The evolution of British airborne warfare cannot be fully appreciated without reference to the technological development required to convert the detail contained in the doctrine and concept into operational reality. My original contribution to knowledge is the detailed investigation of the British technological investment in an airborne capability in order to determine whether the development of new technology was justifiable, or indeed, entirely achievable. The thesis combines the detail contained in the original policy for airborne warfare and the subsequent technological investigations to determine whether sufficient strategic requirement had been demonstrated and how policy impacted upon the research programme. Without clear research parameters technological investment could not achieve maximum efficiency and consequent military effectiveness. The allocation of resources was a crucial factor in the technological development and the fact that aircraft suitability and availability remained unresolved throughout the duration of the war would suggest that the development of airborne forces was much less of a strategic priority for the British than has previously been suggested. Ultimately, despite the creation of a dedicated research institution in 1942 (Airborne Forces Experimental Establishment), and the development of specialist hardware such as the assault glider, the British did not possess the material resources required for the large-scale deployment of airborne troops. Analysis of the technology has revealed that the development of airborne warfare was as much for the purpose of psychological warfare and British morale as it was for offensive operations.

Many efforts have been made in recent years to address issues surrounding the use of fossil fuels for energy. However, it must be conceded that world’s dependence on fossil fuels cannot cease overnight. In reality, the switch is expected to be a relatively slow migration of technologies over many decades. During this transition period the world will need bridging technologies to aid in the transition to alternate energy sources. One such technology, which shows much promise in boosting energy efficiency while reducing emissions and costs, is the adoption of hybrid power systems. This thesis investigates the motives behind seeking alternate energy sources and discusses the future need to move away from fossil fuels and the likely role hybrid power systems will play in the future. A general outline of a hybrid power system is presented, and its key subsystems identified and discussed, paying attention to power generation, energy storage technologies and the performance of these systems. A novel method of specifying the power sources in bespoke hybrid power systems are presented. A custom software tool aimed at evaluating how different hardware configurations and output duty cycles affect the performance of a hybrid power system is then presented and used in several case studies to investigate the effectiveness of the presented method in specifying power sources for a given application. It was found that the hardware, output application and control strategy of a hybrid power system affects the overall performance of the system. Furthermore, if the output duty cycle of a hybrid power system is repetitive and predictable in nature, it was found that the hardware and control strategy of the system can be fine-tuned using simple techniques to optimise the overall system configuration and performance.

This thesis is aimed at the identification of causes for the instability of Ti-49.8Ni and Ti-40.8Ni-9Cu (at.%)shape memory alloys during thermomechanical cycling. To assess the macroscopical and microstructural behaviour several techniques were employed. Thermo-mechanical tests (TMT) revealed that TiNi did not stabilise under the tested conditions. In contrast, TiNiCu showed a more stable behaviour. Whereas the maximum testing temperatures were found to be detrimental for the strain output in TiNi, none such influence could be found in TiNiCu. In TiNiCu increasing stresses seems to prevent the material stabilisation.During in-situ TMTs under high energy X-ray radiation in a synchrotron, microstructural factors influencing the stability of the material were assessed. No hint on a negative influence of remnant or intermediate phases and texture or variant selection was found. Instead increasingly negative strains build up in austenite possibly causing instabilities. In TiNiCu differences in the processing where found to cause changes in the phase transformation temperatures. These could be linked with differences in the chemical composition and in the level of inhomogeneity of precipitates.

This thesis proposes a new modular multilevel converter with embedded cell balancing for battery electric vehicles. In this topology, the battery cells are directly connected to the half-bridge choppers of the sub-modules, allowing the highest flexibility for the discharge and recharge of each individual cell. Tht: traditional battery management system is replaced by the control of the converter, which individually balances all the cells. A new balancing algorithm is presented and discussed in. the thesis, showing that the converter generates symmetric three-phase voltages with low harmonic distortion even for significantly unbalanced cells. The thesis also analyses stationary recharge of the battery cells from both three-phase and single-phase ac sources. The performance of the converter as a traction drive is assessed in terms of torque-speed characteristic and power losses for the full frequency range, including field weakening. A simplified model for estimating conduction and switching losses for the proposed modular multilevel converter is presented and the results for a typical driving cycle are compared with a traditional two-level converter. Simulation and experimental results on a kW-size prototype have confirmed the feasibility of the proposed traction modular converter in terms of effectiveness of the cell balancing control, validity of the proposed loss model, suitability of use for traction and effectiveness of recharging operations.

This thesis reports initial experimental results that provide the foundation for low-THz radar imagery for outdoor scenarios as expected in automotive sensing. The requirements for a low-THz single imaging radar sensor are outlined. The imaging capability of frequency-modulated continuous-wave (FMCW) radar operating at 150 GHz is discussed. A comparison of experimental images of on-road and off- road scenarios made by a 150 GHz FMCW radar and a reference 30 GHz stepped frequency radar is made, and their performance is analysed.

High Pressure Die Casting (HPDC) is an attractive option for automotive manufacturers, as it has a number of advantages over wrought process routes. An improved understanding of the defects which may result from the process could allow castings to deliver lighter vehicle structures. A novel algorithm was developed to predict the formation of entrainment defects, which may limit the strength of castings. This model was integrated into FLOW-3D, a fluid dynamics solver. Theoretical advances were made, which offer a means of extrapolating a spatial distribution of damage to location specific statistical distributions, an improved way of characterising the contribution of each defect type to strength, and a means of correlating parameters for statistical distributions, allowing the variation in strength may be predicted at arbitrary locations within a casting. Casting and numerical experiments were performed, to evaluate these algorithms and underlying fluid flow solution, and to test the influence of entrainment defects on the strength of HPDC parts. Defects formed by air entrainment were found to significantly limit the strength of the studied castings. The methods and techniques explored in this work showed promise, but further advances would be needed, before ab intio strength prediction for HPDC parts can be realised.

Airport airside planning and design is an essential process to provide guidance for construction, rehabilitation and development phases and to accommodate the required capacity and efficiency for airport operations based on international safety standards, recommendations, regulations and local limitations. However, airport operators are suffering from infrequent and unexpected risks that could occur and lead to reduced safety margins in airport airsides. Furthermore, safety is one of the most common challenges in airside operations; it should be periodically assessed and deeply investigated, tracking the causes of the risks and their potential impacts. To cope with these challenges, this thesis demonstrates a novel approach of safety design assessment process models to assess, review and manage planning and design during the existing conditions of an airport airside lifecycle by combining three techniques. This is a new methodology for incorporating risk assessment in airport airside planning and design systems and provides a helpful and periodical evaluation and decision-making tool. It is a useful model for airport stakeholders to investigate, quantify, and mitigate the possible functional safety threats to their operation. It will help to avoid underlying precursory hazards that contribute to airside safety risks and could increase awareness of potential risk situations.

The competitive and ever growing business of aerospace technology is constantly pushing for improvements in the engine efficiency to deliver high performance with lower costs and reduced environmental impact. Over the past 50 years, the Turbine Entry Temperature (TET) has been increased by more than 400˚C to deliver improved engine performance. This has mainly been made possible with the advancement of materials and manufacturing technologies alongside improvements in computational capabilities. With the temperature capabilities of new materials ever expanding to meet efficiency targets, use of modelling tools not only to predict material behaviour, but also to improve processing techniques are becoming common. An integrated approach to design and manufacturing is being heavily pursued especially by aerospace companies to help design and manufacture of components right first time. The main objectives of this research are twofold. Firstly, this research aims to model the development and distribution of residual stresses for two representative aerospace turbine discs made from a nickel- based superalloy U720Li after heat treatment, and predict the subsequent distortions during machining operations. Secondly, this research provides the much needed integrated manufacturing modelling approach that enables process optimisation and design of experiments based problem solving to be adapted to highly non-linear heat treatment and machining manufacturing models

State-of-the-art diesel exhaust gas aftertreatment systems have proved to substantially decrease vehicles’ emissions. However, their effectiveness depends on the temperature of the exhaust gas and catalysts to activate the emissions’ conversion reactions. In this research study, different strategies for thermal management of diesel aftertreatment systems were investigated to reduce vehicles’ emissions. A thermal energy storage (TES) system was developed and implemented for a light-duty diesel aftertreatment system. In this approach, the extra thermal energy of the exhaust gas during engine’s high-load conditions can be stored and reused when required, in order to maintain the emissions’ conversion reactions during a driving cycle. The results indicated that by increasing the thermal conductivity of the thermal energy storage medium and the catalyst’s substrate, the TES system can reduce the vehicle’s cumulative CO and THC emissions by 91.7% and 41.2% respectively. Active heating of the aftertreatment system was studied to provide the catalysts with the required thermal energy, in order to shorten the catalyst’s light-off period and also prevent the catalyst from light-out during a driving cycle. A pulsating electrical catalyst heating strategy and a combined electrical heating and fuel post-injection approach were developed to increase the heating efficiency while minimizing the vehicle’s emissions.

The thesis reports work aimed at assessing diffusion bonding during Hot Isostatic Pressing (HIPping), with the long term aim of developing re-usable tooling for the manufacture of near net shape aero-engine components from Ti-6Al-4V (Ti-6-4). Microstructural analysis and mechanical property assessment have been carried out on several different types of sample in order to define the potential of this process-route when using different starting materials and different HIP procedures. This research work is split into three sections; the first section consists of optimising the process parameters for solid-state or solid-to-powder HIP-DB of Ti-6-4 to produce monolithic or integrated engineering components, the second section consists of developing a two-stage approach, which would be required if reusable tooling is to be developed for near net shape HIPping for solid-to-powder HIP-DB of Ti-6-4. Finally the third section consists of work to develop a fixed tool process using high temperature-resistant reusable tooling and solid or powder Ti-6-4 to produce near net shape (NNS) components using mild steel as a sacrificial canister or encapsulation material.