The finite element technique of structural analysis, though well known, is not exploited to its full potential in the automobile industry. Although some limited static analyses are carried out on automobile structures using finite element methods, dynamic analyses are almost entirely limited to experimental test programmes on prototypes. It-was the aim of this. project to develop computer programmes capable of carrying out the dynamic analysis of automobile structures using the finite element approach, checking their accuracy at each stage of development by comparing computed predictions with experimental results obtained from specimen structures. Three programming techniques have been developed. The first is an accurate non-iterative method, the second an iterative technique and the third utilises a matrix reduction technique in conjunction with the non-iterative method. The first two methods are limited as to the size of structure with which they can cope. The third method can handle large structures, since the sizes of the stiffness and mass matrices involved are reduced prior to frequency evaluation. The problems of exciting experimentally the pure modes of a complex structure have been reviewed and a special purpose multi-point excitation apparatus has been evaluated and used with success in determining the natural frequencies and mode shapes of a chassis frame beam structure and a complex car underbody plate and beam shell structure.

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The use of in-wheel motors, often referred to as hub motors as a source of propulsion for pure electric or hybrid electric vehicles has recently received a lot of attention. Since the motor is housed in the limited space within the wheel rim it must have a high torque density and efficiency, whilst being able to survive the rigours of being in-wheel in terms of environmental cycling, ingress, shock, vibration and driver abuse. Part of the work of this PhD involved an investigation into different slot and pole combinations in order determine a superior machine design, within given constraints based upon an existing in-wheel motor drive built by Protean Electric. Finite element analysis and optimisation have been applied in order to investigate the machine designs and achieve the optimum combination. The main work of this PhD, presents a high torque dense machine employing a new method of construction, which improves the torque capability with a smaller diameter, compared to that of the existing Protean in-wheel drive system. The machine is designed with an open slot stator and using magnetic slot wedges to close the slots. Having an open slot stator design means the coils can be pre-pressed before being inserted onto the stator teeth, this improves the electrical loading of the machine as the fill factor in the slot is increased. The electromagnetic impact of the slot wedges on the machine design has been studied, also a method of coil pressing has been studied and the impact upon coil insulation integrity verified. To ensure adequate levels of functional safety are met it is essential that failures do not lead to loss of control of the vehicle. Studies on a fault tolerant concept which can be applied to the design of in-wheel motors are presented. The study focuses on the ability to sustain an adequate level of performance following a failure, while achieving a high torque density. A series of failures have been simulated and compared with experimental tests conducted on a Protean motor. Finally a prototype is constructed and tested to determine the true level of performance. The prototype is compared to a new motor built in-house by Protean and achieves an improved level of performance.

The world faces a major problem. Fossil fuel sources are finite and the economic and environmental cost of those that actually remain make finding an alternative one of the great technological challenges of our age. Nearly 70% of refined oil is used for transportation making it one of the key sectors where change could yield large-scale global benefits. Combustion engine passenger vehicle technology is after a long period of stagnation progressing at a pace. Hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs) are also starting to penetrate the mass market. Unfortunately, HEVs do not remove our dependency on oil and the prospects of battery technology advancing sufficiently to allow BEVs to progressively replace the entire oil fuelled vehicles are currently slim. Their limited range and long recharge times prohibit them being useful for most modes of driving. One solution to the problem may be hydrogen fuel cell electric vehicles (H2FCEVs) as they offer great promise, but realistically face many challenges. The fuel cell allowed man to voyage to the moon in the 1960s and recent material advances have enabled them to be packaged into motor vehicles, so providing a zero emission replacement for the internal combustion engine. However, substantial infrastructure and geopolitical changes are required to make hydrogen production and delivery economic but this gas potentially offers a clean and sustainable energy pathway to entirely replace fossil fuels in motor vehicles. Few reported studies have comprehensively examined the optimal method of building power drive train subsystems and integrating them into an architecture that delivers energy from a fuel cell into driven road wheels. This project investigated the optimisation on the most efficient drive train topology using critical analysis and computer modeling to determine a practical system. No single drivetrain was found suitable for all driving modes and worldwide markets as the current ones typically offered either optimal performance or optimal efficiency. Consequently, a new drivetrain topology was proposed, developed, tested with a simulation environment that yielded efficiency and performance gains over existing systems. Also analysed was the effect of wider vehicle design optimisation to the development of sustainable hydrogen powered passenger vehicles and this was set against the wider social, scientific and engineering challenges that fuel cell adoption will face.

The aim of the research is to investigate multiple-speed transmissions for electric vehicles. This research is driven by the requirement to reduce emissions within the automotive industry increasing the demand for electric vehicles. The typical torque characteristics of an electric motor allow a clutchless single-speed transmission to be used, yet it is suggested by literature that the adoption of multiple-speed transmissions can benefit the energy consumption and vehicle performance. However, the published research up to date is limited in this field and lacks credible quantifiable evidence and as such motivates this research. The author developed complex non-linear models in Matlab/Simulink of case study vehicles with single and multiple-speed transmissions to analyse vehicle performance and simulate driving cycles to calculate energy consumption. The main focus of the research was based around a single and two-speed transmission developed by Vocis Drivelines and Oerlikon Graziano. The two-speed transmission has a novel mechanical layout comprising a friction clutch and sprag clutch allowing seamless gearshifts, a gearshift controller was developed as part of the research. The two transmissions were modelled in simulation with the gearshift dynamics of the two-speed transmission being simulated and considered with multiple controllers. In addition, a hardware-in-the-loop test rig was built at the University of Surrey by the author to test the prototype single and two-speed transmissions. The vehicle models were validated using the hardware-in-the-loop test rig whilst allowing performance tests and driving cycles to be carried out. The research showed that the adoption of the two-speed transmission over the single-speed transmission gave rise to reductions in energy consumption over numerous driving cycles of up to 4% for the case study vehicles. The vehicle performance was also improved with the top speed increased by 12% and the 0-100 km/h time reduced by 2%. In addition, a novel four-speed dual-motor drivetrain was investigated through simulations and compared with optimised single-speed and two-speed variants. The novel four-speed transmission delivered up to a 9% and 5% improvement in energy consumption during standard driving cycles over the single-speed and two-speed transmissions, respectively. The four-speed transmission allowed up to a 25% improvement in top speed and a 10% improvement in 0-100 km/h time over the two-speed transmission.

Brushless permanent magnet machines are a preferred topology for electric vehicle traction due to their inherent high efficiencies and excellent power densities. Electric and hybrid vehicles are a rapidly growing sector in the global automotive industry due to concerns regarding man made climate change, pollution in urban areas and the rising and volatile cost of fossil fuels. This research thesis investigates the design of brushless permanent magnet motors for electric vehicle applications from a technical and commercial perspective. A set of computationally efficient techniques are presented that enable the performance of any sinusoidal BPM machine to be evaluated over the entire operational envelope. By applying these techniques torque/speed characteristics, efficiency maps, complex duty cycles and thermally constrained performance envelopes can be modelled within a few minutes of computation. The techniques are comprehensively validated using experimental results from a 36 slot 10 pole interior permanent magnet motor designed for a small electric vehicle traction application. A complete design methodology is presented that provides a simple and rigorous approach to the design of BPM electric motors for traction applications. A number of modern CAD tools are utilised and electromagnetic, thermal and mechanical performance aspects are taken into account. It is shown that the use of this methodology can result in a significantly improved design, compared to the use of a unstructured iterative design approach, when used by an inexperienced designer.

Future electrical low voltage (LV) distribution networks are expected to have higher penetration of distributed generation (DG) systems, e.g. small wind turbines (SWTs), and battery electric vehicles (BEVs). The intermittent and time-varying characteristics of wind speed and BEV charging bring difficulties in evaluating the adverse performance, e.g. voltage violation and unbalance, on the residential distribution networks (RDNs). This thesis develops two probabilistic power flow methods, i.e. statistical time series (STS) and point estimate method (PEM), for evaluating voltage violation and voltage unbalance in RDNs caused by integration of SWTs and BEVs. The STS method combines statistical distribution analysis (SDA) and time series analysis (TSA). PEM is an approximation method using deterministic routines for solving probabilistic problems. The STS supports the Distribution Network Operators (DNOs) to obtain daily probability of voltage violations in RDNs, considering the time varying characteristics of network load, wind speed and BEV charging in a statistical manner. In PEM, evaluating the voltage unbalance takes into account the disparity of the loads at the three phases and also the unbalanced distribution of SWT outputs. The PEM calculation can also obtain daily probability of voltage unbalance factor in RDNs. The results presented prove that STS and PEM can provide faster evaluation of the probability of voltage violation and unbalance of a RDN than TSA. Based on the statistics of one year's seasonal load, wind data, at the same level of time granularity, the STS method can reduce computational power by over 98%. The assessment difference is approximately 6%. PEM evaluation, using one year's load and wind speed data, without distinguishing these data into seasonal categories or weekdays and weekends, reduces the computational power required by over 97.8%. The evaluation estimate is within 16%. The proposed methods can provide DNOs with a global picture of the voltage violation and unbalance profiles of RDNs under various SWT and BEV penetrations. For the distribution network planning, the quick evaluation of voltage violation and unbalance can help DNOs determine the maximum capacity of SWTs and BEVs a network can accommodate without voltage violation or unbalance.

Though hybrid, electric or fuel cell cars have the potential to lower carbon emissions in transport, they have not yet penetrated the market sufficiently. Policy makers want to solve that issue but have only limited insights on how to actually allocate their limited resources. To address this, research has started examining the transition of socio-technical systems and the roll-out of past technologies. This has led to the Multi-Level Perspective (MLP) framework, which offers a basis to discuss sustainability transitions, transition patterns and pathways. Though it already has provided relevant insights for policy makers on how they can achieve their transition targets, the MLP currently only offers a qualitative framework that only focuses on a narrative understanding of transitions. Quantitative approaches, however, lack the insights from the MLP research strand. Hence, an appropriate mean to assess the effectiveness of policies or firm strategies with regard to future transition pathways is missing. This PhD addresses these shortcomings, creating links between transition science and modelling to allow the examination of sustainability transitions. The outputs help identify suitable policy measures to achieve desired transitions that are compatible with governments' targets - hence to create (Mission-Oriented) Transition Policies that satisfy environmental and industrial targets.

This research develops a methodology and model formulation which suggests locations for rapid chargers to help assist infrastructure development and enable greater battery electric vehicle (BEV) usage. The model considers the likely travel patterns of BEVs and their subsequent charging demands across a large road network, where no prior candidate site information is required. Using a GIS-based methodology, polygons are constructed which represent the charging demand zones for particular routes across a real-world road network. The use of polygons allows the maximum number of charging combinations to be considered whilst limiting the input intensity needed for the model. Further polygons are added to represent deviation possibilities, meaning that placement of charge points away from the shortest path is possible, given a penalty function. A validation of the model is carried out by assessing the expected demand at current rapid charging locations and comparing to recorded empirical usage data. Results suggest that the developed model provides a good approximation to real world observations, and that for the provision of charging, location matters. The model is also implemented where no prior candidate site information is required. As such, locations are chosen based on the weighted overlay between several different routes where BEV journeys may be expected. In doing so many locations, or types of locations, could be compared against one another and then analysed in relation to siting practicalities, such as cost, land permission and infrastructure availability. Results show that efficient facility location, given numerous siting possibilities across a large road network can be achieved. Slight improvements to the standard greedy adding technique are made by adding combination weightings which aim to reward important long distance routes that require more than one charge to complete.

This investigation is concerned with the mitigation of hazards associated with ignited releases of hydrogen from compressed gas tanks aboard fuel cell vehicles. These releases are controlled through a safety valve installed on the tank known as a pressure relief device, but current designs use round nozzles and initially high mass flow rates for the release of hydrogen from the tank. Consequently, the separation distances from pressure relief device releases due to ignited hydrogen can approach 50 m for a "no harm" criterion. The present investigation is divided into four parts. The first body chapter extends previous work which simulated experimental releases from round and plane jet fires using a two-stage modelling approach. The same calculation domains as in the previous investigation are employed for consistency, with a one-equation turbulence model and with combustion simulated in the near-to-nozzle field. It was demonstrated that the new model yields results which are 20% more conservative than those found previously. The flow features of the combusting near-to-nozzle field are described qualitatively. The results from this investigation serve primarily as a model validation for subsequent chapters. The second chapter explores the efficacy of using a variable-aperture pressure relief device to reduce the initially high mass flow rate after a nozzle is opened. To that end, the motion of a spring-loaded throttle immediately upstream of the nozzle is modelled. Parameters for the spring coefficient and throttle geometry are chosen so that the initial mass flow rate does not exceed a prescribed value. Compared to a fixed nozzle with the same initial mass flow rate, the variable-aperture device reduced the blow-down time from 120 minutes to 21 minutes. A simple spring system (constant spring coefficient) was able to constrain the throttle motion appropriately. The use of a plane nozzle achieved a substantial reduction in a jet flame length with the same release conditions, but with an associated increase in the width of the flame. The third body chapter investigates the use of a radial jet to reduce the flame length further. To facilitate comparison, the radial jet had the same opening area as the earlier-studied round and plane jets. The radial jet flame took the shape of a thin, flat disc and reduced the flame length by 75% compared to the round nozzle (33% compared to the plane jet). The rate of increase of flame length with increasing pressure was compared with previous experimental results for round and plane jets, and it was observed that the power law correlation between flame length and inlet pressure had a lower exponent (0.3) compared to round jets (0.43). The fourth body chapter examines the effects of external air movement on the shape and size of the round hydrogen jet fire. Wind velocities of 5, 10, 20, and 30 m/s were examined in directions parallel to, orthogonal to, and directly opposing the direction of release. Deflections from side winds were measured and compared with experiments. A correlation was developed using the momentum flux ratio which collapsed the results from the highly underexpanded hydrogen jet fire onto the same curve as jet fires from other fuels at a variety of velocities, thus expanding the range of applicability of a previously stated correlation. Wind velocities in excess of 10 m/s reduced the flame length by half, but did not vary appreciably in the range examined. Co-flowing and counter-flowing wind yielded results qualitatively consistent with theoretical predictions. This thesis proposes two ways to manage hazards associated with releases of hydrogen from pressure relief devices. The use of a variable-aperture pressure relief device would allow the mass flow rate to be chosen a priori and to be set in such a way as to reduce hazards to life safety and to property for a known container volume and pressure. A radial jet pressure relief device reduced the flame length by 75% compared to a free jet and better managed high internal tank pressures than the uni-directional releases. Fina"y, the effects of wind on hydrogen jet fires were contextualised in a framework that captures other fuels at lower velocities. The particular wind velocity of 10 m/s was identified as a "threshold" above which further increases in the wind velocity do not decrease the flame length significantly, a result which was corroborated by contemporary experiments.