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Numerical investigation of wave induced thrust on a submerged hydrofoil
No full textSubmerged flapping hydrofoils have the capability to directly convert wave energy into thrust, offering a sustainable approach to marine propulsion. This research employs computational fluid dynamics (CFD) to analyze the propulsion mechanism of wave-induced flapping hydrofoils. Initially validated through established benchmarks and experimental results with foil in uniform flow, the CFD model was then applied to examine the generation of thrust by flapping hydrofoils in heading regular wave. The study reveals a distinct transition from drag to thrust, characterized by the patterns of vortex flow. For the first time, the influence of pitch stiffness on this propulsion process is extensively explored, identifying optimal wave conditions and pitch stiffness for the application of future eco-friendly marine systems.Ministry of Education of the People's Republic of China, China Scholarship CouncilL. Yang acknowledges the support from the Department for Transports (DfT) Transport Research and Innovation Grants (TRIG2022): G-TRANSPORT: greening transportation of cargo ships via hybrid wave propulsion.Journal of Renewable and Sustainable Energ
Re‐orienting leadership coaching for sustainable effectiveness
Get PDFThe authors note that their “personal experience, client conversations, and research has led us to identify and highlight two critical issues where we see organizations consistently making serious errors that hold back the development of their leaders, waste money, and restrict the potential for longer term and sustainable effectiveness.” They note that organizations spend a considerable amount of money on outside coaching, yet this may not always be beneficial or cost‐effective for those organizations: “The first step,” they write, “is to understand when “a coach” can and can’t help. The second is to understand the difference between “a coach” (in other words a professional coach, or someone following such an approach) and leaders‐who‐coach. As a result, organizations can make the most of their coaching dollars, and their people.” They further clarify that “to determine when to use a professional coach, we use a simple question to address whether such coaching is a worthwhile endeavor: Does the executive need to develop and challenge themselves or do they need tools to function within their organization?” They conclude that solutions involve “creating leaders‐who‐coach who, as a result, will gradually enable a change in the underlying systemic issues.”Leader to Leade
A review on liquid hydrogen fuel systems in aircraft applications for gas turbine engines
Get PDFThe transition from traditional aviation fuels to low-emission alternatives such as hydrogen is a crucial step towards a sustainable future for aviation. Conventional jet fuels substantially contribute to greenhouse gas emissions and climate change. Hydrogen fuel, especially "green" hydrogen, offers great potential for achieving full sustainability in aviation. Hybrid/electric/fuel cell technologies may be used for shorter flights, while long-range aircraft are more likely to combust hydrogen in gas turbines. Liquid hydrogen is necessary to minimize storage tank weight, but the required fuel systems are at a low technology readiness level and differ significantly from Jet A-1 systems in architecture, operation, and performance. This paper provides an in-depth review covering the development of liquid hydrogen fuel system design concepts for gas turbines since the 1950s, compares insights from key projects such as NASA studies and ENABLEH2, alongside an analysis of recent publications and patent applications, and identifies the technological advancements required for achieving zero-emission targets through hydrogen-fuelled propulsion.The authors thank Innovate UK, part of UK Research and Innovation (UKRI), for funding the UK Aerospace Technology Institute project: Zero Emissions for Sustainable Transport (ZEST1), under grant agreement No: 103136.International Journal of Hydrogen Energ
Self-seal laser ablation open cell for trace elements analysis of full-size archaeological artefacts: application on Famille Rose enamel
Get PDFLaser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is a technique that is increasingly becoming the standard analytical approach in archaeological science, especially for the analysis of glass, glaze, and metal. Its low detection limits, high precision and wide element range is twinned with a very small sample size, which makes it ideal for culturally valuable objects. However, in the past, the small sample chamber size in commercial laser systems has meant that the size of object that could be analysed is very limited. Ongoing work by various groups has demonstrated the potential of open architecture and portable systems to overcome this issue. This paper reports an example of this − the results of a validation on a self-seal open ablation cell coupled with a very large sample chamber developed by Cranfield University and Elemental Scientific Lasers LLC. Comparison of the analysis of standard reference materials between the self-seal open cell and a conventional closed cell in a two-volume chamber show that, the count rates for most elements drop in the open cell to between 40–70% with our configuration, but precision, accuracy, fractionation, and limits of detection are barely affected. This means that the result outputs of both chambers are very similar and shows that the open cell is a very real solution to the problem of the small sample chambers in conventional LA-ICP-MS facilities.
The functionality of the open cell is demonstrated using a case study of two Chinese, polychrome enamelled copperwares dating from the late 18th or early 19th century Qianlong or Jiaqing period, a tray and a writing set. Due to conservation work on the pieces, five small enamel samples were available, which meant that the results derived from these samples in the conventional laser chamber could be compared to results from the objects themselves in the large sample chamber. Time resolved analysis was carried out giving more information on the thickness of enamel layers and variability between colours and across the object demonstrating the usefulness of having large, complete objects in the chamber.Microchemical Journa
Data related to "A Mixed-Elastohydrodynamic Lubrication Model of a Capped-T-ring Seal with a Sectioned Multi-Material Film Thickness in Landing Gear Shock Absorber Applications"
No full textA lubrication model using the Elastohydrodynamic lubrication theory and deformation mechanics is developed in a multi-material contact zone, and a procedure for coupling fluid and deformation mechanics is introduced. By conducting Finite Element Method (FEM) simulations, the static contact pressure is obtained, which subsequently is used within the herein developed model consisting of a modified Reynolds equation and an asperity contact model, to calculate the fluid film pressure and the deformation of the fluid channel is determined using an elastic deformation model applied to a multi-component multi-mechanical property channel. These computational results are used for estimations of the seal leakage and friction under various conditions.Engineering and Physical Sciences Research Council (EPSRC
Comprehensive techno-economic and environmental assessment for 2,3-butanediol production from bread waste
Get PDFBread waste (BW) is a common food waste in Europe and North America and has enormous potential as a biorefinery substrate for the sustainable synthesis of various platform chemicals. Our previous work made use of BW for the fermentative production of 2,3–butanediol (BDO). The present work evaluated the economic prospects and environmental consequences associated with the overall processes, handling 100 metric tons BW per day. The comprehensive process design using Aspen Plus and integrated techno-economic and environmental assessment was carried out for two different BW hydrolysis scenarios: acid and enzyme hydrolysis, followed by fermentation and extraction-based downstream BDO separation. The optimal heat exchanger network was designed using pinch analysis, which improved the energy efficiency of the processes significantly, with about 10 % savings of BDO production costs. Despite this improvement, the BDO derived from BW was exorbitant (4.2–6.9 /kg) due to relatively higher capital investment for the current plant capacity. Further, the process inventory was modelled in SimaPro v9.1.0 to estimate the environmental consequences of these production processes for various impact categories, such as global warming (2.63 – 3.19 kg CO2 eq.), marine eutrophication (3.55 × 10-4 – 4.01 × 10-4 kg N eq.), terrestrial ecotoxicity (6.44 – 7.88 kg 1,4 − DCB), etc. Sensitivity and uncertainty analyses were also conducted to establish the reliability of the results. It was found that the enzyme hydrolysis was associated with lower environmental impacts than acid hydrolysis. This comprehensive study can be used as a guideline for developing sustainable BW-based biorefinery in the future.Natural Sciences and Engineering Research CouncilThe authors would like to acknowledge NSERC CRD grants and James and Joanne Love Chair in Environmental Engineering for funding this research.Chemical Engineering Journa
Base flow characteristics for a sub-scale high-speed exhaust at over-expanded mode
Get PDFThis paper presents a numerical investigation on the base flow characteristics of a sub-scale, high-speed exhaust system at over-expanded state. The geometry is representative of future, advanced propulsion concepts. It features a truncated, ideal-contoured (TIC) nozzle and an axisymmetric cavity embedded at the base. Scale resolving simulations are performed using the Delayed Detached Eddy Simulation (DDES) turbulence modelling approach. The configuration is mounted on the test section of a wind tunnel through a wing-pylon to facilitate ongoing experiments. The proper orthogonal decomposition (POD) method is employed to identify the salient flow features at the base in terms of energy content. Time-averaged base pressure results show slightly reduced levels of pressure behind the pylon by approximately 1.2%. Additionally, reduced levels of pressure fluctuations in the region directly downstream of the pylon are identified, suggesting a severe impact on the base flow. This is further confirmed through the modal decomposition of the base flow. The first two most energetic modes of the flow exhibit strong spatial asymmetry in the intensity of velocity fluctuations, the latter being significantly reduced in the region behind the pylon. This is important for future, high-speed vehicles, which typically employ wingtip mounted nacelles and could exhibit increased levels of side loads as a result of this azimuthal asymmetry in the flow development.The authors would like to express their gratitude to Reaction Engines Ltd. and the Cranfield Air and Space Propulsion Institute (CASPI) for funding this project and for granting permission to publish this research.34th Congress of the International Council of the Aeronautical Sciences 202
Data "Geophysics data (ERT) for water loss from sand dams"
No full textThe data includes all raw and processed geophysical data from two fieldtrips in Kenya. LS toolbox was used to process the raw data. Res2DInv was used following LS toolbox. Information regarding parameterisation is available in chapter 5 of the thesis (link to be attached when available) and in the published paper (link to be attached when available). The data includes coordinates for each electrode used in each geophysics profile in excel and in Google Earth, as well as DAT files of the raw data collected with the Terrameter for each profile
Supply chain 4.0 and the digital twin approach: a framework for improving supply chain visibility
Get PDFThe emergence of Industry 4.0 has led to an increased level of complexity in supply chain operations. As a result, innovative approaches are required to improve visibility. Conventional approaches such as optimisation and simulation are no longer adequate for ensuring visibility across the entire supply chain. The aim of this study is to explore the potential of digital twins (DT) within the domain of supply chain management. A comprehensive DT framework is formulated utilising the Genetic Algorithm (GA). The results emphasise the potential of DT in promoting data-driven decision-making, improving visibility, and optimising SC operations. This study attempts to fill the current gaps in knowledge, offering significant insights for stakeholders in the supply chain.34th CIRP Design Conference 2024Procedia CIR
Data for "SINATRA - Complex intake flow distortion measurements"
No full textDataset list:
3D velocity measurements obtained with Stereo Particle Image Velocimetry at the S-duct outlet plane for inlet Mach = 0.27.
3D velocity measurements, pressure and temperature obtained with Filtered Rayleigh Scattering (FRS) at the S-duct outlet plane for inlet Mach = 0.27, with use of MLRBS methods.
3D velocity measurements, pressure and temperature obtained with Filtered Rayleigh Scattering (FRS) at the S-duct outlet plane for inlet Mach = 0.27, with use of MLRBS and MLFRS methods
Supporting datasets for the journal paper "Pathway to non-intrusive in-flight flow diagnostics with Filtered Rayleigh Scattering (FRS)".European CommissionEuropean Research Counci