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Organic friction modifiers have long been added to oil formulations to help improve lubricity, particularly in the boundary lubrication regime. Many aspects of organic friction modifier behaviour remain unknown. In this thesis these aspects are isolated and probed using numerous different techniques. Organic friction modifiers are amphiphilic molecules comprising a head group and a hydrocarbon chain. The chemistry of the organic friction modifier employed affects the observed film forming properties and frictional behaviour. Factors of interest include the effects of the head group type and of alkyl chain unsaturation. Commercially employed organic friction modifiers tend to comprise a mono-unsaturated oleyl group. This project deals with the impact this has on organic friction modifier performance. Another area of interest is the behaviour of glycerol monooleate. Glycerol monooleate is one of the most commercially employed organic friction modifiers and is atypical to model organic friction modifiers in that it has a rather bulky polar moiety. Model organic friction modifiers usually have only one functional group; however, glycerol monooleate has two alcohol groups and an ester group. Although glycerol monooleate is widely employed in oil formulations, many aspects of its behaviour remain uncertain. In this thesis several techniques are used including upscale friction experiments such as High Frequency Reciprocating Rig tests, Ball on Disc pure sliding friction tests and Mini-Traction Machine mixed sliding-rolling tests. Organic friction modifier film formation on ferrous and non-ferrous surfaces is investigated in situ from solution in hydrocarbon solvent using the Atomic Force Microscope. Organic friction modifier films formed on surfaces during friction tests are investigated ex situ by Atomic Force Microscopy and Time-of-Flight Secondary Ion Mass Spectroscopy.

The concept of gasoline direct injection engines is at the forefront of modern research. Two major concerns with the design are the incomplete evaporation of the injected fuel that leads to increased engine-out emissions and the process of injector fouling caused by the direct exposure of the injector to the flame. The latter also reduces the lifetime of this component and also increases emissions at the same time. These are critical issues for OEMs as emissions legislations around the world demand increasingly stricter thresholds. The research presented is split into two separate parts, to tackle both concerns. First, a series of fuel blends and operating conditions and their effect towards spray shape, droplet size and velocity as well as wall wetting will be investigated in a dedicated injection chamber. In order to quantify the amount of fuel that forms a liquid deposit on the surface a novel measurement technique is presented. The data gathered in these measurements is then used to show trends between the blends investigated and to give suggestions for potential improvements of future engine designs and modified engine operating conditions to reduce the amount of particulate emissions. In the second part of the research a series of injectors that were previously fouled are investigated. The fouling caused a significant increase of particulate emissions in test engines and the focus here is to provide possible explanations for this drift. Additionally, some of the injectors were treated with a detergent fuel which reverted the change in emissions. A comparison of these injectors shall provide information about potential applications of such blends and how they would benefit the longevity of modern engines.

Development of computational methods to solve reactor physics and shielding problems has been a constant area of research since the 1940s and the Manhattan project. As technology and improved methods have been developed more detailed simulations have been possible. However, solving the neutron transport equation for full-core heterogeneous problems is still a challenging proposition, even for modern numerical methods and petaflop high performance computers. The high dimensionality of the physical problem combined with the complex geometries of reactor cores and their shields has meant that approximations in all dimensions have to be made in order to make finding a solution tractable. Such approximations include using a simple diffusion approximation and coarse geometric approximations typically discretised with polygonal finite elements. This thesis details the investigation into the application of Isogeometric Analysis (IGA) to second-order forms of the neutron transport equation with application to reactor physics and the development of a new parallel reactor physics code PIRANA. Isogeometric Analysis is a generalisation of the finite element method which uses the mathematical basis of computer aided design (CAD) for numerical analysis. By using the CAD model directly in analysis the geometry is modelled exactly with no approximation. The results of this study have found that the exact geometric representation of the IGA method can significantly improve the accuracy of solutions to the neutron transport equation compared to the finite element method. Additionally, the exact geometric representation has allowed for local refinement to be performed for non-Cartesian geometries within the analysis program which can result in a significant reduction of the computational cost. Finally, IGA allows for optimisation of the multigroup form of the neutron transport equation by solving each group on a uniquely refined spatial mesh significantly reducing the total number of spatial degrees-of- freedom for the same overall solution accuracy.

To fully understand mechanical and structural performance of laminated glass, seven laminated cases were designed to assess the influence of glass types, polymer interlayer thickness, polymer interlayer types and multi-layered interlayer. An innovative apparatus combining 3D-Digital-Image-Correlation and ring on ring tests have been tested successfully, major strain and out of plane displacement at the supporting side were monitored. Novel sabot design helped the rubber projectile to eject without deformation in gas gun tests. The third innovative design was the gas gun system which allowed a stereo system of two high speed cameras for 3D-Digital-Image-Correlation and one camera monitoring impact performance, strain gauge system, and detecting velocity to be synchronised at the same time. Regarding major research findings, for monolithic glasses, an approximate 0.8% major failure strain was identified regardless of its thickness which was used as a failure criterion for laminated glass. For laminated glasses, an increase of thermoplastic-polyurethane thickness will allow laminate to absorb more energy at quasi static and low velocity ranges, but lower the supporting face strain at high velocity. Chemically strengthened glass used as frontal glass layer has better performance in terms of energy consumption in quasi static and low velocity ranges comparing to thermally strengthened glass. Different types of interlayer have different functionalities. Sentry-glass-plus is more rigid comparing thermoplastic-polyurethane and polyvinyl-butyral which can transfer more shear between layers and lower the strain at the back. However, it has poor adhesion on glass proven by large peeling off of the glass fragments after gas gun experiments. Comparing with polyvinyl-butyral, thermoplastic-polyurethane has good adhesive properties with Sentry-glass-plus and glass. A multi-layered interlayer system using structural Sentry-glass-plus and adhesive thermoplastic-polyurethane as interlayers can significantly reduce the strain during impact and prevent glass fragments from flying off at high velocity which is favourable in real scenarios (e.g. bird-strike).

Accurate prediction of the vibration response of friction joints is of great importance when estimating both the performance and the life of built-up structures. The relative motion at the frictional interfaces can lead to a highly nonlinear dynamic response and cause fretting wear at the contact. The latter, by changing the contact surface geometry, affects the contact conditions of the interface and consequently impacts the nonlinear dynamic response of the entire assembly, which today is ignored in the analysis. To address the above issue, a novel multiscale approach that incorporates wear into the nonlinear dynamic analysis is presented. A contact solver, based on boundary integral equations, is implemented to compute local contact stresses and stiffness which, in combination with an energy wear approach, allow to compute fretting wear at the contact interface. The nonlinear dynamic response of the whole system is computed using a multi-harmonic balance approach and a continued iteration between the contact and nonlinear dynamic solvers allows the prediction of the nonlinear dynamic response over time. After describing its implementation in detail, the contact solver results are fully verified against a range of test cases for which an analytical solution is available. A comparison against finite element simulations demonstrates the accuracy and computational benefits of the implemented solver. The limitations of the solver due to its underlying half-space assumption are also discussed. The proposed multiscale approach is applied to an underplatform damper-blade system. A significant impact of fretting wear on the nonlinear dynamic behaviour of the blade-damper system is observed, highlighting the sensitivity of the nonlinear dynamic response to changes at the contact interface due to wear. A strong effect of rough interfaces on the wear rate and the resulting interface parameters was also discovered, making them a crucial component for nonlinear dynamic response predictions over time.