312 research outputs found

    Comparison of calculated and experimental cascade performance for controlled-diffusion compressor stator blading

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    The mid-span section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements are taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length is 12.7 cm, aspect ratio is 2.0, and solidity is 1.67. Measurements include conventional cascade performance parameters as well as blade surface pressures. Computations are made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, are compared against corresponding data

    A critical evaluation of the water supply and stormwater management performance of retrofittable domestic rainwater harvesting systems

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    Rainwater harvesting systems are often used as both an alternative water source and a stormwater management tool. Many studies have focused on the water-saving potential of these systems, but research into aspects that impact stormwater retention—such as demand patterns and climate change—is lacking. This paper investigates the short-term impact of demand on both water supply and stormwater management and examines future and potential performance over a longer time scale using climate change projections. To achieve this, data was collected from domestic rainwater harvesting systems in Broadhempston, UK, and used to create a yield-after-spillage model. The validation process showed that using constant demand as opposed to monitored data had little impact on accuracy. With regards to stormwater management, it was found that monitored households did not use all the non-potable available water, and that increasing their demand for this was the most effective way of increasing retention capacity based on the modelling study completed. Installing passive or active runoff control did not markedly improve performance. Passive systems reduced the outflow to greenfield runoff for the longest time, whereas active systems increased the outflow to a level substantially above roof runoff in the 30 largest events

    Application of finite element code Q3DFL0-81 to turbomachinery flow fields

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    Through-flow and blade-to-blade calculations were made in association with a number of experimental research activities at the Turbopropulsion Laboratory, Naval Postgraduate School. The Q3DFL0-81 code was operated on an IBM 370-3033 mainframe computer. The flow through a single stage axial research compressor was computed and compared with both probe survey and stage performance map measurments. Swirling flow produced by a vaned out-flow generator for a radial diffuser test facility was calculated for both large low-speed and small-scale high-speed versions of the device. Flow through a two-dimensional compressor cascade of "controlled-dif fusion" blade shapes was calculated and the results compared with experimental data, and with predictions obtained using the NASA code QSONIC.Prepared for: Naval Air Systems Command, Washington DChttp://archive.org/details/applicationoffin00schuN0001984WR 41099, N0001984WR 41134N

    Reliability in CMOS IC processing

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    Critical CMOS IC processing reliability monitors are defined in this paper. These monitors are divided into three categories: process qualifications, ongoing production workcell monitors, and ongoing reliability monitors. The key measures in each of these categories are identified and prioritized based on their importance

    Wake Measurements and Loss Evaluation in a Controlled Diffusion Compressor Cascade

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    The article of record as published may be located at http://dx.doi.org/10.1115/1.2929120The results of two component laser-Doppler velocimeter (LDV) surveys made in the near wake (to one fifth chord) of a controlled diffusion (CD) compressor blade in a large-scale cascade wind tunnel are reported. The measurements were made at three positive incidence angles from near design to angles thought to approach stall. Comparisons were made with calibrated pressure probe and hot-wire wake measurements and good agreement was found. The flow was found to be fully attached at the trailing edge at all incidence angles and the wake profiles were found to be highly skewed. Despite the precision obtained in the wake velocity profiles, the blade loss could not be evaluated accurately without measurements of the pressure field. The blade trailing edge surface pressures and velocity profiles were found to be consistent with downstream pressure probe measurements of loss, allowing conclusions to be drawn concerning the design of the trailing edge

    Subsonic cascade wind tunnel tests of a sundstrand controlled-diffusion fan blade section

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    Results are given of subsonic cascade wind tunnel tests of a controlled diffusion fan blade section designed by Sundstrand Corporation. Data were obtained successfully at air inlet angles less than and approaching design incidence. Operation at design and higher incidence angles would require side wall suction. It was concluded that the design was successful and that a fan test should be consideredThis report formally documents the results and conclusions of a cascade wind tunnel test program sponsored by Sundstrand Aviation Operations, Sundstrand Corporation, (Purchase Order No. E2E4745-24M, dated 9/20/82) under the cognizance of Dr. Paul Hermann.http://archive.org/details/subsoniccascadew00mcg

    Engineering Comes Home: Co-designing nexus infrastructure from the bottom-up

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    The ‘nexus’ between water, food and energy systems is well established. It is conventionally analysed as a supply-side problem of infrastructure interdependencies, overlooking demand-side interactions and opportunities. The home is one of the most significant sites of nexus interactions and opportunities for redesigning technologies and infrastructure. New developments in ‘smart city’ technologies have the potential to support a bottom-up approach to designing and managing nexus infrastructure. The Engineering Comes Home was a research project that turned infrastructure design on its head. The objectives of the project were to: Demonstrate a new paradigm for engineering design starting from the viewpoint of the home, looking out towards systems of provision to meet household demands. Integrate thinking about water, energy, food, waste and data at the domestic scale to support userled innovation and co-design of technologies and infrastructure. Test new design methods that connect homes to communities, technologies and infrastructure, enhancing positive interactions between data, water, energy, food and waste systems. Develop a robust Lifecycle Assessment (LCA) Calculator tool to support environmental decisionmaking in co-design. Working with residents of the Meakin Estate in South London, the project followed a co-design method to identify requirements, analyse options and develop and test a detailed design for a preferred option. The outputs were: 1) Ethnographic study of how residents use water, energy and food resources in their homes and key opportunities for engineering design to improve wellbeing and reduce resource consumption. 2) Co-design of decentralised infrastructural systems in three workshops in 2016-2017. The first workshop identified key priorities for development from the community using a novel token-based system design method, to enable participants to build up alternative designs for local provision of water, energy, food and waste services. The second workshop provided participants with factsheets and photographs of the candidate technologies, which were then analysed using a LCA Calculator tool. 47 Rainwater harvesting was selected as the technology for further co-design in the third workshop, which focussed on scaling up a pilot installation. 3) Pilot-scale smart rainwater system was installed in partnership with the Over The Air Analytics (OTA). OTA’s system enables remote control of the rainwater storage tanks to optimise their performance as stormwater attenuation as well as non-potable water supply. 4) Lifecycle Assessment (LCA) Calculator to enable quick estimation of the impacts of new systems and technology to deliver water, energy and food, and manage waste at the household and neighbourhood scale. 5) Stakeholders, including utilities, design consultancies and community based organisations, were engaged in three workshops to inform the wider relevance and development of the co-design methods and tools. 6) Toolbox and method statements to standardise and disseminate the methods used in the project for wider application and development

    Death feigning as an adaptive anti‐predator behaviour: Further evidence for its evolution from artificial selection and natural populations

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    Death feigning is considered to be an adaptive antipredator behaviour. Previous studies on Tribolium castaneum have shown that prey which death feign have a fitness advantage over those that do not when using a jumping spider as the predator. Whether these effects are repeatable across species or whether they can be seen in nature is, however, unknown. Therefore, the present study involved two experiments: (a) divergent artificial selection for the duration of death feigning using a related species T. freemani as prey and a predatory bug as predator, demonstrating that previous results are repeatable across both prey and predator species, and (b) comparison of the death‐feigning duration of T. castaneum populations collected from field sites with and without predatory bugs. In the first experiment, T. freemani adults from established selection regimes with longer durations of death feigning had higher survival rates and longer latency to being preyed on when they were placed with predatory bugs than the adults from regimes selected for shorter durations of death feigning. As a result, the adaptive significance of death‐feigning behaviour was demonstrated in another prey–predator system. In the second experiment, wild T. castaneum beetles from populations with predators feigned death longer than wild beetles from predator‐free populations. Combining the results from these two experiments with those from previous studies provided strong evidence that predators drive the evolution of longer death feigning

    Co-producing research with academics and industry to create a more resilient UK water sector

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    This is the final version. Available on open access from UCL Press via the DOI in this recordSocietal, economic and environmental impact generated by academic research is a key focus of publicly funded research in the UK. Drawing on experiences from the Safe & SuRe project, a five-year research project that was co-produced with industry, this paper explores the challenges, learnings and benefits of co-producing research with academics and practitioners to create a more resilient UK water sector. Three aspects of the project are explored in detail: the use of a steering group, co-developing research intensively with a water company, and co-dissemination industry-facing events. Emerging themes include: (1) benefits of the industry steering group to develop working relationships and trust among the group; (2) increased dialogue and sharing of information between industry and academics going beyond the one-way communication more commonly reported by STEM academics; and (3) the value of co-disseminating research to maintain and engage new connections and spark new research questions.Engineering and Physical Sciences Research Council (EPSRC
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