A knowledge system to support manufacturing knowledge during preliminary design

The integration of manufacturing knowledge into the product introduction process is presented as a knowledge management problem. Concurrent engineering techniques are highly effective in sharing manufacturing knowledge, particularly for the re-use of knowledge at the detail design stage when the geometry has been developed. This research considers the use of manufacturing knowledge in the earlier, preliminary stage of design where the geometry is not so developed and where development of manufacturing technology may be required. An exploratory case study was carried out with a manufacturer of gas turbine engines for the civil aviation market. Semi-structured interviews were carried out to investigate the manufacturing knowledge required and its format. Using a data-driven analysis, a thematic code was developed and three themes emerged: manufacturing impact, expressions of impact and knowledge type. These themes indicate the requirement for a hybrid social-technical system to support both the tacit and explicit elements of manufacturing knowledge. An indication of the maturity of the manufacturing process also emerged as a major requirement in order to synchronize manufacturing technology developments with future product requirements. A prototype knowledge system is now being developed to meet the requirements identified through the coding analysis. The specification of the system, which uses a combination of information and social systems, is discussed

Hydraulic fracturing: a review of theory and field experience

This report summarises the current state-of-the-art knowledge of the hydraulic fracturing process used by the shale gas/oil industry using open peer-reviewed literature and from government commissioned research reports. This report has been written to make statements on our knowledge of the following questions: • How do hydrofractures form? • How far do hydrofractures extend during stimulation? • What dictates where hydrofractures propagate? • How do hydrofractures interact with the existing fracture network? • Can the size and distribution of hydrofractures be controlled? Gaps in our knowledge have been highlighted, with the largest of these resulting from differences between North American and European shale rocks

CONTAIN D11 : integrated final results and conclusions

Carbon capture and storage is a technology capable of reducing CO2 outputs on a large scale; the concept usually requires CO2 to be removed from post-combustion flue gases and sequestered in geological formations. Depleted gas fields constitute “the most important storage type for the UK” and will provide a large and important potential future offshore storage capacity (DECC, 2012). Over the last 4 years, the CONTAIN research project has focussed on the geomechanical behaviour of depleted hydrocarbon fields in response to injection with CO2, combining a modelling and experimental approach with the public perceptions of CCS into three work packages. The project has provided a better understanding of the hydromechanical impacts of depletion on caprocks and the effect of subsequent CO2 injection, in order to assist with the implementation of CCS in this type of reservoir. Work package 1 outlined a phenomenological approach to assessing possible deformation during operation. Focus was placed on rock mechanics and transport experiments on material from the geologies of target formations in the North Sea, providing information that could be incorporated into numerical simulations. Work package 2 expanded this understanding by considering fractured caprock. Numerical modelling was used to study the deformation of an initially intact caprock caused by the depletion of an underlying reservoir during oil extraction. Deformation and flow were geomechanically modelled in three dimensions using a fully coupled poroelastic model, incorporating discrete fractures and faults into the caprock. Work package 3 offered new and valuable insight on future public awareness campaigns aimed at gaining acceptance of CCS. Qualitative expert interviews have been used, a CCS expert survey and a public survey across four countries to gain an understanding of perceptions of CCS risks and benefits, and has allowed for comparison of views on CCS between experts and public. In addition, the work package has explored the impact of different message framings on CCS attitudes. The findings of each work package are summarised in this report, with each work package represented by a report chapter. A synthesis of the findings and discussion of the work as a whole follows

Some aspects of laser design

This project was concerned with the design, construction and testing of a low powered carbon dioxide laser and a discharge pumped XeCl excimer laser. The thesis is presented in two separate parts; section A covers the carbon dioxide laser and section B covers the excimer laser. The reason for this separation is that the common overlap of design features and operation is very small [continued]..

Transferring Design Research Into Rolls-Royce

This paper will take a holistic view of technology transfer and discuss its nature based on the experience gained with the UTC

Transferring design research into Rolls-Royce

SIGLEAvailable from British Library Document Supply Centre-DSC:8019.322(92825) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Generalising optimal mean setting for any number and combination of serial and parallel manufacturing operations

Consider a production system where products are continuously manufactured and their features inspected for conformance within specification limits. If features are produced above or below the specification limits, they are either subject to rework or the product scrapped. Optimal mean setting may be applied to adjust the manufacturing means to influence the amount of rework or scrap produced, maximising profit. Within the production system, manufacturing and then inspecting each feature in turn is termed serial production, whereas manufacturing multiple features before inspection is termed parallel production. This paper develops a generalised expression to optimise the mean values of each feature (optimal mean setting), where n number of features are produced in any combination of serial and parallel operations. Previous literature is restricted to considering two features in parallel. The production of multiple features in combinations of serial and parallel operations is not fully considered. The new generalised expression is validated by showing it is consistent with specific cases from past literature. The approach is then applied to a practical example of a gearbox shaft, considering the expected profit of eight possible manufacturing sequences, as well as the deviation of the manufactured means relative to the design intent. The generalised expression is widely applicable in component design and manufacturing planning where the process capability index (Cpk) of features is below one. The generalised expression also forms the basis for trade-offs between profitability and minimising deviations of manufactured means, which is the subject of further development

Flow measurements in turbomachinery using laser anomometry and holography

Paper at the 3rd International Conference on Laser Anemometry - Advances and Applications, Wales (GB), 26-29 Sep 1989Available from British Library Document Supply Centre- DSC:8019.3153(RRR-PNR--90171) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo