Measurement of Wind Flow Behavior at the Leeward Side of Porous Fences Using Ultrasonic Anemometer Device

Efficiency of wind fences is evaluated by the reduction of wind velocity and the effective shelter area behind the fence. Fence porosity is the most influential structural parameters in the porous fence design, and has significant impact on the structure of wind velocity and turbulence leeward. In this work, three fences with porosity of 23%, 35% and 45% have been tested under 10m/s inlet velocity in an environmental wind tunnel. An ultrasonic anemometer was used to measure three dimensional velocity vectors and the fluctuations of velocity vectors with a designed spatial resolution. The obtained data were used to calculate velocity magnitudes, turbulence intensities and turbulent kinetic energies in the test domain. Porosity influencing the structure of turbulence intensity and effective fence zone were discussed in this paper. Neither the distribution of wind velocities nor the structure of turbulence alone can provide sufficient information to assess the performance of porous fences. Consideration of the targeted reduction rate of wind velocity needs to be taken for optimal fence desig

Investigation of vehicle ride height and diffuser ramp angle on downforce and efficiency

© 2018 The Author(s). The final, definitive version of this paper has been published in Knight, J., Spicak, M., Kuzenko, A., Haritos, G., & Ren, G. (2019). Investigation of vehicle ride height and diffuser ramp angle on downforce and efficiency. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 233(8), 2139–2145. by Sage Publications Ltd. All rights reserved. It is available at: https://doi.org/10.1177/0954407018776767.Diffusers are typically used in motorsport to generate negative lift (downforce). They also reduce aerodynamic drag and so significantly enhance aerodynamic efficiency. The amount of downforce generated is dependent on ride height, diffuser ramp angle and its relative length to that of the vehicle length. This paper details a numerical investigation of the effects of ride height and diffuser ramp angle in order to find an optimum downforce and efficiency for the inverted Ahmed model. A short and long diffuser with ratios of 10% and 35%, respectively, to that of vehicle length are studied. The short diffuser produced lower maximum downforce and efficiency at a lower ride height and lower angle when compared to the longer diffuser. The long diffuser produced highest downforce and the best efficiency with a ramp angle of 25° at ride height ratio of 3.8% when compared to vehicle length. Different ride heights were found to correspond to different diffuser ramp angles to achieve optimum downforce and efficiencies.Peer reviewe

Low-velocity impact behaviour of woven laminate plates with fire retardant resin

The understanding of the damage mechanisms for woven laminate plates under low-velocity impact is challenging as the damage mechanisms at the interface of adjacent layers are dominated by the fibre architecture. This work presents an experimental investigation of the behaviour of woven glass and carbon fibre composite laminates in a matrix of fire retardant resin under low-velocity impact. The performance is evaluated in terms of damage mechanisms and force time history curves. Six impact energy levels were used to test standard plates to identify the type of damage observed at various energy levels. Scanning electron microscopy (SEM) along with C-scans were used to characterise the damage. It has been observed that in woven composites, the damage occurs mostly between the fibre bundles and matrix. As the impact energy increases, the failure involves extended matrix cracking and fibre fracture. Moreover, due to the fibre architecture, both the contact forces between bundles of fibres and stretching of the bundles are responsible for the dominant matrix cracking damage mode observed at the low-impact energy level. As the impact energy increases, the damage also increases resulting in fibre fracture. The experimental evidence collected during this investigation shows that for both the carbon fibre and the glass fibre woven laminates the low-velocity impact behaviour is characterised by extended fibre fracture without a noticeable sudden load drop

Corrigendum to "An Analytical Model for the Identification of the Threshold of Stress Intensity Factor Range for Crack Growth"

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Enhancing satellite & terrestrial networks integration through NFV/SDN technologies

NFV and SDN technologies can become key facilitators for the combination of terrestrial and satellite networks. Enabling NFV into the SatCom domain will provide operators with appropriate tools and interfaces in order to establish end-to-end fully operable virtualized satellite networks to be offered to third-party operators/service providers. Enabling SDNbased, federated resource management paves way for a unified control plane that would allow operators to efficiently manage and optimize the operation of the hybrid network. The proposed solution is expected to bring improved coverage, optimized communication resources use and better network resilience, along with improved innovation capacity and business agility for deploying communications services over combined networks.Postprint (author's final draft

Fluid–structure interaction of symmetrical and cambered spring-mounted wings using various spring preloads and pivot point locations

The fluid–structure interaction of a pivoting rigid wing connected to a spring and subjected to freestream airflow in a wind tunnel is presented. Fluid–structure interactions can, on the one hand, lead to undesirable aerodynamic behaviour or, in extreme cases, to structural failure. On the other hand, improved aerodynamic performance can be achieved if a controlled application within certain limitations is provided. One application is the reduction of drag of road vehicles at higher speeds on a straight, while maintaining downforce at lower speeds during cornering. Conversely, another application concerns increased downforce at higher windspeeds, enhancing vehicle stability. In our wind tunnel experiments, the angle of incidence of the spring-mounted wing is either increased or decreased depending on the pivot point location and spring torque. Starting from a specified initial angle, the aerodynamic forces overcome a pre-set spring preload at incrementally increased freestream velocity. Reynolds numbers at a range of Re = 3 × 104 up to Re = 1.37 × 105 are considered. The application of a symmetrical NACA 0012 and a cambered NACA 6412 airfoil are tested in the wind tunnel and compared. For both airfoils mounted ahead of the aerodynamic centre, stable results were achieved for angles above 15 and below 12 degrees for the symmetrical airfoil, and above 25 and between 10 and −2 degrees for the cambered airfoil. Unsteady motions were observed around the stall region for both airfoils with all spring torque settings and also below −2 degrees for the cambered airfoil. Stable results were also found outside of the stall region when both airfoils were mounted behind the aerodynamic centre, although the velocity ranges were much smaller and highly dependent on the pivot point location. An analysis is reported concerning how changing the spring torque settings at each pivot point location effects performance. The differences in performance between the symmetrical and cambered profiles are then presented. Finally, an evaluation of the systems’ effects was conducted with conclusions, future improvements, and potential applications

Attribute and technology value mapping for conceptual product design phase

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Mechanical Engineering Science following peer review. The final, definite version of this paper has been published in Journal of Mechanical Engineering Science, Aris Georgiou, George Haritos, Moyra Fowler, and Yasmin Imani, ‘Attribute and technology value mapping for conceptual product design phase’, Vol. 230(11): 1745-1756, May 2016, published by SAGE Publishing, available online at doi: https://doi.org/10.1177/0954406215585595. Copyright © 2016 The Author(s).The main focus of this paper is how the concept design phase of the product development process can be improved by using an objective data-driven approach in selecting a final concept design to progress further. A quantitative new test-bed ‘Product Optimisation Value Engineering’ (PROVEN) is presented to critically assess new and evolving powertrain technologies at the concept design phase. The new test-bed has the ability to define a technology value map to assess multiple technical options as a function of its attributes, whose precise values can be determined at a given cost. A mathematical model that incorporates a highly adaptable, data-driven and multi-attribute value approach to product specification and conceptual design is developed, novel to the concept design process. This creates a substantially optimised product offering to the market, reducing overall development costs while achieving customer satisfactionPeer reviewe

Proceedings of Abstracts Engineering and Computer Science Research Conference 2019

© 2019 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Note: Keynote: Fluorescence visualisation to evaluate effectiveness of personal protective equipment for infection control is © 2019 Crown copyright and so is licensed under the Open Government Licence v3.0. Under this licence users are permitted to copy, publish, distribute and transmit the Information; adapt the Information; exploit the Information commercially and non-commercially for example, by combining it with other Information, or by including it in your own product or application. Where you do any of the above you must acknowledge the source of the Information in your product or application by including or linking to any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/This book is the record of abstracts submitted and accepted for presentation at the Inaugural Engineering and Computer Science Research Conference held 17th April 2019 at the University of Hertfordshire, Hatfield, UK. This conference is a local event aiming at bringing together the research students, staff and eminent external guests to celebrate Engineering and Computer Science Research at the University of Hertfordshire. The ECS Research Conference aims to showcase the broad landscape of research taking place in the School of Engineering and Computer Science. The 2019 conference was articulated around three topical cross-disciplinary themes: Make and Preserve the Future; Connect the People and Cities; and Protect and Care

Proceedings of Abstracts, School of Physics, Engineering and Computer Science Research Conference 2022

© 2022 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Plenary by Prof. Timothy Foat, ‘Indoor dispersion at Dstl and its recent application to COVID-19 transmission’ is © Crown copyright (2022), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: [email protected] present proceedings record the abstracts submitted and accepted for presentation at SPECS 2022, the second edition of the School of Physics, Engineering and Computer Science Research Conference that took place online, the 12th April 2022

Greek Town' 1915-1916

Date:200