Research, pilot scale and field developments of In-Situ Combustion (ISC) for enhanced oil recovery (EOR) in shallow, low pressure, heavy oil reservoirs intensified between the first and the second oil crisis from 1973 to 1981. A decline of interest in EOR followed the collapse of the oil prices in 1986. Renewed interest on in-situ combustion EOR research in the late 1980’s and beginning of the 1990’s was expanded and focused on high pressure medium and light oil reservoirs. The applicability of air injection in deep high pressure light petroleum reservoirs was established by research work of Greaves et al. in 1987 & 1988, Yannimaras et al. in 1991 and Ramey et a l in 1992. Accelerating rate calorimeter (ARC) tests were used to screen the applicability of various types of light oil reservoirs for in-situ combustion EOR by Yannimaras and Tiffin in 1994. The most successful light oil air injection project in the 1990s in the Medicine Pole Hills Unit, Williston Basin, N. Dakota started in 1987 and was reported by Kumar, Fassihi & Yannimaras, in 1994. Low temperature oxidation of light North Sea petroleum was studied at the University of Bath. A high-pressure combustion tube laboratory system was built at Bath University to evaluate performance of medium and light petroleum in-situ combustion processes. Gravity effects and the impact of horizontal wells in Forced Flow In-Situ Combustion Drainage Assisted by Gravity (FFISCDAG) were studied with three-dimensional combustion experiments. In this study, the university of Bath combustion tube experiments have been simulated and history matched. The tube experiments were up-scaled and field simulation studies were performed. A generic PVT characterization scheme based on 5 hydrocarbon pseudo-components was used, which was validated for light Australian and medium ‘Clair’ oil. A generic chemical reaction characterization scheme was used, which was validated for light Australian and medium ‘Clair’ oil. Advanced PVT and chemical reaction characterizations have been recommended for future work with more powerful hardware platforms. Extensive front track and flame extinction studies were performed to evaluate the performance of currently available non-iso-thermal simulators and to appraise their necessity in air injection processes. Comparative ISC field scale numerical simulation studies of Clair medium oil and light Australian petroleum were based on up-scaled combustion tube experimental results. These studies showed higher than expected hydrocarbon recovery in alternative EOR processes for both pre and post water flood implementation of ISC. Further in this study field scale numerical simulation studies revealed high incremental hydrocarbon recovery was possible by gravity assisted forced flow. The applicability of light oil ISC to gas condensate and sour petroleum reservoirs has been examined in this study with promising results. Light petroleum ISC implemented by a modified water flood including oxidants such as H2O2 and NH4NO3 are expected to widen the applicability of ISC processes in medium and light petroleum reservoirs, especially water flooded North Sea reservoirs.

The utilisation of alternative fuels, specifically gaseous fuel, in diesel engines has some disadvantages such as reduced engine thermal efficiency and increased exhaust gas emissions, although showing good results in reducing soot and NOX, simultaneously. Therefore, the effect of the hydrogen – enriched gaseous fuel in the dual fuelled combustion process was studied as a mean of improving further the combustion process and control emissions. The hydrogen addition was very effective in overcoming the penalty of the biogas or LPG-diesel dual fuelled engine operation. With the presence of hydrogen the oxidation rate of combustion product was improved thus reducing emissions (HC, CO and PM except NOX) whilst the engine thermal efficiency was also improved. The implementation of exhaust gas recirculation (EGR) and advanced injection timing showed great potential for dual fuelled engine. The utilisation of EGR at high LPG concentration further improved soot – NOX trade-off through low in-cylinder temperatures and reduced amount of liquid fuel used for combustion. Moreover, the properties of the injected diesel fuels as a pilot fuel have been shown to significantly affect the combustion process, rate of heat release, and emissions formation and oxidation. Oxygenated fuel like RME contributed to the reduction of emissions, except NOX, while a high cetane number fuel like GTL showed better tolerance to EGR addition and soot – NOX trade-off.

As a part of the sign-off procedure for body and power unit mounted components, random vibration testing is carried out to original equipment manufacturer (OEM) specification which the components must survive without damage. With the current move to minimise design and development costs and time-scales in the development of new vehicles, the use of CAE to validate system design through the use of virtual testing is becoming ever more important. The desire is therefore to develop computer aided analysis/numerical techniques that will replicate the vibration testing of body and power unit mounted components. The research demonstrates the development of numerical analysis to replicate the vibration testing of a Diesel Engine EGR Coolant Rail. A Finite element model of the coolant rail with rubber hoses was developed. The rubber material properties were derived from a series of tests (tensile test, relaxation test and DMA test) and were modelled using visco-hyperelastic constitutive equations. In order to check the validity of the simulation results, a test rig was designed and developed. In this research, the influence of the fluid dynamics on the vibration of a mechanical structure is also presented using the FSI method. A FE analysis was conducted to simulate the vibration behaviour of an EGR coolant rail consisting of a metal tube and rubber tubes at both ends of the metal tube with water inside it. The correlation study suggests a close agreement between the test and simulation results in terms of the prediction of the natural frequencies. This analysis enables design engineers to extract the natural modes and frequencies of vibrating parts with flowing fluid in order to investigate the failure modes and redesign brackets, supports, and fittings for desired strength.

The efficiency of a gas turbine engine is determined, in part, by the dimensional conformity of the turbine blades to the nominal design dimensions. Doncasters Precision Castings in Droitwich UK (DPCD) is involved in the development of next generation designs and as feature complexity increases, so does the dimensional variation of the part. The particle size distribution (P.S.D) of the zircon flour used to make investment slurries was found to significantly impact process capability. P.S.D influenced the rheological properties of slurry, shell build, sintering mechanisms and as a result the annulus length of solid equiaxed tip-shrouded turbine blades. The supplier of zircon flour to DPCD was not capable of controlling the P.S.D during the milling process so a blending technique was developed to reduce the variation of the incoming raw material. Implementation of enhanced process control methods significantly improved the DPCD process. Capabilities of the key process measures; plate weight, viscosity flow time, slurry stability and fired flexural strength were increased. As well as reducing dimensional variation, shell related scrap levels were also improved as a consequence of producing a more consistent ceramic mould system.

Contact of fuels with engine components at low and elevated temperatures for various amounts of time is found to be challenging as this contact has several effects on engine fuel system components and fuels. Also, storage of fuels for a long period of time is found to have almost the same effect on both engine components and fuels upon engine use. In this thesis fuel and engine components’ contact have been studied for four typical metals used in the construction of many engine fuel systems; in form of pure or alloys (copper, aluminium, mild carbon steel and stainless steel), studied after contact with three of the currently available fuels for use in compression ignition engines. Ultra-low sulphur diesel fuel (ULSD) was used as the fossil fuel, rapeseed methyl ester (RME) as the first generation biofuel and finally gas-to-liquid (GTL) as the second generation of biofuel, obtained via the Fischer-Tropsch process. The investigation was performed in different sections: fuels and metals have been studied for any degradation after contact at low and high temperatures for short and long exposure times, and an understanding of the corrosion process and any degradation on both metals and fuels has been achieved; due to the high hygroscopic character of these fuels and the presence of possible impurities in the fuel, the investigation was extended for analysis of the effect of the presence or absence of absorbed water and dissolved air (in the form of Oxygen) in fuels on degradation and corrosion characteristics of these fuels.

The weakness of a conventional Eulerian soot model in capturing primary soot size and its inability to access individual soot information led to the development of a Lagrangian soot tracking (LST) model as reported in this thesis. The LST model aimed to access the history of individual soot particles and capture the soot concentration and primary soot size distribution in high pressure spray flames, under diesel-like conditions. The model was validated in a constant volume spray combustion chamber by comparing the predicted soot volume fraction (SVF), mean primary soot diameter and primary soot size distribution to the experimental data of n-heptane and n-dodecane spray combustion. The inception, surface growth and oxidation models were adopted and modified from the multistep Moss-Brookes (MB) soot model, which was used in this study as the representative of Eulerian soot model. Parametric studies were carried out to investigate the influence of soot surface ageing and oxidation rates on the overall soot formation. Following the parametric study, the developed LST model which incorporated surface ageing effect and higher oxidation rates was implemented to investigate the effect of ambient oxygen and density on soot morphology in n-heptane spray flame. The LST model was shown to have better primary soot size prediction capability while still maintaining comparable performance in predicting SVF with respect to its Eulerian counterpart. The SVF distributions predicted by the LST model qualitatively correspond to the experimental results despite the peak soot location being predicted further downstream by 30 mm. The primary soot size distribution predicted by the LST model had the same order as the measured primary soot size distribution despite predicting larger soot size. The presence of surface ageing factor had a significant effect on the primary soot size distribution whereas only a slight effect on the SVF profile. A maximum soot size reduction of 48% was obtained when incorporating surface ageing effect. The consideration of surface ageing effect led to smaller primary soot size predicted and better agreement with the measured primary soot size distribution. The peak and mean primary soot sizes increased with increasing ambient density, from 14.8 kg/m3 to 30 kg/m3, at the core of spray jet. Meanwhile, the decrease in oxygen level from 21% to 12% at an ambient density of 14.8 kg/m3 caused a non-monotonic effect on the primary soot sizes at the core of spray jet. Trivial differences were predicted when oxygen level decreased from 21% to 15%. However, a significantly smaller primary soot sizes were predicted when oxygen level decreased further to 12%. In addition to net growth rates, soot cloud span and soot age were also found to play an important role in evolution of primary soot size. An increase in ambient oxygen and density resulted in a more upstream first-soot location. The effect of ambient density on soot age was not significant, whereas a lower oxygen level resulted in a longer soot age. A maximum soot age of 0.50 ms was obtained for both 21% and 15% O2 cases at both density levels. As oxygen level decreased to 12%, the maximum soot age increased to 0.58 ms due to lower combustion temperature. Overall, the LST model was shown to perform better in predicting primary soot size and can access information of individual soot particles which are both shortcomings of the Eulerian method. In addition, the LST model was also demonstrated to be able to predict soot age. Apart from playing a role in determining primary soot size, soot age can also serve as a useful parameter to answer various fundamental questions, such as when and where soot particles grow to a certain size, and help in the understanding of fundamental soot processes. Optimisation of the model and extension of its capability to capture soot aggregate structure, size and fractal dimension will be of interest in the future.

This document is the statement of independent and original contribution to knowledge represented by the published works in partial fulfilment of the requirements of the University of Brighton for the degree of Doctor of Philosophy (by publication). The thesis reviews the impact of research work conducted between 1992 and 1998 on various concepts to improve the economy and emissions of gasoline engines in order to address environmental and legislative pressures. The research has a common theme, examining the dilution of the intake charge (with either recycled exhaust gas [EGR], excess air, or the two in combination) in both conventional port injected [MPI] and direct injection [G-DI] combustion systems. After establishing the current status of gasoline engine technology before the programme of research was started, the thesis concentrates on seven major pieces of research between 1992 and 1996. These explored a subsequently patented method of applying recycled exhaust gas to conventional port injected gasoline engines to improve their economy and emissions whilst staying compatible with three-way catalyst systems. Nine other studies are reviewed which took place between 1992 and 1999 covering other methods of improving gasoline engines, specifically direct injection and two-stroke operation. Together, all the studies provide a treatise on methods to improve the gasoline engine and the thesis allows a view from a broader perspective than was possible at the time each study was conducted. In particular, the review identifies a range of strategies that use elements of the research that can be used to improve economy and emissions. Four major categories of systems researched include: conventional stoichiometric MPI engines developed to tolerate high EGR rates [CCVS]; two-stroke G-DI engines; G-DI engines operating stoichiometrically with high EGR rates; and G-DI engines operating with high dilution from both excess air and EGR. The findings of the studies illustrate that although good fuel economy improvements and emissions can be obtained with EGR dilution of stoichiometric engines, the highest fuel economy improvements require lean deNOx aftertreatment [LNA] and these, in turn, require new aftertreatment technologies and preferably new fuel specifications. The development of suitable LNA and the cost of implementation of these approaches represents one of the main barriers to improving gasoline engine fuel economy and emissions.

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This thesis details the development and evaluation of a procedure to predict the fuel consumption and pollutant emissions of spark ignition engines during cold-started drive cycles. Such predictions are of use in the early development and optimisation of an engine and vehicle combination with regard to legislated limits on vehicle performance over defined drive cycles. Although levels of pollutant emissions are the main focus of legislation, reducing fuel consumption is also of interest and drive cycle fuel consumption figures provide a useful benchmark of vehicle performance appraisals. The procedure makes use of a combination of engine friction models and experimentally defined correction functions to enable the application of fully-warm engine test bed data to cold-start conditions. This accounts for the effects of engine temperature on friction levels, mixture preparation and start-up transient behaviour. Experimental data to support the models and assumptions used are presented and discussed. Although not an essential part of the procedure, neural networks have been used to characterise the fully-warm engine mapping data. These are shown to provide an effective way of interpolating between engine mapping points. To facilitate the prediction of tail-pipe emissions, a simple catalyst efficiency model has been included and the complete procedure incorporated into a single software package enabling second-by-second fuel and emissions flow rates to be predicted for a given engine and vehicle combination over a defined drive cycle. This package is called CECSP or the Cold Emissions Cycle Simulation Program. The program has been designed to run on PC machines. The procedure has been validated by application to a typical 1.8 litre medium sized vehicle driven over the ECE+EUDC drive cycle and the predictions found to be within the target accuracy of +/-5% for fuel consumption and +/-10% for engine-out emissions. Envisaged applications of the procedure to rank the sources of increased fuel consumption and emissions due to cold-starting and engine and vehicle details are outlined.

The purpose of this project was to optimise a diesel engine converted to operate on natural gas, to suit the requirements for: low emissions, a high efficiency and sufficient power delivery within the constraints of cogeneration (combined heat and power) systems. Cogeneration Installations seek to improve the efficiency of power generation by utilising waste heat from the prime mover, as well as the production of electricity. Many small scale systems are based on open chamber gas engines, and, to reduce the payback time for the installation, the overall engine efficiency is of prime importance. Stationary engines can be subject to strict standards for emissions, the greatest challenge being presented by the control of NO emissions. The main difficulty is that the highest efficiency operating point of a spark ignition engine is also the point of maximum NO emissions. The extent of this problem was analysed by conducting tests across the entire operating map of the baseline engine at the required speed of 1500 rpm. The solution, in the form of a new high compression ratio combustion system was based on the following: An extensive literature review, the previous Brunel experience with gas engines, an evaluation of the baseline combustion and emissions performance, and the predictions of the Integrated Spark Ignition engine Simulation (ISIS) thermodynamic model. Tests were conducted on the new Fast Bum High Compression Ratio combustion system at compression ratios of 15:1 and 13:1, which demonstrated an extended lean burn capability such that an operating point was identified, that satisfied the conflicting requirements of: low emissions (less than 1g NOx/kWh or 360mg/m3), and a high brake efficiency (above 30%), as well as particular cogeneration criteria. The bmep was mostly above 6 bar. After further tuning and calibration with experimental data, the ISIS model was used to predict the engine power output, efficiency and emissions (NOx and CO) for the compression ratio of 15:1, across the entire operating map for both naturally aspirated and turbocharged configurations. The naturally aspirated results showed good agreement with the results of the experimental 15:1 FBHCR combustion system. The turbocharged engine was simulated with a bmep of 10 bar. The results identified much larger operating areas and all emissions limits were met above a brake efficiency of 36%. The conclusions are, that an open chamber fast bum high compression ratio combustion system can achieve very low emissions, particularly of NOx, and a high efficiency by having the capability of operating with lean enough mixtures. Further improvement in the efficiency is likely if other engine parameters (such as the valve timing) were to be optimised for 1500 rpm. The results from the turbocharged simulation show that turbocharging, whilst restoring the output can also achieve low emissions, and a higher efficiency than a naturally aspirated engine.