor is modelled as a flow in a pipe network. Various flow resistances, pressure differentials and viscous pump effects are determined. Closed network equations are formulated. The equations are solved simultaneously, and the lubricant flowrates at various clearances of the compressor are calculated.
Lubrication Analysis of a Rolling Piston Rotary Compressor: Part 2: Experimental Validation and Results
Authors: Padhy S K
Published: February 2007

In this paper the experiments conducted for the measurement of oil flow in the rotary compressor are described. The experimental data are compared against the theoretical prediction from the mathematical model developed (1) and a good agreement is found. In addition, experimental data from previously published literature are also used to verify the mathematical model. A sensitivity study is carried out to predict the behaviour of the rotary compressor for the oil flow at different conditions and with different dimensions.
Pressure Distribution in Squeeze Film Dampers with Oil Hole Feed
Authors: Chen P Y P , Hahn E J
Published: February 2007

To improve the damping capability of squeeze film dampers, oil hole feed rather than circumferential groove feed is a practical proposition. However, circular orbit response can no longer be assumed, significantly complicating the design analysis. This paper details a feasible transient solution procedure for such dampers, with particular emphasis on the additional difficulties due to the introduction of oil holes. It is shown how a trigonometric power series solution may be utilized to evaluate the oil hole pressure contributions, enabling appropriate tabular data to be compiled. The solution procedure is shown to be applicable even in the presence of flow restrictors, albeit at the expense of introducing an iteration at each time step. Though not of primary interest, the procedure is also applicable to dynamically loaded journal bearings with oil hole feed.
Prediction of Temperature Fade in the Cavitation Region of Two-Lobe Journal Bearings
Authors: Ma M-T , Taylor C M
Published: February 2007

Experimental evidence has shown that there often exists a considerable drop in bush temperature (the so-called temperature fade) in the cavitation region of journal bearings. This is contrary to the predictions of the conventional thermohydrodynamic analyses which give more or less rising temperatures. In order to bring theory into accord with experiment, an elemental heat-balance method was established by the authors to predict the temperatures in the cavitation region of two-lobe journal bearings. In this approach, the effect of oil back-flow from feed grooves was included on the basis of the separation cavitation model. Comparison between theory and experiment for a two-axial-groove circular bearing and an elliptical bearing has indicated that the present method is very effective in predicting the temperature fade. The analysis for the prediction of temperatures in the exit cavitation region is in principle applicable to multi-lobe journal bearing situations.
Wear Testing and Ceramics
Authors: Gee M G
Published: February 2007

This paper discusses many aspects of wear testing relevant to ceramic materials. It starts with a description of those properties of ceramics that are of particular importance for tribological performance, and then discusses the rationale that underlies wear testing. Some results of the wear of ceramics are discussed, with a particular emphasis on the importance of tribochemical behaviour and on the effect of test machine dynamics. After also discussing surface examination techniques and the pre-standardization work that has been carried out in the friction and wear testing area, the paper concludes with a discussion of future priorities in tribological testing.
Thermohydrodynamic Analysis of Journal Bearings Lubricated by Non-Newtonian Fluids—Theory and Experiments
Authors: Sheeja O , Prabhu B S
Published: February 2007

Viscosity index improvers cause the lubricants to exhibit non-Newtonian flow behaviour and display shear thinning and normal stress differences. Shear thinning behaviour is studied by using a rotary shear viscometer. Owing to the non-availability of a rheogoniometer (for the measurement of normal stress differences), the first normal stress difference is calculated from the viscometric data using the Carreau viscosity function. The influence of the first normal stress difference on the hydrodynamic lubrication is analysed and shows that most of the commercial oils are inelasticoviscous in nature. Regression analysis shows that a large number of commercial lubricants follow the inelasticoviscous cubic law fluid model. Hence the cubic law fluid model is considered for the theoretical analysis.

An experimental programme is developed to measure the effect of test parameters on the performance of a journal bearing lubricated with different types of non-Newtonian fluids. The experiments mainly include the measurements of the steady state characteristics like film thickness and fluid film friction. The experimental film thickness values are compared with the respective theoretical ones and are in good agreement. The theoretical performance characteristics are obtained through the simultaneous solution of the modified Reynolds equation using the cubic law fluid model and energy equation.

The fluid film friction in a hydrodynamic journal bearing is experimentally determined through coastdown analysis. The results are presented in the form of an apparent Stribeck diagram of friction and are compared with the respective theoretical values.
Measurement of Lubricating Film Thickness in Low Elastic Modulus Lined Bearings, with Particular Reference to Models of Cushion Form Bearings for Total Joint Replacements: Part 2: Squeeze-Film Motion
Authors: Jin Z M , McClure G , Dowson D , Fisher J , Jobbins B
Published: February 2007

An optical interferometry technique has been successfully used to study the lubricant film thickness in a compliant layered bearing model for total joint replacements under squeeze-film motion. Experiments have been carried out for both thin and thick layers of compliant bearing material. It has been demonstrated that the film thickness patterns depend significantly upon the layer thickness if other parameters are kept constant. For the thin layer, the film thickness in the contact region was found to be essentially uniform and quite good agreement was found with the theoretical predictions based upon a simplified analysis due to Dowson et al. (13) and Higginson (14). However, for the thick layer, a central dimple or pocket was formed and a relatively large difference was found between the experimentally determined central film thickness and the simple parallel circular disc theoretical predictions. The practical implications of the present results are discussed in relation to the lubrication mechanism in the natural synovial joint and its replacement.
Identification of Non-Linear Force Coefficients for the Radial Motion of a Squeeze Film Damper
Authors: Zhang J X , Roberts J B
Published: February 2007

The fluid force generated in a squeeze film damper undergoing large amplitude radial motion is described in terms of non-linear hydrodynamic inertial and damping coefficients, together with afluid static force. Linear-in-the-parameter polynomial forms are introduced to represent the variation of these contributions with radial position. A generalized state variable filter identification method is developed which enables all the parameters in the non-linear model to be estimated from experimental data. The method is validated by processing simulated data and then applied to some new experimental data. Experimental results, relating to the influence of the supply pressure and the operating frequency on the coefficients, are presented and discussed. Comparisons are made with corresponding predictions derived from existing lubrication theory. The parametric non-linear model is found to give a good fit to experimental data over a significant region within the vicinity of the initial static equilibrium position. Through a combination of results, the variation of the fluid force coefficients and the fluid static force with eccentricity, over nearly the whole range of the radial clearance, is obtained. Temporal inertia is found to be more important than convective inertia for motion near the centre of the clearance circle. The existence of a fluid static force, suggested by previous work is confirmed. It is found that this force is linearly proportional to the oil supply pressure.
Numerical Modelling of the Contact between Lithographic Printing Press Rollers by Soft EHL Theory
Authors: Xue Y-K , Gethin D T , Lim C H
Published: February 2007

The contact behaviour in a coating roller or printing press roller nip is investigated in this paper by using soft elastohydrodynamic lubrication (EHL) theory. Film thickness, roller deformation and pressure profiles are evaluated for a range of possible dimensionless speed, load, elastomer thickness, Poisson's ratio and fluid inlet positions. To achieve the simultaneous iterative solution of the describing equations, the Reynolds equation is transformed into a form of boundary integral equation which is solved by Simpson's rule and surface distortion is obtained by a boundary element method. The numerical scheme proved to be very effective for such layered soft EHL problems. Results show that relatively thick fluid films exist in the nip because of the large deformation of the elastomer under normal working conditions. The dimensionless speed parameter has more influence on film formation at a fully flooded condition than any of the other parameters. Because the layer is easily deformable, film thickness may increase when load increases. The shape and thickness of the film and pressure profile are also controlled by the degree of starvation. At severely starved fluid supply, speed and load parameters have the most significant effect on the minimum film thickness. Larger Poisson's ratios produce a little smaller film thicknesses and larger surface displacements than the small values, and small elastomer thickness gives small indentation and large pressures in the nip.
United Kingdom and Western Assistance to RBMK Reactors
Authors: Hayns M R , Davies N W
Published: February 2007

Western safety assistance to RBMK reactors has been growing over recent years through various bilateral programmes and also through multi-lateral programmes funded by the Commission of the European Communities (CEC) and by the European Bank for Reconstruction and Development (EBRD) on behalf of the Nuclear Safety Account Donors. The paper gives an overview of these programmes, what their objectives are and how they are implemented.
PFBC for Coal-Fired Combined Cycle Power Generation
Authors: Minchener A J
Published: February 2007

The development of pressurized fluidized bed combustion (PFBC) has reached the stage where the technology is available on a commercial basis. Four plants are operating with further units either on order or being commissioned. This paper describes the basis for PFBC, the technical issues that have been resolved, with particular reference to British experiences, the development route being undertaken and options for system enhancement.
Modelling the Transient Behaviour of Heat Recovery Steam Generators
Authors: Dechamps P J
Published: February 2007

This paper describes a method used to compute the transient performances of assisted circulation heat recovery steam generators. These heat recovery steam generators are composed of several heat exchangers, each of which is a bundle of tubes. The method presented here treats each heat exchanger in a similar way, replacing the bundle of tubes with an ‘equivalent’ linear heat exchanger.

This equivalent linear heat exchanger is then discretized in as many slices as required by the accuracy. The mass and enthalpy equations on each of these control volumes are solved by a fully explicit numerical method, adapted for the special conditions encountered in this kind of problem, allowing a considerable reduction of the computation time compared to other methods.

Some emphasis is put on the modifications required to solve the equations for the evaporators because they are two-phase heat exchangers. A model for the steam drums is also presented together with simple models for the main control loops used in such systems. An example is presented in which an existing dual pressure level heat recovery steam generator is started from a cold state. The numerical predictions are in good agreement with measurements.
Nomenclature for Exergy Analysis
Authors: Kotas T J , Mayhew Y R , Raichura R C
Published: February 2007

In this paper a system of names and symbols for exergy analysis is put forward for further discussion. The concept of exergy is shown to be dependent on that of the environment. The conceptual environment provides a natural reference state for calculating absolute values of exergy. For calculating loss of exergy, or process irreversibility, an exergy balance or the Gouy–Stodola relation can be used. The concept of chemical exergy can facilitate the computational work involved in exergy analysis. The paper offers a glossary of terms used in exergy analysis and shows the proposed symbols in the context of expressions in which they might be used.
The Economics of Wet Versus Dry Cooling for Combined Cycle
Authors: Lees M
Published: February 2007

The privatization of the British power generation industry has been accompanied by a major change in the technology employed in power station construction. Large coal- or oil-fired steam stations based on the Rankine cycle have been superseded for the moment by gas-fired combined cycle stations. Of equal significance has been the change from large concrete hyperbolic cooling towers to low profile mechanical draught towers, or even air-cooled condensers. This paper examines the technoeconomic factors that have led to the shift in cooling system design and assesses the factors that will dictate the direction of future cooling system designs.
Design and Performance of a Variable Valve Timing System on a Highly Turbocharged Diesel Engine—Experimental and Predicted Results
Authors: Stone C R , Leonard H J , Elliott C , Newman M J , Charlton S J , Johnston D N
Published: February 2007

A previous study using a cycle simulation program had identified the possibility that highly rated diesel engines might benefit from a variable valve timing (VVT) system. In particular, the study had shown that, by delaying the start of inlet valve opening at part load, it should be possible to eliminate the reverse flow that can lead to inlet port fouling. The work reported here encompasses the design and implementation of a variable valve timing system on a highly rated high-speed marine diesel engine. The principal topics addressed are the selection and design of a mechanism, a comparison between the predictions and results from mechanism testing on a single-cylinder valve-train rig and the engine performance predictions and results obtained when the mechanism was tested on the engine.

The results from the single-cylinder test rig demonstrated that the mechanism performed satisfactorily, and this led to a design suitable for retro-fitting to the engine. The engine was comprehensively instrumented and the experimental results were in good agreement with the cycle simulation predictions.
Design of Hydraulic Ram Pump Systems
Authors: Young B W
Published: February 2007

Automatic hydraulic ram pumps are environmentally friendly devices using a renewable energy resource to pump water for domestic or agricultural use. Since being superseded by pumps using electrical or fossil fuel energy nearly a century ago, they are now coming back into favour in many parts of the developing world.

In the past, hydraulic ram pumps have been designed by rules-of-thumb having limited scientific basis. On-site adjustment has been used in the hope of rectifying the inevitable shortcomings of this process and ideal performance is rarely achieved. The present proposal for optimum design allows relevant system parameters (including the beat frequency) to be selected prior to installation.

The paper shows how a ram pump system may be designed using two simple equations containing empirical factors dependent upon ram size, delivery head, material and wall thickness of the drive pipe and the configuration of the impulse valve. The design method is illustrated with reference to a number of existing tests. New experimental results for a 53 mm ram with five different impulse valve strokes are also presented.
A Waste-to-Energy Recycling Plant for Beirut
Authors: Wilson D G , Saba E F , Nuwayhid R Y , Hamrin D
Published: February 2007

A recommended optimum near-term solution to Beirut's serious solid-waste problem would involve a separation plant to achieve the maximum economic degree of recycling, including the separation of food and vegetable matter for composting and incineration of the non-recyclable combustible fraction with energy recovery. A gas turbine running on the supplementary-fired exhaust-heated cycle, giving high-efficiency power production at small land use and first cost, is proposed.
Secondary Flow in Repeating Stages of Axial Turbomachines
Authors: Horlock J H
Published: February 2007

In a well-designed multi-stage axial flow compressor, the flow settles down to a repeating condition, in which the axial velocity profile does not deteriorate further; it is more or less unchanged between the entry and the exit of a deeply embedded stage. However, experimental data also show that the flow angles repeat, and it is this flow phenomenon that is discussed in the paper.

Secondary flow analysis, coupled with empirical data on clearance flows, is used to give a description of the flow in such a repeating stage. The secondary flow at exit from a row involves both the streamwise vorticity generated in that row and the vorticity that exists at entry—the so-called ‘skew’ vorticity due to a non-uniform velocity from a stator being received by a moving rotor (and a similar effect from the rotor to the stator). However, clearance vorticity—shed from the rotor tip (casing) section and the stator root (hub) section—is also present and can be taken into account.

Calculations made using the analyses are compared with some limited experimental data drawn from the published literature. Predicted underturning at rotor tip (casing) sections is confirmed by experiments; similarly, predicted underturning at stator tip (casing) sections accords with observations in one compressor but not in another.

However, no universal conclusion (on whether underturning or overturning usually occurs) can be drawn for the flow through the rotor and stator root (hub) sections, as either entry or generated secondary vorticity may dominate.
Correlation and Prediction of Efficiency of Centrifugal Pumps Due to Tip Clearance effects
Authors: Engeda A
Published: February 2007

A wide range of specific speeds (ns = 17–80), based on five centrifugal pumps, was experimentally analysed to study the performance deterioration associated with tip clearance effects. Consequently and systematically, an empirical expression was developed that predicted the efficiency deterioration as a function of specific speed and tip clearance within a fairly good margin.
Development of a Thermodynamic Method for Diagnosis and Tuning of Diesel Engines And its Application on Marine Engines
Authors: Kouremenos D A , Hountalas D T , Kotsiopoulos P N
Published: February 2007

In the present paper a method is proposed for fault diagnosis and correct tuning of diesel engines. It is based on a thermodynamic simulation model of the engine and its components: the fuel injection system, the turbocharger and the air cooler. The method requires the experimental cylinder and fuel injection system pressure diagrams and operational data of the various engine sub-systems, air cooler, turbocharger, etc. It is known that it is very difficult to measure the TDC (top dead centre) on commercial engines. In order to overcome this difficulty the TDC is determined via a thermodynamic method introduced and verified by the present research group. In this paper an application of the proposed method on a low-speed two-stroke marine diesel engine is presented. The results obtained reveal the present condition of the engine and its sub-systems while a comparison between calculated and experimental results reveals the accuracy of the simulation model used.
Village Planning of Isolated Energy Schemes
Authors: Harvey A
Published: February 2007

The majority of rural populations in developing countries do not have access to modernized energy supplies such as grid electricity. There is a move now among international lending institutions and several governments to sanction private ownership and distribution of power. This paper proposes that revised rural energy policies should include official encouragement for isolated village-scale energy schemes. On the basis of relevant experience in Nepal, certain infrastructural supports are recommended to underpin widespread uptake of such schemes. A major constraint currently in many countries is the lack of a methodology for planning and managing schemes at the village level. A methodology is needed for three reasons: to reduce costs, to promote local financial commitment and responsibility, and to provide a common frame of reference linking the local management/planning body to agencies distributing subsidies, to banks providing loans and to national professional advisory bodies. On the basis of experience with pilot projects in Sri Lanka, some proposals are made here as to the content of such a methodology.
Assistance to Nuclear Safety Regulatory Bodies in the Central and Eastern European countries and the Former Soviet Union
Authors: Campbell R J , Vaughan G J
Published: February 2007

The Regulatory Bodies of the former Eastern Bloc countries are striving towards the adoption of internationally recognized regulatory practices. This paper provides some background and an update on the assistance being provided to them by the Western regulatory community.
Uncertainty in Computational Fluid Dynamics
Authors: Fisher E H , Rhodes N
Published: February 2007

The Fifth Joint Engineering and Physical Sciences Research Council and Institution of Mechanical Engineers Expert Meeting was held in Bournemouth on 27-29 November 1994.

The Fifth Joint Engineering and Physical Sciences Research Council and Institution of Mechanical Engineers Expert Meeting was held in Bournemouth on 27–29 November 1994.
Renewable Energy in the United Kingdom
Authors: Laughton M A
Published: February 2007

The United Kingdom is particularly well endowed with renewable energy sources relating to wind, waves and tide as well as the normal waste products arising from an industrialized society. These and other renewable energy sources have much technological scope for development but less scope for economic use. Government support for these industries has been significant in recent years in allowing a number of schemes to become commercially possible. The technologies are diverse, the design engineering is in its early stages in many cases and the extent of the eventual integration of such energy sources into existing energy supply systems is not easy to foresee. Aspects of the economic, institutional and environmental factors influencing the exploitation of renewable energy sources for electricity generation are reviewed along with an assessment of the present developments in the various technologies. The need for further support within a long-term view of the whole energy supply scene is stressed as necessary to balance shorter-term commercial considerations.
A Comparison of the Means and Cost of Subsidizing Wind Energy
Authors: Mitchell C
Published: February 2007

The support mechanisms for wind in the United Kingdom, the Netherlands, Denmark and Germany are reviewed. Their cost to the consumer is calculated and compared. The benefits and disbenefits of the differing systems are discussed.
A Methodology for Wells Turbine Design for Wave Energy Conversion
Authors: Raghunathan S
Published: February 2007

The wave energy devices currently being built in the United Kingdom and elsewhere have adopted the Wells air turbine for converting pneumatic energy in the device to mechanical energy of rotation. A monoplane (single-plane) Wells turbine can operate efficiently over a certain maximum flowrate and pneumatic pressure drop due to blade stall and tip speed limitations respectively. The knowledge base on the monoplane Wells turbine is reviewed. An interactive methodology for an aerodynamic design of this turbine is presented.
Solar Photovoltaic Systems and Their Use As Grid-Connected Generators in the United Kingdom
Authors: Munro D K , Hacker R J , Thornycroft J M
Published: February 2007

There is increasing interest in the use of building-integrated solar photovoltaic generators as grid-connected generators. This paper discusses the experience with this technology in Europe. Typical systems and their integration into domestic and non-domestic buildings are described. Information is provided on the energy output that can be expected from the systems and the economics of their use. The paper provides an overview of the requirements for photovoltaic systems as grid-connected generation plant in the United Kingdom.
Speeding up Rapid Prototyping by Offset
Authors: Yu K M , Li C L
Published: February 2007

Rapid prototyping methods, like stereolithography, have gained wide industrial acceptance in recent years. The main advantage of rapid prototyping over conventional methods is faster speed. Unlike material removal from a stock (as in machining), most rapid prototyping methods have to build the solid volume layer by layer. The tracing of the cross-sectional solid area in each layer is the most time consuming process. The paper proposes to use solid offset to cut down the solid volume to be built. Faster speed can thus be achieved by tracing less solid. The background theory for obtaining the reduced-volume solid is explained in the paper. The approach is applicable to solids defined by constructive solid geometry (CSG).
Optimization of Tool/Workpiece Orientation in Designing Die-Face of Automobile Outer Panels
Authors: Park J C , Lee K , Cho K H
Published: February 2007

A procedure has been developed to optimize the product's tipping position, that is the relative orientation of the product surface with respect to the punch direction in a die, in designing a die-face for the manufacture of automobile outer panels. The two design requirements that are considered in optimizing the tipping position are: to satisfy that all points on the product have the most uniform drawing depths and to guarantee that the user-specified area on the product should contact initially with the binder wrap prior to other regions. The problem to solve when satisfying the design requirements described above is analogous to the flatness calculation problem in the area of metrology if some constraints can be imposed. Thus the problem can be solved by the simulated annealing method, which is one of the optimization methods. The developed procedure was applied to an actual die-face design and the results showed that the procedure was useful through the distribution diagram of the drawing depths.
A Numerical Method for Determining Temperature Distributions in Machining with Coolant: Part 1: Modelling the Process
Authors: Li X , Kopalinsky E M , Oxley P L B
Published: February 2007

A computational method is developed for determining temperature distributions in machining with coolant. Realistic models are proposed for heat-generation rates in the cutting regions and for heat-transfer coefficients for cooled boundaries. In Part 1 the models used in the analysis are presented while in Part 2 the computational method and results are given.
A Study of the Residual Stress Reduction Method Through the Mechanical Loading Cycle in Metal-To-Ceramic Brazed Joints
Authors: Kim W-B , Na S-J
Published: February 2007

The transient thermal and residual stresses in the metal-to-ceramic brazed joints were analysed by using the finite element method (FEM). The thermal and residual stresses which were induced mainly by the difference in the thermal expansion coefficients between the brazed materials were successively calculated. The high tensile residual stress occurred in the brazed joint interface, which has the potential to cause internal cracks in the brazed joints. In order to reduce the tensile residual stress in the brazed joint, the mechanical loading cycle was adopted during the brazing thermal cycle. The calculation results revealed that the tensile residual stress in the brazed ceramics can be reduced by the mechanical loading cycle and that the magnitude of the applied load and the temperature at which the mechanical loading cycle started greatly influence the reduction amount of the tensile residual stress.

For a comparison of the simulation results, the residual stress in the brazed joints was measured by using the X-ray diffraction method. The results calculated by the FEM analysis showed a similar tendency to the results measured by the X-ray diffraction method. In the case of brazed joints with 0.1 mm thick filler metal, the residual stress in the ceramic part after the mechanical loading cycle showed a lower tensile stress compared to that of brazed joints without the mechanical loading cycle. The larger the applied load, the smaller was the tensile residual stress occurring in the metal-to-ceramic brazed joint.
Determination of the Bending Sequence in Progressive Die Design
Authors: Wang F , Chang L
Published: February 2007

The design of a progressive die in bending and forming sheet metal into its final three-dimensional shape in a single set-up is a complex and challenging task. The interlocking features to substitute welding and soldering impose extra constraints on the bending sequence. This paper presents an algorithm for determining the bending sequence. The algorithm is first formulated in a case study of an electronic computer component produced using a progressive die, whose walls are interlocked during bending with inserts and slots. The general cases are then considered. The algorithm provides a systematic approach in determining the bending sequence and can be incorporated easily into a computer aided process planning system.
Manufacturing is the Prime Driving Force for Economic and Social Development—My Management Philosophy and its Practices
Authors: Ohba H
Published: February 2007

This paper gives an outline of the author's management philosophy, how he used four principles in his restructuring programme to turn Kawasaki from a loss-making company to the hugely successful manufacturing complex it is today and how he is promoting three guidelines for management action in order to build up a resilient and tough corporate constitution. In relation to the three guidelines, quality assurance and productivity improvement using the Kawasaki production system are especially emphasized. In addition to its long links with Great Britain, Kawasaki has maintained relationships with many other countries.
Extended Formability Limits for Tubular Components Through Combined Injection Forming/Upsetting—A Finite Element Analysis
Authors: Petersen S B , Rodrigues J M C , Martins P A F
Published: February 2007

In the injection forming/upsetting of tabular parts the ratio between inner and outer diameters of the tube, the ratio between wall thickness and gap height, together with the design of the die chamber are important dimensional parameters that determine the final geometry of a component. Recent published work in this field opened a breakthrough in the understanding of the limits for obtaining sound components without folds. However, some difficulties were still encountered, namely in what concerns avoiding the presence of undesirable models of deformation.

The paper presents comprehensive modelling of previous experimental work in this field, which leads to a re-examination of the process mechanics. This effort resulted in the development of a combined injection forming/upsetting technique. Numerical simulations performed using this technique indicate that a large extension of the formability limit for tubular components is possible.
Analysing the Natural Resting Aspects of a Component for Automated Assembly
Authors: Ngoi B K A , Lim L E N , Lee S S G , Lye S W
Published: February 2007

This paper proposes the construction of an energy envelope that can be used to advantage with the energy barrier method to analyse the natural resting aspect of engineering parts destined for automatic assembly. Unlike the energy barrier method, the energy envelope does not require any visualization of the projection of the energy barrier on the aspect of interest. The energy envelope is the three-dimensional topology of the changes in height of the centroid, as the part attempts changes of aspect. The paper describes how it may be computed in a CAD (computer aided design) solid modeller. The results of applying the energy envelope to prisms of square and cylindrical cross-sections are the same as those predicted by the energy barrier method. When extended to the analysis of a rectangular prism, the results were consistent with Boothroyd's dynamic solution and Boothroyd's experimental data. This conclusion is encouraging as there is no irrefutable evidence that the energy barrier method may be applied to the analysis of the rectangular prism.
The Effect of the Manufacturing Test Load on the Fatigue of Hoist Chains
Authors: Abolfathi E , Modlen G F , Webster P J , Mills G
Published: February 2007

The residual stresses, introduced into high-tensile steel chains during their manufacture as the result of the application of a manufacturing test load, have been determined by the neutron diffraction technique. The results are consistent with finite element calculations and with the effects of the manufacturing test load on the fatigue properties of the chains.
Intelligent Tool Selection for Machining Cylindrical Components: Part 1: Logic of the Knowledge-Based Module
Authors: Maropoulos P G , Gill P A T
Published: February 2007

This paper presents the logic of a knowledge-based system for turning tool selection. The selection philosophy is based on machining performance and the system uses information regarding tools and cutting data from ‘approved’ operations which have been proved on machine tools following a specific testing procedure. For any new operation, rules are used to identify its level of similarity to previously performed, approved operations. The similarity criteria are based on metal cutting theory and practical engineering knowledge and incorporate considerations in relation to the component and cutting profile geometry, material type and operation type as well as tool and insert characteristics. The goal is to identify similar approved operations, retrieve the corresponding tool and cutting data and sort them in order of preference. A key function of the system is that according to the level of similarity, the retrieved information is either used as it is or is automatically modified to suit the new operation. The main benefits from using the system are improved engineering consistency in the decision making for selecting tools and cutting conditions, improved utilization of tools and definition of efficient machining conditions.
Aggregate Production Planning Using Genetic Algorithms
Authors: Stockton D J , Quinn L
Published: February 2007

An aggregate plan is a statement of future resources and finished goods inventory levels that must be made available to enable a manufacturing organization to meet its forecast sales demand. The aggregate planning process must enable the strategic business objectives of a manufacturing organization to be quickly converted into short-term operational plans that are economical to implement. This link between strategy and the day-to-day activities of an organization is becoming increasingly important in enabling organizations to cope with the faster rate at which business objectives must be changed in order to remain competitive.

This paper initially examines the aggregate planning process and describes the basic tasks involved. Current methods of setting aggregate plans are then compared and the main limitations of such techniques highlighted. Using an aggregate planning example, the paper then explains how genetic algorithms can be used to develop such plans and illustrates how this type of algorithm provides the means by which the limitations of existing aggregate planning techniques can be overcome.
Theoretical and Experimental Investigations of Coolant Flow in Inlet Channels of the BTA and Ejector Drills
Authors: Astakhov V P , Subramanya P S , Osman M O M
Published: February 2007

The coolant flow through inlet annular channels in BTA and ejector drills is investigated. The study was conducted in order to understand the influence of the channel's parameters (the channel's clearance variation along its length and eccentricity) on the coolant pressure distribution and hydraulic resistance. A new design of the ejector drill with the eccentrical location on the inner tube is proposed.

A study is made of the stability in the coolant flow in the inlet annular channels. The appearance of instability is explained by the presence of Taylor macrovortices in these channels under certain combinations of boring bar rotating velocity and axial flow velocity. In order to define the unstable regimes (the critical Reynolds numbers), the mathematical model for non-isothermal flow through the annular channel is solved. The heat transfer from the swarf to the incoming coolant is investigated under different flow conditions.
Prediction of Surface Depression of a Tungsten Inert Gas Weld Pool in the Full-Penetration Condition
Authors: Wu C S , Dorn L
Published: February 2007

A three-dimensional model is set up to predict the surface depression of a tungsten inert gas (TIG) weld pool in a full-penetration condition in order to find out the relation between pool depression and weld penetration. It solves pool surface depression, fluid flow and heat transfer simultaneously and determines the configuration of a weld pool surface based on the dynamic balance among arc pressure, pool gravity and surface tension at the deformed weld pool surface. In the numerical simulation, difficulties associated with the irregular shape of the deformed weld pool surface and the liquid/solid interface have been overcome by adopting a boundary-fitted non-orthogonal curvilinear coordinate system. A series of data about pool surface depression under different TIG welding conditions are obtained. The validity of the model is verified through TIG welding experiments.
Implementation of Focused Manufacturing Techniques in a Hand Tool Company
Authors: McCarthy I , Ridgway K
Published: February 2007

This paper details the process of change at Footprint Tools Limited, Sheffield, using a teaching company scheme as the transfer medium and teaching company associates as the transfer co-ordinators. The technology introduced was neither ‘sophisticated’ nor ‘new’, but was considered appropriate to achieve the business and operational goals required. Cellular manufacturing (the technology) is an established concept which has evolved from the principles of group technology. Cellular manufacturing identifies and exploits the ‘underlying sameness’ of parts and the processes used for their manufacture. It is a total manufacturing system which involves the complex interaction of market, management and people.