Novel instrumentation has been developed and evaluated in a low-cost, purpose built, single-cylinder internal combustion engine test facility designed to simulate many of the combustion features that are common between an internal combustion engine, a gas turbine combustor and a steel rolling furnace. High bandwidth in-cylinder surface temperature measurements are demonstrated with a new application of platinum thin film resistance thermometers. These gauges are exposed to the combustion gases and are mounted to both the cylinder head and piston. It is shown that calculation of flame speed, determination of heat flux levels and flame structure observation are possible. Fibre optic probes capable of high frequency spectral measurements of the combustion emission are presented. The spectral measurements are shown to complement the temperature measurement by being able to differentiate the flame front from the general combustion emission and hot by-products. Beyond this, other optical techniques have been explored in order to gain an understanding of the flame front and flow within the combustion chamber. The novel spark plug described is capable of combustion imaging and its application to in-cylinder PIV and flow visualisation is demonstrated. Combustion modelling has been undertaken using published engine models and a comparison between measured and predicted values of pressure and heat flux is provided as a validation of the in-cylinder heat flux measurements.

This dissertation documents the thermodynamic and fluid mechanic analysis of an engine lubrication system. A comprehensive thermofluid computer model was developed to provide a flexible design analysis tool for the accurate prediction of oil pressures, flow rates and temperatures at any point within any lubrication system. Technical and financial support for the study was provided by Jaguar Cars. A comprehensive literature review revealed that the past research in this field had concentrated on either the thermofluid analysis of the lubrication system by engine testing, or the detailed analysis of individual components. A small number of computer models were developed for the flow analysis of the whole lubrication system. However, these models had limited heat transfer prediction capabilities, some requiring measured engine temperature data, and were not flexible enough to be employed as design tools. The objective of this study was to develop a flexible steady-state thermofluid design analysis tool, by integrating a flow analysis approach with a detailed analysis of the heat transfer within the engine block. Mathematical models of the thermofluid behaviour of the lubrication system components were developed and were implemented in a suite of FORTRAN computer programs which formed the design analysis package. A simple, linear flow model was initially developed to represent the system with a combination of laminar pipes, pumps, filters, journal bearings, crank-shaft transfer holes and cam bearing transfer holes. The linear program provided a rapid analysis tool, but the accuracy of the results were limited by the simplified flow characteristics of the system components. A more comprehensive and flexible non-linear flow model was developed, which solved for the unknowns with an iterative technique. Additional component models with non-linear flow characteristics, such as turbulent pipes, annular pipes, strainers, and oil coolers, were developed. The non-linear solution technique was proven to be robust and flexible and was subsequently used in all the analysis programs. The heat transfer to the oil within the pressurised part of the lubrication system is modelled by the heat transfer program. The engine block temperatures are calculated by the engine block program. This program accounts for the heat transfer to the oil splashed on to the internal surfaces of the engine. The engine geometry is represented by a series of block elements and modelled as a nodal resistance network. This capability has particular importance during the design stage, rapidly providing an estimate of the temperature profile through the engine block, results which were previously only available from expensive and slow FEA models. It was shown that both the Jaguar AJ6 and V8 engine lubrication systems could be analyzed in great detail. Engine tests showed that the predicted flow rates, pressures and temperatures were in excellent agreement with measured values. The overall accuracy of the results induced a high degree of confidence in the thermofluid model. The final analysis package was proven to be easy to use, robust, rapid, flexible and accurate. The design analysis package, developed during the course of this study, represents a unique stand-alone simulation tool which can rapidly analyze any engine lubrication system configuration. This package provides a valuable analysis tool which can be used to optimise system designs at the initial design stage and the diagnosis of performance problems during the development phase. Parametric studies can be easily carried out on the lubrication system and engine block configuration to identify areas which can enhance heat transfer to the oil. The steady-state analysis package forms an excellent platform for the development of a full transient model. This would allow a detailed analysis of the lubrication system during engine warm-up, with the aim of reducing engine emissions and determining minimum oil requirements.

The machining of aluminium 2618 particulate reinforced Metal Matrix Composite (MMC) with 18 vol. % silicon carbide (SiC) using cemented carbide cutting tools has been undertaken. Two grades of cemented carbide inserts, uncoated K68 grade and coated KC910 grade (coated with TiC and A1203) having negative and positive rake angles (with and without chip breaker) have been used to machine this material in order to understand the machining process, tool failure modes and wear mechanisms. Turning tests in the speed range 15 - 10 m/min have been carried out at 0.2,0.4 and 0.6 mm/rev feed rates and 2 mm and 4 mm depths of cut. Both cemented carbide tools have been shown to be capable of machining the MMC and give reasonable tool lives. Low speed and high feed rate are found to be a good combination in order to machine this material effectively. Coated KC910 grade inserts with negative rake angle gave the best performance. The use of a chip breaker has no significant effect on the machining process of the NMC because the material is one which inherently short chips due to ductility limitations caused by the particles. Tool failure mode studies showed that the tools failed by flank wear. Tool wear mechanism analysis indicated that abrasion wear was the tool life controlling factor under all cutting conditions. The tool wear is related to the direct contact between the abrasive hard SiC particles and the cutting edge and their relative motion to the rake and clearance face. Hence, the hardness of the SiC particles is a dominant factor for the tool wear. Two separatem odels of abrasio. n haye.b een suggested.B uilt-up edge (BUE) which has a distinct shape was more pro i1ounced at lower cutting speeds, high feed rates and greater depth of cut. The presence of BUE has been found to increase tool life and reduce tool wear but at the expense of surface finish. The increase in tool life or reduction in tool wear is likely due to the protective layer that the BUE formed on the tool surface preventing a direct contact between the tool and chip. Linear regression analysis showed that the value of Taylor exponent n is high (0.8-1.0) compared to the values of n (0.2-0.3) obtained when machining steel. This indicates that the tool life is less sensitive to cutting speed for MMC than it is for steel.

The thesis describes an investigation into the fundamental phenomena governing the electrochemical machining process. It excludes a detailed investigation of the electrochemistry of the anode surface, work on which is in hand at the University of Nottingham. Photographs have been obtained of both electrode surfaces during machining in a two dimensional channel, showing the important role of gas evolution both at currents below the limit and in limiting the current density achievable. The distribution of electrical potential across the gap has been measured, clearly showing that the limiting current phenomenon is governed by a process occurring very close to the cathode. Measurements have been made of the streamwise current distribution; the distribution is essentially uniform at low currents, but as the limit is approached the current at the downstream end falls, and this fall then propagates upstream to fill about two-thirds of the channel. It has been found that the limiting current is proportional to (absolute pressure)^1/3, that the size of bubbles produced is inversely proportional to (absolute pressure)^1/3, and that reduction of the surface tension of the electrolyte leads to a marked fall in limiting current. The efficiency of the process has been investigated by a technique involving the measurement of the gas evolved during machining. An analysis of these results leads to the formulation of an explanation of the cell voltage-current characteristic, a hypothesis to explain the current limiting process, and a suggestion of the detailed mechanism of the latter. The cell voltage-current curve (above) can be explained as follows: - AB is equilibrium dissolution with etching, BC is caused by the formulation of a solid ( impure oxide? ) film on the anode surface. The rise in current from C to D is caused by the anodic evolution of a gas (oxygen? ), causing better mixing conditions in the diffusion layer near the anode and hence a higher metal dissolution rate. The ratio of current used for metal dissolution to current used for gas evolution appears to be a constant for this region. This process would be expected to continue along DE, but the current is limited by the achievement of a maximum rate of cathodic hydrogen evolution which brings about the reduction in current to F. This limiting current crisis has been analysed in terms of the mechanics of bubble formation, and a detailed explanation in terms of various mechanisms has been attempted. The experimental data is fitted by a model in which the hydrodynamic conditions give a velocity at which bubbles can be removed from a fixed number of nucleation sites. The limiting current is then predicted to be proportional to (surface tension)^2 x (absolute pressure)^1/3. Several proposals are made for further experiments to investigate these proposals, and for data needed to extend the industrial application of the theory developed.

Experimental and numerical experiments were carried out on different heat exchanger section types to determine the performance of vortex generators. The heat exchanger sections investigated were plain channel fin types with delta and rectangular winglet pairs, rectangular wings and embossed vortex generators. Fin-tube heat exchangers were also investigated in both in-line and staggered arrangements with and without vortex generators over the Reynolds number range 65 - 653 and angle of attack of vortex generators 15° - 60°. With the need for improved heat exchanger performance fin modifications are normally used to enhance the gas side heat transfer coefficient. However, with many of these fin modifications a significant pressure drop penalty can result. Vortex generators enhance heat transfer with a minimal increase in pressure drop. The effect of vortex generators in heat exchanger sections at low Reynolds numbers need to be assessed so that optimal positioning can be determined. To do this local heat transfer coefficients need to be measured. Steady steady state physical tests with a constant heat flux boundary condition were used to measure local and average heat transfer values and thereby measure the effect of vortex generators on heat transfer and pressure drop. Numerical modelling allows a detailed picture of the flow field and local heat transfer to be seen. Such numerical modelling by Computational Fluid Dynamics (CFD) is still in its infancy and comparisons against detailed experimental data are still needed before simulations can be used without physical testing. The advantage of CFD is that a large number of simulations can be completed in a short time span when compared to full size physical tests. At low Reynolds numbers, it was found that the inclusion of vortex generators in all heat exchanger types had the effect of increasing the average heat transfer coefficient and pressure drop. In all but one of the cases investigated, the in increase average heat transfer coefficient was larger than the increase in pressure drop. For the case of a staggered tube arrangement, with vortex generators at 60°, there was a reduction in pressure drop when compared to the case without vortex generators. This was due to delayed separation and reduced wake region behind the tube. This specific vortex generator position is considered to be near optimal. It is shown that CFD can successfully reproduce data from physical tests on heat exchanger sections with and without vortex generators. The procedures given can be generalised to optimise further geometries. The benefits of including vortex generators in heat exchangers will enable smaller heat exchangers to be utilised or an increase in effectiveness for the user.

The use of sailwing aerofoils in vertical axis wind turbines has been investigated. It was anticipated that this could make vertical axis turbines more suitable for water pumping and that this might help to meet the need for a cheap pump for irrigation existing in many parts of the world. A numerical analysis of the theoretical performance of such a turbine, using existing aerodynamic data for simply constructed sailwings, has been made. This gave an improved understanding of the operation of such turbines but showed a need for further aerodynamic data. Some new wind tunnel tests of sailwings are described in which the effect of pre-tension was investigated and four different fabrics were tested. The results are presented for angles of incidence up to 180 degrees and compared with previous data. With the fresh data, new performance predictions were made which led to the design of a two metre diameter prototype turbine. This used an inclined blade configuration with a guyed top bearing. Canvas was used for the sails. It was predicted that the turbine performance would be significantly affected by windspeed. The turbine was built and later tested in the open air. An acceleration test method was used and the tests generally confirmed the predictions. The averaged starting torque coefficient was about 0.07; the averaged peak power coefficient was about 0.1 at a tip speed ratio of 1.4. Consideration has been given to improving windpump system efficiency by improving the gust energy utilisation. Some tests of a diaphragm pump are described in which inertia flow effects were used. A pair of such pumps were later connected to the prototype turbine. A number of problems were encountered and satisfactory operation was not achieved in the time available. The main problem was the cyclic driving torque produced by the three bladed turbine.

The use and formation of small holes in different materials is critical to the efficient operation of many industrial processes. The application of such technology spreads across a very broad spectrum of problems, from the efficient ejection of diesel spray to the quality of drawn synthetic yarns. However, there is a lack of suitable non-destructive methods available for evaluating the quality of such holes below the size of 200 μm. This work has been further stimulated by evolving manufacturing technology which has both increased production throughput and the need to assess the quality of the hole. The thesis concentrates on the application of digital image processing to conventional microscopy. In particular random edge detection and internal surface shadow image reconstruction algorithms have been devised to achieve an internal view of the hole. This has been achieved by selectively filtering the infocus- strip formed by the microscope objective. Measurements have been made of the diameter, straightness and interior surface roughness. The method has been applied successfully to the following applications: The internal 3-dimensional visualisation within a 0.2 mm diameter diesel injector hole. The objective is to give a complete account of the hole diameter and straightness at the same speed as a spark erosion tool formed the hole. The internal surface roughness has also been measured. The measurement of a spinneret holes used in the production of synthetic yarn. In this case the hole size varies from 0.07 to 0.5 mm in diameter. Investigations have been performed for Rolls-Royce where an accurate measuremenits required of the straightness and diameter within a typical turbine coolant hole. The exercise has also measured the wall thickness between the hole and the blade surface. A research exercise has been tried for Marconi Electronics, their research specification being to construct the equivalent of a RS232 connector for fibre optic inter-connects. To achieve this they required a series of 0.1 mm holes through which to run a series of fibre optic cables. Again research has been performed to assess the straightness and diameter of these holes. Further investigations has been made to investigate more general applications of the technique for the interior mapping of large production components. Finally although the initial stages of this study were performed using a high cost research microscope an exercise to make a low cost dedicated automated inspection process has been successfully been completed.

This study was initiated by the need to improve current techniques used in the design of pneumatic conveying systems. At present, the commonly used method to predict the pressure drop in a vertical pipeline in a pneumatic conveying system is to obtain the pressure gradient in a horizontal for the identical conveying conditions and double the pressure gradient in the horizontal pipeline to give the pressure gradient in the vertical pipeline. In addition, scaling for pipeline bore in vertical pipelines is simply undertaken by considering the change in cross-sectional area. This is another area where sufficient investigation has not been undertaken. Therefore, as part of remit of this research study into improving current design techniques, an investigation into the effect of pipeline bore in vertical conveying would also be undertaken. This thesis documents the systematic approach that was used in order to produce some usable models that may be used in improving the understanding and design of pneumatic conveying systems. The models produced were based on data obtained by testing a range of products in an industrial scale pneumatic conveying test facility. The experimental data that was obtained from the pneumatic conveying tests form the basis of the ensuing analysis. The basic experimental data, which is primarily in the form of pressure gradient data for pneumatic conveying in horizontal and vertical pipelines, is explained in detail, along with the subsequent analysis of the data.

An investigation into the applicability of the bond-graph methodology, using the so-called Model Transformation Tools software, has been undertaken to model parallel robots. This software is a novel, non-commercial, program developed at the University of Glasgow, and in addition to the standard bond graph, it contains a powerful tool called the Hierarchical Bond Graph for dealing with very large-scale dynamical systems. It is the first time this tool has been applied for the modelling of parallel manipulators. A General Method for modelling parallel robots using the Hierarchical Bond-Graph concept has been developed. The method is based on related work on the modelling of closed chain robots using the Lagrange method. Introduction of a new design concept to be known as the Multi-cell Parallel Planar Manipulator. The methodology allows for an increase in the workspace of the manipulator by increasing the number of cells without affecting the number of DOF. It can also be shown to enhance the manoeuvrability of the system. Application of the multi-cell approach to a specific 2-DOF planar parallel manipulator and recognition of the need for a general model led to the development of a general dynamic model for the multi-cell manipulator using the Lagrange method. The reason for using the Lagrange formulation is that the necessary generalisation cannot be formalised using the Bond Graph technique due to the dependency of a bond graph on the specified structure of the system being modelled. Static balancing of the new general manipulator was addressed and a new method for balancing has been introduced. The method reduces the number of parameters to be adjusted to only one.

This thesis explores the different aspects of robotic manipulator modelling and covers both the dynamic and the kinematic issues for the purpose of improving the overall manipulator accuracy. It is shown that the modelling should not stop at producing the model, but rather the model should be validated. The thesis presents a description of the modelling process and examines the three most important formulations for dynamic modelling. A comparison of their performance and ease of use is made, both for manual and computer assisted implementation. Three commercial computer modelling packages are also described and compared with regard to their performance and ease of use for robotic manipulator modelling. It is shown that some software development is required to make the packages easy to use for manipulator specific modelling. As part of this work, one such development was a programme written as a back end to AUTOLEV. This combination provides a powerful tool for dynamic modelling and simulation of manipulators. A more integrated computer aided engineering approach is also discussed through modelling a large industrial manipulator using a geometric modelling package along with another dynamic modelling and simulation program. This approach is very efficient in providing useful information which is difficult to otherwise obtain from direct measurements. The thesis emphasises validation as part of the modelling process. A model does not have to be an exact mathematical description of the manipulator, inclusive of all characteristics, but rather a valid description for the intended use. It is shown that a manipulator model can be split into several joint models and validation performed on each using a parameter estimation technique. It is also shown that friction parameter tuning produces acceptable parameter values for a valid model of a Puma 560 manipulator.