Browsing by Author "Gore, David"

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    Aircraft cost modelling, integrated in a multidisciplinary design context
    (Science Publishing Group, 2019-12-17) Di Pasquale, Davide; Gore, David; Savill, Mark A.; Kipouros, Timoleon; Holden, Carren
    Most of the current cost models focus on a particular manufacturing process or a specific maintenance aspect, therefore not providing the whole picture. The main challenge in modelling the manufacturing cost, associated to a new aircraft at the initial design stage, is to examine all the cost features and the way to link them into the decision making process. It is important to understand the cost related to different competing designs, and this can be tackled by including cost estimation in the design process. Estimating the cost at the early design stage is paramount to reduce the life cycle cost of the aircraft. This paper presents the development of a new methodology for the generation of a cost estimation approach for preliminary aircraft design in a multidisciplinary environment. The framework is able to capture the design attributes that drive the cost allowing a designer to assess cost changes with respect to different design configurations. The cost model is built in Excel using a Visual Basic interface and it is integrated within Model Centre platform, where it can be treated as a component of a computational design process. The paper concludes by presenting the results from a real wing trade-off study that includes all the components of a complete design system.
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    Dynamic multi-phase partitioning of decamethylcyclopentasiloxane (D5) in river water
    (Elsevier , 2010-12-31T00:00:00Z) Whelan, Michael J.; van Egmond, Roger A.; Gore, David; Sanders, David A.
    The behaviour of decamethylcyclopentasiloxane (D5) in river water was evaluated by measuring concentration changes in open beakers. Effective values for the partition coefficient between organic carbon and water (K) were derived by least-squares optimisation of a dynamic model which accounted for partitioning between the sorbed and dissolved phases of D5, and for losses via volatilisation and hydrolysis. Partial mass transfer coefficients for volatilisation were derived from model fits to controls containing deionised water. Effective values of log (K) were between 5.8 and 6.33 (mean 6.16). These figures are higher than some other experimentally-derived values but much lower than those estimated from the octanol: water partition coefficient using single-parameter linear free energy relationships (LFERs). A poly-parameter LFER gave a predicted log (K) of 5.5. Differences in partitioning are believed to be due to the nature of the organic matter present. The new value for effective K was employed in a simple model of D5 behaviour in rivers to ascertain the extent to which a higher affinity for organic carbon would depress volatility. The results suggest that despite the revised K value, volatilisation of D5 remains a significant removal mechanism in surface waters. © 2010 Elsevier Ltd