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The increased severity and prevalence of insoluble deposits formed on fuel injectors in gasoline direct injection (GDI) engines precipitates negative environmental, economic and healthcare impacts. A necessary step in mitigating deposits is to unravel the molecular compositions of these complex layered materials. But very little molecular data has been acquired. Mass spectrometry shows promise but most techniques require the use of solvents, making them unsuited for analyzing insoluble deposits. Here, we apply the high mass-resolving power and in-situ analysis capabilities of 3D OrbitrapTM secondary ion mass spectrometry (3D OrbiSIMS) to characterize deposits formed on the external tip and internal needle from a GDI injector. This is the first application of the technique to study internal GDI deposits. Polycyclic aromatic hydrocarbons (PAHs) are present up to higher maximum masses in the external deposit.

The determination of size distribution of soot particles and agglomerates in oil samples using a Nanosight LM14 to perform Nanoparticle Tracking Analysis (NTA) is described. This is the first application of the technique to sizing soot-in-oil agglomerates and offers the advantages of relatively high rates of sample analysis and low cost compared to Transmission Electron Microscopy (TEM). Lubricating oil samples were drawn from the sump of automotive diesel engines run under a mix of light duty operating conditions. The oil samples were diluted with heptane before analysing. Results from NTA analysis were compared with the outputs of a more conventional analysis based on Dynamic Light Scattering (DLS). This work shows that soot-in-oil exists as agglomerates with average size of 115 nm. This is also in good agreement with TEM analysis carried out in a previous work. NTA can measure soot particles in polydisperse oil solutions and report the size distribution of soot-in-oil aggregates.

The oil distribution system of an automotive light duty engine typically has an oil pump mechanically driven through the front-endancillaries-drive or directly off the crankshaft. Delivery pressure is regulated by a relief valve to provide an oil gallery pressure of typically 3 to 4 bar absolute at fully-warm engine running conditions. Electrification of the oil pump drive is one way to decouple pump delivery from engine speed, but this does not alter the flow distribution between parts of the engine requiring lubrication. Here, the behaviour and benefits of a system with an electrically driven, fixed displacement pump and a distributor providing control over flow to crankshaft main bearings and big end bearings is examined. The aim has been to demonstrate that by controlling flow to these bearings, without changing flow to other parts of the engine, significant reductions in engine friction can be achieved.

Airbus commercial wings are assembled manually in dedicated steel structures. The lead time to design, manufacture and commission these fixtures is often in excess of 24 months. Due to the nature of these fixtures, manufacturing is slow in responding to changes in demand. There is underused capacity in some areas and insufficient ramp-up speed where increased production rate is needed. Reconfigurable Manufacturing Systems and Reconfigurable Assembly Systems (RAS) provide an approach to system design that provides appropriate capacity when needed. The aim of the paper is to review RAS technologies that are suitable for cost-effective wing structure assembly and what knowledge gaps exist for a RAS to be achieved. The paper examines successful cases of RAS and reviews relevant system design approaches. Cost savings are acknowledged and tabularised where demonstrated in research. The research gaps to realising a RAS for wing assembly are identified and different approaches are considered.

Electric machines in aerospace applications are subjected to extremely high operating temperatures. This increases coercivity or decreases saturation flux density of the electrical steel resulting in increased core loss. The need for high power density and increased operating speed favours the use of thin gauge Silicon Steel (Si-Fe) and Cobalt Iron (Co-Fe) laminations for aerospace applications. Therefore, the variation in iron loss is studied for three grades of Si-Fe laminations by subjecting them to controlled ageing in laboratory. The analysis is also provided over a range of flux density and frequency to generalize the phenomenon over the operating domain. The results of ageing the laminations are in turn used to predict the degradation in performance of a 1.15 MW, 16-pole 48-slot propulsion machine for aerospace application. The degradation is estimated in terms of variation in iron loss.

The size and morphology of soot particles and agglomerates extracted from lubricating oil drawn from the sump of a diesel engine have been investigated and compared using Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). Samples were prepared for electron microscopy imaging by both centrifugation and solvent extraction to investigate the impact of these procedures on the morphological characteristics, such as skeleton length and width and circularity, of the obtained soot. It was shown that centrifugation increases the extent of agglomeration within the sample, with 15% of the agglomerates above 200 nm compared to only 11% in the solvent extracted soot. It was also observed that the width of centrifugation extracted soot was typically 10 nm to 20 nm larger than that of solvent extracted soot, suggesting that centrifugation forces the individual agglomerate chains together.

The thermal efficiency of an internal combustion engine at steady state temperatures is typically in the region of 25-35%[1]. In a cold start situation, this reduces to be between 10% and 20% [2]. A significant contributor to the reduced efficiency is poor performance by the engine lubricant. Sub optimal viscosity resulting from cold temperatures leads to poor lubrication and a subsequent increase in friction and fuel consumption. Typically, the engine lubricant takes approximately twenty minutes [3] to reach steady state temperatures. Therefore, if the lubricant can reach its steady state operating temperature sooner, the engine's thermal efficiency will be improved. It is hypothesised that, by decoupling the lubricant from the thermal mass of the surrounding engine architecture, it is possible to reduce the thermal energy loss from the lubricant to the surrounding metal structure in the initial stages of warm-up.

Characterization of soot nanoparticle morphology can be used to develop understanding of nanoparticle interaction with engine lubricant oil and its additives. It can be used to help direct modelling of soot-induced thickening, and in a more general sense for combatting reductions in engine efficiency that occur with soot-laden oils. Traditional 2D transmission electron microscopy (TEM) characterization possesses several important shortcomings related to accuracy that have prompted development of an alternative 3D characterization technique utilizing electron tomography, known as 3D-TEM. This work details progress made towards facilitating semi-automated image acquisition and processing for location of structures of interest on the TEM grid. Samples were taken from a four cylinder 1.4 L gasoline turbocharged direct injection (GTDI) engine operated in typically extra-urban driving conditions for 20,284 km, with automatic cylinder deactivation enabled.

Reconfigurable tooling frames consisting of steel box sections and bolted friction clamps offer an opportunity to replace traditional expensive welded steel tooling. This well publicized reconfigurable reusable jig tooling has been investigated for use in the assembly of a prototype compound helicopter wing. Due to the aircraft configuration, the wing design is pinned at both ends and therefore requires a higher degree of end to end accuracy, over the 4m length, than conventional wings. During the investigation some fundamental issues are approached, including: Potential cost savings and variables which effect the business case. Achievable Jig accuracy. Potential sources of instability that may affect accuracy over time. Repeatability of measurements with various features and methods. Typical jig stability over 24hrs including effects of small temperature fluctuations. Deflections that occur due to loading.

The influence of size and concentration of carbon nanoparticle on the viscosity of an SAE 5W-30 lubricant oil has been investigated experimentally. Data were collected for oil samples drawn from sump of light duty automotive diesel engines. The average size of soot particles in the used oil samples was in the range of 180-320nm with concentrations ranging from 0 to 2 percentage by weight (wt. %.). A Brookfield DV-II Pro rotary viscometer was used to measure dynamic viscosity at low shear rates and temperatures of 40°C and 90°C. Nanoparticle concentration and particle size distribution were evaluated using Thermo-Gravimetric Analysis (TGA) and Dynamic Light Scattering (DLS) respectively. The viscosity of suspensions of graphite powder in lubricant oil was also investigated for concentrations ranging from 0 to 2 wt. %. The results show that dynamic viscosity increases with increasing soot content and decreasing temperature.

Electric machines offering a high power density are required for aerospace applications. Soft magnetic material with a high saturation flux density is one of the key component which is required to realize these power density targets. The need for a high saturation flux density necessitates the use of cobalt iron lamination over the conventional silicon steel. However, cobalt iron is very expensive i.e. order of 10 in comparison to silicon steel. Stator segmentation is identified as an appropriate method to reduce the wastage and cost associated with lamination. Consequently, in this paper, stator segmentation is analyzed on a 1.35 MW, 16-pole 48-slot propulsion machine. The impact of manufacturing is accounted by controlling the resulting airgap between the segmented structures. Electromagnetic performance for various segmented topologies are compared in terms of torque, torque ripple, and iron loss.

The dilution of lubricating oil by fuel has adverse effects on engine wear, oil lubricity, air/fuel ratio control and feedgas emissions. Dilution is one of the factors limiting oil change intervals. The level and rate of accumulation depend on engine operating conditions and patterns of vehicle use. The work reported here develops and evaluates an empirical model to predict accumulation characteristics. This is aligned to requirements for predictions of dilution build-up in service. Predictions are shown to be in good agreement with data given in the literature. The model is used to investigate the influence of patterns of vehicle use on dilution.