Browsing by Author "Robinson, M."

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    Innovations for sustainable lifestyles – an agent based model approach
    (Springer, 2018-06-28) Allen, Peter; Robinson, M.; Butans, Eugene; Varga, Liz
    An important aspect of any scientific approach to sustainability must be methods by which the impacts of possible innovations can be assessed. Clearly, we need to make massive changes in our lifestyles if we are to get anywhere near ‘sustainability’. In this paper, an ‘agent-based model’ is developed which for this initial presentation explores probable impacts on household consumption and emissions of possible innovations. The model randomly picks a large number (here 10,000, but it can be much larger) of households from four different countries and calculates the effects resulting from the adoption of specific innovations. The ‘lifestyle’ of the households within the area studied is divided into four different ‘domains’. These are living, food, mobility and energy. Innovations are launched in the four different domains and the model shows the overall effects on the total input requirements (materials, energy, etc.), the household and food wastes and the CO2 emissions, showing how far the system moves towards sustainability. By using the sustainability criteria of 8000 kg ‘input material’ per year per individual developed by the Wuppertal Institute (Lettenmeier et al. in Resources 3:488–515, 2014, https://doi.org/10.3390/resources3030488, http://www.mdpi.com/journal/resources, ISSN 2079-9276), we can calculate how far the nation or region is from sustainability after adopting possible innovations. This is a measure of the total inputs required per individual per year. It allows us to show that for different countries, with widely different climates (e.g. Finland and Spain), different household innovations would have a greater or lesser impact on attaining ‘sustainable lifestyles’. The model does not pretend to develop a full simulation of each system, including the ecosystem, type of economy, etc., but does look at the effect an innovation in one household domain will have on all four domains, thereby providing information that can improve current decisions. It also demonstrates that, although ‘households’ can do much to improve the situation by reducing their demand for energy and materials, some actions at a national/regional level will be required to achieve sustainability. For example, sustainability will require an end to the use of fossil fuels for transportation and a switch to ‘clean’ electrical power generation from renewables and nuclear sources. Without this change, these countries will find it impossible to reach a sustainable lifestyle.
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    An optimization method for nacelle design
    (American Institute of Aeronautics and Astronautics, 2017-01) Robinson, M.; MacManus, David G.; Heidebrecht, A.
    A multi-objective optimiZation method is demonstrated using an evolutionary genetic algorithm. The applicability of this method to preliminary nacelle design is demonstrated by coupling it with a response surface model of a wide range of nacelle designs. These designs were modelled using computational fluid dynamics and a Kriging interpolation was carried out on the results. The NSGA-II algorithm was tested and verified on established multi-dimensional problems. Optimisation on the nacelle model provided 3-dimensional Pareto surfaces of optimal designs at both cruise and off-design conditions. In setting up this methodology several adaptations to the basic NSGA-II algorithm were tested including constraint handling, weighted objective functions and initial sample size. The influence of these operators is demonstrated in terms of the hyper volume of the determined Pareto set.
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    Short and slim nacelle design for ultra-high BPR engines
    (American Institute of Aeronautics and Astronautics, 2017-01) Robinson, M.; MacManus, David G.
    An optimisation method consisting of the non-dominated sorting genetic algorithm (NSGA-II) and computational fluid dynamics of aero-engine nacelles is outlined. The method is applied to three nacelle lengths to determine the relative performance of different ultra-high bypass ratio engine nacelles. The optimal designs at each nacelle length are optimised for three objective functions: cruise drag, drag rise Mach number and change in spillage drag from mid to end of cruise. The Pareto sets generated from these optimisation computations demonstrate that the design space for short nacelles is much narrower in terms of these performace metrics and there are significant penalties in the off design conditions compared to the longer nacelle. Specifically the minimum spillage drag coefficient attainable, for a nacelle with a drag rise Mach number above 0.87, was 0.0040 for the shortest nacelle compared to 0.0005 for a nacelle which was 23% longer.