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Several new technologies are now emerging to improve adhesive supply and formulation along with surface treatments that have the potential to offer significant improvements to both surface energy and cleanliness [3]. Additionally, the miniaturisation of laboratory techniques into portable equipment offers potential for online surface energy and chemical analysis measurement for use as quality control measures in a production environment. An overview of newly available technology is given here with several devices studied in further detail. Technologies assessed further in this paper are; portable surface contact angle measurement, ambient pressure plasma cleaning, portable FTIR measurement and adhesive mixing equipment. A number of potential applications are outlined for each device based on the operational technique. The practical aspects of implementation and the perceived technology readiness levels for operation, implementation and results are also given.

A physics based, lumped thermal capacity model of a 1litre, 3 cylinder, turbocharged, directly injected spark ignition engine has been developed to investigate the effects of cylinder deactivation on the thermal behaviour and fuel economy of small capacity, 3 cylinder engines. When one is deactivated, the output of the two firing cylinders is increased by 50%. The largest temperature differences resulting from this are between exhaust ports and between the upper parts of liners of the deactivated cylinder and the adjacent firing cylinder. These differences increase with load. The deactivated cylinder liner cools to near-coolant temperature. Temperatures in the lower engine structure show little response to deactivation. Temperature response times following deactivation or reactivation events are similar. Motoring work for the deactivated cylinder is a minor loss; the net benefit of deactivation diminishes with increasing load.

Through improving the 48V hybrid vehicle archetype, governmental emission targets could be more easily met without incurring the high costs associated with increasing levels of electrification. The braking energy recovery function of hybrid vehicles is recognised as an effective solution to reduce emissions and fuel consumption in the short to medium term. The aim of this study was to evaluate methods to maximise the braking energy recovery capability of the 48V hybrid electric vehicle over pre-selected drive cycles using appropriately sized electrified components. The strategy adopted was based upon optimising the battery chemistry type via specific power capability, so that overall brake power is equal to the maximum battery charging power in a typical medium-sized passenger car under typical driving. This will maximise the regenerative braking energy whilst providing a larger torque assistance for a lower battery capacity.

Currently the wing box rib assembly process requires the manual location and temporary fixing of components within product specific jig or fixtures for drilling. After drilling and reaming, parts are separated, cleaned, deburred prior to adding sealant, reclaiming and final bolting, but this may significantly increase cost, manufacturing lead-time, reduces flexibility and cannot usually be economically modified for use on other aircraft types. Due to potential increase in demand for the next generation single isle aircraft, existing tooling solutions have to be improved and new technologies have to be developed. This paper describes the development and testing of flexible tooling to provide clamping and support for drilling wing box ribs to mating rib posts within a restricted environment. Results are presented along with a discussion of the problems that may be encountered during clamping trials.

A Ford 2.4-liter 115PS light-duty diesel engine was modified to allow solenoid control of the oil feed to the piston cooling jets, enabling these to be switched on or off on demand. The influence of the jets on piston temperatures, engine thermal state, gaseous emissions and fuel economy has been investigated. With the jets switched off, piston temperatures were measured to be between 23 and 88°C higher. Across a range of speed-load points, switching off the jets increased engine-out emissions of NOx typically by 3%, and reduced emissions of CO by 5-10%. Changes in HC were of the same order and were reductions at most conditions. Fuel consumption increased at low-speed, high-load conditions and decreased at high-speed, low-load conditions. Applying the results to the NEDC drive cycle suggests active on/off control of the jets could reduce engine-out emissions of CO by 6%, at the expense of a 1% increase in NOx, compared to the case when the jets are on continuously.

Current assembly systems that deal with large, complex structures present a number of challenges with regard to improving operational performance. Specifically, aerospace assembly systems comprise a vast array of interrelated elements interacting in a myriad of ways, resulting in a deeply complex process that requires a multi-disciplined team of engineers. The current approach to ramp-up production rate involves building additional main assembly fixtures which require large investment and lead times up to 24 months. Within Airbus Operations Ltd there is a requirement to improve the capacity and flexibility of assembly systems, thereby reducing non-recurring costs and time-to-market. Recent trends to improve manufacturing agility advocate Reconfigurable Assembly Systems (RAS) as a viable solution. Yet, adding reconfigurability to assembly systems further increases both the operational and design complexity.

The replacement for the current single-aisle aircraft will need to be manufactured at a rate significantly higher that of current production. One way that production rate can be increased is by reducing the processing time for assembly operations. This paper presents research that was applied to the build philosophy of the leading edge of a laminar flow European wing demonstrator. The paper describes the implementation of determinate assembly for the rib to bracket assembly interface. By optimising the diametric and the positional tolerances of the holes on the two bracket types and ribs, determinate assembly was successfully implemented. The bracket to rib interface is now secured with no tooling or post processes other than inserting and tightening the fastener. This will reduce the tooling costs and eliminates the need for local drilling, de-burring and re-assembly of the bracket to rib interface, reducing the cycle time of the operation.

The assembly and manufacture of aerospace structures, in particular legacy products, relies in many cases on the skill, or rather the craftsmanship, of a human operator. Compounded by low volume rates, the implementation of a fully automated production facility may not be cost effective. A more efficient solution may be a mixture of both manual and automated operations but herein lies an issue of human error when stepping through the build from a manual operation to an automated one. Hence the requirement for an advanced automated assembly system to contain functionality for inline structural quality checking. Machine vision, used most extensively in manufacturing, is an obvious choice, but existing solutions tend to be application specific with a closed software development architecture.

Aerospace assembly systems comprise a vast array of interrelated elements interacting in a myriad of ways. Consequently, aerospace assembly system design is a deeply complex process that requires a multi-disciplined team of engineers. Recent trends to improve manufacturing agility suggest reconfigurability as a solution to the increasing demand for improved flexibility, time-to-market and overall reduction in non-recurring costs. Yet, adding reconfigurability to assembly systems further increases operational complexity and design complexity. Despite the increase in complexity for reconfigurable assembly, few formal methodologies or frameworks exist specifically to support the design of Reconfigurable Assembly Systems (RAS). This paper presents a novel reconfigurable assembly system design framework (RASDF) that can be applied to wing structure assembly as well as many other RAS design problems.

An experimental study has been carried out to explore what limits fuel injection and EGR strategies when trying to run a PCCI-type mode of combustion on an engine with current generation hardware. The engine is a turbocharged V6 DI diesel with (1600 bar) HPCR fuel injection equipment and a cooled external EGR system. The variables examined have been the split and timings of fuel injections and the level of EGR; the responses investigated have been ignition delay, heat release, combustion noise, engine-out emissions and brake specific fuel consumption. Although PCCI-type combustion strategies can be effective in reducing NOx and soot emissions, it proved difficult to achieve this without either a high noise or a fuel economy penalty.

DISI engine emissions and fuel economy are strongly dependent upon fuel injection and spark timings, particularly when the engine is operating in stratified charge mode. Experimental studies of the effects of injection and spark timings and the interaction between these are described. The sensitivity of HC and NOx emissions to timings during stratified charge operation, the comparison of performance under stratified and homogeneous charge modes of operation and the rationale for mode switch point settings are investigated. The high sensitivity of emissions to injection and spark timing settings gives rise to potential robustness issues. These are described.

An experimental study of the performance of a reverse tumble, DISI engine is reported. Specific fuel consumption and engine-out emissions have been investigated for both homogeneous and stratified modes of fuel injection. Trends in performance with varying AFR, EGR, spark and injection timings have been explored. It is shown that neural networks can be trained to describe these trends accurately for even the most complex case of stratified charge operation with exhaust gas recirculation.

This paper presents novel development of a reconfigurable assembly cell which assembles multiple aerostructure products. Most aerostructure assembly systems are designed to produce one variant only. For multiple variants, each assembly typically has a dedicated assembly cell, despite most assemblies requiring a process of drilling and fastening to similar tolerances. Assembly systems that produce more than one variant do exist but have long changeover or involve extensive retrofitting. Quick assembly of multiple products using one assembly system offers significant cost savings from reductions in capital expenditure and lead time. Recent trends advocate Reconfigurable Assembly Systems (RAS) as a solution; designed to have exactly the functionality necessary to produce a group of similar components. A state-of-the-art review finds significant benefits in deploying RAS for a group of aerostructures variants.

Aircraft manufacturers desire to increase production to keep up with anticipated demand. To achieve this, the aerospace industry requires a significant increase in the manufacturing and assembly performance to reach required output levels. This work therefore introduces the Variation Aware Assembly (VAA) concept and identifies its suitability for implementation into aircraft wing assembly processes. The VAA system concept focuses on achieving assemblies towards the nominal dimensions, as opposed to traditional tooling methods that aim to achieve assemblies anywhere within the tolerance band. It enables control of the variation found in Key Characteristics (KC) that will allow for an increase in the assembly quality and product performance. The concept consists of utilizing metrology data from sources both before and during the assembly process, to precisely position parts using motion controllers.

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.

Diesel engines have traditionally been favoured in heavy-duty applications for their fuel economy, robustness, reliability and relative lack of fuel sensitivity. Recently it has seen a growth in its popularity in light duty applications due particularly to its fuel efficiency. However, as the engine technology and particularly the fuel injection equipment has evolved to meet ever stricter emissions legislation the engines have become more sensitive to deposit formation resulting from changes in fuel quality. This paper reviews bouts of concern over diesel fuel injector deposits, possible causes for the phenomenon and test methods designed to screen fuels to eliminate problems.

The aerospace manufacturing sector is continuously seeking automation due to increased demand for the next generation single-isle aircraft. In order to reduce weight and fuel consumption aircraft manufacturers have increasingly started to use more composites as part of the structure. The manufacture and assembly of composites poses different constraints and challenges compared to the more traditional aircraft build consisting of metal components. In order to overcome these problems and to achieve the desired production rate existing manufacturing technologies have to be improved. New technologies and build concepts have to be developed in order to achieve the rate and ramp up of production and cost saving. This paper investigates how to achieve the rib hole key characteristic (KC) in a composite wing box assembly process. When the rib hole KC is out of tolerances, possibly, the KC can be achieved by imposing it by means of adjustable tooling and fixturing elements.

The effect of compression ratio on sensitivity to changes in start of injection and air-fuel ratio has been investigated on a single-cylinder DI diesel engine at fixed low and medium speeds and loads. Compression ratio was set to 17.9:1 or 13.7:1 by using pistons with different bowl sizes. Injection timing and air-to-fuel ratio were swept around a nominal map point at which gross IMEP and NOx values were matched for the two compression ratios. It was found that CO, HC and ISFC were higher at low compression ratio, but the soot/NOx trade-off improved and this could be exploited to reduce the fuel economy penalty. Sensitivity to inputs is generally similar, but high compression ratio tended to have steeper response gradients. Reducing compression ratio to 13.7 gave rise to a marked degradation of performance at light load, producing high CO emissions and a fall in combustion efficiency. This could be eased by reducing rail pressure, but the advantage in smoke emission was lost.

The largest contribution to engine rubbing friction is made by the piston and piston rings running in the cylinder liner. The magnitude and characteristics of the friction behaviour and the influence on these of factors such as surface roughness, piston design and lubricant properties are of keen interest. Investigating presents experimental challenges, including potential problems of uncontrolled build-to-build variability when component changes are made. These are addressed in the design of a new motored piston and floating liner rig. The design constrains transverse movement of a single liner using cantilevered mounts at the top and bottom. The mounts and two high stiffness strain gauged load cells constrain vertical movement. The outputs of the load cells are processed to extract the force contribution associated with friction. The liner, piston and crankshaft parts were taken from a EuroV-compliant, HPCR diesel engine with a swept capacity of 550cc per cylinder.

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.