Powered by OpenAIRE graph

US Air Force Research Laboratory

Country: United States

US Air Force Research Laboratory

6 Projects, page 1 of 2
  • Funder: UK Research and Innovation Project Code: EP/H004025/1
    Funder Contribution: 1,183,660 GBP

    Insects are the most diverse order of animals on earth and flight may be the key to this success. However, despite hundreds of millions of years of evolution, insect wings have not converged on a single optimal shape. Instead, there is an extraordinary range of wing morphologies visible in the world today (and even more fossilized), yet fundamentally, they all perform the same task - to enable flight. This led me to ask 'why is there no single wing shape that is best-suited to flapping flight?'The answer may well lie in assorted locally optimal solutions, specifically adapted to the tasks each insect undertakes during its life. The mission-profile of flight is unique for each insect species and so the selection pressures on wing morphology and kinematics is also species specific. A dragonfly that catches its prey on the wing and engages in aerial combat against rivals must be fast and manoeuvrable. Contrast this with the death's-head hawkmoth, migrating across Europe raiding bees' nests. They must be highly efficient since energy is at a premium during migration, but also robust enough to withstand attacks from bees when in their honey-stores. Understanding the morphologies of over a million described flying insect species is unfeasible, yet trends run through them which are exciting for aerodynamic engineering because they show solutions to specific requirements that have been tried, tested, and proven to succeed.My research seeks to understand how and why insect wing shapes have such variation despite intense selective pressure for aerodynamic performance, and why morphologies change when transitioning between ecological niches. The best way to examine this is to look at examples of convergent evolution, species which have similar ecology and morphology, yet originate from disparate taxonomic branches. Selecting species which are quite unrelated from one another allows discrimination of the aspects of wing shape which are part of design optimisation as opposed to those which are simply due to their historical starting point. My experiment therefore utilizes a comparative approach to evaluate representative species from across the class.In Track 1 of my research programme, a Postdoc will measure the aerodynamic output of flying insects directly, because it is essential to know how fast and in which direction the air is moving around the wings and in the wake. Flow velocities will be calculated around insects tethered in a wind tunnel by seeding the air with a light fog, and illuminating the particles with pulsing laser light. This technique is called Digital Particle Image Velocimetry and is the technique of choice for engineers studying complex flows. Recently, I successfully applied the technique to flying insects despite their small size and high wingbeat frequencies.Insects have no musculature in their wings. All the deforming complexities of the flapping cycle are controlled either actively by muscles at the wing hinge, or passively by inertial and aerodynamic forces on the wing architecture. The aerodynamic output is a result of wing motion so it is vital to know how the wing shape changes during flapping. In Track 2 of my research, a PhD student will record the kinematics of individuals from the same representative insects. The student will test predictions about the role of wing shape in ecology, by artificially selecting strains of fruit fly for alternate morphologies (e.g. more slender wings) and characterising the new morphs' flight performance. Simultaneously, the student will validate their results, by selecting strains based upon flight performance, and measuring the resulting modification in wing morphology.The output from these two tracks will be: 1) an explanation for the diversity of insect wing shapes from the perspective of biomechanical adaptation; 2) detailed kinematic data for Computational Fluid Dynamics studies; 3) clear design guidelines for engineers constructing insect-sized vehicles.

    more_vert
  • Funder: UK Research and Innovation Project Code: EP/E048439/1
    Funder Contribution: 268,248 GBP

    In the present research proposal we will use a novel biomimetic approach to the synthesis of nanocomposites using silk fusion (chimeric) proteins. The experimental design for the project involves the design, cloning, expression, analysis and characterisation of the fusion proteins in a range of physical forms (David Kaplan, Tufts University, USA) and the use of these proteins in materials synthesis (Carole Perry, Nottingham Trent University, UK) with some of the materials being assessed for their mechanical and other properties as they arise(Rajesh Naik, Airforce research Laboratories, USA) . Our aims are (1) to evaluate silk protein chimeric designs to optimize materials 'assembly space' (structure, morphology), (2) to prepare silk nanocomposites with a range of metal/oxide functionality in a variety of different material forms (from solution, and as fibres and films) under environmentally benign reaction conditions (aqueous processing), (3) to investigate the possibility of making multifunctional silk-based nanocomposites, and (4) correlate mechanical properties with design chemistry. The hypothesis for the proposed study is that nanocomposite material features can be optimized (structure, morphology, etc) and controlled (on a range of length scales) through appropriate design of chimeric (fusion) proteins in which the self-assembling structural domains and the functional (mineral or metal forming) domains are linked at the molecular level. Our goal is to elucidate how alterations in the chemistry of the two domains will lead to predictable changes in composite materials properties including tensile strength. The outcome of the proposed studies will be an entirely new family of novel nanocomposite materials, embracing the self-assmbly and remarkable mechanical properties of silk proteins but with added functions due to the chimeric mineralizing domains encoded in the new bioengineered proteins. We anticipate an entirely new approach to polymer design to generate novel composite materials through the proposed three year programme. The range of potenital applications for these materials is vast and includes military, space, performance car racing, elite sports wear, functional filters and materials for wound dressing and medical applications.

    more_vert
  • Funder: UK Research and Innovation Project Code: EP/H004025/2
    Funder Contribution: 363,412 GBP

    Insects are the most diverse order of animals on earth and flight may be the key to this success. However, despite hundreds of millions of years of evolution, insect wings have not converged on a single optimal shape. Instead, there is an extraordinary range of wing morphologies visible in the world today (and even more fossilized), yet fundamentally, they all perform the same task - to enable flight. This led me to ask 'why is there no single wing shape that is best-suited to flapping flight?'The answer may well lie in assorted locally optimal solutions, specifically adapted to the tasks each insect undertakes during its life. The mission-profile of flight is unique for each insect species and so the selection pressures on wing morphology and kinematics is also species specific. A dragonfly that catches its prey on the wing and engages in aerial combat against rivals must be fast and manoeuvrable. Contrast this with the death's-head hawkmoth, migrating across Europe raiding bees' nests. They must be highly efficient since energy is at a premium during migration, but also robust enough to withstand attacks from bees when in their honey-stores. Understanding the morphologies of over a million described flying insect species is unfeasible, yet trends run through them which are exciting for aerodynamic engineering because they show solutions to specific requirements that have been tried, tested, and proven to succeed.My research seeks to understand how and why insect wing shapes have such variation despite intense selective pressure for aerodynamic performance, and why morphologies change when transitioning between ecological niches. The best way to examine this is to look at examples of convergent evolution, species which have similar ecology and morphology, yet originate from disparate taxonomic branches. Selecting species which are quite unrelated from one another allows discrimination of the aspects of wing shape which are part of design optimisation as opposed to those which are simply due to their historical starting point. My experiment therefore utilizes a comparative approach to evaluate representative species from across the class.In Track 1 of my research programme, a Postdoc will measure the aerodynamic output of flying insects directly, because it is essential to know how fast and in which direction the air is moving around the wings and in the wake. Flow velocities will be calculated around insects tethered in a wind tunnel by seeding the air with a light fog, and illuminating the particles with pulsing laser light. This technique is called Digital Particle Image Velocimetry and is the technique of choice for engineers studying complex flows. Recently, I successfully applied the technique to flying insects despite their small size and high wingbeat frequencies.Insects have no musculature in their wings. All the deforming complexities of the flapping cycle are controlled either actively by muscles at the wing hinge, or passively by inertial and aerodynamic forces on the wing architecture. The aerodynamic output is a result of wing motion so it is vital to know how the wing shape changes during flapping. In Track 2 of my research, a PhD student will record the kinematics of individuals from the same representative insects. The student will test predictions about the role of wing shape in ecology, by artificially selecting strains of fruit fly for alternate morphologies (e.g. more slender wings) and characterising the new morphs' flight performance. Simultaneously, the student will validate their results, by selecting strains based upon flight performance, and measuring the resulting modification in wing morphology.The output from these two tracks will be: 1) an explanation for the diversity of insect wing shapes from the perspective of biomechanical adaptation; 2) detailed kinematic data for Computational Fluid Dynamics studies; 3) clear design guidelines for engineers constructing insect-sized vehicles.

    more_vert
  • Funder: UK Research and Innovation Project Code: EP/J008052/1
    Funder Contribution: 1,135,910 GBP

    This platform grant will underpin integrated photonics research in advanced laser sources, photonic circuits, and sensors, at the Optoelectronics Research Centre (ORC) at the University of Southampton, leveraging the recent investment of >£100M in the new Mountbatten Fabrication Complex. Photonic materials and device research has been the key driver of many disruptive advances in telecommunications, healthcare, data storage, display and manufacturing, and this platform grant will provide the group with the horizon and stability to build upon its international standing to explore new high-risk, high-reward research avenues. Integrated photonic materials and devices of the future will play a huge role in the next generation of cheaper, faster, greener, disposable, miniaturised and more versatile systems based on silica and silicon, glasses, crystal and polymer hosts, in both channel and planar geometries. The broad range of expertise within our group and our access to the unequalled brand-new planar fabrication facilities will allow us to fully explore this diverse research area. Impact will be realised through applications in compact kW-class waveguide lasers (new manufacturing techniques), pollution sensors (monitoring climate change), optical amplifiers and switches (high-speed data control), early threat detection devices (homeland security), and fast universally accessible disease screening (point-of-care medical diagnostics). Applications for the photonic materials, processes and devices developed during this platform grant will play a key role in fields of interest to society, Industry as well as university-based research and development, and will be pursued in collaboration with both existing and newly-identified partners during the programme.

    more_vert
  • Funder: UK Research and Innovation Project Code: EP/X019284/1
    Funder Contribution: 684,477 GBP

    It is well established that long-term exposure to aircraft and wind turbine noise is responsible for many physiological and psychological effects. According to the recent studies, noise not only creates a nuisance by affecting amenity, quality of life, productivity, and learning, but it also increases the risk of hospital admissions and mortality due to strokes, coronary heart disease, and cardiovascular disease. The World Health Organization estimated in 2011 that up to 1.6 million healthy life years are lost annually in the western European countries because of exposure to high levels of noise. The noise is also acknowledged by governments as a limit to both airline fleet growth, acceptability of Urban Air Mobility, operation and expansion of wind turbines, with direct consequences to the UK economy. With regards to aerodynamic noise, aerofoil noise is perhaps one of the most important sources of noise in many applications. While aerofoils are designed to achieve maximum aerodynamic performance by operating at high angles of attack, they become inevitably more susceptible to flow separation and stall due to changing inflow conditions (gusts, wind shear, wake interaction). Separation and stall can lead to a drastic reduction in aerodynamic performance and significantly increased aerodynamic noise. In applications involving rotating blades, the near-stall operation of blades, when subjected to highly dynamic inflows, gives rise to an even more complex phenomenon, known as dynamic stall. While the very recent research into the aerodynamics of dynamic stall has shown the complexity of the problem, the understanding of dynamic stall noise generation has remained stagnant due to long-standing challenges in experimental, numerical and analytical methods. This collaborative project, which includes contributions from strong industrial and academic advisory boards, aims to develop new understanding of dynamic stall flow and noise and develop techniques to control dynamic stall noise. The team will make use of the state-of-the-art experimental rigs, dedicated to aeroacoustics of dynamic stall and GPU-accelerated high-fidelity CFD tools to generate unprecedented amount of flow and noise data for pitching aerofoils over a wide range of operating conditions (flow velocity, pitching frequency/amplitude, etc.). The data will then be used to identify flow mechanisms that contribute to the different aerofoil noise sources at high angles of attack, including aerofoil unsteady loading and flow quadrupole sources, and detailed categorisation of dynamic stall regimes. A set of new frequency- and time-domain analytical tools will also be developed for the prediction of dynamic stall noise at different dynamic stall regimes, informed by high-fidelity experimental and numerical datasets. This project will bring about a step change in our understanding of noise from pitching aerofoils over a wide range of operations and pave the way to more accurate noise predictions and development of potential noise mitigation strategies.

    more_vert
  • chevron_left
  • 1
  • 2
  • chevron_right

Do the share buttons not appear? Please make sure, any blocking addon is disabled, and then reload the page.

Content report
No reports available
Funder report
No option selected
arrow_drop_down

Do you wish to download a CSV file? Note that this process may take a while.

There was an error in csv downloading. Please try again later.