The maturity of simulation codes for aerodynamics (CFD) and structures (CSD) now leads to high fidelity computations of single discipline problems. The problem of aircraft flutter involves the coupling of aerodynamics and structures and has led to an interest in coupling CFD and CSD codes. There is strong motivation to couple existing codes to simulate this problem to avoid developing new methods since current single discipline methods are both well established and differ in their formulation (Eulerian fluids descriptions based on finite volume methods and Lagrangian finite element methods for structures). Recent work on the sequencing of codes has addressed the time sequencing issue which can be resolved by an iterative scheme to make sure that both simulations advance simultaneously in time. The regeneration of volume grids around a deforming geometry has also received attention. A third problem involves the passing of loads and displacement information between the fluid and structural surface grids. These grids will not in general coincide and it is likely that they will not even lie on the same surface. This thesis considers this problem and evaluates several existing and proposed solutions from the point of view of geometrical considerations and time marching flutter analysis. The test cases considered are for the AGARD 445.6 wing and the MDO wing. A boundary element formulation is also considered both for the elimination of the transfer problem and also a transformation method. A successful evaluation of the influence of the transformation method on the time marching response of a wing in a transonic flow is given and is based on the decomposition of the transformation into two components inwards and outwards of the plane of the structural model's plane.

Multi-resolution modelling differs from standard modelling in that it employs multiple abstractions of a system rather than just one. In describing the system at several degrees of resolution, it is possible to cover a broad range of system behaviours with variable precision. Typically, model resolution is chosen by the modeller, however the choice of resolution for a given objective is not always intuitive. A multi-resolution model provides the ability to select optimal resolution for a given objective. This has benefits in a number of engineering disciplines, particularly in autonomous systems engineering, where the behaviours and interactions of autonomous agents are of interest. To investigate both the potential benefits of multi-resolution modelling in an autonomous systems context and the effect of resolution on systems engineering objectives, a multi-resolution model family of the quadrotor micro air vehicle is developed. The model family is then employed in two case studies. First, non-linear dynamic inversion controllers are derived from a selection of the models in the model family, allowing the impact of resolution on a model-centric control strategy to be investigated. The second case study employs the model family in the optimisation of trajectories in a wireless power transmission. This allows both study of resolution impact in a multi-agent scenario and provides insight into the concept of laser-based wireless power transmission. In addition to the two primary case studies, models of the quadrotor are provided through derivation from first principles, system identification experiments and the results of a literature survey. A separate model of the quadrotor is employed in a state estimation experiment with low-fidelity sensors, permitting further discussion of both resolution impact and the benefits of multi-resolution modelling. The results of both the case studies and the remainder of the investigations highlight the primary benefit of multi-resolution modelling: striking the optimal balance between validity and efficiency in simulation. Resolution is demonstrated to have a non-negligible impact on the outcomes of both case studies. Finally, some insights in the design of a wireless power transmission are provided from the results of the second case study.

The continual expansion in requirements for vehicle features results in a rapidly increasing complexity of automotive electronic systems. Automotive electronics exhibit properties of systems of systems including that of emergent behaviour and validation complexity. This brings with it major financial risks for automotive manufacturers due to field failures, launch delays, recalls and loss of customers. The contention of this thesis is that robustness, i.e. the ability of a system to avoid service failures resulting from external faults, is a key design criterion for automotive electronics as a mass-market system of systems. Hence effective tools and techniques for the robust design of complex automotive electronic systems are required, but initial research suggests that limited published work on robustness, as opposed to safety, has been done in this field. This thesis addresses the research question of whether a viable framework of methods to substantially improve robustness in the design of complex automotive electronics systems can be developed. A literature review is conducted of potential methods for robust design from automotive and other domains, which identifies opportunities for contributions to knowledge in the following areas. The development of domain knowledge of the prevalence and causes of robustness related failures in the area of automotive electronics. The development of a “design for robustness” framework for complex automotive electronic systems, which should leverage best practices identified during the literature review. Particular items identified to be addressed are the adaptation of safety cases to robustness cases and the development of an approach to robustness modelling based on understanding of what are important factors to model pertaining to robustness of automotive electronics. A review is conducted of 43 well-documented field issues in the area of automotive electronic systems. It is found that these were predominantly (60%) robustness related issues, supporting the need for improved techniques. The results confirm robustness issues as complex, interactive and emergent in nature which are generally not present during normal operation but under transient conditions, in particular during initialisation and shut-down, during failures in other systems, as a result of tolerance spread and of unforeseen (ab)use cases. A design for robustness framework approach is developed incorporating the two proposed new methods of “robustness cases” and “robustness modelling”. A “robustness case” is a structured argument for the robustness of a system analogous to a safety case. A “robustness model” is a model based approach to early robustness verification of complex systems. These new methods are developed through their application to case study of infotainment and evaluated through subsequent application to a hybrid propulsion system. The design methods and artefacts are described in detail, including as generic approaches, and the test results from their use are shown and discussed. Finally the viability of the methods developed and their contribution to knowledge is discussed. The knowledge gained through the study of field issues of root causes of robustness issues in automotive electronics ensured the methods were well targeted. From the application of the methods to infotainment and hybrid propulsion systems a number of positive indicators of the effectiveness of the technique are observed. An analysis is conducted of whether the likely benefits would justify the incremental costs of implementing the methods. This shows that the methods became viable at the point where they can detect a single issue which would otherwise have been undetected until final testing. Deployment approaches, known limitations and areas for further work are also described.

This thesis has examined the applicability of steel–polypropylene–steel sandwich materials for the role of axial energy absorbers, an application previously undescribed in the literature. The results show that energy absorption performance of steel–polypropylene–steel sandwich materials can be predicted to within –2% and +8%, as well as highlighting the potential for their use in automotive applications. The work has demonstrated that the deformation modes in the steel–polypropylene–steel sandwich mimic the monolithic metal crash structure, however, with smaller fold radii, hypothesised to be due to shear in the polypropylene core. It was observed that increasing the core thickness increased the radius of the folds in the structure when undergoing collapse. Though due to the variability in the folding patterns of sandwich material in the crash structures seen in this work, it could not be stated with certainty. From the physical testing, the effect of core thickness for a fixed skin thickness is also defined. The physical tests showed a linear relationship between increasing core thickness and mean crush force. Further, the effectiveness of increasing the core thickness on the specific energy absorption was identified. The testing also showed an unprecedented >60% increase in energy absorption from quasi–static to dynamic for all three thicknesses of Steelite sandwich material, a level not seen in monolithic metal crash structures. Hence, suggesting an increased strain rate sensitivity of steel in MPM sandwich materials over the monolithic steel, a property which has been suggested in the literature for tensile tests but unknown in axial crash deformation. The testing demonstrated the potential for the crushing mode to change from a desirable progressive crushing mode to an undesirable and difficult to predict progressive failure. This occurred with a 7:1 core to skin thickness ratio, though failure of the steel skin is seen at all ratios. A 70%:30% ratio of thickness for the polypropylene core to steel skin is shown to minimise steel skin failure, i.e. the individual steel skin thickness should be no less than 15% of the total sandwich thickness. Finite element analysis presented in this thesis shows a single shell element model with laminated shell theory invoked can be used in LS–DYNA to predict the performance of the steel–polypropylene–steel sandwich materials. However, there is a potential thickness limit for which the model is applicable for the single hat and backplate crash structure considered; further research would be required to increase the confidence in the model. The single shell element model was accurate to within +8% of the physical test results. An analytical solution fitted the LS–DYNA single shell element model well and showed increasing the core thickness is more effective at increasing the specific energy absorption than increasing the skin thickness. The analytical solution also shows the potential for a steel–polypropylene–steel sandwich with a core to skin ratio of 70%:30% ratio by thickness to equal the performance of high strength aluminium alloys.

Hybrid electric vehicles are becoming increasingly common within the automotive market. Whilst there have been a large number of studies investigating hybrid electric vehicle drive-train control, for efficiency and active safety purposes, there is little work reflecting the effects of such technologies on pure vehicle dynamics. This thesis investigates the effects of hybrid drive-trains on vehicle ride and handling. A specific case study based on the hybridisation of a conventionally powered vehicle into a series hybrid electric vehicle is utilised as a means of doing so. In order to investigate the effects of the hybrid drive-train components on the vehicle’s ride and handling responses, detailed multibody models of both the Standard Vehicle (SV) and the hybrid General Technology Vehicle (GTV) were produced. As work was conducted in parallel with the Low Carbon Vehicle Technology Project (LCVTP), these models were created in a modular and physical fashion, as to allow for their easy parameterisation and adaption into other hybrid vehicle architectures. Prior to detailed investigation the standard vehicle model was successfully validated against real world test data collected as part of this work. Model responses for both the standard and hybrid vehicle models were investigated and analysed in the ride and handling domain. Ride analysis focused on statistical investigation of contact patch load and occupant comfort levels inside the vehicle. It was shown that there was a higher comfort region within both vehicles around the Cog and spring centre, as these two vehicle parameters moved with changes that were made to the GTV, the occupants within were subjected to different comfort levels. As the weight shifted rearwards in the GTV, occupants seated at the front were subjected to higher levels of discomfort, however those in the rear actually saw a slight increase in comfort levels. Levels of vertical acceleration within the GTV were found to generally be slightly larger, resulting from increased pitch and bounce motions due to an increase in coupling between these modes. Furthermore levels of low speed damping on the GTV were shown to be incorrect for its new mass parameters, which led to a further deterioration in ride quality. The handling analysis took on a novel form of investigating trends in specific handling metrics over the entire vehicle operating range. Said trends were then investigated further through more detailed model outputs. The GTV was shown to have a lower understeer gradient than the SV, due to the rearward shift in mass distribution and stiffer rear suspension. Transient handling responses were shown to be quite speed and manoeuvre specific, but all differences between the two vehicles could be explained by the differences in their dynamic indices and understeer gradients. Lateral acceleration response times were governed by the dynamic index and were always slower for the GTV, the magnitude of these responses were speed dependant, below the GTV’s tangent speed they were smaller than the SV’s, however above this speed they were larger. Yaw rate responses were more mixed, but were also seen to be governed by the dynamics index, at lower speeds or during simple unidirectional manoeuvres the GTV could obtain large faster yaw rates than the SV, during a transient to transient manoeuvre the GTV’s yaw rate responses were generally smaller, this was seen to be due to the way in which a higher dynamic index effects rear tyre slip angle generation having a larger effect at low speeds but a smaller effect when large slip angles are already present at the rear tyres. The results obtained have given a clear picture of how the inclusion of hybrid drive-trains can affect vehicle ride and handling. Something that was re-enforced by the results being generalised and applied to a few types of hybrid vehicle architecture in order to make recommendations on layout/packaging of these vehicles and highlight areas of importance for future hybrid vehicle design in terms of ride and handling.

In today’s global economy, competition is increasingly driven by a high rate of product renewal. In this context, with market demands for the development of high quality products at lower costs, highly customisable and with short life cycles, new technologies have been adopted by the automotive manufacturers in the move away from a local economy towards the global economy. The continuous evolution of this technology often requires the updating and integration of existing systems within new environments, in order to avoid technological obsolescence. To allow companies to compete in the global market, they (the companies) can no longer be seen acting as standalone entities and are having to reconsider their organisational and operational structure. This thesis presents a Knowledge Sharing Framework Design Roadmap to support rapid prototyping in the automotive and collaborative supply chain. IranKhodro Diesel (IKD) is the automotive company and CarGlass Company (Iran) is the supplier and sponsor of this research study. These two companies will be used to develop and test the Knowledge Sharing Framework Design Roadmap (KSFDR) methodology. An industrially based case study was conducted in IKD and CarGlass to identify key elements in the Knowledge Sharing Framework and provide the focus for this study. The study itself drew on empirical sources of data, including interviews with IKD personnel via an internal company survey. The absence of mechanisms to make information accessible in a multilingual environment and its dissemination to geographically dispersed NPD project team members was identified along with the lack of explicit information about the knowledge used and generated to support first stage rapid prototyping in the product development process with respect to reduction of costs and lead times. The Knowledge Sharing Framework Design Roadmap was tested between IKD and CarGlass. The business objectives in both IKD and CarGlass are the main drivers of knowledge system development. The main novel point from this research study is that this particular framework can be used to capture and disseminate information and knowledge. This was supported by positive feedback from a series of interviews with NPD practitioners. The Knowledge Sharing Framework Design Roadmap (KSFDR) methodology, however, can also be applied in other manufacturing and business environments. Further testing of the framework is strongly advised to minimise any minor flaws, which remain.

This thesis contributes to the research issue pertaining to the management of multiple energy sources on-board a pure electric vehicle; particularly the energy dense traction battery and the power dense supercapacitor or ultracapacitor. This is achieved by analysing real world drive data on the interaction between lead acid battery pack and supercapacitor module connected in parallel while trying to fulfil the load demands of the vehicle. The initial findings and performance of a prototype electric vehicle conversion of a famous Malaysian city car; the perodual kancil, is presented in this thesis. The 660 cc compact city car engine was replaced with a brushless DC motor rated at 8KW continuous and 20KW peak. The battery pack consists of eight T105 Trojan 6V, 225 Ah deep cycle lead acid battery which builds up a voltage of 48V. In addition to this, a supercapacitor module (165F, 48V) is connected in parallel using high power contactors in order to investigate the increase in performance criteria such as acceleration, range, battery life etc. which have been proven in various literatures via simulation studies. A data acquisition system is setup in order to collect real world driving data from the electric vehicle on the fly along a fixed route. Analysis of collected driving data is done using MATLAB software and comparison of performance of the electric vehicle with and without supercapacitor module is made. Results show that with a parallel connection, battery life and health is enhanced by reduction in peak currents of up to 49%. Peak power capabilities of the entire hybrid source increased from 9.5KW to 12.5KW. A 41% increase in range per charge was recorded. The author of this work hopes that by capitalizing on the natural peak power buffering capabilities of the supercapacitor, a cost effective energy management system can be designed in order to utilize more than 23.6% of the supercapacitor energy.

This thesis investigates the development of structural health monitoring systems (SHM) for aerospace applications. The work focuses on each aspect of a SHM system covering novel transducer technologies and damage detection techniques to detect and locate damage in metallic and composite structures. Secondly the potential of energy harvesting and power arranagement methodologies to provide a stable power source is assessed. Finally culminating in the realisation of smart SHM structures. 1. Transducer Technology A thorough experimental study of low profile, low weight novel transducers not normally used for acoustic emission (AE) and acousto-ultrasonics (AU) damage detection was conducted. This included assessment of their performance when exposed to aircraft environments and feasibility of embedding these transducers in composites specimens in order to realise smart structures. 2. Damage Detection An extensive experimental programme into damage detection utilising AE and AU were conducted in both composites and metallic structures. These techniques were used to assess different damage mechanism within these materials. The same transducers were used for novel AE location techniques coupled with AU similarity assessment to successfully detect and locate damage in a variety of structures. 3. Energy Harvesting and Power Management Experimental investigations and numerical simulations were undertaken to assess the power generation levels of piezoelectric and thermoelectric generators for typical vibration and temperature differentials which exist in the aerospace environment. Furthermore a power management system was assessed to demonstrate the ability of the system to take the varying nature of the input power and condition it to a stable power source for a system. 4. Smart Structures The research conducted is brought together into a smart carbon fibre wing showcasing the novel embedded transducers for AE and AU damage detection and location, as well as vibration energy harvesting. A study into impact damage detection using the techniques showed the successful detection and location of damage. Also the feasibility of the embedded transducers for power generation was assessed.

A parallelisation of the fully-implicit fractional step based in-house DNS code was implemented. Utilising this, DNS of streamwise travelling waves of spanwise wall velocity in a turbulent channel flow were performed at Reτ = 200; 400; 800 and 1600, scaling the input parameters in wall units. Studying the drag reduction at varying Reynolds number showed that the maximum drag reduction decreased as Re was increased. The scaling with Reynolds number was dependent on the control parameters and therefore the optimal parameters changed with Re. An oscillation in the drag reduction over the forcing period was observed and associated with strong variations in the turbulent statistics, angling of the streaks and coherent structures, and the deterioration of the drag reduction. The conditionally averaged λ2 structures were found and behaved differently depending on the sign of the vorticity. This included a strong angling of the structure which rotated in agreement with the wall velocity, and this angle reduced over the half- period. The λ2 structures were moved away from the wall over the period, a feature also visible in the variation of the vorticity fluctuations. The relationship between the drag reduction and the extrema of the turbulent profiles were compared, and showed a good correlation between the maximum of the v rms profile and the DR achieved. This was seen to be independent of Reynolds number when the maximum v rms of the no control flow was subtracted. The variation of the power spent and net power saving with Reynolds number was also studied. The power spent scaled well with Reτ-0.16, and the net power saving scaled differently depending on the control parameters used. Although the maximum value was reduced as the Reynolds number increased.

Environmental legislation is driving research into new technologies for future automotive products. Electric vehicle technologies have the potential to meet these legislative requirements, but are currently restricted by cost implications. This work focuses on the potential for offsetting this cost against potential benefits of the technology. In particular, the application of a motor at each wheel, facilitating Independent Wheel Control (IWC). A scale model vehicle is incorporated into a Hardware-in-the-Loop (HIL) simulation for the application of developing IWC strategies. The model uses four motors, each driving a single wheel in order to effect this control. Control strategies are 'rapid prototyped' in MathWorks Simulink™ using an industrial standard tool, dSPACE™, to operate the strategies in real-time HIL simulation. The application of a control strategy, representative of a conventional 4x4 behaviour, incorporating a lockable centre differential is applied. Shaft compliance is modelled in order to provide a test of the system operation with a transient dynamic response. Stability issues raised through this application are related to signal processing. An estimator is devised in software to overcome these issues, producing a stable system response. The work concludes that the use of a physical scale model for the development of IWC strategies is inappropriate in the context of supporting the development of a full-scale vehicle due to the complexity of reproducing a scaled tyre. However, in a broader sense, the approach of utilising a physical model has demonstrated significant benefits in promoting the concept of lWC within an industrial organisation, and in assisting product development.