WorldWideScience

Sample records for wing air education

  1. Flapping Wing Micro Air Vehicle Wing Manufacture and Force Testing

    Science.gov (United States)

    2011-03-03

    manufacturing techniques have been developed by various universities for research on Flapping Wing Micro Air Vehicles. Minimal attention though is given...collected at 2kHz (www.polytec.com/psv3d). A 0.25V band-limited white noise input signal is input to a Bogen HTA -125 High Performance Amplifier, which...manufacturing techniques have been developed by various universities for research on Flapping Wing Micro Air Vehicles. Minimal attention though is given

  2. Logistics Supply of the Distributed Air Wing

    Science.gov (United States)

    2014-09-01

    Event Graph The Consumption Process first instantiates the variables . The model follows a conveyor belt pattern, whereby after processing an event...to any part of the world. A capstone project, conducted by the system engineering curriculum, proposed to distribute the air assets from the aircraft...SUBJECT TERMS distributed air wing, logistics, supply, unmanned air systems , cargo UAS, unmanned systems , discrete event simulation, vehicle routing

  3. Air Base Wing and Air Mobility Wing Consolidating on AMC-LED Joint Bases: A Delphi Study

    Science.gov (United States)

    2014-06-13

    AIR BASE WING AND AIR MOBILITY WING CONSOLIDATION ON AMC-LED JOINT BASES: A DELPHI STUDY GRADUATE RESEARCH PAPER Mason E. MacGarvey... DELPHI STUDY GRADUATE RESEARCH PAPER Presented to the Faculty Graduate School of Engineering Management Air Force Institute of Technology...iv AIR BASE WING AND AIR MOBILITY WING CONSOLIDATION ON AMC-LED JOINT BASES: A DELPHI STUDY Mason E. MacGarvey, BS, MBA

  4. Fixed-Wing Micro Air Vehicles with Hovering Capabilities

    National Research Council Canada - National Science Library

    Bataille, Boris; Poinsot, Damien; Thipyopas, Chinnapat; Moschetta, Jean-Marc

    2007-01-01

    Fixed-wing micro air vehicles (MAV) are very attractive for outdoor surveillance missions since they generally offer better payload and endurance capabilities than rotorcraft or flapping-wing vehicles of equal size...

  5. Artificial insect wings of diverse morphology for flapping-wing micro air vehicles

    International Nuclear Information System (INIS)

    Shang, J K; Finio, B M; Wood, R J; Combes, S A

    2009-01-01

    The development of flapping-wing micro air vehicles (MAVs) demands a systematic exploration of the available design space to identify ways in which the unsteady mechanisms governing flapping-wing flight can best be utilized for producing optimal thrust or maneuverability. Mimicking the wing kinematics of biological flight requires examining the potential effects of wing morphology on flight performance, as wings may be specially adapted for flapping flight. For example, insect wings passively deform during flight, leading to instantaneous and potentially unpredictable changes in aerodynamic behavior. Previous studies have postulated various explanations for insect wing complexity, but there lacks a systematic approach for experimentally examining the functional significance of components of wing morphology, and for determining whether or not natural design principles can or should be used for MAVs. In this work, a novel fabrication process to create centimeter-scale wings of great complexity is introduced; via this process, a wing can be fabricated with a large range of desired mechanical and geometric characteristics. We demonstrate the versatility of the process through the creation of planar, insect-like wings with biomimetic venation patterns that approximate the mechanical properties of their natural counterparts under static loads. This process will provide a platform for studies investigating the effects of wing morphology on flight dynamics, which may lead to the design of highly maneuverable and efficient MAVs and insight into the functional morphology of natural wings.

  6. Experimental Characterization of Wings for a Hawkmoth-Sized Micro Air Vehicle

    Science.gov (United States)

    2014-03-27

    Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of...24 3.1.2 Abaqus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.1.3 FEA Design Update Process...26 3.5 Abaqus Assembled Wing Layers . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.6 Sample Results

  7. Damage Considerations of a Flexible Micro Air Vehicle Wing Using 3-D Laser Vibrometry

    National Research Council Canada - National Science Library

    Mendoza, Jr, Leo L

    2007-01-01

    .... The flexible micro air vehicle wing studied was based on a University of Florida micro air vehicle wing design and was examined using measurements from the Polytec 400-3D Scanning Vibrometer. Comparisons of the wing?s natural frequencies and displacements were made between the wing?s undamaged and damaged states.

  8. Pitching stability analysis of half-rotating wing air vehicle

    Science.gov (United States)

    Wang, Xiaoyi; Wu, Yang; Li, Qian; Li, Congmin; Qiu, Zhizhen

    2017-06-01

    Half-Rotating Wing (HRW) is a new power wing which had been developed by our work team using rotating-type flapping instead of oscillating-type flapping. Half-Rotating Wing Air Vehicle (HRWAV) is similar as Bionic Flapping Wing Air Vehicle (BFWAV). It is necessary to guarantee pitching stability of HRWAV to maintain flight stability. The working principle of HRW was firstly introduced in this paper. The rule of motion indicated that the fuselage of HRWAV without empennage would overturn forward as it generated increased pitching movement. Therefore, the empennage was added on the tail of HRWAV to balance the additional moment generated by aerodynamic force during flight. The stability analysis further shows that empennage could weaken rapidly the pitching disturbance on HRWAV and a new balance of fuselage could be achieved in a short time. Case study using numerical analysis verified correctness and validity of research results mentioned above, which could provide theoretical guidance to design and control HRWAV.

  9. Flapping and flexible wings for biological and micro air vehicles

    Science.gov (United States)

    Shyy, Wei; Berg, Mats; Ljungqvist, Daniel

    1999-07-01

    Micro air vehicles (MAVs) with wing spans of 15 cm or less, and flight speed of 30-60 kph are of interest for military and civilian applications. There are two prominent features of MAV flight: (i) low Reynolds number (10 4-10 5), resulting in unfavorable aerodynamic conditions to support controlled flight, and (ii) small physical dimensions, resulting in certain favorable scaling characteristics including structural strength, reduced stall speed, and low inertia. Based on observations of biological flight vehicles, it appears that wing motion and flexible airfoils are two key attributes for flight at low Reynolds number. The small size of MAVs corresponds in nature to small birds, which do not glide like large birds, but instead flap with considerable change of wing shape during a single flapping cycle. With flapping and flexible wings, birds overcome the deteriorating aerodynamic performance under steady flow conditions by employing unsteady mechanisms. In this article, we review both biological and aeronautical literatures to present salient features relevant to MAVs. We first summarize scaling laws of biological and micro air vehicles involving wing span, wing loading, vehicle mass, cruising speed, flapping frequency, and power. Next we discuss kinematics of flapping wings and aerodynamic models for analyzing lift, drag and power. Then we present issues related to low Reynolds number flows and airfoil shape selection. Recent work on flexible structures capable of adjusting the airfoil shape in response to freestream variations is also discussed.

  10. The effects of wing flexibility on the flight performance and stability of flapping wing micro air vehicles

    Science.gov (United States)

    Bluman, James Edward

    Insect wings are flexible. However, the influence of wing flexibility on the flight dynamics of insects and flapping wing micro air vehicles is unknown. Most studies in the literature consider rigid wings and conclude that the hover equilibrium is unstable. This dissertation shows that a flapping wing flyer with flexible wings exhibits stable natural modes of the open loop system in hover, never reported before. The free-flight insect flight dynamics is modeled for both flexible and rigid wings. Wing mass and inertia are included in the nonlinear equations of motion. The flapping wing aerodynamics are modeled using a quasi-steady model, a well-validated two dimensional Navier Stokes model, and a coupled, two dimensional Navier Stokes - Euler Bernoulli beam model that accurately models the fluid-structure interaction of flexible wings. Hover equilibrium is systematically and efficiently determined with a coupled quasi-steady and Navier-Stokes equation trimmer. The power and stability are reported at hover while parametrically varying the pitch axis location for rigid wings and the structural stiffness for flexible wings. The results indicate that the rigid wings possess an unstable oscillatory mode mainly due to their pitch sensitivity to horizontal velocity perturbations. The flexible wings stabilize this mode primarily by adjusting their wing shape in the presence of perturbations. The wing's response to perturbations generates significantly more horizontal velocity damping and pitch rate damping than in rigid wings. Furthermore, the flexible wings experience substantially less wing wake interaction, which, for rigid wings, is destabilizing. The power required to hover a fruit fly with actively rotating rigid wings varies between 16.9 and 34.2 W/kg. The optimal power occurs when the pitch axis is located at 30% chord, similar to some biological observations. Flexible wings require 23.1 to 38.5 W/kg. However, flexible wings exhibit more stable system dynamics and

  11. A program for scheduling a Patrol Air Wing training plan.

    OpenAIRE

    Hutson, David V.

    1988-01-01

    Approved for public release; distribution in unlimited. This research examined the feasibility of a computerized scheduling system to assist the development of an annual training plan for a Patrol Air Wing. A prototype is proposed incorporating a modified A* search control structure to handle the combinatorial part of the problem. The system uses a pre-existing file for its database and is implemented on an ISI workstation using the Prolog computer language. Comparisons with...

  12. High Performance Piezoelectric Actuators and Wings for Nano Air Vehicles

    Science.gov (United States)

    2012-08-26

    process to monolithically fabricate flying robotic insects at the pico air ve- hicle ( PAV ) scale from SUEX dry film, an epoxy based negative photoresist...cost. It simul- taneously defines the PAV airframe, compliant flapping mechanism, and artificial insect wing using photolithography. Using this process...81 4.4.3 Simulated Average Lift Versus Frequency of the Redesigned LionFly 82 5.1.1 Potential Fabrication Process for PAV Flapping

  13. Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings

    Directory of Open Access Journals (Sweden)

    Adetunji Oduyela

    2014-01-01

    Full Text Available Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system.

  14. Piezoelectric energy harvesting from morphing wing motions for micro air vehicles

    KAUST Repository

    Abdelkefi, Abdessattar

    2013-09-10

    Wing flapping and morphing can be very beneficial to managing the weight of micro air vehicles through coupling the aerodynamic forces with stability and control. In this letter, harvesting energy from the wing morphing is studied to power cameras, sensors, or communication devices of micro air vehicles and to aid in the management of their power. The aerodynamic loads on flapping wings are simulated using a three-dimensional unsteady vortex lattice method. Active wing shape morphing is considered to enhance the performance of the flapping motion. A gradient-based optimization algorithm is used to pinpoint the optimal kinematics maximizing the propellent efficiency. To benefit from the wing deformation, we place piezoelectric layers near the wing roots. Gauss law is used to estimate the electrical harvested power. We demonstrate that enough power can be generated to operate a camera. Numerical analysis shows the feasibility of exploiting wing morphing to harvest energy and improving the design and performance of micro air vehicles.

  15. Environmental Assessment for the 920th Rescue Wing Beddown Patrick Air Force Base, Florida

    Science.gov (United States)

    2005-10-01

    Vista Technologies Inc. Environmental Assessment, Development and Maintenance of Patrick Air Force Base, Florida. January 1997. Canter , Larry W...Space Wing 45 CES/CEVC PAFB, Florida 920th Rescue Wing Beddown Environmental Assessment 8-1 8.0 LIST OF PREPARERS 1. David B

  16. Air Force ALP AEF Initiative Wing-Level Cluster Development and Demonstration

    National Research Council Canada - National Science Library

    Stute, Nicholas

    2001-01-01

    The purpose of this document is to describe the results for the Air Force ALP AEF Initiative Wing-Level Cluster Development and Demonstration task jointly sponsored by the Logistics Readiness Branch...

  17. Damage Considerations of a Flexible Micro Air Vehicle Wing Using 3-D Laser Vibrometry

    National Research Council Canada - National Science Library

    Mendoza, Jr, Leo L

    2007-01-01

    .... The focus of this research is to evaluate the effects of damage on a flexible micro air vehicle wing, particularly its natural frequencies and mode shapes, using three dimensional laser vibrometry...

  18. Air Forces and Moments on Triangular and Related Wings With Subsonic Leading Edges Oscillating in Supersonic Potential Flow

    National Research Council Canada - National Science Library

    Watkins, Charles

    1961-01-01

    This analysis treats the air forces and moments in supersonic potential flow on oscillating triangular wings and a series of sweptback and arrow wings with subsonic leading edges and supersonic trailing edges...

  19. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

    Directory of Open Access Journals (Sweden)

    Sutthiphong Srigrarom

    2015-05-01

    Full Text Available In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings are able to produce sufficient lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on different wing designs and materials were conducted and a paramount wing was built for a test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g. A mechanism which produced a flapping motion was fabricated and designed to create flapping flight. The flapping flight was produced by using a single motor and a flexible and light wing structure. A force balance made of load cell was then designed to measure the thrust and lift force of the ornithopter. Three sets of wings varying flexibility were fabricated, therefore lift and thrust measurements were acquired from each different set of wings. The lift will be measured in ten cycles computing the average lift and frequency in three different speeds or frequencies (slow, medium and fast. The thrust measurement was measure likewise but in two cycles only. Several observations were made regarding the behavior of flexible flapping wings that should aid in the design of future flexible flapping wing vehicles. The wings angle or phase characteristic were analyze too and studied. The final ornithopter prototype weighs only 160 g, has a wing span of 88.5 cm, that could flap at a maximum flapping frequency of 3.869 Hz, and produce a maximum thrust and lift of about 0.719 and 0.264 N respectively. Next, we proposed resonance type flapping wing utilizes the near

  20. Design and mechanical analysis of a 3D-printed biodegradable biomimetic micro air vehicle wing

    Science.gov (United States)

    Salami, E.; Ganesan, P. B.; Ward, T. A.; Viyapuri, R.; Romli, F. I.

    2016-10-01

    The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. There are still many technological challenges involved with designing the BMAV. One of these is designing the ultra-lightweight materials and structures for the wings that have enough mechanical strength to withstand continuous flapping at high frequencies. Insects achieve this by having chitin-based, wing frame structures that encompass a thin, film membrane. The main objectives of this study are to design a biodegradable BMAV wing (inspired from the dragonfly) and analyze its mechanical properties. The dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. A chitosan nanocomposite film membrane was applied to the BMAV wing frames through casting method. Its mechanical performance was analyzed using universal testing machine (UTM). This analysis indicates that the tensile strength and Young's modulus of the wing with a membrane is nearly double that of the wing without a membrane, which allow higher wing beat frequencies and deflections that in turn enable a greater lifting performance.

  1. Repeatable Manufacture of Wings for Flapping Wing Micro Air Vehicles Using Microelectromechanical System (MEMS) Fabrication Techniques

    Science.gov (United States)

    2011-03-01

    life span, and must be cared for and used expeditiously. Once a hawkmoth hatches from its cocoon, its wing is liberated, taking care to cut the...more controlled fashion than the butterfly, but is not sufficiently so for a Micro- MAV (courtesy of http://www.science-store.com/ life /specimens/la460...50. Michelson, Robert C. and Naqvi, Messam A. Extraterrestrial Flight. s.l. : RTO- AVT von Karman Institute for Fluid Dynamics Lecture Series, 2003

  2. Reliable Force Predictions for a Flapping-wing Micro Air Vehicle : A "Vortex-lift" Approach

    NARCIS (Netherlands)

    Thielicke, W.; Kesel, A. B.; Stamhuis, Eize

    2011-01-01

    Vertical and horizontal force of a flapping-wing micro air vehicle (MAV) has been measured in slow-speed forward flight using a force balance. Detailed information on kinematics was used to estimate forces using a blade-element analysis. Input variables for this analysis are lift and drag

  3. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.

    Science.gov (United States)

    Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

    2011-12-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s⁻¹, operate in a Reynolds number regime of 10⁵ or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  4. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle

    International Nuclear Information System (INIS)

    Nakata, T; Liu, H; Nishihashi, N; Wang, X; Sato, A; Tanaka, Y

    2011-01-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s −1 , operate in a Reynolds number regime of 10 5 or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4–3.0 g and a wingspan of 10–12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  5. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    Science.gov (United States)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

  6. Design of flapping wings for application to single active degree of freedom micro air vehicles

    Science.gov (United States)

    Chang, Kelvin Thomas

    This dissertation covers an experimental program to understand how wing compliance influences the performance of flapping micro air vehicle wings. The focus is the design of a membraned flapping wing for a single active degree of freedom mechanism, looking to maximize thrust performance in hover conditions. The optimization approach is unique in that experiments were the chosen engine as opposed to a computation model; this is because of the complexity involved in hover-mode flapping aerodynamics. The flapping mechanism and manufacturing process for fabricating the wings were carefully developed. The uncertainty in the thrust measurement was identified and reduced by implementing precision machining and repeatable techniques for fabrication. This resulted in a reduction of the manufacturing coefficient of variation from 16.8% to 2.6%. Optimization was then conducted for a single objective (Maximize thrust), using a three parameter design space, finding the highest thrust performance in wings with high aspect ratio; then, a multi-objective optimization was conducted with two objectives (Thrust and Power) and a four parameter space. The research then shifted focus to identifying the stiffness and deformation characteristics of high performance wing designs. Static stiffness measurements with a simple line load suggested that high chordwise stiffness or lower spanwise stiffness would be favorable for aerodynamic performance. To explore more components of the deformation, a full-field imaging technique was used and a uniform load was substituted to engage with the membrane. It was found that there is a range of torsional compliance where the wing is most efficient especially at higher flapping frequencies. The final component of the study was the dynamic deformation measurement. The two system, four camera digital image correlation setup uses stroboscopic measurement to capture the wing deformation. The phase shift between the twist and stroke, and the tip deflection

  7. Design and verification of a smart wing for an extreme-agility micro-air-vehicle

    International Nuclear Information System (INIS)

    Wickramasinghe, Viresh; Chen, Yong; Martinez, Marcias; Kernaghan, Robert; Wong, Franklin

    2011-01-01

    A special class of fixed-wing micro-air-vehicle (MAV) is currently being designed to fly and hover to provide range superiority as well as being able to hover through a flight maneuver known as prop-hanging to accomplish a variety of surveillance missions. The hover maneuver requires roll control of the wing through differential aileron deflection but a conventional system contributes significantly to the gross weight and complexity of a MAV. Therefore, it is advantageous to use smart structure approaches with active materials to design a lightweight, robust wing for the MAV. The proposed smart wing consists of an active trailing edge flap integrated with bimorph actuators with piezoceramic fibers. Actuation is enhanced by preloading the bimorph actuators with a compressive axial load. The preload is exerted on the actuators through a passive latex or electroactive polymer (EAP) skin that wraps around the airfoil. An EAP skin would further enhance the actuation by providing an electrostatic effect of the dielectric polymer to increase the deflection. Analytical modeling as well as finite element analysis show that the proposed concept could achieve the target bi-directional deflection of 30° in typical flight conditions. Several bimorph actuators were manufactured and an experimental setup was designed to measure the static and dynamic deflections. The experimental results validated the analytical technique and finite element models, which have been further used to predict the performance of the smart wing design for a MAV

  8. Design and verification of a smart wing for an extreme-agility micro-air-vehicle

    Science.gov (United States)

    Wickramasinghe, Viresh; Chen, Yong; Martinez, Marcias; Wong, Franklin; Kernaghan, Robert

    2011-12-01

    A special class of fixed-wing micro-air-vehicle (MAV) is currently being designed to fly and hover to provide range superiority as well as being able to hover through a flight maneuver known as prop-hanging to accomplish a variety of surveillance missions. The hover maneuver requires roll control of the wing through differential aileron deflection but a conventional system contributes significantly to the gross weight and complexity of a MAV. Therefore, it is advantageous to use smart structure approaches with active materials to design a lightweight, robust wing for the MAV. The proposed smart wing consists of an active trailing edge flap integrated with bimorph actuators with piezoceramic fibers. Actuation is enhanced by preloading the bimorph actuators with a compressive axial load. The preload is exerted on the actuators through a passive latex or electroactive polymer (EAP) skin that wraps around the airfoil. An EAP skin would further enhance the actuation by providing an electrostatic effect of the dielectric polymer to increase the deflection. Analytical modeling as well as finite element analysis show that the proposed concept could achieve the target bi-directional deflection of 30° in typical flight conditions. Several bimorph actuators were manufactured and an experimental setup was designed to measure the static and dynamic deflections. The experimental results validated the analytical technique and finite element models, which have been further used to predict the performance of the smart wing design for a MAV.

  9. Understanding of Low Reynolds Number Aerodynamics and Micro Rotary-Wing Air Vehicles

    Science.gov (United States)

    Winslow, Justin Michael

    The goal of the present research is to understand aerodynamics at low Reynolds numbers and synthesize rules towards the development of hovering micro rotary-wing air vehicles (MRAVs). This entailed the rigorous study of airfoil characteristics at low Reynolds numbers through available experimental results as well as the use of an unsteady Reynolds-Averaged Navier-Stokes solver. A systematic, experimental, variation of parameters approach with physical rotors was carried out to design and develop a micro air vehicle-scale rotor which maximizes the hover Figure of Merit. The insights gained in low Reynolds number aerodynamics have been utilized in the systematic design of a high endurance micro-quadrotor. Based on available characteristics, the physical relations governing electric propulsion system and structural weights have been derived towards a sizing methodology for small-scale rotary-wing vehicles.

  10. Functional Alignment of the Wing-Level Logistics Plans Division in the Strategic Air Command.

    Science.gov (United States)

    1987-04-01

    PERFORMING ORGANIZATION REPORT NUMBER(S) S. MONITORING ORGANIZATION REPORT NUMBER(S) 87-2250 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME...THIS PA(:4___ TTNC LASSI FIZD PREFACE What’s to be gained, or lost, if the Strategic Air Command (SAC) function- ally realigned Its wing-level...product as meeting academic requirements for graduation, the views and opinions expressed or implied are solely those of the author and should , not be

  11. An insect-inspired flapping wing micro air vehicle with double wing clap-fling effects and capability of sustained hovering

    Science.gov (United States)

    Nguyen, Quoc-Viet; Chan, Woei Leong; Debiasi, Marco

    2015-03-01

    We present our recent flying insect-inspired Flapping-Wing Micro Air Vehicle (FW-MAV) capable of hovering flight which we have recently achieved. The FW-MAV has wing span of 22 cm (wing tip-to-wing tip), weighs about 16.6 grams with onboard integration of radio control system including a radio receiver, an electronic speed control (ESC) for brushless motor, three servos for attitude flight controls of roll, pitch, and yaw, and a single cell lithium-polymer (LiPo) battery (3.7 V). The proposed gear box enables the FW-MAV to use one DC brushless motor to synchronously drive four wings and take advantage of the double clap-and-fling effects during one flapping cycle. Moreover, passive wing rotation is utilized to simplify the design, in addition to passive stabilizing surfaces for flight stability. Powered by a single cell LiPo battery (3.7 V), the FW-MAV flaps at 13.7 Hz and produces an average vertical force or thrust of about 28 grams, which is sufficient for take-off and hovering flight. Finally, free flight tests in terms of vertical take-off, hovering, and manual attitude control flight have been conducted to verify the performance of the FW-MAV.

  12. Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

    Science.gov (United States)

    Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

    2017-06-01

    The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a

  13. Nano-mechanical properties and structural of a 3D-printed biodegradable biomimetic micro air vehicle wing

    Science.gov (United States)

    Salami, E.; Montazer, E.; Ward, T. A.; Ganesan, P. B.

    2017-06-01

    The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. The main objectives of this study are to design a BMAV wing (inspired from the dragonfly) and analyse its nano-mechanical properties. In order to gain insights into the flight mechanics of dragonfly, reverse engineering methods were used to establish three-dimensional geometrical models of the dragonfly wings, so we can make a comparative analysis. Then mechanical test of the real dragonfly wings was performed to provide experimental parameter values for mechanical models in terms of nano-hardness and elastic modulus. The mechanical properties of wings were measured by nanoindentre. Finally, a simplified model was designed and the dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. Then mechanical test of the BMAV wings was performed to analyse and compare the wings under a variety of simplified load regimes that are concentrated force, uniform line-load and a torque. This work opened up the possibility towards developing an engineering basis for the biomimetic design of BMAV wings.

  14. Unsteady Aerodynamics of Flapping Wings at Re=10,000-100,000 for Micro-Air Vehicles

    Science.gov (United States)

    2014-02-11

    MICO AIR VEHICLE (MAV) APPLICATIONS , Proceedings of the 37th National & 4th International Conference on Fluid Mechanics and Fluid Power, IIT...deviations on the aerodynamic forces. Then we used the knowledge gathered in this domain to attack the complex measured kinematics of a bat wing. The...immersed in a background grid. One surprising conclusion from this work was that in spite of the apparent complexity of wing motion, the motion could be

  15. Modeling and Closed Loop Flight Testing of a Fixed Wing Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    Harikumar Kandath

    2018-03-01

    Full Text Available This paper presents the nonlinear six degrees of freedom dynamic modeling of a fixed wing micro air vehicle. The static derivatives of the micro air vehicle are obtained through the wind tunnel testing. The propeller effects on the lift, drag, pitching moment and side force are quantified through wind tunnel testing. The dynamic derivatives are obtained through empirical relations available in the literature. The trim conditions are computed for a straight and constant altitude flight condition. The linearized longitudinal and lateral state space models are obtained about trim conditions. The variations in short period mode, phugoid mode, Dutch roll mode, roll subsidence mode and spiral mode with respect to different trim operating conditions is presented. A stabilizing static output feedback controller is designed using the obtained model. Successful closed loop flight trials are conducted with the static output feedback controller.

  16. A Finite Element Analysis of a Carbon Fiber Composite Micro Air Vehicle Wing

    Science.gov (United States)

    2012-03-22

    Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the...using a developed MATLAB code that generated finite element input files to be solved using ABAQUS , a finite element program. The developed MATLAB code...program that is capable of generating an input file to be submitted to ABAQUS , a finite element model solver. This technique was used in order to

  17. Power Requirements for Bi-Harmonic Amplitude and Bias Modulation Control of a Flapping Wing Micro Air Vehicle

    Science.gov (United States)

    2013-03-01

    nature, would have the inherent benefit of stealth through mimicry of insects. Such a MAV is referred to as a flapping wing micro air vehicle (FWMAV...S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. “The Animal Diversity Web”, 2013. URL http://animaldiversity.ummz.umich.edu/accounts/Manduca_sexta

  18. Aircraft impact risk assessment data base for assessment of fixed wing air carrier impact risk in the vicinity of airports

    International Nuclear Information System (INIS)

    Akstulewicz, F.; Read, J.

    1979-06-01

    The FIXED WING AIRCRAFT accidents occurring to US air carriers during the years 1956 through 1977 are listed, with those resulting in impact within five miles of airports in the contiguous US being considered in detail as to location of impact relative to the airport runways

  19. Experimental Investigation of Pitch Control Enhancement to the Flapping Wing Micro Air Vehicle

    National Research Council Canada - National Science Library

    Kian, Chin C

    2006-01-01

    .... The MAV without the main fixed-wing is placed in a laminar flow field within a low speed wind tunnel with the wake after the flapping wings characterized with a constant temperature anemometer...

  20. An efficient fluid-structure interaction method for conceptual design of flexible micro air vehicle wings: Development, comparison, and application

    Science.gov (United States)

    Combes, Thomas P.

    This thesis summarizes the development, comparison, and applications of an efficient fluid-structure interaction method capable of simulating the effects that wing flexibility has on micro air vehicle (MAV) performance. Micro air vehicles wing designs often incorporate flexible wing structures that mimic the skeleton / membrane designs found in natural flyers such as bats and insects. However, accurate performance prediction for these wings requires the coupling of the simulation of the fluid physics around the wing and the simulation of the structural deformation. These fluid-structure interaction (FSI) simulations are often accomplished using high fidelity, computationally expensive techniques such as computational fluid dynamics (CFD) for the fluid physics and nonlinear finite element analysis (FEA) for the structural simulation. The main drawback of these methods, especially for use simulating vehicles that are able to be manufactured relatively quickly, is that the computational cost required to perform relevant trade studies on the design is prohibitively large and time-consuming. The main goal of this research is the development of a coupled fluid-structure interaction method computationally efficient and accurate enough to be used for conceptual design of micro air vehicles. An advanced potential flow model is used to calculate aerodynamic performance and loading, while a simplified finite element structural model using frame and shell elements calculates the wing deflection due to aerodynamic loading. The contents of this thesis include a literature survey of current approaches, an introduction to the efficient FSI formulation, comparison of the presented FSI method with higher-fidelity simulation methods, demonstrations of the method's capability for tradeoff and optimization studies, and an overview of contributions to a nonlinear dynamic algorithm for the simulation of flapping flight.

  1. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    International Nuclear Information System (INIS)

    Wissman, James; Perez-Rosado, Ariel; Edgerton, Alex; Levi, Benjamin M; Karakas, Zeynep N; Kujawski, Mark; Philipps, Alyssa; Papavizas, Nicholas; Fallon, Danielle; Bruck, Hugh A; Smela, Elisabeth

    2013-01-01

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 Ω με −1 and the gauge factor was 28; in compression, the gauge factor was −5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle. (paper)

  2. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    Science.gov (United States)

    Wissman, James; Perez-Rosado, Ariel; Edgerton, Alex; Levi, Benjamin M.; Karakas, Zeynep N.; Kujawski, Mark; Philipps, Alyssa; Papavizas, Nicholas; Fallon, Danielle; Bruck, Hugh A.; Smela, Elisabeth

    2013-08-01

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 Ω μɛ-1 and the gauge factor was 28; in compression, the gauge factor was -5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle.

  3. Experimental characterization and multidisciplinary conceptual design optimization of a bendable load stiffened unmanned air vehicle wing

    Science.gov (United States)

    Jagdale, Vijay Narayan

    Demand for deployable MAVs and UAVs with wings designed to reduce aircraft storage volume led to the development of a bendable wing concept at the University of Florida (UF). The wing shows an ability to load stiffen in the flight load direction, still remaining compliant in the opposite direction, enabling UAV storage inside smaller packing volumes. From the design prospective, when the wing shape parameters are treated as design variables, the performance requirements : high aerodynamic efficiency, structural stability under aggressive flight loads and desired compliant nature to prevent breaking while stored, in general conflict with each other. Creep deformation induced by long term storage and its effect on the wing flight characteristics are additional considerations. Experimental characterization of candidate bendable UAV wings is performed in order to demonstrate and understand aerodynamic and structural behavior of the bendable load stiffened wing under flight loads and while the wings are stored inside a canister for long duration, in the process identifying some important wing shape parameters. A multidisciplinary, multiobjective design optimization approach is utilized for conceptual design of a 24 inch span and 7 inch root chord bendable wing. Aerodynamic performance of the wing is studied using an extended vortex lattice method based Athena Vortex Lattice (AVL) program. An arc length method based nonlinear FEA routine in ABAQUS is used to evaluate the structural performance of the wing and to determine maximum flying velocity that the wing can withstand without buckling or failing under aggressive flight loads. An analytical approach is used to study the stresses developed in the composite wing during storage and Tsai-Wu criterion is used to check failure of the composite wing due to the rolling stresses to determine minimum safe storage diameter. Multidisciplinary wing shape and layup optimization is performed using an elitist non-dominated sorting

  4. Active Air Force Wings as of 1 October 1995; USAF Active Flying, Space, and Missile Squadrons as of 1 October 1995

    National Research Council Canada - National Science Library

    Endicott, Judy G; Bailey, Carl E; Cully, George W; Harris, W. S; Hartman, Sara K; Heskett, K. D; Light, J. R; Perdue, Johnna A

    1998-01-01

    .... Among other initiatives, he directed the Air Force Historical Research Agency to compile a two-volume series publicizing the lineage and heraldry of the wings and flying squadrons that would remain...

  5. Unsteady Aerodynamic Investigation of the Propeller-Wing Interaction for a Rocket Launched Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    G. Q. Zhang

    2013-01-01

    Full Text Available The aerodynamic characteristics of propeller-wing interaction for the rocket launched UAV have been investigated numerically by means of sliding mesh technology. The corresponding forces and moments have been collected for axial wing placements ranging from 0.056 to 0.5D and varied rotating speeds. The slipstream generated by the rotating propeller has little effects on the lift characteristics of the whole UAV. The drag can be seen to remain unchanged as the wing's location moves progressively closer to the propeller until 0.056D away from the propeller, where a nearly 20% increase occurred sharply. The propeller position has a negligible effect on the overall thrust and torque of the propeller. The efficiency affected by the installation angle of the propeller blade has also been analyzed. Based on the pressure cloud and streamlines, the vortices generated by propeller, propeller-wing interaction, and wing tip have also been captured and analyzed.

  6. A helicopter that flaps its wings : The Ornicopter flaps its wings like a bird to get into the air

    NARCIS (Netherlands)

    Van Holten, T.; Mols, B.

    2003-01-01

    No other type of aircraft is as manoeuvrable as a helicopter. Reverse in full flight, rotate in the air, hover at a standstill, the helicopter can do it all. The police, fire services, medical services, military and civil aviation all use the helicopter for the freedom of flight it offers. However,

  7. Flow characteristics of air in square duct using delta wing vortex generators

    Directory of Open Access Journals (Sweden)

    Mahesh R. Ingalagi

    2016-09-01

    Full Text Available Performance improvement in terms of improving heat transfer coefficient and reducing pressure drop becomes essential in heat exchange applications and a large number of methods for reducing pressure drop exist in the literature and the present work is an investigation on use of delta wings as vortex generators for reducing pressure drop. Methodology includes air from a blower entering the test section through orificemeter and differential-micro manometer to measure the flow rate and pressure drop across the test section. Depending upon the pressure drops, friction factors for smooth and rough surface of the duct are estimated. The effect of geometrical parameters of delta wing and duct aspect ratio on friction factor ratios are reported Based on Reynolds number in the range of 8000−24000. The geometrical parameters of vortex generators varied in this study were the pitch-to-vortex generator height ratio (p/e, vortex generator height to duct hydraulic diameter ratio (e/Dh, aspect ratio of vortex generator (ar. Results are reported for 0.1 < e/Dh < 0.5, p/e = 4,8,12,16, (ar = 1.6,2.3,4, N = 1 in ducts having aspect ratio AR = 1, Detailed friction factor analysis for Re 8000−24000 has been presented for different configurations of vortex generators used in the square duct. The experimental results of the present study for friction factor in smooth square duct matches well with values taken from formula proposed by Blasius. The friction factor ratio increases with increase in e/Dh value, which may be attributed to increased blockage of the flow passage. For a given p/e, increasing e/Dh ratio for the same (ar has the effect of increasing circulation strength and core size of the vortex thereby offering more resistance to flow that results into a higher friction factor ratio. The results have been presented in the form of the friction factor ratio of the roughened and smooth ducts operating at equal Reynolds numbers. Semi

  8. Spreading Our Wings: International Education as Journeys of Enriched Learning

    Science.gov (United States)

    Foster, Karen K.; Yao, Yuankun; Buchanan-Butterfield, Dawna Lisa; Powell-Brown, Ann

    2013-01-01

    In the 21st century, the impact of globalization has increased the importance of the internationalization of education (Jiang, 2010; Lam, 2010). Because it is imperative for the success of their graduates, colleges are encouraged to offer international educational experiences to gain a competitive edge over other institutions of higher learning…

  9. Inerting a Boeing 747SP Center Wing Tank Scale Model With Nitrogen-Enriched Air

    National Research Council Canada - National Science Library

    Cavage, William

    2002-01-01

    Tests were performed in a 0.24 scale model of a Boeing 747SP center wing tank to validate the existing assumptions for inerting complex geometric spaces, which were developed from previous experiments, and to facilitate design...

  10. Flow Control and High-Lift Performance for Flying-Wing Unmanned Combat Air Vehicle Configurations by inserting slots

    Directory of Open Access Journals (Sweden)

    U Ali

    2016-06-01

    Full Text Available The objectives of the present study on Unmanned Combat Air Vehicles (UCAVs are two-fold: first to control the flow by inserting leading-edge and cross-flow slots and analysing the viscous flow development over the outer panels of a flying-wing configuration to maximise the performance of the elevons control surfaces; second to predict high-lift performance particularly the maximum-lift characteristics. This is demonstrated using a variety of inviscid Vortex Lattice Method (VLM and Euler, and viscous CFD Reynolds Averaged Navier-Stokes (RANS methods. The computational results are validated against experiment measured in a wind tunnel. Two flying-wing planforms are considered based around a generic 40˚ edge-aligned configuration. The VLM predicts a linear variation of lift and pitching moment with incidence angle, and substantially under-predicts the induced drag. Results obtained from RANS and Euler agree well with experiment.

  11. Inertial attitude control of a bat-like morphing-wing air vehicle.

    Science.gov (United States)

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-03-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (ϕ) and pitch (θ) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms⁻¹.

  12. Inertial attitude control of a bat-like morphing-wing air vehicle

    International Nuclear Information System (INIS)

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-01-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (φ) and pitch (θ) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F net ) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms −1 . (paper)

  13. Active Air Force Wings as of 1 October 1995; USAF Active Flying, Space, and Missile Squadrons as of 1 October 1995

    Science.gov (United States)

    1998-01-01

    Office of Air Force History, 1984], by Charles A. Ravenstein , showed the overlapping of the lineages that conformed to the orders of the time. The...appeared in Charles A. Ravenstein , Air Force Combat Wings: Lineage and Honors Histories, 1947–1977, (Washington, DC: US Government Printing Office

  14. Initial Investigation on the Aerodynamic Performance of Flapping Wings for Nano Air Vehicles

    Science.gov (United States)

    2008-02-01

    drag) in still fluid [4, 5]. However, as the high aerodynamic performance of insect’s wings is achieved by three-degrees-of-freedom ( 3DOF ) motions...it will be very important to study its aerodynamic behavior under 3DOF conditions. Thus, a 3DOF system, i.e. pitch motion (α), dihedral motion (γ...the wing, all of the equipment was above the water surface, including a 3DOF gearbox, a 3DOF control system and a small five-component strain gauge

  15. An Experimental Investigation of Flapping Wing Propulsion for Micro Air Vehicles

    National Research Council Canada - National Science Library

    Duggan, Sean

    2000-01-01

    ...). Experimental work is conducted in the NPS 1.5 m x 1.5 m in-draft wind tunnel. A previously constructed model is suspended by thin wires and is used to measure the thrust performance of the flapping-wing MAV...

  16. Relocation of the Air National Guard 176th Wing to Elmendorf AFB, Alaska

    Science.gov (United States)

    2007-09-01

    widely (from a soft whisper to a jet engine) and is measured on a logarithmic scale to accommodate this wide range. The use of logarithms is a...abbreviated SEL or LAE ) combines both of these characteristics into a single metric. Relocation of the ANG 176th Wing to Elmendorf AFB Page D-4

  17. Computational Fluid Dynamics Studies of a Flapping Wing Nano Air Vehicle (NAV)

    Science.gov (United States)

    2008-12-31

    24 Propeller as a flapper ... flapper The propeller blade described above was used as a flapping wing with reversing camber and twist. The robot fly rotation angle profile (Eq. 6c...frequency reduced to 80Hz, the mean thrust developed by this propeller blade as a flapper is 0.04725N and the mean aerodynamic power is 0.971 W, as

  18. An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

    International Nuclear Information System (INIS)

    Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

    2011-01-01

    Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

  19. Development of Photographic Dynamic Measurements Applicable to Evaluation of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2011-12-01

    Selectable error plot from calib_gui.m……………………………………………… 27 Figure 16: O’Hara flapper ……………………………………………………………………….. 30 Figure 17: Record tab in Motion...Wing downstroke three dimensional point cloud, from the top of the wing stroke... 57 Figure 38: Deleón flapper with hightlighted reference points...purposes. One point is directly over the flapper mount and the other is placed near the mount. The two points can be considered rigid to one another

  20. Air Pollution Primer. Revised Education.

    Science.gov (United States)

    Corman, Rena

    This revised and updated book is written to inform the citizens on the nature, causes, and effects of air pollution. It is written in terms familiar to the layman with the purpose of providing knowledge and motivation to spur community action on clean air policies. Numerous charts and drawings are provided to support discussion of air pollution…

  1. A Rotary Wing System for Micro Air Vehicle Applications. Part 1

    Directory of Open Access Journals (Sweden)

    Valentin BUTOESCU

    2011-09-01

    Full Text Available The goal of the paper is to propose a new type of ornithopter that avoids the mechanical difficulties of a flapping system. It uses a modified design of a cycloidal propulsor. The modification regards the special setting of the wings that is intended to help the formation of a stable leading edge vortex (LEV. It is known that the LEV is the main feature that allows the insects to achieve the necessary lift to fly.

  2. Pointed wings, low wingloading and calm air reduce migratory flight costs in songbirds.

    Science.gov (United States)

    Bowlin, Melissa S; Wikelski, Martin

    2008-05-14

    Migratory bird, bat and insect species tend to have more pointed wings than non-migrants. Pointed wings and low wingloading, or body mass divided by wing area, are thought to reduce energy consumption during long-distance flight, but these hypotheses have never been directly tested. Furthermore, it is not clear how the atmospheric conditions migrants encounter while aloft affect their energy use; without such information, we cannot accurately predict migratory species' response(s) to climate change. Here, we measured the heart rates of 15 free-flying Swainson's Thrushes (Catharus ustulatus) during migratory flight. Heart rate, and therefore rate of energy expenditure, was positively associated with individual variation in wingtip roundedness and wingloading throughout the flights. During the cruise phase of the flights, heart rate was also positively associated with wind speed but not wind direction, and negatively but not significantly associated with large-scale atmospheric stability. High winds and low atmospheric stability are both indicative of the presence of turbulent eddies, suggesting that birds may be using more energy when atmospheric turbulence is high. We therefore suggest that pointed wingtips, low wingloading and avoidance of high winds and turbulence reduce flight costs for small birds during migration, and that climate change may have the strongest effects on migrants' in-flight energy use if it affects the frequency and/or severity of high winds and atmospheric instability.

  3. Pointed wings, low wingloading and calm air reduce migratory flight costs in songbirds.

    Directory of Open Access Journals (Sweden)

    Melissa S Bowlin

    Full Text Available Migratory bird, bat and insect species tend to have more pointed wings than non-migrants. Pointed wings and low wingloading, or body mass divided by wing area, are thought to reduce energy consumption during long-distance flight, but these hypotheses have never been directly tested. Furthermore, it is not clear how the atmospheric conditions migrants encounter while aloft affect their energy use; without such information, we cannot accurately predict migratory species' response(s to climate change. Here, we measured the heart rates of 15 free-flying Swainson's Thrushes (Catharus ustulatus during migratory flight. Heart rate, and therefore rate of energy expenditure, was positively associated with individual variation in wingtip roundedness and wingloading throughout the flights. During the cruise phase of the flights, heart rate was also positively associated with wind speed but not wind direction, and negatively but not significantly associated with large-scale atmospheric stability. High winds and low atmospheric stability are both indicative of the presence of turbulent eddies, suggesting that birds may be using more energy when atmospheric turbulence is high. We therefore suggest that pointed wingtips, low wingloading and avoidance of high winds and turbulence reduce flight costs for small birds during migration, and that climate change may have the strongest effects on migrants' in-flight energy use if it affects the frequency and/or severity of high winds and atmospheric instability.

  4. Wingbeat Shape Modulation for Flapping-Wing Micro-Air-Vehicle Control During Hover (Postprint)

    Science.gov (United States)

    2010-06-01

    AUTHOR(S) David B. Doman, Michael W. Oppenheimer, and David O. Sigthorsson (AFRL/ RBCA ) 5d. PROJECT NUMBER 2401 5e. TASK NUMBER N/A 5f. WORK UNIT...AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air Vehicles Directorate Wright-Patterson Air Force Base, OH 45433-7542 Air

  5. Precision Position Control of the DelFly II Flapping-wing Micro Air Vehicle in a Wind-tunnel

    NARCIS (Netherlands)

    Cunis, T.; Karasek, M.; de Croon, G.C.H.E.

    2016-01-01

    Flapping-wing MAVs represent an attractive alternative to conventional designs with rotary wings, since they promise a much higher efficiency in forward flight. However, further insight into the flapping-wing aerodynamics is still needed to get closer to the flight performance observed in natural

  6. Effects of external stores on the air combat capability of a delta wing fighter

    Science.gov (United States)

    Spearman, M. L.; Sawyer, W. C.

    1977-01-01

    Delta wing point-design fighters with two pylon mounted missiles and aft tail controls (similar to several Soviet designs) have been investigated for a Mach number range from about 0.6 to 2.0. Whereas minimum drag penalties that are expected with the addition of external stores do occur, the effects at higher lifts, corresponding to maneuvering flight, are less severe and often favorable. The drag-due-to-lift factor is less with stores on although the lift curve slope is unaffected. The longitudinal stability level is reduced by the addition of stores while the pitch control effectiveness is unchanged. The directional stability was generally reduced at subsonic speeds and increased at supersonic speeds by the addition of stores but sufficiently high stability levels are obtainable that are compatible with the longitudinal maneuvering limits. Some examples of the potential maneuvering capability in terms of normal acceleration and turn radius are included.

  7. Altitude Control of a Single Degree of Freedom Flapping Wing Micro Air Vehicle (Postprint)

    Science.gov (United States)

    2009-08-01

    NUMBER 62201F 6. AUTHOR(S) David B. Doman, Michael W. Oppenheimer, Michael A. Bolender, and David O. Sigthorsson (AFRL/ RBCA ) 5d. PROJECT NUMBER...NUMBER Control Design and Analysis Branch (AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air Vehicles Directorate Wright

  8. DEVELOPMENT OF EDUCATIONAL SOFTWARE FOR STRESS ANALYSIS OF AN AIRCRAFT WING

    Directory of Open Access Journals (Sweden)

    TAZKERA SADEQ

    2012-06-01

    Full Text Available A stress analysis software based on MATLAB, Graphic user interface (GUI has been developed. The developed software can be used to estimate load on a wing and to compute the stresses at any point along the span of the wing of a given aircraft. The generalized formulation allows performing stress analysis even for a multispar (multicell wing. The software is expected to be a useful tool for effective teaching learning process of courses on aircraft structures and aircraft structural design.

  9. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    Fei-Bin Hsiao

    2011-03-01

    Full Text Available This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV. The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA and angle of sideslip (AoS measurement, and an Attitude and Heading Reference System (AHRS that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS smoother, which consists of a forward pass Extended Kalman Filter (EKF and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS. It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly.

  10. Relocation of the 146th Tactical Airlift Wing of the California Air National Guard. Appendices

    Science.gov (United States)

    1984-12-01

    Desert iguana Cnemidophorous tivis Western whiptail (observed) Cal lisau rus draconoide s Zebra -tailed lizard Crotaphytus collaris Collared lizard Uma...general plan amendments involving the El Toro Marine Corp Air Station (ETMAS) and its relationship to the urbanizing South Orange County area. I see many

  11. The Impacts of a Fully Funded Postgraduate Education on Promotion and Command Screen for Fixed-Wing, Carrier-Based Pilots and Naval Flight Officers

    National Research Council Canada - National Science Library

    Phillips, William

    2001-01-01

    This thesis evaluates the effect of fully-funded graduate education on the joint outcome of promote to Pay Grade 5 and screen for squadron command for fixed-wing, carrier-based aviator lieutenant commanders (Pay Grade 4...

  12. Mapping the Far Right: Geomedia in an Educational Response to Right-Wing Extremism

    Directory of Open Access Journals (Sweden)

    Thomas Jekel

    2017-09-01

    Full Text Available Across Europe, and probably the world, messages of the extreme right surface with increasing and alarming regularity in both public and virtual space. Within the virtual space, geomedia are increasingly used in nationalist propaganda, a trend which is embedded in a wider development in public discourse, election results, and policies. In Austria and Germany, particular sensibilities due to the responsibility for the Holocaust have developed, leading to various specific education initiatives that address this part of history. This paper presents an activist learning environment using geomedia to deconstruct right-wing extremist discourses, and has been tested used in university settings in Salzburg and Vienna. Using a combination of Instagram and geospatial technologies not visible to learners, results of reflection and learning processes are analyzed qualitatively across two slightly different enactments of the learning environment. Experiences suggest an encouraging potential of geomedia use in critical learning processes, as long as the technology is hidden from learners, forming an incentive, support, and contextualization of the learning process.

  13. Air Force Host and Tenant Agreements Between the 50th Space Wing, the Joint National Integration Center, and Tenants

    National Research Council Canada - National Science Library

    2007-01-01

    .... The 50th Space Wing makes available by permit two buildings on the base's real property records, 720 and 730, to the Joint National Integration Center, a Component of the Missile Defense Agency...

  14. Nonlinear Structures Optimization for Flexible Flapping Wing MAVs

    Science.gov (United States)

    2009-02-01

    nonlinear optimization, flapping wing, fluid structure interaction, micro -air vehicles, flexible wing, flapping mechanism 16. SECURITY... Structures Optimization for Flexible Flapping Wing Micro -Air Vehicles” was funded with Chief Scientist Innovative Research funds. This project was divided...predict a 10% resisting load to the model, and Python Scripting to wrap around everything. 2 Building the Model in Abaqus CAE The flapping wing

  15. Reading, Writing and Radicalism: Right-Wing Women and Education in the Post-War Years

    Science.gov (United States)

    Benowitz, June Melby

    2009-01-01

    The headlines "Who's Trying to Ruin Our Schools?" and "Danger's Ahead in the Public Schools" grabbed the attention of the American public during the early 1950s as mainstream publications reacted to efforts by right-wing organizations to influence the curricula of America's elementary and secondary schools. "A bewildering disease that threatens to…

  16. Maximizing Student Potential versus Building Community: An Exploration of Right-Wing Authoritarianism, Social Dominance Orientation, and Preferred Practice among Supporters of Gifted Education

    Science.gov (United States)

    Cross, Jennifer Riedl; Cross, Tracy L.; Finch, Holmes

    2010-01-01

    Social dominance orientation (SDO), right-wing authoritarianism (RWA), and socially desirable responding were examined among a sample of self-identified supporters of gifted education (N = 341), 70% of whom had an official role in gifted education as researchers, teachers, or gifted-talented (G/T) trainers. The sample was primarily female, White,…

  17. The Distributed Air Wing

    Science.gov (United States)

    2014-06-01

    typhoon strikes the Philippines, where nearly 100 million people live in an area of 116,000 square miles. Following the catastrophic storm food ...perform any designated missions. Thus, it is imperative to provide the operating crew with basic essentials like food and water, as well as hygienic...consist of both specially outfitted surveillance vessels as well as disguised fishing junks capable of passing along location data. It is assumed that

  18. Indoor Air Quality Building Education and Assessment Model Forms

    Science.gov (United States)

    The Indoor Air Quality Building Education and Assessment Model (I-BEAM) is a guidance tool designed for use by building professionals and others interested in indoor air quality in commercial buildings.

  19. Indoor Air Quality Building Education and Assessment Model

    Science.gov (United States)

    The Indoor Air Quality Building Education and Assessment Model (I-BEAM), released in 2002, is a guidance tool designed for use by building professionals and others interested in indoor air quality in commercial buildings.

  20. WHEN COMPASSION GROWS WINGS

    African Journals Online (AJOL)

    Nicky

    antiretroviral roll-out in full swing, the. WHEN COMPASSION GROWS WINGS. The free time and expertise given by its deeply committed core of professional volunteers. (including pilots) is the lifeblood of the operation. Red Cross Air Mercy Service volunteer, German national Dr Florian Funk, at the AMS Durban base.

  1. Multispectral and DSLR sensors for assessing crop stress in corn and cotton using fixed-wing unmanned air systems

    Science.gov (United States)

    Valasek, John; Henrickson, James V.; Bowden, Ezekiel; Shi, Yeyin; Morgan, Cristine L. S.; Neely, Haly L.

    2016-05-01

    As small unmanned aircraft systems become increasingly affordable, reliable, and formally recognized under federal regulation, they become increasingly attractive as novel platforms for civil applications. This paper details the development and demonstration of fixed-wing unmanned aircraft systems for precision agriculture tasks. Tasks such as soil moisture content and high throughput phenotyping are considered. Rationale for sensor, vehicle, and ground equipment selections are provided, in addition to developed flight operation procedures for minimal numbers of crew. Preliminary imagery results are presented and analyzed, and these results demonstrate that fixed-wing unmanned aircraft systems modified to carry non-traditional sensors at extended endurance durations can provide high quality data that is usable for serious scientific analysis.

  2. Design and stable flight of a 21 g insect-like tailless flapping wing micro air vehicle with angular rates feedback control.

    Science.gov (United States)

    Phan, Hoang Vu; Kang, Taesam; Park, Hoon Cheol

    2017-04-04

    An insect-like tailless flapping wing micro air vehicle (FW-MAV) without feedback control eventually becomes unstable after takeoff. Flying an insect-like tailless FW-MAV is more challenging than flying a bird-like tailed FW-MAV, due to the difference in control principles. This work introduces the design and controlled flight of an insect-like tailless FW-MAV, named KUBeetle. A combination of four-bar linkage and pulley-string mechanisms was used to develop a lightweight flapping mechanism that could achieve a high flapping amplitude of approximately 190°. Clap-and-flings at dorsal and ventral stroke reversals were implemented to enhance vertical force. In the absence of a control surface at the tail, adjustment of the location of the trailing edges at the wing roots to modulate the rotational angle of the wings was used to generate control moments for the attitude control. Measurements by a 6-axis load cell showed that the control mechanism produced reasonable pitch, roll and yaw moments according to the corresponding control inputs. The control mechanism was integrated with three sub-micro servos to realize the pitch, roll and yaw controls. A simple PD feedback controller was implemented for flight stability with an onboard microcontroller and a gyroscope that sensed the pitch, roll and yaw rates. Several flight tests demonstrated that the tailless KUBeetle could successfully perform a vertical climb, then hover and loiter within a 0.3 m ground radius with small variations in pitch and roll body angles.

  3. Quad-thopter: Tailless Flapping Wing Robot with 4 Pairs of Wings

    NARCIS (Netherlands)

    de Wagter, C.; Karasek, M.; de Croon, G.C.H.E.; J.-M. Moschetta G. Hattenberger, H. de Plinval

    2017-01-01

    We present a novel design of a tailless flapping wing Micro Air Vehicle (MAV), which uses four independently driven pairs of flapping wings in order to fly and perform agile maneuvers. The wing pairs are arranged such that differential thrust generates the desired roll and pitch moments, similar to

  4. Twisted Winged Endoparasitoids

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 10. Twisted Winged Endoparasitoids - An Enigma for Entomologists. Alpana Mazumdar. General Article Volume 9 Issue 10 October 2004 pp 19-24. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Air Pollution. Environmental Ecological Education Project.

    Science.gov (United States)

    Parkway School District, Chesterfield, MO.

    This unit, designed for senior high school students, focuses on air pollution by examining its effect on man, plants and animals, the causes of air pollution, and possible solutions to the air pollution problems. It approaches each of these topics through both natural science and social science perspectives. The unit is divided into seven separate…

  6. Air. Ag Ed Environmental Education Series.

    Science.gov (United States)

    Tulloch, Rodney W.

    The document is a student resource unit to be used in teaching high school vocational agriculture students about air. The following natural processes are described: carbon dioxide cycle, nitrogen cycle, gravity and atmosphere, energy of the sun, greenhouse effect, atmospheric circulation, and precipitation. Sources of air pollution are discussed.…

  7. Flutter-by Interactive Butterfly Using interactivity to excite and educate children about butterflies and the National Museum of Play at The Strong's Dancing Wings Butterfly Garden

    Science.gov (United States)

    Powers, Lydia

    The National Museum of Play at The Strong's Dancing Wings Butterfly Garden is a tropical rainforest that allows visitors to step into the world of butterflies, but lacks a more comprehensive educational element to teach visitors additional information about butterflies. Flutter-by Interactive Butterfly is a thesis project designed to enhance younger visitors' experience of the Dancing Wings Butterfly Garden with an interactive educational application that aligns with The Strong's mission of encouraging learning, creativity, and discovery. This was accomplished through a series of fun and educational games and animations, designed for use as a kiosk outside the garden and as a part of The Strong's website. Content, planning, and organization of this project has been completed through research and observation of the garden in the following areas: its visitors, butterflies, best usability practices for children, and game elements that educate and engage children. Flutter-by Interactive Butterfly teaches users about the butterfly's life cycle, anatomy, and characteristics as well as their life in the Dancing Wings Butterfly Garden. Through the use of the design programs Adobe Illustrator, Flash, and After Effects; the programming language ActionScript3.0; a child-friendly user interface and design; audio elements and user takeaways, Flutter-by Interactive Butterfly appeals to children of all ages, interests, and learning styles. The project can be viewed at lydiapowers.com/Thesis/FlutterByButterfly.html

  8. Error analysis and assessment of unsteady forces acting on a flapping wing micro air vehicle: free flight versus wind-tunnel experimental methods.

    Science.gov (United States)

    Caetano, J V; Percin, M; van Oudheusden, B W; Remes, B; de Wagter, C; de Croon, G C H E; de Visser, C C

    2015-08-20

    An accurate knowledge of the unsteady aerodynamic forces acting on a bio-inspired, flapping-wing micro air vehicle (FWMAV) is crucial in the design development and optimization cycle. Two different types of experimental approaches are often used: determination of forces from position data obtained from external optical tracking during free flight, or direct measurements of forces by attaching the FWMAV to a force transducer in a wind-tunnel. This study compares the quality of the forces obtained from both methods as applied to a 17.4 gram FWMAV capable of controlled flight. A comprehensive analysis of various error sources is performed. The effects of different factors, e.g., measurement errors, error propagation, numerical differentiation, filtering frequency selection, and structural eigenmode interference, are assessed. For the forces obtained from free flight experiments it is shown that a data acquisition frequency below 200 Hz and an accuracy in the position measurements lower than ± 0.2 mm may considerably hinder determination of the unsteady forces. In general, the force component parallel to the fuselage determined by the two methods compares well for identical flight conditions; however, a significant difference was observed for the forces along the stroke plane of the wings. This was found to originate from the restrictions applied by the clamp to the dynamic oscillations observed in free flight and from the structural resonance of the clamped FWMAV structure, which generates loads that cannot be distinguished from the external forces. Furthermore, the clamping position was found to have a pronounced influence on the eigenmodes of the structure, and this effect should be taken into account for accurate force measurements.

  9. Final Supplemental Environmental Assessment of Proposed Actions by the 58th Special Operations Wing, Kirtland Air Force Base, New Mexico

    Science.gov (United States)

    2008-06-01

    Recreation - Commercial Service - Public & Institutional - Drainage & Flood Control D Single Family N Noise Contour D Industrial & Manufacturing D...Generator Saw 81 Industrial Saw 83 Welder 74 Truck 80 Forklift 67 Crane 83 Source: COL 2001 Final Supplemental Environmental Assessment of...Naval Air Systems Command  Hotaling ,  Jim R  USAF AFSOC/A5RX  CV‐22 Logistics  Air Force Special Operations Command/Plans and  Programs  Vandzura

  10. Toward an Educational Sphereology: Air, Wind, and Materialist Pedagogy

    Science.gov (United States)

    Ford, Derek R.; Zhao, Weili

    2018-01-01

    It's not uncommon for people to make reference to atmospheres, including in relationship with educational spaces. In this article, we investigate educational atmospheres by turning to Western and Chinese literature on the air and wind. We pursue this task in three phases. First, we examine the Western literature to see the possible strings of…

  11. The Effects of Leadership on Carrier Air Wing Sixteen’s Loss Rates during Operation Rolling Thunder, 1965-1968

    Science.gov (United States)

    2006-06-16

    forces could operate freely in a Soviet SAM environment, there were serious repercussions for Soviet forces in Europe . Likewise, if North...... neophytes in the air war. But these junior aviators were going to be wingmen for them during an extremely dangerous combat tour, and the senior officers

  12. The Roots of the Right-Wing Attack on Higher Education

    Science.gov (United States)

    Schrecker, Ellen

    2010-01-01

    The enormous changes that took place on American campuses during the 1960s not only opened those campuses to new constituencies and new ideas, but also created a powerful conservative movement that sought to reverse those changes. Along with the rising cost of higher education, the right's campaign against the academic reforms of the sixties has…

  13. Final Environmental Assessment for Proposed Construction Projects for the 140th Wing, Colorado Air National Guard at Buckley Air Force Base, Colorado

    Science.gov (United States)

    2004-09-01

    biologica l resou rces, cultura l resomces, environmenta l justice, socioeconomics, geology, soUs and topography, water resources, solid and hazardous...emissions associated with the implementation of the Proposed Action were to cause or contribute to a violation of any national or state ambient air...control technology MOA Memorandum of Agreement MSA munitions storage areas NAAQS National Ambient Air Quality Standards NEPA National Environmental

  14. Study of design parameters of flapping-wings

    NARCIS (Netherlands)

    Wang, Q.; Goosen, J.F.L.; Van Keulen, F.

    2014-01-01

    As one of the most important components of a flapping-wing micro air vehicle (FWMAV), the design of an energy-efficient flapping-wing has been a research interest recently. Research on insect flight from different perspectives has been carried out, mainly with regard to wing morphology, flapping

  15. Wind-Tunnel Investigation of Rectangular Air-Duct Entrances in the Leading Edge of an NACA 23018 Wing, Special Report

    Science.gov (United States)

    Biermann, David; McLellan, Charles H.

    1940-01-01

    A preliminary investigation of a number of duct entrances of rectangular shape installed in the leading edge of a wing was conducted in the NACA 20-foot tunnel to determine the external drag, the available pressure, the critical Mach numbers, and the effect on the maximum lift. The results showed that the most satisfactory entrances, which had practically no effect on the wing characteristics, had their lips approximately in the vertical plane of the leading edge of the wing. This requirement necessitated extending the lips outside the wing contour for all except the small entrances. Full dynamic pressure was found to be available over a fairly wide range of angle of attack. The critical Mach number for a small entrance was calculated to be as high as that for the plain wing but was slightly lower for the larger entrances tested.

  16. Relocation of the 146th Tactical Airlift Wing of the California Air National Guard. Volume 2. Appendices

    Science.gov (United States)

    1985-08-01

    lAth Street Sacr,•eto. CA 9M14 SaerMa . CA 9614916/322-2996 916/445-7416 James R--groueO Dept. of G*eeCl Services 1125 Teeth Street Sacramento . CA 9...Species from Fish and Wildlife Service’s Endnagered Species Office in Sacramento at 2800 Cottage Way, Room E-1823, Sacramento , California 95825...proposed addition to Naval Air Station Point Mugu was located within the Rancho El Rio de Santa Clara o La Colonia . The rancho was granted in 1837, by

  17. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  18. The Realization and Study of Optical Wings

    Science.gov (United States)

    Artusio-Glimpse, Alexandra Brae

    Consider the airfoil: a carefully designed structure capable of stable lift in a uniform air flow. It so happens that air pressure and radiation (light) pressure are similar phenomena because each transfer momentum to flow-disturbing objects. This, then, begs the question: does an optical analogue to the airfoil exist? Though an exceedingly small effect, scientists harness radiation pressure in a wide gamut of applications from micromanipulation of single biological particles to the propulsion of large spacecrafts called solar sails. We introduce a cambered, refractive rod that is subjected to optical forces analogous to those seen in aerodynamics, and I call this analogue the optical wing. Flight characteristics of optical wings are determined by wing shape and material in a uniform radiation field. Theory predicts the lift force and axial torque are functions of the wing's angle of attack with stable and unstable orientations. These structures can operate as intensity-dependent, parametrically driven oscillators. In two-dimensions, the wings exhibit bistability when analyzed in an accelerating frame. In three-dimensions, the motion of axially symmetric spinning hemispherical wings is analogous to a spinning top. Experiments on semi-buoyant wings in water found semicylindrically shaped, refractive microparticles traversed a laser beam and rotated to an illumination-dependent stable orientation. Preliminary tests aid in the development of a calibrated force measurement experiment to directly evaluate the optical forces and torque on these samples. A foundational study of the optical wing, this work contributes to future advancements of flight-by-light.

  19. Veins improve fracture toughness of insect wings.

    Directory of Open Access Journals (Sweden)

    Jan-Henning Dirks

    Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

  20. Gliding swifts attain laminar flow over rough wings.

    Directory of Open Access Journals (Sweden)

    David Lentink

    Full Text Available Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the wing surface and minimize drag for extended glides. To understand why the swift does not rely on smooth wings, we used a stethoscope to map laminar flow over preserved wings in a low-turbulence wind tunnel. By combining laminar area, lift, and drag measurements, we show that average area of laminar flow on swift wings is 69% (n = 3; std 13% of their total area during glides that maximize flight distance and duration--similar to high-performance sailplanes. Our aerodynamic analysis indicates that swifts attain laminar flow over their rough wings because their wing size is comparable to the distance the air travels (after a roughness-induced perturbation before it transitions from laminar to turbulent. To interpret the function of swift wing roughness, we simulated its effect on smooth model wings using physical models. This manipulation shows that laminar flow is reduced and drag increased at high speeds. At the speeds at which swifts cruise, however, swift-like roughness prolongs laminar flow and reduces drag. This feature gives small birds with rudimentary wings an edge during the evolution of glide performance.

  1. Veins Improve Fracture Toughness of Insect Wings

    Science.gov (United States)

    Dirks, Jan-Henning; Taylor, David

    2012-01-01

    During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect’s flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material’s resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m). However, the cross veins increase the wing’s toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm). This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically ‘optimal’ solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial ‘venous’ wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species. PMID:22927966

  2. The Morphological Characterization of the Forewing of the Manduca sexta Species for the Application of Biomimetic Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2012-01-01

    on tobacco and tomato plants, but will occasionally feed on potato and pepper crops and other plants in the Solenaceae family, hence their name... composite plates and is applied here [8]. The experimental sample is harvested from a wing in which the membrane scales have been removed. Then a section

  3. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Banana River at the Eastern Range... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to...

  4. Low Reynolds Number Wing Transients in Rotation and Translation

    Science.gov (United States)

    Jones, Anya; Schlueter, Kristy

    2012-11-01

    The unsteady aerodynamic forces and flow fields generated by a wing undergoing transient motions in both rotation and translation were investigated. An aspect ratio 2 flat plate wing at a 45 deg angle of attack was driven over 84 deg of rotation (3 chord-lengths of travel at 3/4 span) and 3 and 10 chord-lengths of translation in quiescent water at Reynolds numbers between 2,500 and 15,000. Flow visualization on the rotating wing revealed a leading edge vortex that lifted off of the wing surface, but remained in the vicinity of the wing for the duration of the wing stroke. A second spanwise vortex with strong axial flow was also observed. As the tip vortex grew, the leading edge vortex joined the tip vortex in a loop-like structure over the aft half of the wing. Near the leading edge, spanwise flow in the second vortex became entrained in the tip vortex near the corner of the wing. Unsteady force measurements revealed that lift coefficient increased through the constant-velocity portion of the wing stroke. Forces were compared for variations in wing acceleration and Reynolds number for both rotational and translational motions. The effect of tank blockage was investigated by repeating the experiments on multiple wings, varying the distance between the wing tip and tank wall. U.S. Air Force Research Laboratory, Summer Faculty Fellowship Program.

  5. Rice- and butterfly-wing effect inspired self-cleaning and low drag micro/nanopatterned surfaces in water, oil, and air flow

    Science.gov (United States)

    Bixler, Gregory D.; Bhushan, Bharat

    2013-12-01

    In search of new solutions to complex challenges, researchers are turning to living nature for inspiration. For example, special surface characteristics of rice leaves and butterfly wings combine the shark skin (anisotropic flow leading to low drag) and lotus leaf (superhydrophobic and self-cleaning) effects, producing the so-called rice and butterfly wing effect. In this paper, we study four microstructured surfaces inspired by rice leaves and fabricated with photolithography techniques. We also present a method of creating such surfaces using a hot embossing procedure for scaled-up manufacturing. Fluid drag, self-cleaning, contact angle, and contact angle hysteresis data are presented to understand the role of sample geometrical dimensions. Conceptual modeling provides design guidance when developing novel low drag, self-cleaning, and potentially antifouling surfaces for medical, marine, and industrial applications.

  6. Structural Technology Evaluation and Analysis Program (STEAP). Delivery Order 0035: Dynamics and Control and Computational Design of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2012-10-01

    prototype FWMAVs. A brushless DC motor was used to drive a four-bar crank- rocker mechanism to transform rotational motion into a rocking motion, i.e...stroke actuation using brushless DC motors . Furthermore, the microcontrollers were required to communicate with a remote controller and with each other...low-level motor control laws that enable wing beat motion profiles to be produced that generate desired cycle-averaged control forces and moments

  7. Bibliography for the Indoor Air Quality Building Education and Assessment Model

    Science.gov (United States)

    The Indoor Air Quality Building Education and Assessment Model (I-BEAM) is a guidance tool designed for use by building professionals and others interested in indoor air quality in commercial buildings.

  8. Links Related to the Indoor Air Quality Building Education and Assessment Model

    Science.gov (United States)

    The Indoor Air Quality Building Education and Assessment Model (I-BEAM) is a guidance tool designed for use by building professionals and others interested in indoor air quality in commercial buildings.

  9. Air

    Science.gov (United States)

    ... gov/ Home The environment and your health Air Air While we don’t often think about the ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be ...

  10. Flapping wing actuation using resonant compliant mechanisms : An insect-inspired design

    NARCIS (Netherlands)

    Bolsman, C.T.

    2010-01-01

    The realization of a wing actuation mechanism for a flapping wing micro air vehicle requires a move away from traditional designs based on gears and links. An approach inspired by nature’s flyers is better suited. For flapping flight two wing motions are important: the sweeping and the pitching

  11. Measurement of shape and deformation of insect wing

    Science.gov (United States)

    Yin, Duo; Wei, Zhen; Wang, Zeyu; Zhou, Changqiu

    2018-01-01

    To measure the shape and deformation of an insect wing, a scanning setup adopting laser triangulation and image matching was developed. Only one industry camera with two light sources was employed to scan the transparent insect wings. 3D shape and point to point full field deformation of the wings could be obtained even when the wingspan is less than 3 mm. The venation and corrugation could be significantly identified from the results. The deformation of the wing under pin loading could be seen clearly from the results as well. Calibration shows that the shape and deformation measurement accuracies are no lower than 0.01 mm. Laser triangulation and image matching were combined dexterously to adapt wings' complex shape, size, and transparency. It is suitable for insect flight research or flapping wing micro-air vehicle development.

  12. Optimization of aerodynamic efficiency for twist morphing MAV wing

    Directory of Open Access Journals (Sweden)

    N.I. Ismail

    2014-06-01

    Full Text Available Twist morphing (TM is a practical control technique in micro air vehicle (MAV flight. However, TM wing has a lower aerodynamic efficiency (CL/CD compared to membrane and rigid wing. This is due to massive drag penalty created on TM wing, which had overwhelmed the successive increase in its lift generation. Therefore, further CL/CDmax optimization on TM wing is needed to obtain the optimal condition for the morphing wing configuration. In this paper, two-way fluid–structure interaction (FSI simulation and wind tunnel testing method are used to solve and study the basic wing aerodynamic performance over (non-optimal TM, membrane and rigid wings. Then, a multifidelity data metamodel based design optimization (MBDO process is adopted based on the Ansys-DesignXplorer frameworks. In the adaptive MBDO process, Kriging metamodel is used to construct the final multifidelity CL/CD responses by utilizing 23 multi-fidelity sample points from the FSI simulation and experimental data. The optimization results show that the optimal TM wing configuration is able to produce better CL/CDmax magnitude by at least 2% than the non-optimal TM wings. The flow structure formation reveals that low TV strength on the optimal TM wing induces low CD generation which in turn improves its overall CL/CDmax performance.

  13. Machine Learning for Flapping Wing Flight Control

    NARCIS (Netherlands)

    Goedhart, Menno; van Kampen, E.; Armanini, S.F.; de Visser, C.C.; Chu, Q.

    2018-01-01

    Flight control of Flapping Wing Micro Air Vehicles is challenging, because of their complex dynamics and variability due to manufacturing inconsistencies. Machine Learning algorithms can be used to tackle these challenges. A Policy Gradient algorithm is used to tune the gains of a

  14. Flow structure of vortex-wing interaction

    Science.gov (United States)

    McKenna, Christopher K.

    streamwise (axial) vorticity, as well as relatively large root-mean-square values of streamwise velocity and vorticity. Along the chord of the wing, the vortex interaction gives rise to distinct modes, which may involve either enhancement or suppression of the vortex generated at the tip of the wing. These modes are classified and interpreted in conjunction with computed modes at the Air Force Research Laboratory. Occurrence of a given mode of interaction is predominantly determined by the dimensionless location of the incident vortex relative to the tip of the wing and is generally insensitive to the Reynolds number and dimensionless circulation of the incident vortex. The genesis of the basic modes of interaction is clarified using streamline topology with associated critical points. Whereas formation of an enhanced tip vortex involves a region of large upwash in conjunction with localized flow separation, complete suppression of the tip vortex is associated with a small-scale separation-attachment bubble bounded by downwash at the wing tip. Oscillation of the wing at an amplitude and velocity nearly two orders of magnitude smaller than the wing chord and free stream velocity respectively can give rise to distinctive patterns of upwash, downwash, and shed vorticity, which are dependent on the outboard displacement of the incident vortex relative to the wing tip. Moreover, these patterns are a strong function of the phase of the wing motion during its oscillation cycle. At a given value of phase, the wing oscillation induces upwash that is reinforced by the upwash of the incident vortex, giving a maximum value of net upwash. Conversely, when these two origins of upwash counteract, rather than reinforce, one another during the oscillation cycle, the net upwash has its minimum value. Analogous interpretations hold for regions of maximum and minimum net downwash located outboard of the regions of upwash. During the oscillation cycle of the wing, the magnitude and scale of the

  15. Margaret and Rachel McMillan: Their Influences on Open-Air Nursery Education and Early Years Teacher Education

    Science.gov (United States)

    Liebovich, Betty

    2014-01-01

    Rachel and Margaret McMillan created an open-air nursery in Deptford, London that has influenced early years education for 100 years. Their vision for young children living in poverty and deprivation to have access to fresh air through outdoor learning, nutritious meals, and an enriching environment to explore and develop has been embraced and…

  16. Basal Complex and Basal Venation of Odonata Wings: Structural Diversity and Potential Role in the Wing Deformation.

    Directory of Open Access Journals (Sweden)

    H Rajabi

    Full Text Available Dragonflies and damselflies, belonging to the order Odonata, are known to be excellent fliers with versatile flight capabilities. The ability to fly over a wide range of speeds, high manoeuvrability and great agility are a few characteristics of their flight. The architecture of the wings and their structural elements have been found to play a major role in this regard. However, the precise influence of individual wing components on the flight performance of these insects remains unknown. The design of the wing basis (so called basal complex and the venation of this part are responsible for particular deformability and specific shape of the wing blade. However, the wing bases are rather different in representatives of different odonate groups. This presumably reflects the dimensions of the wings on one hand, and different flight characteristics on the other hand. In this article, we develop the first three-dimensional (3D finite element (FE models of the proximal part of the wings of typical representatives of five dragonflies and damselflies families. Using a combination of the basic material properties of insect cuticle, a linear elastic material model and a nonlinear geometric analysis, we simulate the mechanical behaviour of the wing bases. The results reveal that although both the basal venation and the basal complex influence the structural stiffness of the wings, it is only the latter which significantly affects their deformation patterns. The use of numerical simulations enabled us to address the role of various wing components such as the arculus, discoidal cell and triangle on the camber formation in flight. Our study further provides a detailed representation of the stress concentration in the models. The numerical analysis presented in this study is not only of importance for understanding structure-function relationship of insect wings, but also might help to improve the design of the wings for biomimetic micro-air vehicles (MAVs.

  17. A Conceptual Development of a Shape Memory Alloy Actuated Variable Camber Morphing Wing

    NARCIS (Netherlands)

    Ferreira, J.P.; De Breuker, R.

    2016-01-01

    This study describes the development of a morphing wing concept for a Portuguese Air Force Unmanned Air Vehicle (UAV), the UAS-30. Nowadays, optimized fuel efficiency is a primary requirement in the aerospace industry, and it can be significantly improved by designing adaptive wings which can change

  18. A Historical Analysis of Basic Air Force Doctrine Education within the United States States Air Force Air Command and Staff College, 1947-1987.

    Science.gov (United States)

    1987-09-01

    doctrine, especially joint doctrine. Because of this we make mistakes. I believe that the Air Force needs to develop a formal doctrinallo education...jresenteo arguments for all three points of view, but ne was particularly critical of tne educacional system within tae United States military. He said tnat

  19. Importance of Plein-Air Practice in Professional Art Education

    Science.gov (United States)

    Shokorova, Larisa Vladimirovna; Grechneva, Natalia Vladislavovna; Bochkovskay, Vera Igorevna

    2016-01-01

    The article discusses the role and importance of plein-air practice in vocational training of art specialties' students. It analyzes the historical aspect of plein-air drawing in nature origin. It identifies psychophysiological characteristics of visual perception in fine and decorative art. It characterizes methods of artistic perception of…

  20. Bending the Eagle’s Wing - How Advanced Air Defenses put the Enemy’s Vital Centers Beyond the Reach of American Airpower

    Science.gov (United States)

    2010-06-04

    29 Carl von Clausewitz, On War, ed. and trans. Michael Howard and Peter Paret (Princeton, NJ: Princeton University Press, 1976), 358. 68 More so...Air University Press, 1994. Clausewitz, Carl von. On War. Edited and Translated by Michael Howard and Peter Paret. Princeton, NJ: Princeton...Randolph, Stephen P. Powerful and Brutal Weapons. Cambridge, MA: Harvard University Press, 2007. Sagan , Scott D. and Kenneth N. Waltz. The Spread of

  1. Variable camber wing based on pneumatic artificial muscles

    Science.gov (United States)

    Yin, Weilong; Liu, Libo; Chen, Yijin; Leng, Jinsong

    2009-07-01

    As a novel bionic actuator, pneumatic artificial muscle has high power to weight ratio. In this paper, a variable camber wing with the pneumatic artificial muscle is developed. Firstly, the experimental setup to measure the static output force of pneumatic artificial muscle is designed. The relationship between the static output force and the air pressure is investigated. Experimental result shows the static output force of pneumatic artificial muscle decreases nonlinearly with increasing contraction ratio. Secondly, the finite element model of the variable camber wing is developed. Numerical results show that the tip displacement of the trailing-edge increases linearly with increasing external load and limited with the maximum static output force of pneumatic artificial muscles. Finally, the variable camber wing model is manufactured to validate the variable camber concept. Experimental result shows that the wing camber increases with increasing air pressure and that it compare very well with the FEM result.

  2. Environmental Assessment for Education Center Buckley Air Force Base, Colorado

    National Research Council Canada - National Science Library

    Meyer, Elizabeth; Myklebust, Jessica; Denier, James; Niosi, Daniel; Christner, Jennifer

    2006-01-01

    ... and social impacts from the construction and operation of the proposed Education Center. The EA considers the No Action Alternative and three action alternatives, including the Proposed Action, for the proposed Education Center...

  3. The Characterization of Material Properties and Structural Dynamics of the Manduca Sexta Forewing for Application to Flapping Wing Micro Air Vehicle Design

    Science.gov (United States)

    O'Hara, Ryan P.

    Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms are presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of differing guidelines, damage functions, and weapon employment selection which significantly alter the location of the optimal aimpoint in this targeting problem. Finally, we have provided a framework for making policy decisions in fast-moving troops-in-contact situations where observers are unsure of the nature of possible enemy forces in both finite and infinite time horizon problems. Through a recursive technique of solving this Markov decision process we have demonstrated the effect of improved intelligence and differing weights in the face of uncertain situations.

  4. WINGS Data Release

    DEFF Research Database (Denmark)

    Moretti, A.; Poggianti, B. M.; Fasano, G.

    2014-01-01

    Context. To effectively investigate galaxy formation and evolution, it is of paramount importance to exploit homogeneous data for large samples of galaxies in different environments. Aims. The WIde-field Nearby Galaxy-cluster Survey (WINGS) project aim is to evaluate physical properties of galaxies...... in a complete sample of low redshift clusters to be used as reference sample for evolutionary studies. The WINGS survey is still ongoing and the original dataset will be enlarged with new observations. This paper presents the entire collection of WINGS measurements obtained so far. Methods. We decided to make......, and on the cluster redshift, reaching on average 90% at V ≲ 21.7. Near-infrared photometric catalogs for 26 (in K) and 19 (in J) clusters are part of the database and the number of sources is 962 344 in K and 628 813 in J. Here again the completeness depends on the data quality, but it is on average higher than 90...

  5. Preliminary development of a wing in ground effect vehicle

    Science.gov (United States)

    Abidin, Razali; Ahamat, Mohamad Asmidzam; Ahmad, Tarmizi; Saad, Mohd Rasdan; Hafizi, Ezzat

    2018-02-01

    Wing in ground vehicle is one of the mode of transportation that allows high speed movement over water by travelling few meters above the water level. Through this manouver strategy, a cushion of compressed air exists between the wing in ground vehicle wings and water. This significantly increase the lift force, thus reducing the necessity in having a long wing span. Our project deals with the development of wing in ground vehicle with the capability of transporting four people. The total weight of this wing in ground vehicle was estimated at 5.4 kN to enable the prediction on required wing area, minimum takeoff velocity, drag force and engine power requirement. The required takeoff velocity is decreases as the lift coefficient increases, and our current mathematical model shows the takeoff velocity at 50 m/s avoid the significant increase in lift coefficient for the wing area of 5 m2. At the velocity of 50 m/s, the drag force created by this wing in ground vehicle is well below 1 kN, which required a 100-120 kW of engine power if the propeller has the efficiency of 0.7. Assessment on the stresses and deflection of the hull structural indicate the capability of plywood to withstand the expected load. However, excessive deflection was expected in the rear section which requires a minor structural modification. In the near future, we expect that the wind tunnel tests of this wing in ground vehicle model would enable more definite prediction on the important parameters related to its performance.

  6. Conduction and Utilization of Research: The Relationship Between Air Force Nurses' Attitudes, Levels of Education, and Rank

    National Research Council Canada - National Science Library

    Moledor, Heather

    1999-01-01

    .... Air Force nurses had an overall good attitude toward nursing research. Air Force nurses at the Diploma, BSN, and MSN education levels in nursing had the most research experience in the past five years...

  7. AERODYNAMIC LOAD OF AN AIRCRAFT WITH A HIGHLY ELASTIC WING

    Directory of Open Access Journals (Sweden)

    Pavel Schoř

    2017-09-01

    Full Text Available In this article, a method for calculation of air loads of an aircraft with an elastic wing is presented. The method can predict a redistribution of air loads when the elastic wing deforms. Unlike the traditional Euler or Navier-Stokes CFD to FEM coupling, the method uses 3D panel method as a source of aerodynamic data. This makes the calculation feasible on a typical recent workstation. Due to a short computational time and low hardware demands this method is suitable for both the preliminary design stage and the load evaluation stage. A case study is presented. The study compares a glider wing performing a pull maneuver at both rigid and and elastic state. The study indicates a significant redistribution of air load at the elastic case.

  8. "Quien Sabe Mas Lucha Mejor": Adult Educators' Care of the Self Practices within Social Movements in Buenos Aires, Argentina

    Science.gov (United States)

    O'Donnell, Jennifer Lee

    2014-01-01

    This article looks at popular adult educators' care of the self practices within social movements in Buenos Aires, Argentina. It answers the following questions: How is popular adult education practiced amongst educators in social movements? What can studying popular adult educators' care of the self practices offer the field of adult education?…

  9. Modeling the Motion of a Flapping Wing Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Vorochaeva L.Y.

    2017-01-01

    Full Text Available The article discusses the vertical flight of a flapping wing aerial vehicle, which is also called an ornithopter. The robot is a chain of five links connected in series by active cylindrical hinges with the central link being the body and the remainder forming folding wings in pairs. The distinctive feature of this device is that the flaps of its wings imitate those of a seagull i.e. the device has a biological prototype. We construct a mathematical model of this device; much attention is given to the model of the interaction of the wings with the air environment and we determine the positions and velocities of points of application of the reduced aerodynamic forces to each of the links. Based on the results of numerical modelling of the vertical flight of the robot three modes of flight were established: ascent, hovering at a certain height and descent. The device can operate in these modes based on the oscillation parameters of the wings in particular flapping frequency and amplitude, the ratio of the amplitudes of two links and one wing and the shift of the equilibrium oscillation position of the wings relative to zero.

  10. Fabrication of corrugated artificial insect wings using laser micromachined molds

    International Nuclear Information System (INIS)

    Tanaka, Hiroto; Wood, Robert J

    2010-01-01

    This paper describes the fabrication of an artificial insect wing with a rich set of topological features by micromolding a thermosetting resin. An example 12 mm long hoverfly-like wing is fabricated with 50–125 µm vein heights and 100 µm corrugation heights. The solid veins and membrane were simultaneously formed and integrated by a single molding process. Employing a layered laser ablation technique, three-dimensional molds were created with 5 µm resolution in height. Safe demolding of the wing was achieved with a water-soluble sacrificial layer on the mold. Measured surface profiles of the wing matched those of the molds, demonstrating the high replication accuracy of this molding process. Using this process, the morphological features of insect wings can be replicated at-scale with high precision, enabling parametric experiments of the functional morphology of insect wings. This fabrication capability also makes it possible to create a variety of wing types for micro air vehicles on scales similar to insects.

  11. Passive samplers and community science in regional air quality measurement, education and communication

    International Nuclear Information System (INIS)

    DeForest Hauser, Cindy; Buckley, Alexandra; Porter, Juliana

    2015-01-01

    Charlotte, in Mecklenburg County, North Carolina, was ranked in the top ten cities with the worst air quality for ozone in the United States by the American Lung Association from 2009 to 2011. Nearby counties that may experience similar air quality do not have state or county monitors. This study utilized NO x and ozone Ogawa passive samplers and community scientists to monitor air quality in five counties surrounding Charlotte and increase public engagement in air quality issues. Community scientists deployed samplers weekly at a residential site within each county. Samples were analyzed using spectrophotometry and ion chromatography. Elevated NO x concentrations were observed in four of the five counties relative to those with existing monitors. Ozone concentrations showed little county to county variation, except Iredell and Cabarrus which had higher concentrations than Rowan. Community involvement in this work led to an increase in local dissemination of the results, thus increasing air quality awareness. - Highlights: • NO x concentrations in four adjacent counties were higher than the Mecklenburg site. • Ozone concentrations showed little county to county variation. • Passive samplers and community science can extend the air quality monitoring network. • Community science increases community awareness of air quality issues. - Regional community air quality monitoring is important in educating communities about air quality science issues that can impact personal health and behavior

  12. Challenges and Opportunities for Using Crowd-Sourced Air Pollution Measurements for Education and Outreach

    Science.gov (United States)

    Stanier, C. O.; Dong, C.; Janechek, N. J.; Bryngelson, N.; Schultz, P.; Heimbinder, M.

    2017-12-01

    As part of the CLE4R air quality education project, the University of Iowa has been working with AirBeam low-cost consumer-grade fine particulate matter (PM2.5) sensors in educational and outreach settings, both in K-12 environments and in informal settings such as science days and technology fairs. Users are attracted to the AirBeam device, in part, because of the easy creation of crowd-sourced maps of air pollution. With over 1000 AirBeam devices in use, extensive measurements are now available at aircasting.org. The AirBeam sensor is a portable, low-cost sensor which measures light scattering due to aerosols as a single bin converting the detected signal to a particle count and uses a calibration fit to estimate particle mass. The AirBeam is able to detect particle sizes of 0.5 - 2.5 µm, concentrations up to 400 µg m-3, and with a time resolution of 1 s. A corresponding Android device is used to visualize, record, and upload measured data to a community website (aircasting.org) that maps the spatial and temporal resolved data. The non-profit vendor's website constructs crowdsourced maps of air quality, environmental, and meteorological variables. As of April 1st, 2017, through the CLE4R project, 109 people had used the AirBeam sensors for educational purposes, for a total of 271 person hours. In the poster, we will explain the outreach that was done, and share best practices for education and outreach using consumer-grade PM sensors. Strengths and needed improvements to the technology for these outreach, education, and classroom uses will also be detailed. Sources of particles that can be artificially generated for educational use, including authentic smoke, spray smoke, and various dust sources will be enumerated. For use in K-12 classrooms, requirements for robust startup, operation, and ease-of-use are high. Mapping of concentrations is a desirable attribute but adds additional sources of failure to the hardware-software system used for education/outreach.

  13. Application of SMP composite in designing a morphing wing

    Science.gov (United States)

    Yu, Kai; Yin, Weilong; Liu, Yanju; Leng, Jinsong

    2008-11-01

    A new concept of a morphing wing based on shape memory polymer (SMP) and its reinforced composite is proposed in this paper. SMP used in this study is a thermoset styrene-based resin in contrast to normal thermoplastic SMP. In our design, the wing winded on the airframe can be deployed during heating, which provides main lift for a morphing aircraft to realize stable flight. Aerodynamic characteristics of the deployed morphing wing are calculated by using CFD software. The static deformation of the wing under the air loads is also analyzed by using the finite element method. The results show that the used SMP material can provide enough strength and stiffness for the application.

  14. Marketing Education Through Benefit Segmentation. AIR Forum 1981 Paper.

    Science.gov (United States)

    Goodnow, Wilma Elizabeth

    The applicability of the "benefit segmentation" marketing technique to education was tested at the College of DuPage in 1979. Benefit segmentation identified target markets homogeneous in benefits expected from a program offering and may be useful in combatting declining enrollments. The 487 randomly selected students completed the 223…

  15. Insect-inspired wing actuation structures based on ring-type resonators

    NARCIS (Netherlands)

    Bolsman, C.T.; Goosen, J.F.L.; Van Keulen, F.

    2008-01-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of

  16. Structural dynamics and aerodynamics measurements of biologically inspired flexible flapping wings.

    Science.gov (United States)

    Wu, P; Stanford, B K; Sällström, E; Ukeiley, L; Ifju, P G

    2011-03-01

    Flapping wing flight as seen in hummingbirds and insects poses an interesting unsteady aerodynamic problem: coupling of wing kinematics, structural dynamics and aerodynamics. There have been numerous studies on the kinematics and aerodynamics in both experimental and computational cases with both natural and artificial wings. These studies tend to ignore wing flexibility; however, observation in nature affirms that passive wing deformation is predominant and may be crucial to the aerodynamic performance. This paper presents a multidisciplinary experimental endeavor in correlating a flapping micro air vehicle wing's aeroelasticity and thrust production, by quantifying and comparing overall thrust, structural deformation and airflow of six pairs of hummingbird-shaped membrane wings of different properties. The results show that for a specific spatial distribution of flexibility, there is an effective frequency range in thrust production. The wing deformation at the thrust-productive frequencies indicates the importance of flexibility: both bending and twisting motion can interact with aerodynamic loads to enhance wing performance under certain conditions, such as the deformation phase and amplitude. By measuring structural deformations under the same aerodynamic conditions, beneficial effects of passive wing deformation can be observed from the visualized airflow and averaged thrust. The measurements and their presentation enable observation and understanding of the required structural properties for a thrust effective flapping wing. The intended passive responses of the different wings follow a particular pattern in correlation to their aerodynamic performance. Consequently, both the experimental technique and data analysis method can lead to further studies to determine the design principles for micro air vehicle flapping wings.

  17. Structural dynamics and aerodynamics measurements of biologically inspired flexible flapping wings

    International Nuclear Information System (INIS)

    Wu, P; Stanford, B K; Ifju, P G; Saellstroem, E; Ukeiley, L

    2011-01-01

    Flapping wing flight as seen in hummingbirds and insects poses an interesting unsteady aerodynamic problem: coupling of wing kinematics, structural dynamics and aerodynamics. There have been numerous studies on the kinematics and aerodynamics in both experimental and computational cases with both natural and artificial wings. These studies tend to ignore wing flexibility; however, observation in nature affirms that passive wing deformation is predominant and may be crucial to the aerodynamic performance. This paper presents a multidisciplinary experimental endeavor in correlating a flapping micro air vehicle wing's aeroelasticity and thrust production, by quantifying and comparing overall thrust, structural deformation and airflow of six pairs of hummingbird-shaped membrane wings of different properties. The results show that for a specific spatial distribution of flexibility, there is an effective frequency range in thrust production. The wing deformation at the thrust-productive frequencies indicates the importance of flexibility: both bending and twisting motion can interact with aerodynamic loads to enhance wing performance under certain conditions, such as the deformation phase and amplitude. By measuring structural deformations under the same aerodynamic conditions, beneficial effects of passive wing deformation can be observed from the visualized airflow and averaged thrust. The measurements and their presentation enable observation and understanding of the required structural properties for a thrust effective flapping wing. The intended passive responses of the different wings follow a particular pattern in correlation to their aerodynamic performance. Consequently, both the experimental technique and data analysis method can lead to further studies to determine the design principles for micro air vehicle flapping wings.

  18. Structural dynamics and aerodynamics measurements of biologically inspired flexible flapping wings

    Energy Technology Data Exchange (ETDEWEB)

    Wu, P; Stanford, B K; Ifju, P G [Department of Mechanical and Aerospace Engineering, MAE-A 231, University of Florida, Gainesville, FL 32611 (United States); Saellstroem, E; Ukeiley, L, E-mail: diccidwp@ufl.edu [Department of Mechanical and Aerospace Engineering, University of Florida, Shalimar, FL 32579 (United States)

    2011-03-15

    Flapping wing flight as seen in hummingbirds and insects poses an interesting unsteady aerodynamic problem: coupling of wing kinematics, structural dynamics and aerodynamics. There have been numerous studies on the kinematics and aerodynamics in both experimental and computational cases with both natural and artificial wings. These studies tend to ignore wing flexibility; however, observation in nature affirms that passive wing deformation is predominant and may be crucial to the aerodynamic performance. This paper presents a multidisciplinary experimental endeavor in correlating a flapping micro air vehicle wing's aeroelasticity and thrust production, by quantifying and comparing overall thrust, structural deformation and airflow of six pairs of hummingbird-shaped membrane wings of different properties. The results show that for a specific spatial distribution of flexibility, there is an effective frequency range in thrust production. The wing deformation at the thrust-productive frequencies indicates the importance of flexibility: both bending and twisting motion can interact with aerodynamic loads to enhance wing performance under certain conditions, such as the deformation phase and amplitude. By measuring structural deformations under the same aerodynamic conditions, beneficial effects of passive wing deformation can be observed from the visualized airflow and averaged thrust. The measurements and their presentation enable observation and understanding of the required structural properties for a thrust effective flapping wing. The intended passive responses of the different wings follow a particular pattern in correlation to their aerodynamic performance. Consequently, both the experimental technique and data analysis method can lead to further studies to determine the design principles for micro air vehicle flapping wings.

  19. Design optimization of deployable wings

    Science.gov (United States)

    Gaddam, Pradeep

    Morphing technology is an important aspect of UAV design, particularly in regards to deployable systems. The design of such system has an important impact on the vehicle's performance. The primary focus of the present research work was to determine the most optimum deployable wing design from 3 competing designs and develop one of the deployable wing designs to test in the research facility. A Matlab code was developed to optimize 3 deployable wing concepts inflatable, inflatable telescopic and rigid-folding wings based on a sequential optimization strategy. The constraints that were part of the code include the packaging constraints during its stowed state, fixed length of the deployed section and the minimum L/D constraint. This code resulted in determining the optimum weight of all the 3 designs, the most optimum weight design is the inflatable wing design. This is a result of the flexible skin material and also due to no rigid parts in the deployed wing section. Another goal of the research involved developing an inflatable telescopic wing. The prototype was tested in a wind tunnel, while the actual wing was tested in the altitude chamber to determine the deployment speed, input pressure, analyze and predict the deployment sequence and behavior of the wing at such high wind speeds and altitudes ranging from 60,000 ft to 90,000 ft. Results from these tests allowed us to conclude the deployment sequence of the telescopic wing followed from the root to the tip section. The results were used to analyze the deployment time of the wing. As expected the deployment time decreased with an increase in input pressure. The results also show us that as the altitude increases, the deployment speed of the wing also increased. This was demonstrated when the wing was tested at a maximum altitude pressure of 90,000ft, well above the design altitude of 60,000ft.

  20. Air

    CERN Document Server

    Rivera, Andrea

    2017-01-01

    Air is all around us. Learn how it is used in art, technology, and engineering. Five easy-to-read chapters explain the science behind air, as well as its real-world applications. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  1. Low Aspect-Ratio Wings for Wing-Ships

    DEFF Research Database (Denmark)

    Filippone, Antonino; Selig, M.

    1998-01-01

    Flying on ground poses technical and aerodynamical challenges. The requirements for compactness, efficiency, manouverability, off-design operation,open new areas of investigations in the fieldof aerodynamic analysis and design. A review ofthe characteristics of low-aspect ratio wings, in- and out...... of ground, is presented. It is shownthat the performance of such wings is generally inferior to that of slender wings, although in ground placement can yield substantial improvements in the aerodynamic efficiency....

  2. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  3. Wake Characteristics of a Flapping Wing Optimized for both Aerial and Aquatic Flight

    Science.gov (United States)

    Izraelevitz, Jacob; Kotidis, Miranda; Triantafyllou, Michael

    2017-11-01

    Multiple aquatic bird species (including murres, puffins, and other auks) employ a single actuator to propel themselves in two different fluid media: both flying and swimming using primarily their flapping wings. This impressive design compromise could be adopted by engineered implementations of dual aerial/aquatic robotic platforms, as it offers an existence proof for favorable flow physics. We discuss one realization of a 3D flapping wing actuation system for use in both air and water. The wing oscillates by the root and employs an active in-line motion degree-of-freedom. An experiment-coupled optimization routine generates the wing trajectories, controlling the unsteady forces throughout each flapping cycle. We elucidate the wakes of these wing trajectories using dye visualization, correlating the wake vortex structures with simultaneous force measurements. After optimization, the wing generates the large force envelope necessary for propulsion in both fluid media, and furthermore, demonstrate improved control over the unsteady wake.

  4. Phasing of dragonfly wings can improve aerodynamic efficiency by removing swirl.

    Science.gov (United States)

    Usherwood, James R; Lehmann, Fritz-Olaf

    2008-11-06

    Dragonflies are dramatic, successful aerial predators, notable for their flight agility and endurance. Further, they are highly capable of low-speed, hovering and even backwards flight. While insects have repeatedly modified or reduced one pair of wings, or mechanically coupled their fore and hind wings, dragonflies and damselflies have maintained their distinctive, independently controllable, four-winged form for over 300Myr. Despite efforts at understanding the implications of flapping flight with two pairs of wings, previous studies have generally painted a rather disappointing picture: interaction between fore and hind wings reduces the lift compared with two pairs of wings operating in isolation. Here, we demonstrate with a mechanical model dragonfly that, despite presenting no advantage in terms of lift, flying with two pairs of wings can be highly effective at improving aerodynamic efficiency. This is achieved by recovering energy from the wake wasted as swirl in a manner analogous to coaxial contra-rotating helicopter rotors. With the appropriate fore-hind wing phasing, aerodynamic power requirements can be reduced up to 22 per cent compared with a single pair of wings, indicating one advantage of four-winged flying that may apply to both dragonflies and, in the future, biomimetic micro air vehicles.

  5. Creating Joint Leaders Today for a Successful Air Force Tomorrow (1REV)

    Science.gov (United States)

    2016-04-01

    military goals must be comprised of personnel who are trained, educated, experienced, and acculturated in jointness.P 32F15P In order to achieve...biographical review of the three- and four-star Air Force officers reveals that none hold degrees from tier-one educational institutions.P239F28P As a...spend a significant portion of their time away from their wings attending professional development courses, management level review boards

  6. Electro-Magnetic Flow Control to Enable Natural Laminar Flow Wings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research team has developed a solid-state electromagnetic device that, when embedded along the leading edge of an aircraft wing, can disrupt laminar air flow on...

  7. Electro-Magnetic Flow Control to Enable Natural Laminar Flow Wings

    Data.gov (United States)

    National Aeronautics and Space Administration — This research team has developed a solid-state electromagnetic device that, when embedded along the leading edge of an aircraft wing, can disrupt laminar air flow on...

  8. Application of Piezoelectrics to Flapping-Wing MAVs

    Science.gov (United States)

    Widstrand, Alex; Hubner, J. Paul

    2015-11-01

    Micro air vehicles (MAVs) are a class of unmanned aerial vehicles that are size-restricted and operate at low velocities and low Reynolds numbers. An ongoing challenge with MAVs is that their flight-related operations are highly constrained by their size and weight, which limits battery size and, therefore, available power. One type of MAV called an ornithopter flies using flapping wings to create both lift and thrust, much like birds and insects do. Further bio-inspiration from bats led to the design of membrane wings for these vehicles, which provide aerodynamic benefits through passive vibration. In an attempt to capitalize on this vibration, a piezoelectric film, which generates a voltage when stressed, was investigated as the wing surface. Two wing planforms with constant area were designed and fabricated. The goal was to measure the wings' flight characteristics and output energy in freestream conditions. Complications with the flapper arose which prevented wind tunnel tests from being performed; however, energy data was obtained from table-top shaker tests. Preliminary results indicate that wing shape affects the magnitude of the charge generated, with a quarter-elliptic planform outperforming a rectangular planform. Funding provided by NSF REU Site Award number 1358991.

  9. Monitoring of a Full-Scale Wing Fatigue Test

    NARCIS (Netherlands)

    Heida, Jaap; Hwang, Joong Sun

    2014-01-01

    A wing of a decommissioned aircraft of the Royal Netherlands Air Force (RNLAF) was fatigue tested to more than two times the design life. Part of the test was the evaluation of load monitoring and Structural Health Monitoring (SHM) techniques. For load monitoring the data of conventional resistance

  10. Aeroelastic Modelling and Design of Aeroelastically Tailored and Morphing Wings

    NARCIS (Netherlands)

    Werter, N.P.M.

    2017-01-01

    In order to accommodate the growth in air traffic whilst reducing the impact on the environment, operational efficiency is becoming more and more important in the design of the aircraft of the future. A possible approach to increase the operational efficiency of aircraft wings is the use of

  11. Study on bird's & insect's wing aerodynamics and comparison of its analytical value with standard airfoil

    Science.gov (United States)

    Ali, Md. Nesar; Alam, Mahbubul; Hossain, Md. Abed; Ahmed, Md. Imteaz

    2017-06-01

    Flight is the main mode of locomotion used by most of the world's bird & insect species. This article discusses the mechanics of bird flight, with emphasis on the varied forms of bird's & insect's wings. The fundamentals of bird flight are similar to those of aircraft. Flying animals flap their wings to generate lift and thrust as well as to perform remarkable maneuvers with rapid accelerations and decelerations. Insects and birds provide illuminating examples of unsteady aerodynamics. Lift force is produced by the action of air flow on the wing, which is an airfoil. The airfoil is shaped such that the air provides a net upward force on the wing, while the movement of air is directed downward. Additional net lift may come from airflow around the bird's & insect's body in some species, especially during intermittent flight while the wings are folded or semi-folded. Bird's & insect's flight in nature are sub-divided into two stages. They are Unpowered Flight: Gliding and Soaring & Powered Flight: Flapping. When gliding, birds and insects obtain both a vertical and a forward force from their wings. When a bird & insect flaps, as opposed to gliding, its wings continue to develop lift as before, but the lift is rotated forward to provide thrust, which counteracts drag and increases its speed, which has the effect of also increasing lift to counteract its weight, allowing it to maintain height or to climb. Flapping flight is more complicated than flight with fixed wings because of the structural movement and the resulting unsteady fluid dynamics. Flapping involves two stages: the down-stroke, which provides the majority of the thrust, and the up-stroke, which can also (depending on the bird's & insect's wings) provide some thrust. Most kinds of bird & insect wing can be grouped into four types, with some falling between two of these types. These types of wings are elliptical wings, high speed wings, high aspect ratio wings and soaring wings with slots. Hovering is used

  12. "Spacearium" and the Educational Mission of the National Air and Space Museum

    Science.gov (United States)

    Shin, Jieun

    2018-01-01

    After a campaign that lasted over a decade, in 1971 the Washington Planetarium and Space Center decided to transfer all of its assets to the Smithsonian to be part of its proposed new National Air and Space Museum (NASM), itself recently redefined from being known as the National Air Museum. Here I will argue that the addition of a planetarium, which they called a “Spacearium,” reflected a new goal of the Smithsonian to emphasize the educational mission of the new museum and thereby secure positive attention from Congress and the aerospace industry, hastening the appropriations process.

  13. Aeroelastic Wing Shaping Using Distributed Propulsion

    Science.gov (United States)

    Nguyen, Nhan T. (Inventor); Reynolds, Kevin Wayne (Inventor); Ting, Eric B. (Inventor)

    2017-01-01

    An aircraft has wings configured to twist during flight. Inboard and outboard propulsion devices, such as turbofans or other propulsors, are connected to each wing, and are spaced along the wing span. A flight controller independently controls thrust of the inboard and outboard propulsion devices to significantly change flight dynamics, including changing thrust of outboard propulsion devices to twist the wing, and to differentially apply thrust on each wing to change yaw and other aspects of the aircraft during various stages of a flight mission. One or more generators can be positioned upon the wing to provide power for propulsion devices on the same wing, and on an opposite wing.

  14. Butterflies regulate wing temperatures using radiative cooling

    Science.gov (United States)

    Tsai, Cheng-Chia; Shi, Norman Nan; Ren, Crystal; Pelaez, Julianne; Bernard, Gary D.; Yu, Nanfang; Pierce, Naomi

    2017-09-01

    Butterfly wings are live organs embedded with multiple sensory neurons and, in some species, with pheromoneproducing cells. The proper function of butterfly wings demands a suitable temperature range, but the wings can overheat quickly in the sun due to their small thermal capacity. We developed an infrared technique to map butterfly wing temperatures and discovered that despite the wings' diverse visible colors, regions of wings that contain live cells are the coolest, resulting from the thickness of the wings and scale nanostructures. We also demonstrated that butterflies use behavioral traits to prevent overheating of their wings.

  15. Pneumatic artificial muscle and its application on driving variable trailing-edge camber wing

    Science.gov (United States)

    Yin, Weilong; Liu, Libo; Chen, Yijin; Liu, Yanju; Leng, Jinsong

    2010-04-01

    As a novel bionic actuator, pneumatic artificial muscle has high power to weight ratio. In this paper, the experimental setup to measure the static output force of pneumatic artificial muscle was designed and the relationship between the static output force and the air pressure was investigated. Experimental result shows the static output force of pneumatic artificial muscle decreases nonlinearly with increasing contraction ratio. A variable camber wing based on the pneumatic artificial muscle was developed and the variable camber wing model was manufactured to validate the variable camber concept. Wind tunnel tests were conducted in the low speed wind tunnel. Experimental result shows that the wing camber increases with increasing air pressure.

  16. Comparative Analysis of Uninhibited and Constrained Avian Wing Aerodynamics

    Science.gov (United States)

    Cox, Jordan A.

    The flight of birds has intrigued and motivated man for many years. Bird flight served as the primary inspiration of flying machines developed by Leonardo Da Vinci, Otto Lilienthal, and even the Wright brothers. Avian flight has once again drawn the attention of the scientific community as unmanned aerial vehicles (UAV) are not only becoming more popular, but smaller. Birds are once again influencing the designs of aircraft. Small UAVs operating within flight conditions and low Reynolds numbers common to birds are not yet capable of the high levels of control and agility that birds display with ease. Many researchers believe the potential to improve small UAV performance can be obtained by applying features common to birds such as feathers and flapping flight to small UAVs. Although the effects of feathers on a wing have received some attention, the effects of localized transient feather motion and surface geometry on the flight performance of a wing have been largely overlooked. In this research, the effects of freely moving feathers on a preserved red tailed hawk wing were studied. A series of experiments were conducted to measure the aerodynamic forces on a hawk wing with varying levels of feather movement permitted. Angle of attack and air speed were varied within the natural flight envelope of the hawk. Subsequent identical tests were performed with the feather motion constrained through the use of externally-applied surface treatments. Additional tests involved the study of an absolutely fixed geometry mold-and-cast wing model of the original bird wing. Final tests were also performed after applying surface coatings to the cast wing. High speed videos taken during tests revealed the extent of the feather movement between wing models. Images of the microscopic surface structure of each wing model were analyzed to establish variations in surface geometry between models. Recorded aerodynamic forces were then compared to the known feather motion and surface

  17. Stiffness of desiccating insect wings

    Energy Technology Data Exchange (ETDEWEB)

    Mengesha, T E; Vallance, R R [Department of Mechanical Engineering, The George Washington University, 738 Phillips Hall, 801 22nd St NW, Washington, DC 20052 (United States); Mittal, R, E-mail: vallance@gwu.edu [Department of Mechanical Engineering, Johns Hopkins University, 126 Latrobe Hall, 3400 N Charles Street, Baltimore, MD 21218 (United States)

    2011-03-15

    The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 {mu}N mm{sup -1} h{sup -1}. For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm{sup -1}. (communication)

  18. Science Education Supporting Weather Broadcasters On-Air and in the Classroom with NASA "Mini-Education Supplements"

    Science.gov (United States)

    Shepherd, J. Marshall; Starr, David OC. (Technical Monitor)

    2001-01-01

    NASA-Goddard Space Flight Center has initiated a new project designed to expand on existing news services and add value to classrooms through the development and distribution of two-minute 'mini-supplements' which give context and teach about current weather and Earth research phenomena. The innovative mini-supplements provide raw materials for weather forecasters to build news stories around NASA related missions without having to edit the more traditional and cumbersome long-form video format. The supplements cover different weather and climate topics and include NASA data, animations, video footage, and interviews with scientists. The supplements also include a curriculum package with educational lessons, educator guide, and hand-on activities. One goal is to give on-air broadcasters who are the primary science educators for the general public what they need to 'teach' about the science related to NASA research behind weather and climate news. This goal achieves increasing public literacy and assures higher accuracy and quality science reporting by the media. The other goal is to enable on-air broadcasters to serve as distributors of high quality, standards-based educational curricula and supplemental material when they visit 8-12 grade classrooms. The focus of 'pilot effort' centers around the success of NASA's Tropical Rainfall Measuring Mission (TRMM) but is likely expandable to other NASA earth or space science missions.

  19. AERODYNAMICS OF WING TIP SAILS

    Directory of Open Access Journals (Sweden)

    MUSHTAK AL-ATABI

    2006-06-01

    Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.

  20. Critical Thinking Skills of U.S. Air Force Senior and Intermediate Developmental Education Students

    Science.gov (United States)

    2016-02-16

    Bloom’s taxonomy and presenting a case study.45 In short, the guide was only an introduction and insufficient for the development of CT skills. The Army...Glaser Critical Thinking Appraisal Test Preparation Program on the Critical Thinking of Teacher Education Program Applicants,” (PhD diss...research project used the Watson-Glaser Critical Thinking Appraisal to establish a baseline of current CT skills among active duty Air Force (AF) officers

  1. Utilization of radon progeny in air for education experiment on radiation

    International Nuclear Information System (INIS)

    Iimoto, Takeshi

    2003-01-01

    Radon progeny with short half-lives in the natural air was utilized in the education experiment on radiation that is for the students in the university of Tokyo. Advantage points of the radon progeny are; 1) their short half-lives around 30-50 minutes whose feature is adequate to draw the decay curve in the class and 2) that they exist in the natural air. The most important point of this education experiment is to perform sampling and measuring the radioactivity in the natural area, not in the radiation controlled area. Through the procedure, the students can understand that natural radio-nuclides surely exist around us. Sampling time is 30 minutes at a flow rate of around 60 litters per minute and a glass-fiber filter of GF/F is used, waiting time is one minute and measuring time is sequence of 10 times of 5 minutes (total measuring time; 35 minutes). The total experiment time is around 100 minutes. In the home-tasks, they calculate the radon progeny's concentration in air using the alpha decay curve of the radon progeny on the sampling filter: In addition, they investigate and learn the natural radiation/radioactivity. The radon progeny is useful and effective natural radioactivity for the radiation education. (author)

  2. Nano-architecture of gustatory chemosensory bristles and trachea in Drosophila wings.

    Science.gov (United States)

    Valmalette, Jean Christophe; Raad, Hussein; Qiu, Nan; Ohara, Satoshi; Capovilla, Maria; Robichon, Alain

    2015-09-18

    In the Drosophila wing anterior margin, the dendrites of gustatory neurons occupy the interior of thin and long bristles that present tiny pores at their extremities. Many attempts to measure ligand-evoked currents in insect wing gustatory neurons have been unsuccessful for technical reasons. The functions of this gustatory activity therefore remain elusive and controversial. To advance our knowledge on this understudied tissue, we investigated the architecture of the wing chemosensory bristles and wing trachea using Raman spectroscopy and fluorescence microscopy. We hypothesized that the wing gustatory hair, an open-ended capillary tube, and the wing trachea constitute biological systems similar to nano-porous materials. We present evidence that argues in favour of the existence of a layer or a bubble of air beneath the pore inside the gustatory hair. We demonstrate that these hollow hairs and wing tracheal tubes fulfil conditions for which the physics of fluids applied to open-ended capillaries and porous materials are relevant. We also document that the wing gustatory hair and tracheal architectures are capable of trapping volatile molecules from the environment, which might increase the efficiency of their spatial detection by way of wing vibrations or during flight.

  3. Heating, Air Conditioning and Refrigeration. Vocational Education Curriculum Guide. Industrial and Technical Education.

    Science.gov (United States)

    West Virginia State Vocational Curriculum Lab., Cedar Lakes.

    This curriculum guide contains 17 units that provides the basic curriculum components required to develop lesson plans for the heating, air conditioning, and refrigeration curriculum. The guide is not intended to be a complete, self-contained curriculum, but instead provides the teacher with a number of informational items related to the learning…

  4. A novel mechanism for emulating insect wing kinematics

    International Nuclear Information System (INIS)

    Seshadri, Pranay; Benedict, Moble; Chopra, Inderjit

    2012-01-01

    A novel dual-differential four-bar flapping mechanism that can accurately emulate insect wing kinematics in all three degrees of freedom (translation, rotation and stroke plane deviation) is developed. The mechanism is specifically designed to be simple and scalable such that it can be utilized on an insect-based flapping wing micro air vehicle. Kinematic formulations for the wing stroke position, pitch angle and coning angle for this model are derived from first principles and compared with a 3D simulation. A benchtop flapping mechanism based on this model was designed and built, which was also equipped with a balance for force measurements. 3D motion capture tests were conducted on this setup to demonstrate the capability of generating complex figure-of-eight flapping motions along with dynamic pitching. The dual-differential four-bar mechanism was implemented on a light-weight vehicle that demonstrated tethered hover. (paper)

  5. Wing bone geometry reveals active flight in Archaeopteryx.

    Science.gov (United States)

    Voeten, Dennis F A E; Cubo, Jorge; de Margerie, Emmanuel; Röper, Martin; Beyrand, Vincent; Bureš, Stanislav; Tafforeau, Paul; Sanchez, Sophie

    2018-03-13

    Archaeopteryx is an iconic fossil taxon with feathered wings from the Late Jurassic of Germany that occupies a crucial position for understanding the early evolution of avian flight. After over 150 years of study, its mosaic anatomy unifying characters of both non-flying dinosaurs and flying birds has remained challenging to interpret in a locomotory context. Here, we compare new data from three Archaeopteryx specimens obtained through phase-contrast synchrotron microtomography to a representative sample of archosaurs employing a diverse array of locomotory strategies. Our analyses reveal that the architecture of Archaeopteryx's wing bones consistently exhibits a combination of cross-sectional geometric properties uniquely shared with volant birds, particularly those occasionally utilising short-distance flapping. We therefore interpret that Archaeopteryx actively employed wing flapping to take to the air through a more anterodorsally posteroventrally oriented flight stroke than used by modern birds. This unexpected outcome implies that avian powered flight must have originated before the latest Jurassic.

  6. Structural Analysis of a Dragonfly Wing

    NARCIS (Netherlands)

    Jongerius, S.R.; Lentink, D.

    2010-01-01

    Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned

  7. Flight Testing of Novel Compliant Spines for Passive Wing Morphing on Ornithopters

    Science.gov (United States)

    Wissa, Aimy; Guerreiro, Nelson; Grauer, Jared; Altenbuchner, Cornelia; Hubbard, James E., Jr.; Tummala, Yashwanth; Frecker, Mary; Roberts, Richard

    2013-01-01

    Unmanned Aerial Vehicles (UAVs) are proliferating in both the civil and military markets. Flapping wing UAVs, or ornithopters, have the potential to combine the agility and maneuverability of rotary wing aircraft with excellent performance in low Reynolds number flight regimes. The purpose of this paper is to present new free flight experimental results for an ornithopter equipped with one degree of freedom (1DOF) compliant spines that were designed and optimized in terms of mass, maximum von-Mises stress, and desired wing bending deflections. The spines were inserted in an experimental ornithopter wing spar in order to achieve a set of desired kinematics during the up and down strokes of a flapping cycle. The ornithopter was flown at Wright Patterson Air Force Base in the Air Force Research Laboratory Small Unmanned Air Systems (SUAS) indoor flight facility. Vicon motion tracking cameras were used to track the motion of the vehicle for five different wing configurations. The effect of the presence of the compliant spine on wing kinematics and leading edge spar deflection during flight is presented. Results show that the ornithopter with the compliant spine inserted in its wing reduced the body acceleration during the upstroke which translates into overall lift gains.

  8. Pulsed eddy current inspection of CF-188 inner wing spar

    Science.gov (United States)

    Horan, Peter Francis

    Royal Canadian Air Force (RCAF) CF-188 Hornet aircraft engineering authorities have stated a requirement for a Non-Destructive Evaluation (NDE) technique to detect Stress Corrosion Cracking (SCC) in the inner wing spars without fastener or composite wing skin removal. Current radiographic inspections involve significant aircraft downtime, and Pulsed Eddy Current (PEC) inspection is proposed as a solution. The aluminum inner wing spars of CF-188 Hornet aircraft may undergo stress corrosion cracking (SCC) along the spar between the fasteners that secure carbon-fiber/ epoxy composite skin to the wing. Inspection of the spar through the wing skin is required to avoid wing disassembly. The thickness of the wing skin varies between 8 and 20 mm (0.3 to 0.8 inch) and fasteners may be either titanium or ferrous. PEC generated by a probe centered over a fastener, demonstrates capability of detecting simulated cracks within spars with the wing skin present. Comparison of signals from separate sensors, mounted to either side of the excitation coil, is used to detect differences in induced eddy current fields, which arise in the presence of cracks. To overcome variability in PEC signal response due to variation in 1) skin thickness, 2) fastener material and size, and 3) centering over fasteners, a large calibration data set is acquired. Multi-dimensional scores from a Modified Principal Components Analysis (PCA) of the data are reduced to one dimension (1D) using a Discriminant Analysis method. Under inspection conditions, calibrated PCA scores combined with discriminant analysis permit rapid real time go/no-go PEC detection of cracks in CF-188 inner wing spar. Probe designs using both pickup coils and Giant Magnetoresistive (GMR) sensors were tested on samples with the same ferrous and titanium fasteners found on the CF-188. Flaws were correctly detected at lift-offs of up to 21mm utilizing a variety of insulating skin materials simulating the carbon-fibre reinforced polymer

  9. Effect of outer wing separation on lift and thrust generation in a flapping wing system

    International Nuclear Information System (INIS)

    Mahardika, Nanang; Viet, Nguyen Quoc; Park, Hoon Cheol

    2011-01-01

    We explore the implementation of wing feather separation and lead-lagging motion to a flapping wing. A biomimetic flapping wing system with separated outer wings is designed and demonstrated. The artificial wing feather separation is implemented in the biomimetic wing by dividing the wing into inner and outer wings. The features of flapping, lead-lagging, and outer wing separation of the flapping wing system are captured by a high-speed camera for evaluation. The performance of the flapping wing system with separated outer wings is compared to that of a flapping wing system with closed outer wings in terms of forward force and downward force production. For a low flapping frequency ranging from 2.47 to 3.90 Hz, the proposed biomimetic flapping wing system shows a higher thrust and lift generation capability as demonstrated by a series of experiments. For 1.6 V application (lower frequency operation), the flapping wing system with separated wings could generate about 56% higher forward force and about 61% less downward force compared to that with closed wings, which is enough to demonstrate larger thrust and lift production capability of the separated outer wings. The experiments show that the outer parts of the separated wings are able to deform, resulting in a smaller amount of drag production during the upstroke, while still producing relatively greater lift and thrust during the downstroke.

  10. Level of Education and Disability among the Elderly People from Buenos Aires

    Directory of Open Access Journals (Sweden)

    Malena Monteverde

    2012-07-01

    Full Text Available The context in which ageing is occurring in Latin America and the Caribbean countries raises questions about future trajectories in the prevalence of disabilities by age. In this sense, it is of great importance to study the behaviour of the prevalence of disabilities and analyse the risk factors in populations of the region. The aim of this study is to analyse the prevalence of disabilities among the individuals 60 years and over in Buenos Aires and to evaluate the differences between groups with different educational levels. The data used come from the study "Health, Welfare and Aging"-SABE (Spanish acronym- for Buenos Aires. Based on this information, we estimate the prevalence of disabilities by level of education and we analyse the effects of different risk factors on the likelihood of experiencing disability among individuals with different levels of education. The results suggest that educational level acts as a major protector against the risk of experiencing disabilities in ADL and IADL and the relationship would be partially mediated by health profiles of the individuals.

  11. Air Enquirer's multi-sensor boxes as a tool for High School Education and Atmospheric Research

    Science.gov (United States)

    Morguí, Josep-Anton; Font, Anna; Cañas, Lidia; Vázquez-García, Eusebi; Gini, Andrea; Corominas, Ariadna; Àgueda, Alba; Lobo, Agustin; Ferraz, Carlos; Nofuentes, Manel; Ulldemolins, Delmir; Roca, Alex; Kamnang, Armand; Grossi, Claudia; Curcoll, Roger; Batet, Oscar; Borràs, Silvia; Occhipinti, Paola; Rodó, Xavier

    2016-04-01

    An educational tool was designed with the aim of making more comprehensive the research done on Greenhouse Gases (GHGs) in the ClimaDat Spanish network of atmospheric observation stations (www.climadat.es). This tool is called Air Enquirer and it consist of a multi-sensor box. It is envisaged to build more than two hundred boxes to yield them to the Spanish High Schools through the Education department (www.educaixa.com) of the "Obra Social 'La Caixa'", who funds this research. The starting point for the development of the Air Enquirers was the experience at IC3 (www.ic3.cat) in the CarboSchools+ FP7 project (www.carboschools.cat, www.carboschools.eu). The Air Enquirer's multi-sensor box is based in Arduino's architecture and contains sensors for CO2, temperature, relative humidity, pressure, and both infrared and visible luminance. The Air Enquirer is designed for taking continuous measurements. Every Air Enquirer ensemble of measurements is used to convert values to standard units (water content in ppmv, and CO2 in ppmv_dry). These values are referred to a calibration made with Cavity Ring Down Spectrometry (Picarro®) under different temperature, pressure, humidity and CO2 concentrations. Multiple sets of Air Enquirers are intercalibrated for its use in parallel during the experiments. The different experiments proposed to the students will be outdoor (observational) or indoor (experimental, in the lab) focusing on understanding the biogeochemistry of GHGs in the ecosystems (mainly CO2), the exchange (flux) of gases, the organic matter production, respiration and decomposition processes, the influence of the anthropogenic activities on the gases (and particles) exchanges, and their interaction with the structure and composition of the atmosphere (temperature, water content, cooling and warming processes, radiative forcing, vertical gradients and horizontal patterns). In order to ensure Air Enquirers a high-profile research performance the experimental designs

  12. Research of Morphing Wing Efficiency

    National Research Council Canada - National Science Library

    Komarov, Valery

    2004-01-01

    This report results from a contract tasking Samara State Aerospace University (SSAU) as follows: The contractor will develop and investigate aerodynamic and structural weight theories associated with morphing wing technology...

  13. Drag Performance of Twist Morphing MAV Wing

    Directory of Open Access Journals (Sweden)

    Ismail N.I.

    2016-01-01

    Full Text Available Morphing wing is one of latest evolution found on MAV wing. However, due to few design problems such as limited MAV wing size and complicated morphing mechanism, the understanding of its aerodynamic behaviour was not fully explored. In fact, the basic drag distribution induced by a morphing MAV wing is still remained unknown. Thus, present work is carried out to compare the drag performance between a twist morphing wing with membrane and rigid MAV wing design. A quasi-static aeroelastic analysis by using the Ansys-Fluid Structure Interaction (FSI method is utilized in current works to predict the drag performance a twist morphing MAV wing design. Based on the drag pattern study, the results exhibits that the morphing wing has a partial similarities in overall drag pattern with the baseline (membrane and rigid wing. However, based CD analysis, it shows that TM wing induced higher CD magnitude (between 25% to 82% higher than to the baseline wing. In fact, TM wing also induced the largest CD increment (about 20% to 27% among the wings. The visualization on vortex structure revealed that TM wing also produce larger tip vortex structure (compared to baseline wings which presume to promote higher induce drag component and subsequently induce its higher CD performance.

  14. Wings of the Night: The Natural History of Bats

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 11. Wings of the Night: The Natural History of Bats. Uttam Saikia. General Article Volume 12 Issue 11 November 2007 pp 63-76. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/11/0063-0076 ...

  15. Local elasticity and adhesion of nanostructures on Drosophila melanogaster wing membrane studied using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Ryan, E-mail: rbwagner@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States); Pittendrigh, Barry R. [Department of Entomology, University of Illinois, Champaign (United States); Raman, Arvind, E-mail: raman@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer We studied the wing membrane of Drosophila melanogaster with atomic force microscopy. Black-Right-Pointing-Pointer We report the structure, elasticity, and adhesion on the wing membrane in air and nitrogen environments. Black-Right-Pointing-Pointer Results provide insight into the nature of the wing membrane enabling the development of biomimetic surface and micro air vehicles. - Abstract: Insect wings have a naturally occurring, complex, functional, hierarchical microstructure and nanostructure, which enable a remarkably water-resistant and self-cleaning surface. Insect wings are used as a basis for engineering biomimetic materials; however, the material properties of these nanostructures such as local elastic modulus and adhesion are poorly understood. We studied the wings of the Canton-S strain of Drosophila melanogaster (hereafter referred to as Drosophila) with atomic force microscopy (AFM) to quantify the local material properties of Drosophila wing surface nanostructures. The wings are found to have a hierarchical structure of 10-20 {mu}m long, 0.5-1 {mu}m diameter hair, and at a much smaller scale, 100 nm diameter and 30-60 nm high bumps. The local properties of these nanoscale bumps were studied under ambient and dry conditions with force-volume AFM. The wing membrane was found to have a elastic modulus on the order of 1000 MPa and the work of adhesion between the probe and wing membrane surface was found to be on the order of 100 mJ/m{sup 2}, these properties are the same order of magnitude as common thermoplastic polymers such as polyethylene. The difference in work of adhesion between the nanoscale bump and membrane does not change significantly between ambient (relative humidity of 30%) or dry conditions. This suggests that the nanoscale bumps and the surrounding membrane are chemically similar and only work to increase hydrophobicity though surface roughening or the geometric lotus effect.

  16. Local elasticity and adhesion of nanostructures on Drosophila melanogaster wing membrane studied using atomic force microscopy

    International Nuclear Information System (INIS)

    Wagner, Ryan; Pittendrigh, Barry R.; Raman, Arvind

    2012-01-01

    Highlights: ► We studied the wing membrane of Drosophila melanogaster with atomic force microscopy. ► We report the structure, elasticity, and adhesion on the wing membrane in air and nitrogen environments. ► Results provide insight into the nature of the wing membrane enabling the development of biomimetic surface and micro air vehicles. - Abstract: Insect wings have a naturally occurring, complex, functional, hierarchical microstructure and nanostructure, which enable a remarkably water-resistant and self-cleaning surface. Insect wings are used as a basis for engineering biomimetic materials; however, the material properties of these nanostructures such as local elastic modulus and adhesion are poorly understood. We studied the wings of the Canton-S strain of Drosophila melanogaster (hereafter referred to as Drosophila) with atomic force microscopy (AFM) to quantify the local material properties of Drosophila wing surface nanostructures. The wings are found to have a hierarchical structure of 10–20 μm long, 0.5–1 μm diameter hair, and at a much smaller scale, 100 nm diameter and 30–60 nm high bumps. The local properties of these nanoscale bumps were studied under ambient and dry conditions with force-volume AFM. The wing membrane was found to have a elastic modulus on the order of 1000 MPa and the work of adhesion between the probe and wing membrane surface was found to be on the order of 100 mJ/m 2 , these properties are the same order of magnitude as common thermoplastic polymers such as polyethylene. The difference in work of adhesion between the nanoscale bump and membrane does not change significantly between ambient (relative humidity of 30%) or dry conditions. This suggests that the nanoscale bumps and the surrounding membrane are chemically similar and only work to increase hydrophobicity though surface roughening or the geometric lotus effect.

  17. Improving Pre-Service Elementary Teachers' Education via a Laboratory Course on Air Pollution: One University's Experience

    Science.gov (United States)

    Mandrikas, Achilleas; Parkosidis, Ioannis; Psomiadis, Ploutarchos; Stoumpa, Artemisia; Chalkidis, Anthimos; Mavrikaki, Evangelia; Skordoulis, Constantine

    2013-01-01

    This paper describes the structure of the "Air Pollution Course", an environmental science laboratory course developed at the Science Education Laboratory of the Faculty of Primary Education, University of Athens, as well as the findings resulting from its implementation by pre-service elementary teachers. The course proposed in this…

  18. Effect of torsional stiffness and inertia on the dynamics of low aspect ratio flapping wings.

    Science.gov (United States)

    Xiao, Qing; Hu, Jianxin; Liu, Hao

    2014-03-01

    Micro air vehicle-motivated aerodynamics in biological flight has been an important subject in the past decade. Inspired by the novel flapping wing mechanisms in insects, birds and bats, we have carried out a numerical study systematically investigating a three-dimensional flapping rigid wing with passively actuated lateral and rotational motion. Distinguishing it from the limited existing studies, this work performs a systematic examination on the effects of wing aspect ratio (AR = 1.0 to infinity), inertia (density ratio σ = 4-32), torsional stiffness (frequency ratio F = 1.5-10 and infinity) and pivot point (from chord-center to leading edge) on the dynamics response of a low AR rectangular wing under an initial zero speed flow field condition. The simulation results show that the symmetry breakdown of the flapping wing results in a forward/backward motion with a rotational pitching. When the wing reaches its stable periodic state, the induced pitching frequency is identical to its forced flapping frequency. However, depending on various kinematic and dynamic system parameters, (i.e. flapping frequency, density ratio and pitching axis), the lateral induced velocity shows a number of different oscillating frequencies. Furthermore, compared with a one degree of freedom (DoF) wing in the lateral direction only, the propulsion performance of such a two DoF wing relies very much on the magnitude of torsional stiffness adding on the pivot point, as well as its pitching axis. In all cases examined here, thrust force and moment generated by a long span wing is larger than that of a short wing, which is remarkably linked to the strong reverse von Kármán vortex street formed in the wake of a wing.

  19. Aerodynamics of wing-assisted incline running in birds.

    Science.gov (United States)

    Tobalske, Bret W; Dial, Kenneth P

    2007-05-01

    Wing-assisted incline running (WAIR) is a form of locomotion in which a bird flaps its wings to aid its hindlimbs in climbing a slope. WAIR is used for escape in ground birds, and the ontogeny of this behavior in precocial birds has been suggested to represent a model analogous to transitional adaptive states during the evolution of powered avian flight. To begin to reveal the aerodynamics of flap-running, we used digital particle image velocimetry (DPIV) and measured air velocity, vorticity, circulation and added mass in the wake of chukar partridge Alectoris chukar as they engaged in WAIR (incline 65-85 degrees; N=7 birds) and ascending flight (85 degrees, N=2). To estimate lift and impulse, we coupled our DPIV data with three-dimensional wing kinematics from a companion study. The ontogeny of lift production was evaluated using three age classes: baby birds incapable of flight [6-8 days post hatching (d.p.h.)] and volant juveniles (25-28 days) and adults (45+ days). All three age classes of birds, including baby birds with partially emerged, symmetrical wing feathers, generated circulation with their wings and exhibited a wake structure that consisted of discrete vortex rings shed once per downstroke. Impulse of the vortex rings during WAIR was directed 45+/-5 degrees relative to horizontal and 21+/-4 degrees relative to the substrate. Absolute values of circulation in vortex cores and induced velocity increased with increasing age. Normalized circulation was similar among all ages in WAIR but 67% greater in adults during flight compared with flap-running. Estimated lift during WAIR was 6.6% of body weight in babies and between 63 and 86% of body weight in juveniles and adults. During flight, average lift was 110% of body weight. Our results reveal for the first time that lift from the wings, rather than wing inertia or profile drag, is primarily responsible for accelerating the body toward the substrate during WAIR, and that partially developed wings, not yet

  20. Follow up Evaluation of Air Force Blood Donors Screening Positive for Chagas Disease

    Science.gov (United States)

    2017-10-05

    evaluation of persons who screen positive in the future. 59th Medical Wing (59th MOW) Institutional Review Board (IRB) 59th Clinical Research Division...59 MDW/SGVU SUBJECT: Professional Presentation Approval 31 JULY2017 Your paper, entitled Follow-up Evaluation of Air Force Blood Donors Screening...Hall Ambulatory Surgical Center (WHASC) internship and residency programs. Please know that if you are a Graduate Health Sciences Education student and

  1. Numerical and Theoretical Considerations for the Design of the AVT-183 Diamond-Wing Experimental Investigations

    Science.gov (United States)

    Boelens, Okko J.; Luckring, James M.; Breitsamter, Christian; Hovelmann, Andreas; Knoth, Florian; Malloy, Donald J.; Deck, Sebatien

    2015-01-01

    A diamond-wing configuration has been developed to isolate and study blunt-leading edge vortex separation with both computations and experiments. The wing has been designed so that the results are relevant to a more complex Uninhabited Combat Air Vehicle concept known as SACCON. The numerical and theoretical development process for this diamond wing is presented, including a view toward planned wind tunnel experiments. This work was conducted under the NATO Science and Technology Organization, Applied Vehicle Technology panel. All information is in the public domain.

  2. Protection against wing icing for Airbus A300 and A310

    Science.gov (United States)

    Woelfer, G.

    1981-01-01

    To improve economy of operation, it is now planned to modify the anti-icing system used on the A300 Airbus wing. Thus, for the A310 Airbus, the deicing system will be applied to only half the wing length. Other essential modifications are a substantial simplification of the warm-air system and discontinuation of the use of a double wall in slats.

  3. Comments on prospects of fully adaptive aircraft wings

    Science.gov (United States)

    Inman, Daniel J.; Gern, Frank H.; Robertshaw, Harry H.; Kapania, Rakesh K.; Pettit, Greg; Natarajan, Anand; Sulaeman, Erwin

    2001-06-01

    New generations of highly maneuverable aircraft, such as Uninhabited Combat Air Vehicles (UCAV) or Micro Air Vehicles (MAV) are likely to feature very flexible lifting surfaces. To enhance stealth properties and performance, the replacement of hinged control surfaces by smart wings and morphing airfoils is investigated. This requires a fundamental understanding of the interaction between aerodynamics, structures, and control systems. The goal is to build a model consistent with distributed control and to exercise this model to determine the progress possible in terms of flight control (lift, drag and maneuver performance) with an adaptive wing. Different modeling levels are examined and combined with a variety of distributed control approaches to determine what types of maneuvers and flight regimes may be possible. This paper describes the current progress of the project and highlights some recent findings.

  4. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings. PMID:27618045

  5. Elastically Shaped Wing Optimization and Aircraft Concept for Improved Cruise Efficiency

    Science.gov (United States)

    Nguyen, Nhan; Trinh, Khanh; Reynolds, Kevin; Kless, James; Aftosmis, Michael; Urnes, James, Sr.; Ippolito, Corey

    2013-01-01

    This paper presents the findings of a study conducted tn 2010 by the NASA Innovation Fund Award project entitled "Elastically Shaped Future Air Vehicle Concept". The study presents three themes in support of meeting national and global aviation challenges of reducing fuel burn for present and future aviation systems. The first theme addresses the drag reduction goal through innovative vehicle configurations via non-planar wing optimization. Two wing candidate concepts have been identified from the wing optimization: a drooped wing shape and an inflected wing shape. The drooped wing shape is a truly biologically inspired wing concept that mimics a seagull wing and could achieve about 5% to 6% drag reduction, which is aerodynamically significant. From a practical perspective, this concept would require new radical changes to the current aircraft development capabilities for new vehicles with futuristic-looking wings such as this concept. The inflected wing concepts could achieve between 3% to 4% drag reduction. While the drag reduction benefit may be less, the inflected-wing concept could have a near-term impact since this concept could be developed within the current aircraft development capabilities. The second theme addresses the drag reduction goal through a new concept of elastic wing shaping control. By aeroelastically tailoring the wing shape with active control to maintain optimal aerodynamics, a significant drag reduction benefit could be realized. A significant reduction in fuel burn for long-range cruise from elastic wing shaping control could be realized. To realize the potential of the elastic wing shaping control concept, the third theme emerges that addresses the drag reduction goal through a new aerodynamic control effector called a variable camber continuous trailing edge flap. Conventional aerodynamic control surfaces are discrete independent surfaces that cause geometric discontinuities at the trailing edge region. These discontinuities promote

  6. How the pterosaur got its wings.

    Science.gov (United States)

    Tokita, Masayoshi

    2015-11-01

    Throughout the evolutionary history of life, only three vertebrate lineages took to the air by acquiring a body plan suitable for powered flight: birds, bats, and pterosaurs. Because pterosaurs were the earliest vertebrate lineage capable of powered flight and included the largest volant animal in the history of the earth, understanding how they evolved their flight apparatus, the wing, is an important issue in evolutionary biology. Herein, I speculate on the potential basis of pterosaur wing evolution using recent advances in the developmental biology of flying and non-flying vertebrates. The most significant morphological features of pterosaur wings are: (i) a disproportionately elongated fourth finger, and (ii) a wing membrane called the brachiopatagium, which stretches from the posterior surface of the arm and elongated fourth finger to the anterior surface of the leg. At limb-forming stages of pterosaur embryos, the zone of polarizing activity (ZPA) cells, from which the fourth finger eventually differentiates, could up-regulate, restrict, and prolong expression of 5'-located Homeobox D (Hoxd) genes (e.g. Hoxd11, Hoxd12, and Hoxd13) around the ZPA through pterosaur-specific exploitation of sonic hedgehog (SHH) signalling. 5'Hoxd genes could then influence downstream bone morphogenetic protein (BMP) signalling to facilitate chondrocyte proliferation in long bones. Potential expression of Fgf10 and Tbx3 in the primordium of the brachiopatagium formed posterior to the forelimb bud might also facilitate elongation of the phalanges of the fourth finger. To establish the flight-adapted musculoskeletal morphology shared by all volant vertebrates, pterosaurs probably underwent regulatory changes in the expression of genes controlling forelimb and pectoral girdle musculoskeletal development (e.g. Tbx5), as well as certain changes in the mode of cell-cell interactions between muscular and connective tissues in the early phase of their evolution. Developmental data now

  7. Aerodynamics and Ecomorphology of Flexible Feathers and Morphing Bird Wings

    Science.gov (United States)

    Klaassen van Oorschot, Brett

    Birds are talented fliers capable of vertical take-off and landing, navigating turbulent air, and flying thousands of miles without rest. How is this possible? What allows birds to exploit the aerial environment with such ease? In part, it may be because bird wings are unlike any engineered wing. They are flexible, strong, lightweight, and dynamically capable of changes in shape on a nearly instantaneous basis (Rayner, 1988; Tobalske, 2007). Moreover, much of this change is passive, modulated only by changes in airflow angle and velocity. Birds actively morph their wings and their feathers morph passively in response to airflow to meet aerodynamic demands. Wings are highly adapted to myriad aeroecological factors and aerodynamic conditions (e.g. Lockwood et al., 1998; Bowlin and Winkler, 2004). This dissertation contains the results of my research on the complexities of morphing avian wings and feathers. I chose to study three related-but-discrete aspects of the avian wing: 1) the aerodynamics of morphing wings during take-off and gliding flight, 2) the presence and significance of wing tip slots across the avian clade, and 3) the aerodynamic role of the emarginate primary feathers that form these wing tip slots. These experiments ask fundamental questions that have intrigued me since childhood: Why do birds have different wing shapes? And why do some birds have slotted wing tips? It's fair to say that you will not find definitive answers here--rather, you will find the methodical, incremental addition of new hypotheses and empirical evidence which will serve future researchers in their own pursuits of these questions. The first chapter explores active wing morphing in two disparate aerodynamic regimes: low-advance ratio flapping (such as during takeoff) and high-advance ratio gliding. This chapter was published in the Journal of Experimental Biology (Klaassen van Oorschot et al., 2016) with the help of an undergraduate researcher, Emily Mistick. We found that wing

  8. Wing Infrastructure and Development Outlook (WINDO) Final Environmental Assessment

    Science.gov (United States)

    2006-06-01

    divert airfield for military aircraft training in the NTTR and support the flying operations of the 57th Wing, other Air Force units, Navy, Marine ...includes desert iguana (Dipsosaurus dorsalis), zebra-tailed lizard (Callosaurus draconoides), side-blotched lizard, horned lizards (Phrynosoma spp...be stored or used in work areas. Marine mammal —any mammal that is morphologically adapted to the marine environment, or primarily inhabits the

  9. We Care for Clean Air! The Contribution of ACCENT to Education and Communication

    Science.gov (United States)

    Schuepbach, Eva; Brimblecombe, Peter; Gross, Krisjanis; Jacobs, Mark J.; Ladstätter-Weißenmayer, Annette; Moussiopoulos, Nicolas; Slini, Theodora; Übelis, Arnolds; Uherek, Elmar

    2010-05-01

    A new booklet on: "We Care for Clean Air! Motivating the Next Generation of Atmospheric Scientists" (ISBN 978-88-95665-01-6) as recently published by the education community in ACCENT (www.accent-network.org/portal/education) is presented. Promoting creative and innovative researchers and teachers and encouraging the next generation to move into the field were among the key issues in ACCENT "Training and Education" (T&E). During the 5-year programme, a wealth of educational events (e.g., workshops) and programmes (e.g., "ACCENT FAR EAST") were organized and tools developed for teachers and learners at Universities and Schools around the globe. Activities such as National ACCENT Days or Cafés Scientifiques also targeted stakeholders, policy makers and the general public to increase the expertise in atmospheric composition change to a common level across Europe. The volume introduces the integrated learning environment, high-quality tools and methods for air quality and climate change science education created by ACCENT T&E, and provides an overview on the unbiased scientific information that has been didactically translated based on knowledge available from ongoing research projects.The core messages are that (i) the translation of complex issues in atmospheric composition and climate change science to non-scientists should be scientifically acceptable and that (ii) scientists should stay in control of the translation process. After the publication of the 4th Assessment Report of the Intergovernmental Panel for Climate Change (IPCC) in 2007, ACCENT intensified its efforts to reach greater visibility and distribute the body of know-how, skills and competencies within the networked community of atmospheric scientists in the World Wide Web. For example, a Special Issue of the "Global Change Magazine for Schools" on IPCC 2007 contains a compact introduction to the basics of global warming for direct application in the classroom, also focusing on uncertainties and

  10. The Air Force Academy’s Falcon Telescope Network: An Educational and Research Network for K-12 and Higher Education

    Science.gov (United States)

    Chun, Francis; Tippets, Roger; Della-Rose, Devin J.; Polsgrove, Daniel; Gresham, Kimberlee; Barnaby, David A.

    2015-01-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. USAFA cadets use the FTN to continue a tradition of satellite characterization and astronomical research; this tradition is the model used for designing the network to serve undergraduate research needs. Additionally, cadets have led the development of the FTN by investigating observation priority schemes and conducting a 'day-in-the-life' study of the FTN in regards to satellite observations. With respect to K-12 outreach, cadets have provided feedback to K-12 students and teachers through evaluation of first-light proposals. In this paper, we present the current status of the network and results from student participation in the project.

  11. Conceptual Study of Rotary-Wing Microrobotics

    National Research Council Canada - National Science Library

    Chabak, Kelson D

    2008-01-01

    This thesis presents a novel rotary-wing micro-electro-mechanical systems (MEMS) robot design. Two MEMS wing designs were designed, fabricated and tested including one that possesses features conducive to insect level aerodynamics...

  12. Aerodynamic control with passively pitching wings

    Science.gov (United States)

    Gravish, Nick; Wood, Robert

    Flapping wings may pitch passively under aerodynamic and inertial loads. Such passive pitching is observed in flapping wing insect and robot flight. The effect of passive wing pitch on the control dynamics of flapping wing flight are unexplored. Here we demonstrate in simulation and experiment the critical role wing pitching plays in yaw control of a flapping wing robot. We study yaw torque generation by a flapping wing allowed to passively rotate in the pitch axis through a rotational spring. Yaw torque is generated through alternating fast and slow upstroke and and downstroke. Yaw torque sensitively depends on both the rotational spring force law and spring stiffness, and at a critical spring stiffness a bifurcation in the yaw torque control relationship occurs. Simulation and experiment reveal the dynamics of this bifurcation and demonstrate that anomalous yaw torque from passively pitching wings is the result of aerodynamic and inertial coupling between the pitching and stroke-plane dynamics.

  13. Waving Wing Aerodynamics at Low Reynolds Numbers

    Science.gov (United States)

    2010-07-01

    wing. An attached leading edge vortex has been observed by multiple research groups on both mechanical wing flappers (8; 22; 21; 4) and revolving wing...observed by Ellington et al. (8) in their earlier experiments on the mechanical hawkmoth flapper at Re ≈ 10,000. In these experiments the spanwise flow...on mechanical wing flappers at similar Reynolds numbers, Re ≈ 1,000 and 1,400 respectively. Both sets of experiments revealed a stable attached

  14. Air pollution and mortality in Latin America: the role of education.

    Science.gov (United States)

    O'Neill, Marie S; Bell, Michelle L; Ranjit, Nalini; Cifuentes, Luis A; Loomis, Dana; Gouveia, Nelson; Borja-Aburto, Victor H

    2008-11-01

    People with less education in Europe, Asia, and the United States are at higher risk of mortality associated with daily and longer-term air pollution exposure. We examined whether educational level modified associations between mortality and ambient particulate pollution (PM10) in Latin America, using several timescales. The study population included people who died during 1998-2002 in Mexico City, Mexico; Santiago, Chile; and São Paulo, Brazil. We fit city-specific robust Poisson regressions to daily deaths for nonexternal-cause mortality, and then stratified by age, sex, and educational attainment among adults older than age 21 years (none, some primary, some secondary, and high school degree or more). Predictor variables included a natural spline for temporal trend, linear PM10 and apparent temperature at matching lags, and day-of-week indicators. We evaluated PM10 for lags 0 and 1 day, and fit an unconstrained distributed lag model for cumulative 6-day effects. The effects of a 10-microg/m increment in lag 1 PM10 on all nonexternal-cause adult mortality were for Mexico City 0.39% (95% confidence interval = 0.13%-0.65%); São Paulo 1.04% (0.71%-1.38%); and for Santiago 0.61% (0.40%-0.83%). We found cumulative 6-day effects for adult mortality in Santiago (0.86% [0.48%-1.23%]) and São Paulo (1.38% [0.85%-1.91%]), but no consistent gradients by educational status. PM10 had important short- and intermediate-term effects on mortality in these Latin American cities, but associations did not differ consistently by educational level.

  15. Wing area, wing growth and wing loading of common sandpipers Actitis hypoleucos

    OpenAIRE

    Yalden, Derek; Yalden, D. W.

    2012-01-01

    This study investigates the changes in wing length, area and loading in Common Sandpipers as chicks grow, and as adults add extra mass (during egg-laying or before migration). Common Sandpiper chicks weigh about 17 g and have "hands" that are about 35 mm long at one week old, when the primaries are just emerging from their sheaths. They grow steadily to reach about 40 g, with hands about 85 mm long, at 19 days, when they are just about fledging. Their wings have roughly adult chord width at t...

  16. Aerodynamic improvement of a delta wing in combination with leading edge flaps

    Directory of Open Access Journals (Sweden)

    Tadateru Ishide

    2017-11-01

    Full Text Available Recently, various studies of micro air vehicle (MAV and unmanned air vehicle (UAV have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold’s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap (LEF is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component load cell and particle image velocimetry (PIV analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.

  17. How Do Wings Generate Lift?

    Indian Academy of Sciences (India)

    Newton's second law of motion. Hence if a wing can generate lift equal to its weight (total weight of the vehicle) it can balance the gravitational pull and can maintain level flight. The equations for fluid flow that are equivalent to the second law are the well- known Navier–Stokes (N–S) equations [1]. These equations have.

  18. Werner helicase wings DNA binding

    OpenAIRE

    Hoadley, Kelly A.; Keck, James L.

    2010-01-01

    In this issue of Structure, Kitano et al. describe the structure of the DNA-bound winged-helix domain from the Werner helicase. This structure of a RecQ/DNA complex offers insights into the DNA unwinding mechanisms of RecQ family helicases.

  19. On Wings: Aerodynamics of Eagles.

    Science.gov (United States)

    Millson, David

    2000-01-01

    The Aerodynamics Wing Curriculum is a high school program that combines basic physics, aerodynamics, pre-engineering, 3D visualization, computer-assisted drafting, computer-assisted manufacturing, production, reengineering, and success in a 15-hour, 3-week classroom module. (JOW)

  20. Developing “the Wings to Really Fly”: The Experiences of Four Postdoctoral Research Fellows within an Australian University Faculty of Education

    Directory of Open Access Journals (Sweden)

    Tuija A. Turunen

    2014-01-01

    Full Text Available Postdoctoral research fellowships are a recent phenomenon in teacher education and little has been documented about them. This paper presents findings from a study in which the experiences of research fellows in a rural university were investigated. The data were gathered as audio recordings from peer mentoring meetings, notes from these meetings, individual reflective journals, and interviews conducted with six key informants. The analysis highlights that the experience of research fellowships was marked by a need to negotiate four competing, though not necessarily exclusive, demands related to the institute’s research productivity, its research culture and teaching, and personal professional goals. A range of institutional practices and individual characteristics mediated these negotiations.

  1. Role of wing color and seasonal changes in ambient temperature and solar irradiation on predicted flight efficiency of the Albatross.

    Science.gov (United States)

    Hassanalian, M; Throneberry, G; Ali, M; Ben Ayed, S; Abdelkefi, A

    2018-01-01

    Drag reduction of the wings of migrating birds is crucial to their flight efficiency. Wing color impacts absorption of solar irradiation which may affect drag but there is little known in this area. To this end, the drag reduction induced by the thermal effect of the wing color of migrating birds with unpowered flight modes is presented in this study. Considering this natural phenomenon in the albatross as an example of migrating birds, and applying an energy balance for this biological system, a thermal analysis is performed on the wings during the summer and winter to obtain different ranges of air density, viscosity, and wing surface temperature brought about from a range of ambient temperatures and climatic conditions seen in different seasons and to study their effects. The exact shape of the albatross wing is used and nine different wing colors are considered in order to gain a better understanding of the effect different colors' absorptivities make on the change in aerodynamic performances. The thermal effect is found to be more important during the summer than during the winter due to the higher values of solar irradiation and a maximum drag reduction of 7.8% is found in summer changing the wing color from light white to dark black. The obtained results show that albatrosses with darker colored wings are more efficient (constant lift to drag ratio and drag reduction) and have better endurance due to this drag reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Wing-pitch modulation in maneuvering fruit flies is explained by an interplay between aerodynamics and a torsional spring.

    Science.gov (United States)

    Beatus, Tsevi; Cohen, Itai

    2015-08-01

    While the wing kinematics of many flapping insects have been well characterized, understanding the underlying sensory, neural, and physiological mechanisms that determine these kinematics is still a challenge. Two main difficulties in understanding the physiological mechanisms arise from the complexity of the interaction between a flapping wing and its own unsteady flow, as well as the intricate mechanics of the insect wing hinge, which is among the most complicated joints in the animal kingdom. These difficulties call for the application of reduced-order approaches. Here this strategy is used to model the torques exerted by the wing hinge along the wing-pitch axis of maneuvering fruit flies as a damped torsional spring with elastic and damping coefficients as well as a rest angle. Furthermore, we model the air flows using simplified quasistatic aerodynamics. Our findings suggest that flies take advantage of the passive coupling between aerodynamics and the damped torsional spring to indirectly control their wing-pitch kinematics by modulating the spring parameters. The damped torsional-spring model explains the changes measured in wing-pitch kinematics during roll correction maneuvers through modulation of the spring damping and elastic coefficients. These results, in conjunction with the previous literature, indicate that flies can accurately control their wing-pitch kinematics on a sub-wing-beat time scale by modulating all three effective spring parameters on longer time scales.

  3. Aerodynamics, sensing and control of insect-scale flapping-wing flight.

    Science.gov (United States)

    Shyy, Wei; Kang, Chang-Kwon; Chirarattananon, Pakpong; Ravi, Sridhar; Liu, Hao

    2016-02-01

    There are nearly a million known species of flying insects and 13 000 species of flying warm-blooded vertebrates, including mammals, birds and bats. While in flight, their wings not only move forward relative to the air, they also flap up and down, plunge and sweep, so that both lift and thrust can be generated and balanced, accommodate uncertain surrounding environment, with superior flight stability and dynamics with highly varied speeds and missions. As the size of a flyer is reduced, the wing-to-body mass ratio tends to decrease as well. Furthermore, these flyers use integrated system consisting of wings to generate aerodynamic forces, muscles to move the wings, and sensing and control systems to guide and manoeuvre. In this article, recent advances in insect-scale flapping-wing aerodynamics, flexible wing structures, unsteady flight environment, sensing, stability and control are reviewed with perspective offered. In particular, the special features of the low Reynolds number flyers associated with small sizes, thin and light structures, slow flight with comparable wind gust speeds, bioinspired fabrication of wing structures, neuron-based sensing and adaptive control are highlighted.

  4. Wings as a new route of exposure to pesticides in the honey bee.

    Science.gov (United States)

    Poquet, Yannick; Kairo, Guillaume; Tchamitchian, Sylvie; Brunet, Jean-Luc; Belzunces, Luc P

    2015-09-01

    In pesticide risk assessment, estimating the routes and levels of exposure is critical. For honey bees subjected to pesticide spray, toxicity is assessed by thorax contact to account for all possible contact exposures. In the present study, the authors tested 6 active substances with different hydrophobicity. For the first time, the authors demonstrated that it is possible to induce mortality by pesticide contact with only the wings of the honey bee. The toxicities induced by contact with the wings and thorax were similar, with the wing median lethal dose (LD50) being 0.99 to 2.23 times higher than that of the thorax. This finding demonstrates that the wings represent a relevant route of exposure in the honey bee. In a second approach, the authors estimated the air volume displaced by the wings during 1 beating cycle to be 0.51 ± 0.03 cm(3), which corresponds to a volume of 116.8 ± 5.8 cm(3)  s(-1) at a wing beat frequency of 230 Hz. The authors then tested realistic scenarios of exposure for bees flying through a pesticide cloud at different concentrations. In the worst-case scenario, the dose accumulated during the flight reached 525 ng bee(-1)  s(-1). These results show that the procedure used to assess the risk posed by contact with pesticides could be improved by accounting for wing exposure. © 2015 SETAC.

  5. Environmental Assessment for Shoreline Stabilization at Langley Air Force Base, Virginia

    National Research Council Canada - National Science Library

    Dischner, David M; Lingner, David; Rock, Howard B; Combs, Jennifer; Brandenburg, Catherine

    2006-01-01

    The United States Air Force (Air Force), 1st Fighter Wing (1 FW) proposes to implement various methods to stabilize the shoreline at several locations along the Back River waterfront at Langley Air Force Base (AFB...

  6. Review Results on Wing-Body Interference

    Directory of Open Access Journals (Sweden)

    Frolov Vladimir

    2016-01-01

    Full Text Available The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combinations may exceed the same value for an isolated wing. This result confirms an experimental data obtained by other authors earlier. Within a framework of the used mathematical models the investigations to optimize the wing-body combination were carried. The present results of the optimization problem for the wing-body combination allowed to select the optimal geometric characteristics for configuration to maximize the values of the lift-curve slopes of the wing-body combination. It was revealed that maximums of the lift-curve slopes for the optimal mid-wing configuration with elliptical cross-section body had a sufficiently large relative width of the body (more than 30% of the span wing.

  7. DAST in Flight just after Structural Failure of Right Wing

    Science.gov (United States)

    1980-01-01

    conducting in-flight experiments from a remote ground site. DAST explored the technology required to build wing structures with less than normal stiffness. This was done because stiffness requires structural weight but ensures freedom from flutter-an uncontrolled, divergent oscillation of the structure, driven by aerodynamic forces and resulting in structural failure. The program used refined theoretical tools to predict at what speed flutter would occur. It then designed a high-response control system to counteract the motion and permit a much lighter wing structure. The wing had, in effect, 'electronic stiffness.' Flight research with this concept was extremely hazardous because an error in either the flutter prediction or control system implementation would result in wing structural failure and the loss of the vehicle. Because of this, flight demonstration of a sub-scale vehicle made sense from the standpoint of both safety and cost. The program anticipated structural failure during the course of the flight research. The Firebee II was a supersonic drone selected as the DAST testbed because its wing could be easily replaced, it used only tail-mounted control surfaces, and it was available as surplus from the U. S. Air Force. It was capable of 5-g turns (that is, turns producing acceleration equal to 5 times that of gravity). Langley outfitted a drone with an aeroelastic, supercritical research wing suitable for a Mach 0.98 cruise transport with a predicted flutter speed of Mach 0.95 at an altitude of 25,000 feet. Dryden and Langley, in conjunction with Boeing, designed and fabricated a digital flutter suppression system (FSS). Dryden developed an RPRV (remotely piloted research vehicle) flight control system; integrated the wing, FSS, and vehicle systems; and conducted the flight program. In addition to a digital flight control system and aeroelastic wings, each DAST drone had research equipment mounted in its nose and a mid-air retrieval system in its tail. The drones

  8. Locating Air Force Base Sites History’s Legacy

    Science.gov (United States)

    2004-01-01

    Ravenstein , Air Force Combat Wings (Washington, D.C.: Office of Air Force History, 1984), (hereafter, Ravenstein ) 141–142; Mueller, 1989 edition, 467–468... Ravenstein , author checked aircraft types and bases under each bombardment and strategic wing; Knaack, 156, 200–201, 292–293. 26. Lemmer, 194. History...Goldberg, 58–89. 36. Charles A. Ravenstein , The Organization and Lineage of the United States Air Force (Washington, D.C.: Office of Air Force History

  9. A structural regression model for relationship between indoor air quality with dissatisfaction of occupants in education environment

    Science.gov (United States)

    Hosseini, Hamid Reza; Yunos, Mohd Yazid Mohd; Ismail, Sumarni; Yaman, Maheran

    2017-12-01

    This paper analysis the effects of indoor air elements on the dissatisfaction of occupants in education of environments. Tries to find the equation model for increasing the comprehension about these affects and optimizes satisfaction of occupants about indoor environment. Subsequently, increase performance of students, lecturers and staffs. As the method, a satisfaction questionnaire (SQ) and measuring environment elements (MEE) was conducted, 143 respondents at five classrooms, four staff rooms and five lectures rooms were considered. Temperature, air velocity and humidity (TVH) were used as independent variables and dissatisfaction as dependent variable. The hypothesis was tested for significant relationship between variables, and analysis was applied. Results found that indoor air quality presents direct effects on dissatisfaction of occupants and indirect effects on performance and the highest effects fallowed by temperature. These results may help to optimize the quality of efficiency and effectiveness in education environments.

  10. The NRL MITE Air Vehicle

    National Research Council Canada - National Science Library

    Kellogg, James; Bovais, Christopher; Dahlburg, Jill; Foch, Richard; Gardner, John; Gordon, Diana; Hartley, Ralph; Kamgar-Parsi, Behrooz; McFarlane, Hugh; Pipitone, Frank; Ramamurti, Ravi; Sciambi, Adam; Spears, William; Srull, Donald; Sullivan, Carol

    2001-01-01

    .... The NRL Micro Tactical Expendable "MITE" air vehicle is a result of this research. The operational MITE is a hand-launched, dual-propeller, fixed-wing air vehicle, with a 9-inch chord and a wingspan of 8 to 18 inches, depending on payload weight...

  11. Sleeping on the wing.

    Science.gov (United States)

    Rattenborg, Niels C

    2017-02-06

    Wakefulness enables animals to interface adaptively with the environment. Paradoxically, in insects to humans, the efficacy of wakefulness depends on daily sleep, a mysterious, usually quiescent state of reduced environmental awareness. However, several birds fly non-stop for days, weeks or months without landing, questioning whether and how they sleep. It is commonly assumed that such birds sleep with one cerebral hemisphere at a time (i.e. unihemispherically) and with only the corresponding eye closed, as observed in swimming dolphins. However, the discovery that birds on land can perform adaptively despite sleeping very little raised the possibility that birds forgo sleep during long flights. In the first study to measure the brain state of birds during long flights, great frigatebirds ( Fregata minor ) slept, but only during soaring and gliding flight. Although sleep was more unihemispheric in flight than on land, sleep also occurred with both brain hemispheres, indicating that having at least one hemisphere awake is not required to maintain the aerodynamic control of flight. Nonetheless, soaring frigatebirds appeared to use unihemispheric sleep to watch where they were going while circling in rising air currents. Despite being able to engage in all types of sleep in flight, the birds only slept for 0.7 h d -1 during flights lasting up to 10 days. By contrast, once back on land they slept 12.8 h d -1 . This suggests that the ecological demands for attention usually exceeded that afforded by sleeping unihemispherically. The ability to interface adaptively with the environment despite sleeping very little challenges commonly held views regarding sleep, and therefore serves as a powerful system for examining the functions of sleep and the consequences of its loss.

  12. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  13. Aerodynamic effects of flexibility in flapping wings

    Science.gov (United States)

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P.

    2010-01-01

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re ≈ 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic

  14. Aerodynamic effects of flexibility in flapping wings.

    Science.gov (United States)

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P

    2010-03-06

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small

  15. Effects of wing locations on wing rock induced by forebody vortices

    Directory of Open Access Journals (Sweden)

    Ma Baofeng

    2016-10-01

    Full Text Available Previous studies have shown that asymmetric vortex wakes over slender bodies exhibit a multi-vortex structure with an alternate arrangement along a body axis at high angle of attack. In this investigation, the effects of wing locations along a body axis on wing rock induced by forebody vortices was studied experimentally at a subcritical Reynolds number based on a body diameter. An artificial perturbation was added onto the nose tip to fix the orientations of forebody vortices. Particle image velocimetry was used to identify flow patterns of forebody vortices in static situations, and time histories of wing rock were obtained using a free-to-roll rig. The results show that the wing locations can affect significantly the motion patterns of wing rock owing to the variation of multi-vortex patterns of forebody vortices. As the wing locations make the forebody vortices a two-vortex pattern, the wing body exhibits regularly divergence and fixed-point motion with azimuthal variations of the tip perturbation. If a three-vortex pattern exists over the wing, however, the wing-rock patterns depend on the impact of the highest vortex and newborn vortex. As the three vortices together influence the wing flow, wing-rock patterns exhibit regularly fixed-points and limit-cycled oscillations. With the wing moving backwards, the newborn vortex becomes stronger, and wing-rock patterns become fixed-points, chaotic oscillations, and limit-cycled oscillations. With further backward movement of wings, the vortices are far away from the upper surface of wings, and the motions exhibit divergence, limit-cycled oscillations and fixed-points. For the rearmost location of the wing, the wing body exhibits stochastic oscillations and fixed-points.

  16. Air quality and students' health in Shanghai (China): an educational and scientific project

    Science.gov (United States)

    Bigot-Cormier, Florence; Nicolaï, Marie-Pierre; Martinez, Claire-Marie; Bethmont, Valérie; Guinot, Benjamin

    2014-05-01

    The quality of our environment and especially air quality is a hot topic in any urban environment. Hourly air quality data tend to be easily available to the populations either in the news or on mobile phones. Studies underlining the relationship between environment and health exist in developed countries, but the results cannot be used in such different environmental and sociological contexts as the ones we have in China. In collaboration with the CNRS, students from the Lycée Français de Shanghai (LFS- 5th and 2nd grade) undertake a study in order to obtain an empiric relationship between the atmospheric pollutants they are exposed to in and out the classrooms, and their own health. This study is a part of a scientific and educational project including Beijing, and possibly other foreign schools in Asia later on. The atmospheric pollution in China is essentially caused by particles from different sizes mainly coming from coal combustion. First, in order to quantify the pollution at Shanghai, the students are recording information regarding fine particles as PM2.5 and PM1.0, NO2, SO2, and O3 using active and passive sensors indoors and outdoors, within the school campus. CO2, temperature and relative humidity are used to qualify the confinement rate indoors. In parallel, approximately 100 students (chosen regarding their age, health records, residence time in China…) and some teachers are going to complete a monthly survey regarding their health. Moreover, they will perform some specific measurements to obtain their breathing performances by spirometry, and an indication of the inflammation of their lower airways by exhaled NO measurements. The protocol of these experimentations and the first results will be presented in the poster. At the end of the project, these results will allow us to get a better knowledge about the air pollution we are exposed to, within the school campus, which will help us to adopt an optimized risk management protocol when pollution

  17. The costae presenting in high-temperature-induced vestigial wings ...

    Indian Academy of Sciences (India)

    Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell death in the ... [Yang D. 2007 The costae presenting in high-temperature-induced vestigial wings of Drosophila: implications for anterior wing margin formation. J. Genet. .... The relevant gene(s) may be.

  18. Analysis of bat wings for morphing

    Science.gov (United States)

    Leylek, Emily A.; Manzo, Justin E.; Garcia, Ephrahim

    2008-03-01

    The morphing of wings from three different bat species is studied using an extension of the Weissinger method. To understand how camber affects performance factors such as lift and lift to drag ratio, XFOIL is used to study thin (3% thickness to chord ratio) airfoils at a low Reynolds number of 100,000. The maximum camber of 9% yielded the largest lift coefficient, and a mid-range camber of 7% yielded the largest lift to drag ratio. Correlations between bat wing morphology and flight characteristics are covered, and the three bat wing planforms chosen represent various combinations of morphological components and different flight modes. The wings are studied using the extended Weissinger method in an "unmorphed" configuration using a thin, symmetric airfoil across the span of the wing through angles of attack of 0°-15°. The wings are then run in the Weissinger method at angles of attack of -2° to 12° in a "morphed" configuration modeled after bat wings seen in flight, where the camber of the airfoils comprising the wings is varied along the span and a twist distribution along the span is introduced. The morphed wing configurations increase the lift coefficient over 1000% from the unmorphed configuration and increase the lift to drag ratio over 175%. The results of the three different species correlate well with their flight in nature.

  19. Aerodynamic efficiency of a bioinspired flapping wing rotor at low Reynolds number.

    Science.gov (United States)

    Li, H; Guo, S

    2018-03-01

    This study investigates the aerodynamic efficiency of a bioinspired flapping wing rotor kinematics which combines an active vertical flapping motion and a passive horizontal rotation induced by aerodynamic thrust. The aerodynamic efficiencies for producing both vertical lift and horizontal thrust of the wing are obtained using a quasi-steady aerodynamic model and two-dimensional (2D) CFD analysis at Reynolds number of 2500. The calculated efficiency data show that both efficiencies (propulsive efficiency- η p , and efficiency for producing lift- P f ) of the wing are optimized at Strouhal number ( St ) between 0.1 and 0.5 for a range of wing pitch angles (upstroke angle of attack α u less than 45°); the St for high P f ( St  = 0.1 ∼ 0.3) is generally lower than for high η p ( St  = 0.2 ∼ 0.5), while the St for equilibrium rotation states lies between the two. Further systematic calculations show that the natural equilibrium of the passive rotating wing automatically converges to high-efficiency states: above 85% of maximum P f can be obtained for a wide range of prescribed wing kinematics. This study provides insight into the aerodynamic efficiency of biological flyers in cruising flight, as well as practical applications for micro air vehicle design.

  20. Performance study of winglets on tapered wing with curved trailing edge

    Science.gov (United States)

    Ara, Ismat; Ali, Mohammad; Islam, Md. Quamrul; Haque, M. Nazmul

    2017-06-01

    Induced drag is the result of wingtip vortex produced from generating lift by finite wing. It is one of the main drags that an aircraft wing encounters during flight. It hampers aircraft performance by increasing fuel consumption and reducing endurance, range and speed. Winglets are used to reduce the induced drag. They weakens wingtip vortex and thus reduces induced drag. This paper represents the experimental investigation to reduce induced drag using winglet at the wingtip. A model of tapered wing with curved trailing edge (without winglet) as well as two similar wings with blended winglet and double blended winglet are prepared using NACA 4412 aerofoil in equal span and surface area. All the models are tested in a closed circuit subsonic wind tunnel at air speed of 108 km/h (0.09 Mach). Reynolds number of the flow is 2.28 × 105 on the basis of average chord length of the wings. The point surface static pressures at different angles of attack from -4° to 24° are measured for each of the wing and winglet combinations through different pressure tapings by using a multi-tube water manometer. From the static pressure distribution, lift coefficient, drag coefficient and lift to drag ratio of all models are calculated. From the analysis of calculated values, it is found that both winglets are able to minimize induced drag; however, the tapered curved trailing edge span with blended winglet provides better aerodynamic performance.

  1. Development of Variable Camber Continuous Trailing Edge Flap for Performance Adaptive Aeroelastic Wing

    Science.gov (United States)

    Nguyen, Nhan; Kaul, Upender; Lebofsky, Sonia; Ting, Eric; Chaparro, Daniel; Urnes, James

    2015-01-01

    This paper summarizes the recent development of an adaptive aeroelastic wing shaping control technology called variable camber continuous trailing edge flap (VCCTEF). As wing flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. The initial VCCTEF concept was developed in 2010 by NASA under a NASA Innovation Fund study entitled "Elastically Shaped Future Air Vehicle Concept," which showed that highly flexible wing aerodynamic surfaces can be elastically shaped in-flight by active control of wing twist and bending deflection in order to optimize the spanwise lift distribution for drag reduction. A collaboration between NASA and Boeing Research & Technology was subsequently funded by NASA from 2012 to 2014 to further develop the VCCTEF concept. This paper summarizes some of the key research areas conducted by NASA during the collaboration with Boeing Research and Technology. These research areas include VCCTEF design concepts, aerodynamic analysis of VCCTEF camber shapes, aerodynamic optimization of lift distribution for drag minimization, wind tunnel test results for cruise and high-lift configurations, flutter analysis and suppression control of flexible wing aircraft, and multi-objective flight control for adaptive aeroelastic wing shaping control.

  2. Modeling, design and optimization of flapping wings for efficient hovering flighth

    NARCIS (Netherlands)

    Wang, Q.

    2017-01-01

    Inspired by insect flights, flapping wing micro air vehicles (FWMAVs) keep attracting attention from the scientific community. One of the design objectives is to reproduce the high power efficiency of insect flight. However, there is no clear answer yet to the question of how to design flapping

  3. Three-dimensional wake reconstruction of a flapping-wing MAV using a Kriging regression technique

    NARCIS (Netherlands)

    Percin, M.; De Baar, J.H.S.; Van Oudheusden, B.W.; Dwight, R.P.

    2013-01-01

    The work explores the three-dimensional unsteady wake of a flapping-wing Micro Air Vehicle (MAV) ‘DelFly II’, applying a Kriging regression technique for the spatial regression of time-resolved Stereoscopic Particle Image Velocimetry (Stereo-PIV) data. In the view of limited number of measurement

  4. Micro-Scale Flapping Wings for the Advancement of Flying MEMS

    Science.gov (United States)

    2009-03-01

    Then in 1959, Nobel Prize winner Richard Feynman would challenge the world to develop microsystems ranging from biological systems to computer data...of flapping wings for nano air vehicles,” tech. rep., FEB 2008. 3. R. P. Feynman , “There’s plenty of room at the bottom,” Journal of Microelec

  5. A Tribute to Professor Rene H. Miller - A Pioneer in Aeromechanics and Rotary Wing Flight Transportation

    Science.gov (United States)

    Friedmann, Peretz P.; Johnson, Wayne; Scully, Michael P.

    2011-01-01

    Rene H. Miller (May 19, 1916 January 28, 2003), Emeritus H. N. Slater Professor of Flight Transportation, was one of the most influential pioneers in rotary wing aeromechanics as well as a visionary whose dream was the development of a tilt-rotor based short haul air transportation system. This paper pays a long overdue tribute to his memory and to his extraordinary contributions.

  6. DYNAMIC TUNING OF INSECT AND BIRD WINGS AND COPEPOD AND DAPHNIA APPENDAGES

    Science.gov (United States)

    Compressible flow theory suggests, and dimensional analysis and growing empirical evidence confirm that, to aid flight, many insects and even some birds, notably hummingbirds, tune their wing-beat frequency to a corresponding characteristic harmonic frequency of air. The same pro...

  7. Vorticity Transport on a Flexible Wing in Stall Flutter

    Science.gov (United States)

    Akkala, James; Buchholz, James; Farnsworth, John; McLaughlin, Thomas

    2014-11-01

    The circulation budget within dynamic stall vortices was investigated on a flexible NACA 0018 wing model of aspect ratio 6 undergoing stall flutter. The wing had an initial angle of attack of 6 degrees, Reynolds number of 1 . 5 ×105 and large-amplitude, primarily torsional, limit cycle oscillations were observed at a reduced frequency of k = πfc / U = 0 . 1 . Phase-locked stereo PIV measurements were obtained at multiple chordwise planes around the 62.5% and 75% spanwise locations to characterize the flow field within thin volumetric regions over the suction surface. Transient surface pressure measurements were used to estimate boundary vorticity flux. Recent analyses on plunging and rotating wings indicates that the magnitude of the pressure-gradient-driven boundary flux of secondary vorticity is a significant fraction of the magnitude of the convective flux from the separated leading-edge shear layer, suggesting that the secondary vorticity plays a significant role in regulating the strength of the primary vortex. This phenomenon is examined in the present case, and the physical mechanisms governing the growth and evolution of the dynamic stall vortices are explored. This work was supported by the Air Force Office of Scientific Research through the Flow Interactions and Control Program monitored by Dr. Douglas Smith, and through the 2014 AFOSR/ASEE Summer Faculty Fellowship Program (JA and JB).

  8. The analysis of the flying wing in morphing concept

    Directory of Open Access Journals (Sweden)

    Ionică CÎRCIU

    2013-06-01

    Full Text Available The combination between the flying wing morphing concept and the use of modern command and control system offers exponential advantages having a leverage effect in the economy and research. The flying wing architecture has the advantage of low cost against efficiency, the morphing of this concept defining the new characteristic frontiers and aerodynamic performances which derive immediately. On designing an unmanned aerial vehicle for a various range of missions, its lifting surface needs to display optimal geometrical features, so that the UAV may maintain the induced drag and the moment coefficient at reasonable levels. The command and control of the lifting surfaces in morphing concept offer characteristics and in-flight performances at a superior level. The limits of the system depend on the reliability of the execution elements and the grade of accuracy for the control laws which are implemented in the calculation module. The paper aims at presenting an analysis regarding the robotic air systems of flying wing type through the aerodynamic analysis and with the help of specific software instruments. The performances and flight qualities depend directly on the geometry of the lifting surface of the aerial vehicle.

  9. Environmental Assessment Addressing the Defense Language Institute English Language Center (DLIELC), and the Inter-American Air Forces Academy (IAAFA) Area Development Plan at Lackland Air Force Base, Texas

    Science.gov (United States)

    2012-01-01

    Medical Wing; the Air Force Intelligence , Surveillance, and Reconnaissance Agency; and the 67th Network Warfare Wing (LAFB undated b). There are 18 Air...Combat Command units under the Air Force Intelligence , Surveillance, and Reconnaissance Agency and the 67th Network Warfare Wing at Lackland AFB. The...recorded in the Texan Biotic Province (LAFB 2006a). Most reptiles and amphibians would likely not occur within the Project area. The majority of

  10. Adaptive wing : Investigations of passive wing technologies for loads reduction in the cleansky smart fixed wing aircraft (SFWA) project

    NARCIS (Netherlands)

    Kruger, W.R.; Dillinger, J; De Breuker, R.; Reyes, M.; Haydn, K.

    2016-01-01

    In the work package “Adaptive Wing” in the Clean-Sky “Smart Fixed Wing Aircraft” (SFWA) project, design processes and solutions for aircraft wings have been created, giving optimal response with respect to loads, comfort and performance by the introduction of passive and active concepts. Central

  11. The Crest Wing Wave Energy Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave...

  12. Effect of leading edge roundness on a delta wing in wing-rock motion

    Science.gov (United States)

    Ng, T. Terry; Malcolm, Gerald N.

    1990-01-01

    The effect of wing leading-edge roundness on wing rock was investigated using flow visualization in a water tunnel. Eighty degree delta wing models were tested on free-to-roll and forced oscillation rigs. The onset of wing rock was delayed by increasing the roundness of the leading edges. The wing rock amplitude and frequency results suggested that damping was increased at lower angles of attack but reduced at higher angles of attack. Vortex lift-off and vortex breakdown, especially during dynamic situations, were strongly affected by the leading edge roundness. Different forms of wing rock motion could be sustained by combinations of vortex breakdown and vortex lift-off. Behaviors of the wing and vortex motions were explained by the influence of leading edge roundness on the separation location, vortex trajectory, and vortex breakdown.

  13. Season, sex, age, and education as modifiers of the effects of outdoor air pollution on daily mortality in Shanghai, China: The Public Health and Air Pollution in Asia (PAPA) Study.

    Science.gov (United States)

    Kan, Haidong; London, Stephanie J; Chen, Guohai; Zhang, Yunhui; Song, Guixiang; Zhao, Naiqing; Jiang, Lili; Chen, Bingheng

    2008-09-01

    Various factors can modify the health effects of outdoor air pollution. Prior findings about modifiers are inconsistent, and most of these studies were conducted in developed countries. We conducted a time-series analysis to examine the modifying effect of season, sex, age, and education on the association between outdoor air pollutants [particulate matter air pollution for the warm season (April-September) and cool season (October-March) separately. For total mortality, we examined the association stratified by sex and age. Stratified analysis by educational attainment was conducted for total, cardiovascular, and respiratory mortality. Outdoor air pollution was associated with mortality from all causes and from cardiorespiratory diseases in Shanghai. An increase of 10 mug/m(3) in a 2-day average concentration of PM(10), SO(2), NO(2), and O(3) corresponds to increases in all-cause mortality of 0.25% [95% confidence interval (CI), 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58), respectively. The effects of air pollutants were more evident in the cool season than in the warm season, and females and the elderly were more vulnerable to outdoor air pollution. Effects of air pollution were generally greater in residents with low educational attainment (illiterate or primary school) compared with those with high educational attainment (middle school or above). Season, sex, age, and education may modify the health effects of outdoor air pollution in Shanghai. These findings provide new information about the effects of modifiers on the relationship between daily mortality and air pollution in developing countries and may have implications for local environmental and social policies.

  14. Aerodynamic performance of two-dimensional, chordwise flexible flapping wings at fruit fly scale in hover flight.

    Science.gov (United States)

    Sridhar, Madhu; Kang, Chang-kwon

    2015-05-06

    Fruit flies have flexible wings that deform during flight. To explore the fluid-structure interaction of flexible flapping wings at fruit fly scale, we use a well-validated Navier-Stokes equation solver, fully-coupled with a structural dynamics solver. Effects of chordwise flexibility on a two dimensional hovering wing is studied. Resulting wing rotation is purely passive, due to the dynamic balance between aerodynamic loading, elastic restoring force, and inertial force of the wing. Hover flight is considered at a Reynolds number of Re = 100, equivalent to that of fruit flies. The thickness and density of the wing also corresponds to a fruit fly wing. The wing stiffness and motion amplitude are varied to assess their influences on the resulting aerodynamic performance and structural response. Highest lift coefficient of 3.3 was obtained at the lowest-amplitude, highest-frequency motion (reduced frequency of 3.0) at the lowest stiffness (frequency ratio of 0.7) wing within the range of the current study, although the corresponding power required was also the highest. Optimal efficiency was achieved for a lower reduced frequency of 0.3 and frequency ratio 0.35. Compared to the water tunnel scale with water as the surrounding fluid instead of air, the resulting vortex dynamics and aerodynamic performance remained similar for the optimal efficiency motion, while the structural response varied significantly. Despite these differences, the time-averaged lift scaled with the dimensionless shape deformation parameter γ. Moreover, the wing kinematics that resulted in the optimal efficiency motion was closely aligned to the fruit fly measurements, suggesting that fruit fly flight aims to conserve energy, rather than to generate large forces.

  15. The effect of aspect ratio on the leading-edge vortex over an insect-like flapping wing.

    Science.gov (United States)

    Phillips, Nathan; Knowles, Kevin; Bomphrey, Richard J

    2015-10-09

    Insect wing shapes are diverse and a renowned source of inspiration for the new generation of autonomous flapping vehicles, yet the aerodynamic consequences of varying geometry is not well understood. One of the most defining and aerodynamically significant measures of wing shape is the aspect ratio, defined as the ratio of wing length (R) to mean wing chord (c). We investigated the impact of aspect ratio, AR, on the induced flow field around a flapping wing using a robotic device. Rigid rectangular wings ranging from AR = 1.5 to 7.5 were flapped with insect-like kinematics in air with a constant Reynolds number (Re) of 1400, and a dimensionless stroke amplitude of 6.5c (number of chords traversed by the wingtip). Pseudo-volumetric, ensemble-averaged, flow fields around the wings were captured using particle image velocimetry at 11 instances throughout simulated downstrokes. Results confirmed the presence of a high-lift, separated flow field with a leading-edge vortex (LEV), and revealed that the conical, primary LEV grows in size and strength with increasing AR. In each case, the LEV had an arch-shaped axis with its outboard end originating from a focus-sink singularity on the wing surface near the tip. LEV detachment was observed for AR > 1.5 around mid-stroke at ~70% span, and initiated sooner over higher aspect ratio wings. At AR > 3 the larger, stronger vortex persisted under the wing surface well into the next half-stroke leading to a reduction in lift. Circulatory lift attributable to the LEV increased with AR up to AR = 6. Higher aspect ratios generated proportionally less lift distally because of LEV breakdown, and also less lift closer to the wing root due to the previous LEV's continuing presence under the wing. In nature, insect wings go no higher than AR ~ 5, likely in part due to architectural and physiological constraints but also because of the reducing aerodynamic benefits of high AR wings.

  16. Examining Reliability and Validity of an Online Score (ALiEM AIR) for Rating Free Open Access Medical Education Resources.

    Science.gov (United States)

    Chan, Teresa Man-Yee; Grock, Andrew; Paddock, Michael; Kulasegaram, Kulamakan; Yarris, Lalena M; Lin, Michelle

    2016-12-01

    Since 2014, Academic Life in Emergency Medicine (ALiEM) has used the Approved Instructional Resources (AIR) score to critically appraise online content. The primary goals of this study are to determine the interrater reliability (IRR) of the ALiEM AIR rating score and determine its correlation with expert educator gestalt. We also determine the minimum number of educator-raters needed to achieve acceptable reliability. Eight educators each rated 83 online educational posts with the ALiEM AIR scale. Items include accuracy, usage of evidence-based medicine, referencing, utility, and the Best Evidence in Emergency Medicine rating score. A generalizability study was conducted to determine IRR and rating variance contributions of facets such as rater, blogs, posts, and topic. A randomized selection of 40 blog posts previously rated through ALiEM AIR was then rated again by a blinded group of expert medical educators according to their gestalt. Their gestalt impression was subsequently correlated with the ALiEM AIR score. The IRR for the ALiEM AIR rating scale was 0.81 during the 6-month pilot period. Decision studies showed that at least 9 raters were required to achieve this reliability. Spearman correlations between mean AIR score and the mean expert gestalt ratings were 0.40 for recommendation for learners and 0.35 for their colleagues. The ALiEM AIR scale is a moderately to highly reliable, 5-question tool when used by medical educators for rating online resources. The score displays a fair correlation with expert educator gestalt in regard to the quality of the resources. The score displays a fair correlation with educator gestalt. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  17. A national environmental/energy workforce assessment. Post-secondary education profile: air. Final report on phase 2

    International Nuclear Information System (INIS)

    1978-12-01

    This study is one of 16 volumes aggregating data on representative environmental education offerings in the United States at post-secondary education institutions and in the private sector of the economy. Structured around on-site interviews, the study describes the institutions' education programs--their program structure, representative course offerings, faculty structure, and program requirements. In addition, the study provides information on the employment history of graduates. Designed as Phase II of a three-phase program, the study presents the information on schools with emphasis on air pollution. The study is an overview. It doesn't include all environmental programs in the United States, and it makes no attempt to evaluate the program offerings

  18. Hovering hummingbird wing aerodynamics during the annual cycle. II. Implications of wing feather moult

    Science.gov (United States)

    Sapir, Nir; Elimelech, Yossef

    2018-01-01

    Birds usually moult their feathers in a particular sequence which may incur aerodynamic, physiological and behavioural implications. Among birds, hummingbirds are unique species in their sustained hovering flight. Because hummingbirds frequently hover-feed, they must maintain sufficiently high flight capacities even when moulting their flight feathers. A hummingbird wing consists of 10 primary flight feathers whose absence during moult may strongly affect wing performance. Using dynamic similarity rules, we compared time-accurate aerodynamic loads and flow field measurements over several wing geometries that follow the natural feather moult sequence of Calypte anna, a common hummingbird species in western North America. Our results suggest a drop of more than 20% in lift production during the early stages of the moult sequence in which mid-wing flight feathers are moulted. We also found that the wing's ability to generate lift strongly depended on the morphological integrity of the outer primaries and leading-edge. These findings may explain the evolution of wing morphology and moult attributes. Specifically, the high overlap between adjacent wing feathers, especially at the wing tip, and the slow sequential replacement of the wing feathers result in a relatively small reduction in wing surface area during moult with limited aerodynamic implications. We present power and efficiency analyses for hover flight during moult under several plausible scenarios, suggesting that body mass reduction could be a compensatory mechanism that preserves the energetic costs of hover flight. PMID:29515884

  19. Pegasus Rocket Wing and PHYSX Glove Undergoes Stress Loads Testing

    Science.gov (United States)

    1997-01-01

    The Pegasus Hypersonic Experiment (PHYSX) Project's Pegasus rocket wing with attached PHYSX glove rests after load-tests at Scaled Composites, Inc., in Mojave, California, in January 1997. Technicians slowly filled water bags beneath the wing, to create the pressure, or 'wing-loading,' required to determine whether the wing could withstand its design limit for stress. The wing sits in a wooden triangular frame which serves as the test-rig, mounted to the floor atop the waterbags. Pegasus is an air-launched space booster produced by Orbital Sciences Corporation and Hercules Aerospace Company (initially; later, Alliant Tech Systems) to provide small satellite users with a cost-effective, flexible, and reliable method for placing payloads into low earth orbit. Pegasus has been used to launch a number of satellites and the PHYSX experiment. That experiment consisted of a smooth glove installed on the first-stage delta wing of the Pegasus. The glove was used to gather data at speeds of up to Mach 8 and at altitudes approaching 200,000 feet. The flight took place on October 22, 1998. The PHYSX experiment focused on determining where boundary-layer transition occurs on the glove and on identifying the flow mechanism causing transition over the glove. Data from this flight-research effort included temperature, heat transfer, pressure measurements, airflow, and trajectory reconstruction. Hypersonic flight-research programs are an approach to validate design methods for hypersonic vehicles (those that fly more than five times the speed of sound, or Mach 5). Dryden Flight Research Center, Edwards, California, provided overall management of the glove experiment, glove design, and buildup. Dryden also was responsible for conducting the flight tests. Langley Research Center, Hampton, Virginia, was responsible for the design of the aerodynamic glove as well as development of sensor and instrumentation systems for the glove. Other participating NASA centers included Ames Research

  20. Semi-automated quantitative Drosophila wings measurements.

    Science.gov (United States)

    Loh, Sheng Yang Michael; Ogawa, Yoshitaka; Kawana, Sara; Tamura, Koichiro; Lee, Hwee Kuan

    2017-06-28

    Drosophila melanogaster is an important organism used in many fields of biological research such as genetics and developmental biology. Drosophila wings have been widely used to study the genetics of development, morphometrics and evolution. Therefore there is much interest in quantifying wing structures of Drosophila. Advancement in technology has increased the ease in which images of Drosophila can be acquired. However such studies have been limited by the slow and tedious process of acquiring phenotypic data. We have developed a system that automatically detects and measures key points and vein segments on a Drosophila wing. Key points are detected by performing image transformations and template matching on Drosophila wing images while vein segments are detected using an Active Contour algorithm. The accuracy of our key point detection was compared against key point annotations of users. We also performed key point detection using different training data sets of Drosophila wing images. We compared our software with an existing automated image analysis system for Drosophila wings and showed that our system performs better than the state of the art. Vein segments were manually measured and compared against the measurements obtained from our system. Our system was able to detect specific key points and vein segments from Drosophila wing images with high accuracy.

  1. Novel Control Effectors for Truss Braced Wing

    Science.gov (United States)

    White, Edward V.; Kapania, Rakesh K.; Joshi, Shiv

    2015-01-01

    At cruise flight conditions very high aspect ratio/low sweep truss braced wings (TBW) may be subject to design requirements that distinguish them from more highly swept cantilevered wings. High aspect ratio, short chord length and relative thinness of the airfoil sections all contribute to relatively low wing torsional stiffness. This may lead to aeroelastic issues such as aileron reversal and low flutter margins. In order to counteract these issues, high aspect ratio/low sweep wings may need to carry additional high speed control effectors to operate when outboard ailerons are in reversal and/or must carry additional structural weight to enhance torsional stiffness. The novel control effector evaluated in this study is a variable sweep raked wing tip with an aileron control surface. Forward sweep of the tip allows the aileron to align closely with the torsional axis of the wing and operate in a conventional fashion. Aft sweep of the tip creates a large moment arm from the aileron to the wing torsional axis greatly enhancing aileron reversal. The novelty comes from using this enhanced and controllable aileron reversal effect to provide roll control authority by acting as a servo tab and providing roll control through intentional twist of the wing. In this case the reduced torsional stiffness of the wing becomes an advantage to be exploited. The study results show that the novel control effector concept does provide roll control as described, but only for a restricted class of TBW aircraft configurations. For the configuration studied (long range, dual aisle, Mach 0.85 cruise) the novel control effector provides significant benefits including up to 12% reduction in fuel burn.

  2. United States Air Force Academy Educational Outcomes Assessment Working Group. Phase 2

    National Research Council Canada - National Science Library

    Porter, David

    1997-01-01

    This publication provides an account of educational outcomes assessment activity undertaken by seven assessment teams under the Phase II Charter of the Dean of the Faculty's Educational Outcomes Assessment Working Group...

  3. Exploration of the rotational power consumption of a rigid flapping wing

    Science.gov (United States)

    Truppel, Michael; Rossi, Lionel

    2011-10-01

    The development of Micro Air Vehicles with flapping wings is inspired from the observation and study of natural flyers such as insects and birds. This article explores the rotational power consumption of a flapping wing using a mechanical flapper at Re ≃ 4,500. This mechanical flapper is simplified to a 2D translation and a rotation in a water tank. Moreover, the wing kinematics are reduced to a linear translation and a rotation for the purpose of our study. We introduce the notion of non-ideal flapper and associated non-ideal rotational power. Such non-ideal devices are defined as consuming power for adding and removing mechanical power to and from the flow, respectively. First, we use a traditional symmetrical wing kinematic which is a simplified kinematic inspired from natural flyers. The lift coefficient of this flapping is about C L ≃ 1.5. This symmetrical wing kinematic is chosen as a reference. Further, wing kinematics with asymmetric rotations are then compared with this one. These new kinematics are built using a differential velocity defined according to the translational kinematics, a time lag and a distance, r kp. The analogy of this distance is discussed as a key point to follow along the chord. First, the wing kinematics are varied keeping a similar shape for the profiles of the angular velocity. It is shown that when compared to the reference wing kinematic, a 10% reduction in the rotational power is obtained whilst the lift is reduced by 9%. Second, we release the limitation to a similar shape for the profiles of the angular velocity leading to a novel shape for the angular velocity profile named here as "double bump" profile. With these new wing kinematics, we show that a 60% reduction in the non-ideal rotational power can be achieved whilst the lift coefficient is only reduced by 1.7%. Such "double bump kinematics" could then be of interest to increase the endurance of Micro Air Vehicles.

  4. Aerodynamic and aeroelastic characteristics of the DARPA Smart Wing Phase II wind tunnel model

    Science.gov (United States)

    Sanders, Brian P.; Martin, Christopher A.; Cowan, David L.

    2001-06-01

    A wind tunnel demonstration was conducted on a scale model of an unmanned combat air vehicle (UCAV). The model was configured with traditional hinged control surfaces and control surfaces manufactured with embedded shape memory alloys. Control surfaces constructed with SMA wires enable a smooth and continuous deformation in both the spanwise and cordwise directions. This continuous shape results in some unique aerodynamic effects. Additionally, the stiffness distribution of the model was selected to understand the aeroelastic behavior of a wing designed with these control surfaces. The wind tunnel experiments showed that the aerodynamic performance of a wing constructed with these control surfaces is significantly improved. However, care must be taken when aeroelastic effects are considered since the wing will show a more rapid reduction in the roll moment due to increased moment arm about the elastic axis. It is shown, experimentally, that this adverse effect is easily counteracted using leading edge control surfaces.

  5. Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control

    Science.gov (United States)

    Nguyen, Nhan T. (Inventor)

    2016-01-01

    An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

  6. Air Education and Training Command Cost and Capacity System: Implications for Organizational and Data Flow Changes

    National Research Council Canada - National Science Library

    Manacapilli, Thomas

    2004-01-01

    .... It briefly reviews training management systems and associated organizational arrangements in the other services and the private sector to draw insights for a model management system for the Air Force...

  7. Generic Wing-Body Aerodynamics Data Base

    Science.gov (United States)

    Holst, Terry L.; Olsen, Thomas H.; Kwak, Dochan (Technical Monitor)

    2001-01-01

    The wing-body aerodynamics data base consists of a series of CFD (Computational Fluid Dynamics) simulations about a generic wing body configuration consisting of a ogive-circular-cylinder fuselage and a simple symmetric wing mid-mounted on the fuselage. Solutions have been obtained for Nonlinear Potential (P), Euler (E) and Navier-Stokes (N) solvers over a range of subsonic and transonic Mach numbers and angles of attack. In addition, each solution has been computed on a series of grids, coarse, medium and fine to permit an assessment of grid refinement errors.

  8. Unemployment and Right-Wing Extremist Crime

    OpenAIRE

    Falk, Armin; Zweimüller, Josef

    2005-01-01

    Right-wing extremism is a serious problem in many societies. A prominent hypothesis states that unemployment plays a crucial role for the occurrence of right-wing extremist crime. In this paper we empirically test this hypothesis. We use a previously not used data set which includes all officially recorded right-wing criminal acts in Germany. These data are recorded by the German Federal Criminal Police Office on a monthly and state level basis. Our main finding is that there is in fact a sig...

  9. Flapping and fixed wing aerodynamics of low Reynolds number flight vehicles

    Science.gov (United States)

    Viieru, Dragos

    Lately, micro air vehicles (MAVs), with a maximum dimension of 15 cm and nominal flight speed around 10m/s, have attracted interest from scientific and engineering communities due to their potential to perform desirable flight missions and exhibit unconventional aerodynamics, control, and structural characteristics, compared to larger flight vehicles. Since MAVs operate at a Reynolds number of 105 or lower, the lift-to-drag ratio is noticeably lower than the larger manned flight vehicles. The light weight and low flight speed cause MAVs to be sensitive to wind gusts. The MAV's small overall dimensions result in low aspect ratio wings with strong wing tip vortices that further complicate the aerodynamics of such vehicles. In this work, two vehicle concepts are considered, namely, fixed wings with flexible structure aimed at passive shape control, and flapping wings aimed at enhancing aerodynamic performance using unsteady flow fields. A finite volume, pressure-based Navier-Stokes solver along with moving grid algorithms is employed to simulate the flow field. The coupled fluid-structural dynamics of the flexible wing is treated using a hyperelastic finite element structural model, the above-mentioned fluid solver via the moving grid technique, and the geometric conservation law. Three dimensional aerodynamics around a low aspect ratio wing for both rigid and flexible structures and fluid-structure interactions for flexible structures have been investigated. In the Reynolds numbers range of 7x10 4 to 9x104, the flexible wing exhibits self-initiated vibrations even in steady free-stream, and is found to have a similar performance to the identical rigid wing for modest angles of attack. For flapping wings, efforts are made to improve our understanding of the unsteady fluid physics related to the lift generation mechanism at low Reynolds numbers (75 to 1,700). Alternative moving grid algorithms, capable of handling the large movements of the boundaries (characteristic

  10. Kinematics and wing shape across flight speed in the bat, Leptonycteris yerbabuenae

    Directory of Open Access Journals (Sweden)

    Rhea Von Busse

    2012-10-01

    The morphology and kinematics of a flying animal determines the resulting aerodynamic lift through the regulation of the speed of the air moving across the wing, the wing area and the lift coefficient. We studied the detailed three-dimensional wingbeat kinematics of the bat, Leptonycteris yerbabuenae, flying in a wind tunnel over a range of flight speeds (0–7 m/s, to determine how factors affecting the lift production vary across flight speed and within wingbeats. We found that the wing area, the angle of attack and the camber, which are determinants of the lift production, decreased with increasing speed. The camber is controlled by multiple mechanisms along the span, including the deflection of the leg relative to the body, the bending of the fifth digit, the deflection of the leading edge flap and the upward bending of the wing tip. All these measures vary throughout the wing beat suggesting active or aeroelastic control. The downstroke Strouhal number, Std, is kept relatively constant, suggesting that favorable flow characteristics are maintained during the downstroke, across the range of speeds studied. The Std is kept constant through changes in the stroke plane, from a strongly inclined stroke plane at low speeds to a more vertical stroke plane at high speeds. The mean angular velocity of the wing correlates with the aerodynamic performance and shows a minimum at the speed of maximum lift to drag ratio, suggesting a simple way to determine the optimal speed from kinematics alone. Taken together our results show the high degree of adjustments that the bats employ to fine tune the aerodynamics of the wings and the correlation between kinematics and aerodynamic performance.

  11. A CFD-informed quasi-steady model of flapping wing aerodynamics.

    Science.gov (United States)

    Nakata, Toshiyuki; Liu, Hao; Bomphrey, Richard J

    2015-11-01

    Aerodynamic performance and agility during flapping flight are determined by the combination of wing shape and kinematics. The degree of morphological and kinematic optimisation is unknown and depends upon a large parameter space. Aimed at providing an accurate and computationally inexpensive modelling tool for flapping-wing aerodynamics, we propose a novel CFD (computational fluid dynamics)-informed quasi-steady model (CIQSM), which assumes that the aerodynamic forces on a flapping wing can be decomposed into the quasi-steady forces and parameterised based on CFD results. Using least-squares fitting, we determine a set of proportional coefficients for the quasi-steady model relating wing kinematics to instantaneous aerodynamic force and torque; we calculate power with the product of quasi-steady torques and angular velocity. With the quasi-steady model fully and independently parameterised on the basis of high-fidelity CFD modelling, it is capable of predicting flapping-wing aerodynamic forces and power more accurately than the conventional blade element model (BEM) does. The improvement can be attributed to, for instance, taking into account the effects of the induced downwash and the wing tip vortex on the force generation and power consumption. Our model is validated by comparing the aerodynamics of a CFD model and the present quasi-steady model using the example case of a hovering hawkmoth. It demonstrates that the CIQSM outperforms the conventional BEM while remaining computationally cheap, and hence can be an effective tool for revealing the mechanisms of optimization and control of kinematics and morphology in flapping-wing flight for both bio-flyers and unmanned air systems.

  12. Autonomous Aerodynamic Control of Micro Air Vehicles

    Science.gov (United States)

    2009-10-19

    29 Design of the Air Force Research Laboratory Micro Aerial Vehicle Research Configuration Kelly Stewart*, Jeffrey Wagener †, and Gregg Abate‡ Air...Development and Initial Flight Tests of a Single-Jointed Articulated-Wing Micro Air Vehicle Kelly C. Stewart*, Ken Blackburn†, Jeffrey Wagener ‡, Lt... Wagener , J., Abate, G., and Salichon, M., “Design of the Air Force Research Laboratory Micro Aerial Vehicle Research Configuration,” AIAA 45th Aerospace

  13. FijiWings: an open source toolkit for semiautomated morphometric analysis of insect wings.

    Science.gov (United States)

    Dobens, Alexander C; Dobens, Leonard L

    2013-08-07

    Development requires coordination between cell proliferation and cell growth to pattern the proper size of tissues, organs, and whole organisms. The Drosophila wing has landmark features, such as the location of veins patterned by cell groups and trichome structures produced by individual cells, that are useful to examine the genetic contributions to both tissue and cell size. Wing size and trichome density have been measured manually, which is tedious and error prone, and although image processing and pattern-recognition software can quantify features in micrographs, this approach has not been applied to insect wings. Here we present FijiWings, a set of macros designed to perform semiautomated morphophometric analysis of a wing photomicrograph. FijiWings uses plug-ins installed in the Fiji version of ImageJ to detect and count trichomes and measure wing area either to calculate trichome density of a defined region selected by the user or generate a heat map of overall trichome densities. For high-throughput screens we have developed a macro that directs a trainable segmentation plug-in to detect wing vein locations either to measure trichome density in specific intervein regions or produce a heat map of relative intervein areas. We use wing GAL4 drivers and UAS-regulated transgenes to confirm the ability of these tools to detect changes in overall tissue growth and individual cell size. FijiWings is freely available and will be of interest to a broad community of fly geneticists studying both the effect of gene function on wing patterning and the evolution of wing morphology.

  14. The hydraulic mechanism in the hind wing veins of Cybister japonicus Sharp (order: Coleoptera

    Directory of Open Access Journals (Sweden)

    Jiyu Sun

    2016-06-01

    Full Text Available The diving beetles (Dytiscidae, Coleoptera are families of water beetles. When they see light, they fly to the light source directly from the water. Their hind wings are thin and fragile under the protection of their elytra (forewings. When the beetle is at rest the hind wings are folded over the abdomen of the beetle and when in flight they unfold to provide the necessary aerodynamic forces. In this paper, the unfolding process of the hind wing of Cybister japonicus Sharp (order: Coleoptera was investigated. The motion characteristics of the blood in the veins of the structure system show that the veins have microfluidic control over the hydraulic mechanism of the unfolding process. A model is established, and the hind wing extending process is simulated. The blood flow and pressure changes are discussed. The driving mechanism for hydraulic control of the folding and unfolding actions of beetle hind wings is put forward. This can assist the design of new deployable micro air vehicles and bioinspired deployable systems.

  15. The hydraulic mechanism in the hind wing veins of Cybister japonicus Sharp (order: Coleoptera).

    Science.gov (United States)

    Sun, Jiyu; Wu, Wei; Ling, Mingze; Bhushan, Bharat; Tong, Jin

    2016-01-01

    The diving beetles (Dytiscidae, Coleoptera) are families of water beetles. When they see light, they fly to the light source directly from the water. Their hind wings are thin and fragile under the protection of their elytra (forewings). When the beetle is at rest the hind wings are folded over the abdomen of the beetle and when in flight they unfold to provide the necessary aerodynamic forces. In this paper, the unfolding process of the hind wing of Cybister japonicus Sharp (order: Coleoptera) was investigated. The motion characteristics of the blood in the veins of the structure system show that the veins have microfluidic control over the hydraulic mechanism of the unfolding process. A model is established, and the hind wing extending process is simulated. The blood flow and pressure changes are discussed. The driving mechanism for hydraulic control of the folding and unfolding actions of beetle hind wings is put forward. This can assist the design of new deployable micro air vehicles and bioinspired deployable systems.

  16. Generation of Fullspan Leading-Edge 3D Ice Shapes for Swept-Wing Aerodynamic Testing

    Science.gov (United States)

    Camello, Stephanie C.; Lee, Sam; Lum, Christopher; Bragg, Michael B.

    2016-01-01

    The deleterious effect of ice accretion on aircraft is often assessed through dry-air flight and wind tunnel testing with artificial ice shapes. This paper describes a method to create fullspan swept-wing artificial ice shapes from partial span ice segments acquired in the NASA Glenn Icing Reserch Tunnel for aerodynamic wind-tunnel testing. Full-scale ice accretion segments were laser scanned from the Inboard, Midspan, and Outboard wing station models of the 65% scale Common Research Model (CRM65) aircraft configuration. These were interpolated and extrapolated using a weighted averaging method to generate fullspan ice shapes from the root to the tip of the CRM65 wing. The results showed that this interpolation method was able to preserve many of the highly three dimensional features typically found on swept-wing ice accretions. The interpolated fullspan ice shapes were then scaled to fit the leading edge of a 8.9% scale version of the CRM65 wing for aerodynamic wind-tunnel testing. Reduced fidelity versions of the fullspan ice shapes were also created where most of the local three-dimensional features were removed. The fullspan artificial ice shapes and the reduced fidelity versions were manufactured using stereolithography.

  17. Dipteran wing motor-inspired flapping flight versatility and effectiveness enhancement.

    Science.gov (United States)

    Harne, R L; Wang, K W

    2015-03-06

    Insects are a prime source of inspiration towards the development of small-scale, engineered, flapping wing flight systems. To help interpret the possible energy transformation strategies observed in Diptera as inspiration for mechanical flapping flight systems, we revisit the perspective of the dipteran wing motor as a bistable click mechanism and take a new, and more flexible, outlook to the architectural composition previously considered. Using a representative structural model alongside biological insights and cues from nonlinear dynamics, our analyses and experimental results reveal that a flight mechanism able to adjust motor axial support stiffness and compression characteristics may dramatically modulate the amplitude range and type of wing stroke dynamics achievable. This corresponds to significantly more versatile aerodynamic force generation without otherwise changing flapping frequency or driving force amplitude. Whether monostable or bistable, the axial stiffness is key to enhance compressed motor load bearing ability and aerodynamic efficiency, particularly compared with uncompressed linear motors. These findings provide new foundation to guide future development of bioinspired, flapping wing mechanisms for micro air vehicle applications, and may be used to provide insight to the dipteran muscle-to-wing interface. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. Beneficial aerodynamic effect of wing scales on the climbing flight of butterflies.

    Science.gov (United States)

    Slegers, Nathan; Heilman, Michael; Cranford, Jacob; Lang, Amy; Yoder, John; Habegger, Maria Laura

    2017-01-30

    It is hypothesized that butterfly wing scale geometry and surface patterning may function to improve aerodynamic efficiency. In order to investigate this hypothesis, a method to measure butterfly flapping kinematics optically over long uninhibited flapping sequences was developed. Statistical results for the climbing flight flapping kinematics of 11 butterflies, based on a total of 236 individual flights, both with and without their wing scales, are presented. Results show, that for each of the 11 butterflies, the mean climbing efficiency decreased after scales were removed. Data was reduced to a single set of differences of climbing efficiency using are paired t-test. Results show a mean decrease in climbing efficiency of 32.2% occurred with a 95% confidence interval of 45.6%-18.8%. Similar analysis showed that the flapping amplitude decreased by 7% while the flapping frequency did not show a significant difference. Results provide strong evidence that butterfly wing scale geometry and surface patterning improve butterfly climbing efficiency. The authors hypothesize that the wing scale's effect in measured climbing efficiency may be due to an improved aerodynamic efficiency of the butterfly and could similarly be used on flapping wing micro air vehicles to potentially achieve similar gains in efficiency.

  19. The leading-edge vortex of swift-wing shaped delta wings

    Science.gov (United States)

    Muir, Rowan; Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-11-01

    Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the Leading-Edge Vortex (LEV) for lift generation in a variety of flight conditions. In this investigation, a model non-slender delta shaped wing with a sharp leading-edge is tested at low Reynolds Number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus. The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the un-modified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift-wing shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds Number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta shaped wing. This work received funding from the Engineering and Physical Sciences Research Council [EP/M506515/1] and the Consejo Nacional de Ciencia y Tecnología (CONACYT).

  20. Fruit fly scale robots can hover longer with flapping wings than with spinning wings.

    Science.gov (United States)

    Hawkes, Elliot W; Lentink, David

    2016-10-01

    Hovering flies generate exceptionally high lift, because their wings generate a stable leading edge vortex. Micro flying robots with a similar wing design can generate similar high lift by either flapping or spinning their wings. While it requires less power to spin a wing, the overall efficiency depends also on the actuator system driving the wing. Here, we present the first holistic analysis to calculate how long a fly-inspired micro robot can hover with flapping versus spinning wings across scales. We integrate aerodynamic data with data-driven scaling laws for actuator, electronics and mechanism performance from fruit fly to hummingbird scales. Our analysis finds that spinning wings driven by rotary actuators are superior for robots with wingspans similar to hummingbirds, yet flapping wings driven by oscillatory actuators are superior at fruit fly scale. This crossover is driven by the reduction in performance of rotary compared with oscillatory actuators at smaller scale. Our calculations emphasize that a systems-level analysis is essential for trading-off flapping versus spinning wings for micro flying robots. © 2016 The Author(s).

  1. Flow Modulation and Force Control of Flapping Wings

    Science.gov (United States)

    2014-10-29

    tested on a flapping wing model in the oil tank. Robotic flapper equipped with DC motors drove the wing model, and the imbedded servo motor could flap...the overall wake structure on the hovering wings. Totally, two volumetric flow measurements were performed on two mechanical flappers with different...wing kinematics but similar wing geometry. On the flappers with small stroke angle and passive rotation, the general vortex wake structure

  2. Topography Analysis and Visualization Software Supports a Guided Comparative Planetology Education Exhibit at the Smithsonian's Air and Space Museum

    Science.gov (United States)

    Roark, J. H.; Masuoka, C. M.; Frey, H. V.; Keller, J.; Williams, S.

    2005-01-01

    The Planetary Geodynamics Laboratory (http://geodynamics.gsfc.nasa.gov) of NASA s Goddard Space Flight Center designed, produced and recently delivered a "museum-friendly" version of GRIDVIEW, a grid visualization and analysis application, to the Smithsonian's National Air and Space Museum where it will be used in a guided comparative planetology education exhibit. The software was designed to enable museum visitors to interact with the same Earth and Mars topographic data and tools typically used by planetary scientists, and experience the thrill of discovery while learning about the geologic differences between Earth and Mars.

  3. Left-Wing Extremism: The Current Threat

    Energy Technology Data Exchange (ETDEWEB)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  4. A galactic microquasar mimicking winged radio galaxies.

    Science.gov (United States)

    Martí, Josep; Luque-Escamilla, Pedro L; Bosch-Ramon, Valentí; Paredes, Josep M

    2017-11-24

    A subclass of extragalactic radio sources known as winged radio galaxies has puzzled astronomers for many years. The wing features are detected at radio wavelengths as low-surface-brightness radio lobes that are clearly misaligned with respect to the main lobe axis. Different models compete to account for these peculiar structures. Here, we report observational evidence that the parsec-scale radio jets in the Galactic microquasar GRS 1758-258 give rise to a Z-shaped radio emission strongly reminiscent of the X and Z-shaped morphologies found in winged radio galaxies. This is the first time that such extended emission features are observed in a microquasar, providing a new analogy for its extragalactic relatives. From our observations, we can clearly favour the hydrodynamic backflow interpretation against other possible wing formation scenarios. Assuming that physical processes are similar, we can extrapolate this conclusion and suggest that this mechanism could also be at work in many extragalactic cases.

  5. Numerical and experimental investigations on unsteady aerodynamics of flapping wings

    Science.gov (United States)

    Yu, Meilin

    suggestions to the design of micro-air-vehicles (MAVs), 3D simulations of the flapping wings are carried out in this work. Both the rectangular and bio-inspired wings with different kinematics are investigated. The formation process of two-jet-like wake patterns behind the finite-span flapping wing is found to be closely related to the interaction between trailing edge vortices and tip vortices. Then the effects of the wing planforms on the aerodynamics performance of the finite-span flapping wings are elucidated in terms of the evolution and dynamic interaction of unsteady vortex structures.

  6. Low-speed wind tunnel investigation of a semispan STOL jet transport wing body with an upper surface blown jet flap

    Science.gov (United States)

    Phelps, A. E., III; Letko, W.; Henderson, R. L.

    1973-01-01

    An investigation of the static longitudinal aerodynamic characteristics of a semispan STOL jet transport wing-body with an upper-surface blown jet flap for lift augmentation was conducted in a low-speed wind tunnel having a 12-ft octagonal test section. The semispan swept wing had an aspect ratio of 3.92 (7.84 for the full span) and had two simulated turbofan engines mounted ahead of and above the wing in a siamese pod equipped with an exhaust deflector. The purpose of the deflector was to spread the engine exhaust into a jet sheet attached to the upper surface of the wing so that it would turn downward over the flap and provide lift augmentation. The wing also had optional boundary-layer control provided by air blowing through a thin slot over a full-span plain trailing-edge flap.

  7. Analytical modeling and experimental evaluation of a passively morphing ornithopter wing

    Science.gov (United States)

    Wissa, Aimy A.

    compliant spine design insert. A research ornithopter platform was tested in air and in vacuum as well as in free and constrained flight with various compliant spine designs inserted in its wings. Results from the constrained flight tests indicated that the ornithopter with a compliant spine inserted in its wings consumed 45% less electrical power and produced 16% of its weight in additional lift, without incurring any thrust penalties. Results from, the vacuum constrained tests attributed these benefits to aerodynamic effects rather than inertial effects. Free flight tests were performed at Wright Patterson Air Force Base, which houses the largest indoor flight laboratory in the country. The wing kinematics along with the vehicle dynamics were captured during this testing using ViconRTM motion tracking cameras. These flight tests proved to be successful in producing consistent and repeatable flight data over more than eight free flight flapping cycles of free flight and validated a new and novel testing technique. The ornithopter body dynamics were shown to be significant, i.e. +/-4gs. Inserting the compliant spine into the leading edge spar of the ornithopter during free flight reduced the baseline configuration body vertical center of mass positive acceleration by 69%, which translates into overall lift gains. It also increased the horizontal propulsive force by 300%, which translates into thrust gains.

  8. [From educational and health tourism for children to social tourism: vacation camps in the Province of Buenos Aires, Argentina].

    Science.gov (United States)

    Bruno, Perla

    2015-12-01

    The early twentieth century saw the rise of vacation camps for frail children as educational and health-giving experiences provided by medical and philanthropic organizations. This article analyzes some of these early experiences, seen here as the predecessors of social tourism, in the Province of Buenos Aires. A combination of written sources are examined, mainly institutional reports, periodicals such as the Monitor de la Educación Común - published by the Consejo Nacional de Educación (National Board of Education) - or laws, with photographs and plans for different examples. I argue that these buildings were both physical and cultural "brands" in the places where they were located, and that their architectural structure encapsulated ideas about leisure space and cures in unique natural environments.

  9. Predictability: Does the Flap of a Butterfly's Wings in Brazil Set off a ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 3. Predictability: Does the Flap of a Butterfly's Wings in Brazil Set off a Tornado in Texas? Edward U Lorenz. Classics Volume 20 Issue 3 March 2015 pp 260-263. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Wing and body kinematics of takeoff and landing flight in the pigeon (Columba livia).

    Science.gov (United States)

    Berg, Angela M; Biewener, Andrew A

    2010-05-01

    Takeoff and landing are critical phases in a flight. To better understand the functional importance of the kinematic adjustments birds use to execute these flight modes, we studied the wing and body movements of pigeons (Columba livia) during short-distance free-flights between two perches. The greatest accelerations were observed during the second wingbeat of takeoff. The wings were responsible for the majority of acceleration during takeoff and landing, with the legs contributing only one-quarter of the acceleration. Parameters relating to aerodynamic power output such as downstroke amplitude, wingbeat frequency and downstroke velocity were all greatest during takeoff flight and decreased with each successive takeoff wingbeat. This pattern indicates that downstroke velocity must be greater for accelerating flight to increase the amount of air accelerated by the wings. Pigeons used multiple mechanisms to adjust thrust and drag to accelerate during takeoff and decelerate during landing. Body angle, tail angle and wing plane angles all shifted from more horizontal orientations during takeoff to near-vertical orientations during landing, thereby reducing drag during takeoff and increasing drag during landing. The stroke plane was tilted steeply downward throughout takeoff (increasing from -60+/-5 deg. to -47+/-1 deg.), supporting our hypothesis that a downward-tilted stroke plane pushes more air rearward to accelerate the bird forward. Similarly, the stroke plane tilted upward during landing (increasing from -1+/-2 deg. to 17+/-7 deg.), implying that an upward-tilted stroke plane pushes more air forward to slow the bird down. Rotations of the stroke plane, wing planes and tail were all strongly correlated with rotation of the body angle, suggesting that pigeons are able to redirect aerodynamic force and shift between flight modes through modulation of body angle alone.

  11. Temperature and saturation dependence in the vapor sensing of butterfly wing scales

    Energy Technology Data Exchange (ETDEWEB)

    Kertész, K., E-mail: kertesz.krisztian@ttk.mta.hu [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary); Piszter, G. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary); Jakab, E. [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, H-1525 Budapest, P O Box 17 (Hungary); Bálint, Zs. [Hungarian Natural History Museum, H-1088, Budapest, Baross utca 13 (Hungary); Vértesy, Z.; Biró, L.P. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary)

    2014-06-01

    The sensing of gasses/vapors in the ambient air is the focus of attention due to the need to monitor our everyday environment. Photonic crystals are sensing materials of the future because of their strong light-manipulating properties. Natural photonic structures are well-suited materials for testing detection principles because they are significantly cheaper than artificial photonic structures and are available in larger sizes. Additionally, natural photonic structures may provide new ideas for developing novel artificial photonic nanoarchitectures with improved properties. In the present paper, we discuss the effects arising from the sensor temperature and the vapor concentration in air during measurements with a photonic crystal-type optical gas sensor. Our results shed light on the sources of discrepancy between simulated and experimental sensing behaviors of photonic crystal-type structures. Through capillary condensation, the vapors will condensate to a liquid state inside the nanocavities. Due to the temperature and radius of curvature dependence of capillary condensation, the measured signals are affected by the sensor temperature as well as by the presence of a nanocavity size distribution. The sensing materials used are natural photonic nanoarchitectures present in the wing scales of blue butterflies. - Highlights: • We report optical gas sensing on blue butterfly wing scale nanostructures. • The sample temperature decrease effects a reversible break-down in the measured spectra. • The break-down is connected with the vapor condensation in the scales and wing surface. • Capillary condensation occurs in the wing scales.

  12. The leading-edge vortex of swift wing-shaped delta wings.

    Science.gov (United States)

    Muir, Rowan Eveline; Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-08-01

    Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the leading-edge vortex (LEV) for lift generation in a variety of flight conditions. A well-documented example of an LEV is that generated by aircraft with highly swept, delta-shaped wings. While the wing aerodynamics of a manoeuvring aircraft, a bird gliding and a bird in flapping flight vary significantly, it is believed that this existing knowledge can serve to add understanding to the complex aerodynamics of natural fliers. In this investigation, a model non-slender delta-shaped wing with a sharp leading edge is tested at low Reynolds number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus . The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the unmodified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift wing-shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta-shaped wing.

  13. The United States Air Force Academy: A Bibliography, 2006-2010

    Science.gov (United States)

    2011-01-01

    Historical Deathmatch!" USAFA Educator 17.1 (Summer 2008): 13. 220. Williams, Blake . "DFL - a Nonstandard Approach to Setting the Standard." USAFA...System Reforms Underway." Checkpoints 36.1 (June 2007): 65-66. 553. Lipka, Sara . “Air Force Academy Restricts Students to the Campus for...34 Journal of Political and Military Sociology 35.2 (Winter 2007): 161-76. 729. Lipka, Sara . “On a Wing and a Prayer.” The Chronicle of Higher

  14. Institutional Funding of Higher Education in Australia. AIR 1991 Annual Forum Paper.

    Science.gov (United States)

    Taylor, Robert L.

    This paper analyzes the relative funding model developed as part of the reorganization resulting from the 1988 Australian Government's White Paper on Higher Education Policy. This reorganization created the Unified National System which has resulted in fewer but larger higher education institutions. The relative funding model is described in terms…

  15. Horizons in Learning Innovation through Technology: Prospects for Air Force Education Benefits

    Science.gov (United States)

    2010-06-10

    discussion of new- media literacy has helped invigorate educators to share why affective learning in a situated place matters for the millennial generation...new media literacy , knowledge, place, affect, and context can impact how well social-knowledge structures, employed by...important with human learning. Increasingly, however, educators also accept the importance of addressing new- media literacy and leveraging new ways learners

  16. Breaking Bad: The Efficacy of Ethics Education in Air Force Officer PME

    Science.gov (United States)

    2015-02-12

    to complete the Myers - Briggs Type Indicator. However, there is no requirement for documented self-reflection pertaining to ethics (e.g. journaling...journaling, self-assessment paper). LW-07 does, however, recommend students complete the Myers - Briggs Type Indicator. Appendix E Air War

  17. Heating, Air Conditioning and Refrigeration Curriculum Guide. Michigan Trade and Industrial Education.

    Science.gov (United States)

    Michigan State Univ., East Lansing. Coll. of Agriculture and Natural Resources Education Inst.

    This task-based curriculum guide for heating, air conditioning, and refrigeration is intended to help the teacher develop a classroom management system where students learn by doing. Introductory materials include a Dictionary of Occupational Titles job code and title sheet, a career ladder, a matrix relating duty/task numbers to job titles, and a…

  18. Refrigeration and Air Conditioning Equipment, 11-9. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This military-developed text consists of three blocks of instructional materials for use by those studying to become refrigeration and air conditioning specialists. Covered in the individual course blocks are the following topics: refrigeration and trouble analysis, thermodynamics, and principles of refrigeration; major components and domestic and…

  19. Socio-spatial and economic stratification in Early Childhood Education and Care services in the City of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Gabriela Lucía Marzonetto

    2017-11-01

    Full Text Available In unequal societies, differences in access and quality of early child education and care services determine children´s opportunities. Considering that Argentina is not alien to this phenomenon, this article asks if the way in which child care is socially organized in the City of Buenos Aires operates as a mechanism of social stratification. To answer this question the article parts of a methodological strategy that combines descriptive statistics –means tests and simple comparison of means using per capita income per family and type of early child education and care services that children attend– and inferential statistic, through the application of a logistic regression model that allows to establish statistical significance in the correlation between attendance to early child education and care services and family income, and to ponderate the probability of attendance to these establishments according to the family income level.Overall, this article aims to contribute to the discussion about social stratification and segmentation prevalent in public services, such as child education and care services, in the region.

  20. An aerodynamic model for insect flapping wings in forward flight.

    Science.gov (United States)

    Han, Jong-Seob; Chang, Jo Won; Han, Jae-Hung

    2017-03-31

    This paper proposes a semi-empirical quasi-steady aerodynamic model of a flapping wing in forward flight. A total of 147 individual cases, which consisted of advance ratios J of 0 (hovering), 0.125, 0.25, 0.5, 0.75, 1 and  ∞, and angles of attack α of  -5 to 95° at intervals of 5°, were examined to extract the aerodynamic coefficients. The Polhamus leading-edge suction analogy and power functions were then employed to establish the aerodynamic model. In order to preserve the existing level of simplicity, K P and K V , the correction factors of the potential and vortex force models, were rebuilt as functions of J and α. The estimations were nearly identical to direct force/moment measurements which were obtained from both artificial and practical wingbeat motions of a hawkmoth. The model effectively compensated for the influences of J, particularly showing outstanding moment estimation capabilities. With this model, we found that using a lower value of α during the downstroke would be an effective strategy for generating adequate lift in forward flight. The rotational force and moment components had noticeable portions generating both thrust and counteract pitching moment during pronation. In the upstroke phase, the added mass component played a major role in generating thrust in forward flight. The proposed model would be useful for a better understanding of flight stability, control, and the dynamic characteristics of flapping wing flyers, and for designing flapping-wing micro air vehicles.

  1. Aeroelasticity of morphing wings using neural networks

    Science.gov (United States)

    Natarajan, Anand

    In this dissertation, neural networks are designed to effectively model static non-linear aeroelastic problems in adaptive structures and linear dynamic aeroelastic systems with time varying stiffness. The use of adaptive materials in aircraft wings allows for the change of the contour or the configuration of a wing (morphing) in flight. The use of smart materials, to accomplish these deformations, can imply that the stiffness of the wing with a morphing contour changes as the contour changes. For a rapidly oscillating body in a fluid field, continuously adapting structural parameters may render the wing to behave as a time variant system. Even the internal spars/ribs of the aircraft wing which define the wing stiffness can be made adaptive, that is, their stiffness can be made to vary with time. The immediate effect on the structural dynamics of the wing, is that, the wing motion is governed by a differential equation with time varying coefficients. The study of this concept of a time varying torsional stiffness, made possible by the use of active materials and adaptive spars, in the dynamic aeroelastic behavior of an adaptable airfoil is performed here. Another type of aeroelastic problem of an adaptive structure that is investigated here, is the shape control of an adaptive bump situated on the leading edge of an airfoil. Such a bump is useful in achieving flow separation control for lateral directional maneuverability of the aircraft. Since actuators are being used to create this bump on the wing surface, the energy required to do so needs to be minimized. The adverse pressure drag as a result of this bump needs to be controlled so that the loss in lift over the wing is made minimal. The design of such a "spoiler bump" on the surface of the airfoil is an optimization problem of maximizing pressure drag due to flow separation while minimizing the loss in lift and energy required to deform the bump. One neural network is trained using the CFD code FLUENT to

  2. Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing.

    Science.gov (United States)

    Achache, Yonathan; Sapir, Nir; Elimelech, Yossef

    2017-08-01

    The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle-especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna's hummingbird ( Calypte anna ). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing's leading-edge differs from the attached vorticity structure that was typically found over insects' wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies.

  3. THE FUTURE OF THE EUROPEAN AIR TRANSPORT COMMAND: AN ANALYSIS OF CAPABILITY ENHANCEMENTS FROM THE ITALIAN AIR FORCE AND AIR MOBILITY COMMAND

    Science.gov (United States)

    2016-02-15

    from 1 July 2009; moreover, in the following years Spain and Luxembourg joined the venture and from January 2016 also Italy is part of the EATC. The...Mazzini is assigned to the Air War College, Air University, Maxwell AFB, AL. He joined the Italian Air Force Academy in 1994. He earned his pilot wings...essay identifies Italy’s decision to join the European Air Transport Command as a pivotal opportunity. The research argues that the European Air

  4. Design and Control of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2011-09-01

    haltere in Diptera . The halteres are small appendages, apparently evolved from the hindwing, that oscillate in flight at the same frequency as the...maneuverability of Diptera , though numerous other sufficiently agile taxa get by without them. Experiments on the pathways between these sensors and the flight...applicable, as MAVs are further miniaturized, they may be an attractive option given their high power density and low voltage requirements

  5. Composite corrugated structures for morphing wing skin applications

    International Nuclear Information System (INIS)

    Thill, C; Etches, J A; Bond, I P; Potter, K D; Weaver, P M

    2010-01-01

    Composite corrugated structures are known for their anisotropic properties. They exhibit relatively high stiffness parallel (longitudinal) to the corrugation direction and are relatively compliant in the direction perpendicular (transverse) to the corrugation. Thus, they offer a potential solution for morphing skin panels (MSPs) in the trailing edge region of a wing as a morphing control surface. In this paper, an overview of the work carried out by the present authors over the last few years on corrugated structures for morphing skin applications is first given. The second part of the paper presents recent work on the application of corrugated sandwich structures. Panels made from multiple unit cells of corrugated sandwich structures are used as MSPs in the trailing edge region of a scaled morphing aerofoil section. The aerofoil section features an internal actuation mechanism that allows chordwise length and camber change of the trailing edge region (aft 35% chord). Wind tunnel testing was carried out to demonstrate the MSP concept but also to explore its limitations. Suggestions for improvements arising from this study were deduced, one of which includes an investigation of a segmented skin. The overall results of this study show that the MSP concept exploiting corrugated sandwich structures offers a potential solution for local morphing wing skins for low speed and small air vehicles

  6. Turbulence investigation of the NASA common research model wing tip vortex

    Directory of Open Access Journals (Sweden)

    Čantrak Đorđe S.

    2017-01-01

    Full Text Available The paper presents high-speed stereo particle image velocimetry investigation of the NASA Common Research Model wing tip vortex. A three-percent scaled semi–span model, without nacelle and pylon, was tested in the 32- by 48-inch Indraft tunnel, at the Fluid Mechanics Laboratory at the NASA Ames Research Center. Turbulence investigation of the wing tip vortex is presented. Measurements of the wing-tip vortex were performed in a vertical cross-stream plane three tip-chords downstream of the wing tip trailing edge with a 2 kHz sampling rate. Experimental data are analyzed in the invariant anisotropy maps for three various angles of attack (0°, 2°, and 4° and the same speed generated in the tunnel (V∞ = 50 m/s. This corresponds to a chord Reynolds number 2.68x105, where the chord length of 3” is considered the characteristic length. The region of interest was x = 220 mm and y = 90 mm. The 20 000 particle image velocimetry samples were acquired at each condition. Velocity fields and turbulence statistics are given for all cases, as well as turbulence structure in the light of the invariant theory. Prediction of the wing tip vortices is still a challenge for the computational fluid dynamics codes due to significant pressure and velocity gradients. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 35046

  7. Multi-disciplinary design optimization of subsonic fixed-wing unmanned aerial vehicles projected through 2025

    Science.gov (United States)

    Gundlach, John Frederick, IV

    Through this research, a robust aircraft design methodology is developed for analysis and optimization of the Air Vehicle (AV) segment of Unmanned Aerial Vehicle (UAV) systems. The analysis functionality of the AV design is integrated with a Genetic Algorithm (GA) to form an integrated Multi-disciplinary Design Optimization (MDO) methodology for optimal AV design synthesis. This research fills the gap in integrated subsonic fixed-wing UAV AV MDO methods. No known single methodology captures all of the phenomena of interest over the wide range of UAV families considered here. Key advancements include: (1) parametric Low Reynolds Number (LRN) airfoil aerodynamics formulation, (2) UAV systems mass properties definition, (3) wing structural weight methods, (4) self-optimizing flight performance model, (5) automated geometry algorithms, and (6) optimizer integration. Multiple methods are provided for many disciplines to enable flexibility in functionality, level of detail, computational expediency, and accuracy. The AV design methods are calibrated against the High-Altitude Long-Endurance (HALE) Global Hawk, Medium-Altitude Endurance (MAE) Predator, and Tactical Shadow 200 classes, which exhibit significant variations in mission performance requirements and scale from one another. All three UAV families show significant design gross weight reductions as technology improves. The overall technology synergy experienced 10--11 years after the initial technology year is 6.68% for Global Hawk, 7.09% for Predator, and 4.22% for the Shadow 200, which means that the technology trends interact favorably in all cases. The Global Hawk and Shadow 200 families exhibited niche behavior, where some vehicles attained higher aerodynamic performance while others attained lower structural mass fractions. The high aerodynamic performance Global Hawk vehicles had high aspect ratio wings with sweep, while the low structural mass fraction vehicles had straight, relatively low aspect ratios and

  8. Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

    Science.gov (United States)

    Platt, Robert C

    1936-01-01

    This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash.

  9. [Wing 1 radiation survey and contamination report

    International Nuclear Information System (INIS)

    Olsen, K.

    1991-01-01

    We have completed the 5480.11 survey for Wing 1. All area(s)/item(s) requested by the 5480.11 committee have been thoroughly surveyed and documented. Decontamination/disposal of contaminated items has been accomplished. The wing 1 survey was started on 8/13/90 and completed 9/18/90. However, the follow-up surveys were not completed until 2/18/91. We received the final set of smear samples for wing 1 on 1/13/91. A total of 5,495 smears were taken from wing 1 and total of 465 smears were taken during the follow-up surveys. There were a total 122 items found to have fixed contamination and 4 items with smearable contamination in excess of the limits specified in DOE ORDER 5480.11 (AR 3-7). The following area(s)/item(s) were not included in the 5480.11 survey: Hallways, Access panels, Men's and women's change rooms, Janitor closets, Wall lockers and item(s) stored in wing 1 hallways and room 1116. If our contract is renewed, we will include those areas in our survey according to your request of April 15, 1991

  10. Flapping wing aerodynamics: from insects to vertebrates.

    Science.gov (United States)

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight. © 2016. Published by The Company of Biologists Ltd.

  11. Environmental health education in schools as strategy for rodent control: an experience in a shantytown of Buenos Aires, Argentina.

    Science.gov (United States)

    Hancke, Diego; Suárez, Olga Virginia

    2014-01-01

    The general aim of this study was to assess the possibility of including elements of environmental health education within the curriculum of a school located in a shantytown of Buenos Aires city, Argentina. An environmental health education campaign was designed to introduce school-aged children to the problems posed by the lack of environmental sanitation, by using rodents as indicators of environmental disorder. The methodology implemented consisted of a lecture and two practical activities where the participating children were the evaluators of their neighborhood environment, recording the environmental factors that indicate direct or indirect presence of rodents and carrying out a survey about rodents among their neighbors. To assess the impact of the activities, an anonymous questionnaire was performed with the students before and after the campaign. The results showed that students were able to identify the man-made factors which favor the presence of rodents and were encouraged to propose strategies related to environmental sanitation to reduce rodent proliferation and the transmission of their parasites. This study demonstrated the feasibility of performing environmental health education campaigns in school-aged children by using practical activities to stimulate observation, participation, and comprehensive understanding of the problems posed by urban pests.

  12. 59th Medical Wing Office of the Chief Scientists Research Highlights Flyer-April 2016

    Science.gov (United States)

    2016-05-09

    Air Force Basic Training " (Pl: Capt Bryant Webber (59 MOOS)), presented to the 37 Training Wing Commander and the 559 Medical Group Commander. Capt... Occlusion of the Aorta (REBOA Inventors: Col Todd Rasmussen, MC, USAF MEDCOM USAMRMC and Jonathan Eliason, MD, University of Michigan) Is a fluoroscopy-free...thoracic aortic balloon occlusion system to control non-compressible hemorrh and assess the effect of an occluding aorta. Research to develop the

  13. Investigation of type and density of bio-aerosols in air samples from educational hospital wards of Kerman city, 2014

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2016-10-01

    Full Text Available Background: Bio-aerosols in the air of hospital wards have an important role in the development of infections. It is important to make quantitative and qualitative estimations of microorganisms in the air of these wards as an index for environmental hygiene applicable to different hospital wards. The aim of the study was to investigate degrees of diversity and density of bio-aerosols in the education hospitals of Kerman city. Methods: This study applied a descriptive-cross-sectional methodology in the second half of 2014 in the education hospitals of Kerman city, with bed capacity of over 300. As many as 200 samples were collected from the air in different wards of each hospital using the standard method of the National Occupational Health and Safety Institute. Following collection, samples were placed in an incubator for 48 hours and then bio-aerosol detections were made for and resulting data reported as colonies/m3. Results: Results indicated that maximum and minimum degrees of bacterial density were observed in operation rooms and in the intensive care unit (ICU of Shafa hospital. Furthermore, comparison showedthat the operating room at Afzalipour hospital had the lowest level of fungal contamination, while ICU at Bahonar hospital had the highest level of fungal contamination. The emitted fungi of Aspergillus and Penicillium along with the bacteria, staphylococci and Acinetobacter had greater frequencies. The means of bacterial density and fungal density were not equal across the studied hospitals and significant statistical, difference was observed between means of bacterial and fungal density (P ≤ 0.001. Conclusion: Amounts of bacterial and fungal density were greater than those proposed in the American Industrial Health State Conference in 73.3% of the wards in the educational hospitals of Kerman city sampled in this study. Therefore it is suggested that implementation of some, necessary measures for continuous monitoring, promotion of

  14. Principle of bio-inspired insect wing rotational hinge design

    Science.gov (United States)

    Fei, Fan

    A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model's prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can

  15. Education

    Science.gov (United States)

    2003-01-01

    Frank Sosa, Dept. of the Air Force Col Juan Urbano , Peruvian Army Dr. Francis A’Hearn, Faculty Prof. William Mayall, Faculty COL Mark McGuire...Germany House of Commons, Parliamentary Undersecretary State for Education, England Ministry of Science, Research, and Art , Stuttgart, Germany...markets. Fifty percent of the elementary market is composed of reading and language arts . Mathematics and a combination social sciences/science and

  16. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    Science.gov (United States)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  17. The Republic of Turkey: Intercultural Education and the Colorado Air National Guard.

    Science.gov (United States)

    1981-05-01

    nap of Colorado printed in Turkish for the deployment. This map was drawn by the Geography department at the U.S. Air Force Academy. 15 The unit... fragrance of the mouth of a fasting man is more pleasant to God than the smell of musk. And fasting is a shield. So when the fasting of some one of...fault, the fragrance of Paradise is forbidden to her. 79 There is no divorce and no emancipation by force. God created nothing on the face of the

  18. Vibration receptive sensilla on the wing margins of the silkworm moth Bombyx mori.

    Science.gov (United States)

    Ai, Hiroyuki; Yoshida, Akihiro; Yokohari, Fumio

    2010-03-01

    Bristles along the wing margins (wm-bristles) of the silkworm moth, Bombyx mori, were studied morphologically and electrophysiologically. The male moth has ca. 50 wm-bristles on each forewing and hindwing. Scanning electron microscopy revealed that these wm-bristles are typical mechanosensilla. Leuco-methylene blue staining demonstrated that each wm-bristle has a single receptor neuron, which is also characteristic of the mechanosensillum. The receptor neuron responded to vibrating air currents but did not respond to a constant air current. The wm-bristles showed clear directional sensitivity to vibrating air currents. The wm-bristles were classified into two types, type I and type II, by their response patterns to sinusoidal movements of the bristle. The neuron in type I discharged bursting spikes immediately following stimulation onset and also discharged a single spike for each sinusoidal cycle for frequencies less than ca. 60 Hz. The neuron in type II only responded to vibrations over 40 Hz and, specifically at 75 Hz, discharged a single spike for each sinusoidal cycle throughout the stimulation period. These results suggest that the two types of wm-bristles are highly tuned in different ways to detect vibrations due to the wing beat. The roles of the wm-bristles in the wing beat are discussed. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  19. The role of wing kinematics of freely flying birds downstream the wake of flapping wings

    Science.gov (United States)

    Krishnan, Krishnamoorthy; Gurka, Roi

    2016-11-01

    Avian aerodynamics has been a topic of research for centuries. Avian flight features such as flapping, morphing and maneuvering make bird aerodynamics a complex system to study, analyze and understand. Aerodynamic performance of the flapping wings can be quantified by measuring the vortex structures present in the downstream wake. Still, the direct correlation between the flapping wing kinematics and the evolution of wake features need to be established. In this present study, near wake of three bird species (western sandpiper, European starling and American robin) have been measured experimentally. Long duration, time-resolved, particle image velocimetry technique has been used to capture the wake properties. Simultaneously, the bird kinematics have been captured using high speed camera. Wake structures are reconstructed from the collected PIV images for long chord distances downstream. Wake vorticities and circulation are expressed in the wake composites. Comparison of the wake features of the three birds shows similarities and some key differences are also found. Wing tip motions of the birds are extracted for four continuous wing beat cycle to analyze the wing kinematics. Kinematic parameters of all the three birds are compared to each other and similar trends exhibited by all the birds have been observed. A correlation between the wake evolutions with the wing motion is presented. It was found that the wings' motion generates unique flow patterns at the near wake, especially at the transition phases. At these locations, a drastic change in the circulation was observed.

  20. Investigating the Force Production of Functionally-Graded Flexible Wings in Flapping Wing Flight

    Science.gov (United States)

    Mudbhari, Durlav; Erdogan, Malcolm; He, Kai; Bateman, Daniel; Lipkis, Rory; Moored, Keith

    2015-11-01

    Birds, insects and bats oscillate their wings to propel themselves over long distances and to maneuver with unprecedented agility. A key element to achieve their impressive aerodynamic performance is the flexibility of their wings. Numerous studies have shown that homogeneously flexible wings can enhance force production, propulsive efficiency and lift efficiency. Yet, animal wings are not homogenously flexible, but instead have varying material properties. The aim of this study is to characterize the force production and energetics of functionally-graded flexible wings. A partially-flexible wing composed of a rigid section and a flexible section is used as a first-order model of functionally-graded materials. The flexion occurs in the spanwise direction and it is affected by the spanwise flexion ratio, that is, the ratio of the length of the rigid section compared to the total span length. By varying the flexion ratio as well as the material properties of the flexible section, the study aims to examine the force production and energetics of flapping flight with functionally-graded flexible wings. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI grant number N00014-14-1-0533.

  1. Aeroelastic Analysis of Modern Complex Wings

    Science.gov (United States)

    Kapania, Rakesh K.; Bhardwaj, Manoj K.; Reichenbach, Eric; Guruswamy, Guru P.

    1996-01-01

    A process is presented by which aeroelastic analysis is performed by using an advanced computational fluid dynamics (CFD) code coupled with an advanced computational structural dynamics (CSD) code. The process is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas Aerospace East CFD code) coupled with NASTRAN. The process is also demonstrated on an aeroelastic research wing (ARW-2) using ENSAERO (an in-house NASA Ames Research Center CFD code) coupled with a finite element wing-box structures code. Good results have been obtained for the F/A-18 Stabilator while results for the ARW-2 supercritical wing are still being obtained.

  2. A Methodology for Data Structure Assessment in Higher Education Administration. AIR Forum Paper 1978.

    Science.gov (United States)

    Baltes, Kenneth G.; Hendrix, Vernon L.

    Two recent developments in management information system technology and higher education administration have brought about the need for this study, designed to develop a methodology for revealing a relational model of the data base that administrators are operating from currently or would like to be able to operate from in the future.…

  3. Economic Long Waves and Higher Education. AIR 1987 Annual Forum Paper.

    Science.gov (United States)

    Sharp, Bobby H.; Nichols, James O.

    Economic long wave research is reviewed and related to major transitions facing higher education. The focus is on economic forecasting as one type of environmental scanning. The Russian economist Kondratieff produced statistical evidence of a long economic wave. The Kondratieff wave appears to be a 45- to 60-year cycle of upswings and downswings…

  4. Active Twist Control for a Compliant Wing Structure, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Blended wing body (BWB) aircraft provide an aerodynamically superior solution over traditional tube-and-wing designs for a number of mission profiles. These...

  5. Combined particle-image velocimetry and force analysis of the three-dimensional fluid-structure interaction of a natural owl wing.

    Science.gov (United States)

    Winzen, A; Roidl, B; Schröder, W

    2016-04-01

    Low-speed aerodynamics has gained increasing interest due to its relevance for the design process of small flying air vehicles. These small aircraft operate at similar aerodynamic conditions as, e.g. birds which therefore can serve as role models of how to overcome the well-known problems of low Reynolds number flight. The flight of the barn owl is characterized by a very low flight velocity in conjunction with a low noise emission and a high level of maneuverability at stable flight conditions. To investigate the complex three-dimensional flow field and the corresponding local structural deformation in combination with their influence on the resulting aerodynamic forces, time-resolved stereoscopic particle-image velocimetry and force and moment measurements are performed on a prepared natural barn owl wing. Several spanwise positions are measured via PIV in a range of angles of attack [Formula: see text] 6° and Reynolds numbers 40 000 [Formula: see text] 120 000 based on the chord length. Additionally, the resulting forces and moments are recorded for -10° ≤ α ≤ 15° at the same Reynolds numbers. Depending on the spanwise position, the angle of attack, and the Reynolds number, the flow field on the wing's pressure side is characterized by either a region of flow separation, causing large-scale vortical structures which lead to a time-dependent deflection of the flexible wing structure or wing regions showing no instantaneous deflection but a reduction of the time-averaged mean wing curvature. Based on the force measurements the three-dimensional fluid-structure interaction is assumed to considerably impact the aerodynamic forces acting on the wing leading to a strong mechanical loading of the interface between the wing and body. These time-depending loads which result from the flexibility of the wing should be taken into consideration for the design of future small flying air vehicles using flexible wing structures.

  6. Nonlinear Dynamics of Wind Turbine Wings

    DEFF Research Database (Denmark)

    Larsen, Jesper Winther

    Wind turbines with a nominal effect of 5MW with a rotor diameter of up to 126m are produced today. With the increasing size wind turbines also become more and more optimized with respect to structural dimensions and material usage, without increasing the stiffness proportionally. Consequently......, large wind turbines become increasingly flexible and dynamically sensitive. This project focuses on the structural analysis of highly flexible wind turbine wings, and the aerodynamic loading of wind turbine wings under large changes in flow field due to elastic deformations and changing wind conditions....

  7. Stability and transition on swept wings

    Science.gov (United States)

    Stuckert, Greg; Herbert, Thorwald; Esfahanian, Vahid

    1993-01-01

    This paper describes the extension and application of the Parabolized Stability Equations (PSE) to the stability and transition of the supersonic three-dimensional laminar boundary layer on a swept wing. The problem formulation uses a general coordinate transformation for arbitrary curvilinear body-fitted computational grids. Some testing using these coordinates is briefly described to help validate the software used for the investigation. The disturbance amplitude ratios as a function of chord position for supersonic (Mach 1.5) boundary layers on untapered, untwisted wings of different sweep angles are then presented and compared with those obtained from local parallel analyses.

  8. Integrated multi-disciplinary design of a sailplane wing

    OpenAIRE

    Strauch, Gregory J.

    1985-01-01

    The objective of this research is to investigate the techniques and payoffs of integrated aircraft design. Lifting line theory and beam theory are used for the analysis of the aerodynamics and the structures of a composite sailplane wing. The wing is described by 33 - 34 design variables which involve the planform geometry, the twist distribution, and thicknesses of the spar caps, spar webs, and the skin at various stations along the wing. The wing design must satisfy 30 â ...

  9. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  10. Wind tunnel and numerical data on the ventilation performance of windcatcher with wing wall

    Directory of Open Access Journals (Sweden)

    Payam Nejat

    2016-12-01

    Full Text Available The data presented in this article were the basis for the study reported in the research articles entitled “Evaluation of a two-sided windcatcher integrated with wing wall (as a new design and comparison with a conventional windcatcher” (P. Nejat, J.K. Calautit, M.Z.A. Majid, B.R. Hughes, I. Zeynali, F. Jomehzadeh, 2016 [1] which presents the effect of wing wall on the air flow distribution under using the windcatchers as a natural ventilation equipment. Here, we detail the wind tunnel testing and numerical set-up used for obtaining the data on ventilation rates and indoor airflow distribution inside a test room with a two-sided windcatcher and wing wall. Three models were integrated with wing wall angled at 30°, 45° and 60° and another windcatcher was a conventional two-sided device. The computer-aided design (CAD three-dimensional geometries which were produced using Solid Edge modeler are also included in the data article.

  11. Wind tunnel and numerical data on the ventilation performance of windcatcher with wing wall.

    Science.gov (United States)

    Nejat, Payam; Calautit, John Kaiser; Abd Majid, Muhd Zaimi; Hughes, Ben Richard; Zeynali, Iman; Jomehzadeh, Fatemeh

    2016-12-01

    The data presented in this article were the basis for the study reported in the research articles entitled "Evaluation of a two-sided windcatcher integrated with wing wall (as a new design) and comparison with a conventional windcatcher" (P. Nejat, J.K. Calautit, M.Z.A. Majid, B.R. Hughes, I. Zeynali, F. Jomehzadeh, 2016) [1] which presents the effect of wing wall on the air flow distribution under using the windcatchers as a natural ventilation equipment. Here, we detail the wind tunnel testing and numerical set-up used for obtaining the data on ventilation rates and indoor airflow distribution inside a test room with a two-sided windcatcher and wing wall. Three models were integrated with wing wall angled at 30°, 45° and 60° and another windcatcher was a conventional two-sided device. The computer-aided design (CAD) three-dimensional geometries which were produced using Solid Edge modeler are also included in the data article.

  12. Wing and body motion and aerodynamic and leg forces during take-off in droneflies.

    Science.gov (United States)

    Chen, Mao Wei; Zhang, Yan Lai; Sun, Mao

    2013-12-06

    Here, we present a detailed analysis of the take-off mechanics in droneflies performing voluntary take-offs. Wing and body kinematics of the insects during take-off were measured using high-speed video techniques. Based on the measured data, the inertia force acting on the insect was computed and the aerodynamic force of the wings was calculated by the method of computational fluid dynamics. Subtracting the aerodynamic force and the weight from the inertia force gave the leg force. In take-off, a dronefly increases its stroke amplitude gradually in the first 10-14 wingbeats and becomes airborne at about the 12th wingbeat. The aerodynamic force increases monotonously from zero to a value a little larger than its weight, and the leg force decreases monotonously from a value equal to its weight to zero, showing that the droneflies do not jump and only use aerodynamic force of flapping wings to lift themselves into the air. Compared with take-offs in insects in previous studies, in which a very large force (5-10 times of the weight) generated either by jumping legs (locusts, milkweed bugs and fruit flies) or by the 'fling' mechanism of the wing pair (butterflies) is used in a short time, the take-off in the droneflies is relatively slow but smoother.

  13. Use of wing morphometry for the discrimination of some Cerceris ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... Figure 12. Thin spline plate graphics for the species belonging to the genus Cerceris. Figure 13. Fore wing landmarks of the significant wing characteristics in the honeybee Apis mellifera. Linnaeus. stated as the traditional wing morphometry that enables the practical discrimination of the honeybee (Apis sp ...

  14. How swifts control their glide performance with morphing wings

    NARCIS (Netherlands)

    Lentink, D.; Muller, U. K.; Stamhuis, E. J.; de Kat, R.; van Gestel, W.; Veldhuis, L. L. M.; Henningsson, P.; Hedenstrom, A.; Videler, J. J.

    2007-01-01

    Gliding birds continually change the shape and size of their wings(1-6), presumably to exploit the profound effect of wing morphology on aerodynamic performance(7-9). That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models(2,10), which

  15. THE EFFECTS OF SWIRL GENERATOR HAVING WINGS WITH HOLES ON HEAT TRANSFER AND PRESSURE DROP IN TUBE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Zeki ARGUNHAN

    2006-02-01

    Full Text Available This paper examines the effect of turbulance creators on heat transfer and pressure drop used in concentric heat exchanger experimentaly. Heat exchanger has an inlet tube with 60 mm in diameter. The angle of swirl generators wings is 55º with each wing which has single, double, three and four holes. Swirl generators is designed to easily set to heat exchanger entrance. Air is passing through inner tube of heat exhanger as hot fluid and water is passing outer of inner tube as cool fluid.

  16. Assessment of radiological status of underground tunnel of radiochemistry wing

    International Nuclear Information System (INIS)

    Patre, D.K.; Thanamani, S.; Ojha, Shashikala; Murali, S.

    2012-01-01

    Radiochemistry Wing, RLG has design based safety systems for lab exhaust and glove box ventilation exhaust. The respective exhaust headers are routed from the lab exhaust point to the filter house. The concretized underground tunnel runs between Radiochemistry wing, RLG and Filter house about 100 m away. It houses the main exhaust tunnel made of MS, has reportedly developed leakage in the MS lines of exhaust due to ageing. It was indicated by the inadequate ventilation to the lab exhaust which reduced ∼ 10 % of the total exhaust. It was decided to carry out the replacement of main exhaust duct subject to radiological safety and clearance from the regulatory agencies. Since the duct had been in use since past 40 years, HP assessment on contamination status, clearance from local safety committee and related regulatory agency are mandatory. In view of the same, the study on radiological parameters was taken up and the paper describes the results of our radiological surveillance. Proposed replacement work involves approximately estimated surface area of duct as 520 m 2 , volume of the material as 106 m 3 and the weight of material of exhaust duct as 12.5 tons. Underground tunnel of radiochemistry wing consists of 3 main segments. It was monitored thoroughly by radiation survey. Spot air sample was collected during the radiological survey. Around 200 swipes were taken from various portions of the segments and the effluent pipelines. Last two tunnel segment were not approachable. Smear swipes were taken from top, side, bottom and floor of each segment. Calibrated scintillation counters were used for assessment of μ air activity and μ contamination check. Spot air samples were taken during different operations showed no activity. Dose rate in the tunnel was found to be less than 1 μSv/h (0.1 mR/h). The μ contamination levels were found in increasing order from the first segment to the last segment. (0.05 - 0.1 Bq/cm 2 ). Effluent pipelines were found to have

  17. Indoor Air Quality in Schools

    Science.gov (United States)

    This web site will educate the public about indoor environmental issues specific to educational facilities and the importance of developing and sustaining comprehensive indoor air quality management programs.

  18. Morphing Wing: Experimental Boundary Layer Transition Determination and Wing Vibrations Measurements and Analysis =

    Science.gov (United States)

    Tondji Chendjou, Yvan Wilfried

    This Master's thesis is written within the framework of the multidisciplinary international research project CRIAQ MDO-505. This global project consists of the design, manufacture and testing of a morphing wing box capable of changing the shape of the flexible upper skin of a wing using an actuator system installed inside the wing. This changing of the shape generates a delay in the occurrence of the laminar to turbulent transition area, which results in an improvement of the aerodynamic performances of the morphed wing. This thesis is focused on the technologies used to gather the pressure data during the wind tunnel tests, as well as on the post processing methodologies used to characterize the wing airflow. The vibration measurements of the wing and their real-time graphical representation are also presented. The vibration data acquisition system is detailed, and the vibration data analysis confirms the predictions of the flutter analysis performed on the wing prior to wind tunnel testing at the IAR-NRC. The pressure data was collected using 32 highly-sensitive piezoelectric sensors for sensing the pressure fluctuations up to 10 KHz. These sensors were installed along two wing chords, and were further connected to a National Instrument PXI real-time acquisition system. The acquired pressure data was high-pass filtered, analyzed and visualized using Fast Fourier Transform (FFT) and Standard Deviation (SD) approaches to quantify the pressure fluctuations in the wing airflow, as these allow the detection of the laminar to turbulent transition area. Around 30% of the cases tested in the IAR-NRC wind tunnel were optimized for drag reduction by the morphing wing procedure. The obtained pressure measurements results were compared with results obtained by infrared thermography visualization, and were used to validate the numerical simulations. Two analog accelerometers able to sense dynamic accelerations up to +/-16g were installed in both the wing and the aileron boxes

  19. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  20. Oblique-Flying-Wing Supersonic Transport Airplane

    Science.gov (United States)

    Van Der Velden, Alexander J. M.

    1992-01-01

    Oblique-flying-wing supersonic airplane proposed as possible alternative to B747B (or equivalent). Tranports passengers and cargo as fast as twice speed of sound at same cost as current subsonic transports. Flies at same holding speeds as present supersonic transports but requires only half takeoff distance.

  1. Chemical evaluation of winged beans ( Psophocarpus ...

    African Journals Online (AJOL)

    Chemical evaluation of winged beans ( Psophocarpus Tetragonolobus ), Pitanga cherries ( Eugenia uniflora) and orchid fruit ( Orchid fruit myristic a) ... The acid value ranged between 0.71 and 2.82 mg/KOH/g while iodine value ranged between 91.15 and 144.57. The refractive index ranged between 1.465 and 1.474 in all ...

  2. ``Schooling'' of wing pairs in flapping flight

    Science.gov (United States)

    Ramananarivo, Sophie; Zhang, Jun; Ristroph, Leif; AML, Courant Collaboration; Physics NYU Collaboration

    2015-11-01

    The experimental setup implements two independent flapping wings swimming in tandem. Both are driven with the same prescribed vertical heaving motion, but the horizontal motion is free, which means that the swimmers can take up any relative position and forward speed. Experiments show however clearly coordinated motions, where the pair of wings `crystallize' into specific stable arrangements. The follower wing locks into the path of the leader, adopting its speed, and with a separation distance that takes on one of several discrete values. By systematically varying the kinematics and wing size, we show that the set of stable spacings is dictated by the wavelength of the periodic wake structure. The forces maintaining the pair cohesion are characterized by applying an external force to the follower to perturb it away from the `stable wells'. These results show that hydrodynamics alone is sufficient to induce cohesive and coordinated collective locomotion through a fluid, and we discuss the hypothesis that fish schools and bird flocks also represent stable modes of motion.

  3. Aerodynamic comparison of a butterfly-like flapping wing-body model and a revolving-wing model

    Science.gov (United States)

    Suzuki, Kosuke; Yoshino, Masato

    2017-06-01

    The aerodynamic performance of flapping- and revolving-wing models is investigated by numerical simulations based on an immersed boundary-lattice Boltzmann method. As wing models, we use (i) a butterfly-like model with a body and flapping-rectangular wings and (ii) a revolving-wing model with the same wings as the flapping case. Firstly, we calculate aerodynamic performance factors such as the lift force, the power, and the power loading of the two models for Reynolds numbers in the range of 50-1000. For the flapping-wing model, the power loading is maximal for the maximum angle of attack of 90°, a flapping amplitude of roughly 45°, and a phase shift between the flapping angle and the angle of attack of roughly 90°. For the revolving-wing model, the power loading peaks for an angle of attack of roughly 45°. In addition, we examine the ground effect on the aerodynamic performance of the revolving-wing model. Secondly, we compare the aerodynamic performance of the flapping- and revolving-wing models at their respective maximal power loadings. It is found that the revolving-wing model is more efficient than the flapping-wing model both when the body of the latter is fixed and where it can move freely. Finally, we discuss the relative agilities of the flapping- and revolving-wing models.

  4. Paleozoic Nymphal Wing Pads Support Dual Model of Insect Wing Origins.

    Science.gov (United States)

    Prokop, Jakub; Pecharová, Martina; Nel, André; Hörnschemeyer, Thomas; Krzemińska, Ewa; Krzemiński, Wiesław; Engel, Michael S

    2017-01-23

    The appearance of wings in insects, early in their evolution [1], has been one of the more critical innovations contributing to their extraordinary diversity. Despite the conspicuousness and importance of wings, the origin of these structures has been difficult to resolve and represented one of the "abominable mysteries" in evolutionary biology [2]. More than a century of debate has boiled the matter down to two competing alternatives-one of wings representing an extension of the thoracic notum, the other stating that they are appendicular derivations from the lateral body wall. Recently, a dual model has been supported by genomic and developmental data [3-6], representing an amalgamation of elements from both the notal and pleural hypotheses. Here, we reveal crucial information from the wing pad joints of Carboniferous palaeodictyopteran insect nymphs using classical and high-tech techniques. These nymphs had three pairs of wing pads that were medially articulated to the thorax but also broadly contiguous with the notum anteriorly and posteriorly (details unobservable in modern insects), supporting their overall origin from the thoracic notum as well as the expected medial, pleural series of axillary sclerites. Our study provides support for the formation of the insect wing from the thoracic notum as well as the already known pleural elements of the arthropodan leg. These results support the unique, dual model for insect wing origins and the convergent reduction of notal fusion in more derived clades, presumably due to wing rotation during development, and they help to bring resolution to this long-standing debate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Air tankers in Southern California Fires...effectiveness in delivering retardants rated

    Science.gov (United States)

    Theodore G. Storey; Leon W. Cooley

    1967-01-01

    Eleven air attack experts were asked to rate 12 models of fixed-wing tankers and light helitankers for effectiveness ill delivering chemical fire retardants under 21 typical situations. They rated fixed-wing tankers as more effective in strong wind crosswinds, and downwind approaches, but helitankers as more effective in narrow canyons and on steep slopes. Certain...

  6. Multiple cues for winged morph production in an aphid metacommunity.

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrparvar

    Full Text Available Environmental factors can lead individuals down different developmental pathways giving rise to distinct phenotypes (phenotypic plasticity. The production of winged or unwinged morphs in aphids is an example of two alternative developmental pathways. Dispersal is paramount in aphids that often have a metapopulation structure, where local subpopulations frequently go extinct, such as the specialized aphids on tansy (Tanacetum vulgare. We conducted various experiments to further understand the cues involved in the production of winged dispersal morphs by the two dominant species of the tansy aphid metacommunity, Metopeurum fuscoviride and Macrosiphoniella tanacetaria. We found that the ant-tended M. fuscoviride produced winged individuals predominantly at the beginning of the season while the untended M. tanacetaria produced winged individuals throughout the season. Winged mothers of both species produced winged offspring, although in both species winged offspring were mainly produced by unwinged females. Crowding and the presence of predators, effects already known to influence wing production in other aphid species, increased the percentage of winged offspring in M. tanacetaria, but not in M. fuscoviride. We find there are also other factors (i.e. temporal effects inducing the production of winged offspring for natural aphid populations. Our results show that the responses of each aphid species are due to multiple wing induction cues.

  7. The biomechanical origin of extreme wing allometry in hummingbirds.

    Science.gov (United States)

    Skandalis, Dimitri A; Segre, Paolo S; Bahlman, Joseph W; Groom, Derrick J E; Welch, Kenneth C; Witt, Christopher C; McGuire, Jimmy A; Dudley, Robert; Lentink, David; Altshuler, Douglas L

    2017-10-19

    Flying animals of different masses vary widely in body proportions, but the functional implications of this variation are often unclear. We address this ambiguity by developing an integrative allometric approach, which we apply here to hummingbirds to examine how the physical environment, wing morphology and stroke kinematics have contributed to the evolution of their highly specialised flight. Surprisingly, hummingbirds maintain constant wing velocity despite an order of magnitude variation in body weight; increased weight is supported solely through disproportionate increases in wing area. Conversely, wing velocity increases with body weight within species, compensating for lower relative wing area in larger individuals. By comparing inter- and intraspecific allometries, we find that the extreme wing area allometry of hummingbirds is likely an adaptation to maintain constant burst flight capacity and induced power requirements with increasing weight. Selection for relatively large wings simultaneously maximises aerial performance and minimises flight costs, which are essential elements of humming bird life history.

  8. Lift and Power Required for Flapping Wing Hovering Flight on Mars

    Science.gov (United States)

    Pohly, Jeremy; Sridhar, Madhu; Bluman, James; Kang, Chang-Kwon; Landrum, D. Brian; Fahimi, Farbod; Aono, Hikaru; Liu, Hao

    2017-11-01

    Achieving flight on Mars is challenging due to the ultra-low density atmosphere. Bio-inspired flapping motion can generate sufficient lift if bumblebee-inspired wings are scaled up between 2 and 4 times their nominal size. However, due to this scaling, the inertial power required to sustain hover increases and dominates over the aerodynamic power. Our results show that a torsional spring placed at the wing root can reduce the flapping power required for hover by efficiently storing and releasing energy while operating at its resonance frequency. The spring assisted reduction in flapping power is demonstrated with a well-validated, coupled Navier-Stokes and flight dynamics solver. The total power is reduced by 79%, whereas the flapping power is reduced by 98%. Such a reduction in power paves the way for an efficient, realizable micro air vehicle capable of vertical takeoff and landing as well as sustained flight on Mars. Alabama Space Grant Consortium Fellowship.

  9. Laser Noise Reduction in Air

    OpenAIRE

    Bejot, Pierre; Kasparian, Jerome; Salmon, Estelle; Ackermann, Roland; Gisin, Nicolas; Wolf, Jean-Pierre

    2006-01-01

    Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuu...

  10. Nellis and Creech Air Force Bases Capital Improvements Program Environmental Assessment

    Science.gov (United States)

    2008-09-01

    57th Wing, other Air Force units, Navy, Marine Corps and allied air forces. Creech AFB is also the primary training site for the United States Air...Forces, Air National Guard, U.S. Air Force Reserve, Army, Navy, Marine Corps, and allied air forces. They are led by a Blue Forces commander who...includes desert iguana (Dipsosaurus dorsalis), zebra-tailed lizard (Callosaurus draconoides), side-blotched lizard, horned lizards (Phrynosoma spp

  11. The optimal design of UAV wing structure

    Science.gov (United States)

    Długosz, Adam; Klimek, Wiktor

    2018-01-01

    The paper presents an optimal design of UAV wing, made of composite materials. The aim of the optimization is to improve strength and stiffness together with reduction of the weight of the structure. Three different types of functionals, which depend on stress, stiffness and the total mass are defined. The paper presents an application of the in-house implementation of the evolutionary multi-objective algorithm in optimization of the UAV wing structure. Values of the functionals are calculated on the basis of results obtained from numerical simulations. Numerical FEM model, consisting of different composite materials is created. Adequacy of the numerical model is verified by results obtained from the experiment, performed on a tensile testing machine. Examples of multi-objective optimization by means of Pareto-optimal set of solutions are presented.

  12. Adjoint-based optimization for flapping wings

    Science.gov (United States)

    Xu, Min; Wei, Mingjun

    2012-11-01

    Adjoint-based methods show great potential in flow control and optimization of complex problems with high- or infinite-dimensional control space. It is attractive to solve an adjoint problem to understand the complex effects from multiple control parameters to a few performance indicators of the flight of birds or insects. However, the traditional approach to formulate the adjoint problem becomes either impossible or too complex when arbitrary moving boundary (e.g. flapping wings) and its perturbation is considered. Here, we use non-cylindrical calculus to define the perturbation. So that, a simple adjoint system can be derived directly in the inertial coordinate. The approach is first applied to the optimization of cylinder oscillation and later to flapping wings. Supported by AFOSR.

  13. Quantifying the dynamic wing morphing of hovering hummingbird.

    Science.gov (United States)

    Maeda, Masateru; Nakata, Toshiyuki; Kitamura, Ikuo; Tanaka, Hiroto; Liu, Hao

    2017-09-01

    Animal wings are lightweight and flexible; hence, during flapping flight their shapes change. It has been known that such dynamic wing morphing reduces aerodynamic cost in insects, but the consequences in vertebrate flyers, particularly birds, are not well understood. We have developed a method to reconstruct a three-dimensional wing model of a bird from the wing outline and the feather shafts (rachides). The morphological and kinematic parameters can be obtained using the wing model, and the numerical or mechanical simulations may also be carried out. To test the effectiveness of the method, we recorded the hovering flight of a hummingbird ( Amazilia amazilia ) using high-speed cameras and reconstructed the right wing. The wing shape varied substantially within a stroke cycle. Specifically, the maximum and minimum wing areas differed by 18%, presumably due to feather sliding; the wing was bent near the wrist joint, towards the upward direction and opposite to the stroke direction; positive upward camber and the 'washout' twist (monotonic decrease in the angle of incidence from the proximal to distal wing) were observed during both half-strokes; the spanwise distribution of the twist was uniform during downstroke, but an abrupt increase near the wrist joint was found during upstroke.

  14. CFD Analysis of UAV Flying Wing

    Directory of Open Access Journals (Sweden)

    Vasile PRISACARIU

    2016-09-01

    Full Text Available Numerical methods for solving equations describing the evolution of 3D fluid experienced a significant development closely related to the progress of information systems. Today, especially in the field of fluid mechanics, numerical simulations allow the study of gas-thermodynamic confirmed by experimental techniques in wind tunnel conditions and actual flight tests for modeling complex aircraft. The article shows a case of numerical analysis of the lifting surface on the UAV type flying wing.

  15. Topology Optimization of an Aircraft Wing

    Science.gov (United States)

    2015-06-11

    can combine the advantages of a variable stiffness design with- out the use of actuators. Curved beams, which couple torsion and bending , counteract... torsional deflection, control natural frequency, exploit coupling of bending and tor- sion to control flutter, reduce thickness to chord ratios due to...disregarded any bending or torsional effects caused by displacement of the wing, and was thus not considered. Therefore, the initial design analysis

  16. Tracing the evolution of avian wing digits.

    Science.gov (United States)

    Xu, Xing; Mackem, Susan

    2013-06-17

    It is widely accepted that birds are a subgroup of dinosaurs, but there is an apparent conflict: modern birds have been thought to possess only the middle three fingers (digits II-III-IV) of an idealized five-digit tetrapod hand based on embryological data, but their Mesozoic tetanuran dinosaur ancestors are considered to have the first three digits (I-II-III) based on fossil evidence. How could such an evolutionary quirk arise? Various hypotheses have been proposed to resolve this paradox. Adding to the confusion, some recent developmental studies support a I-II-III designation for avian wing digits whereas some recent paleontological data are consistent with a II-III-IV identification of the Mesozoic tetanuran digits. A comprehensive analysis of both paleontological and developmental data suggests that the evolution of the avian wing digits may have been driven by homeotic transformations of digit identity, which are more likely to have occurred in a partial and piecemeal manner. Additionally, recent genetic studies in mouse models showing plausible mechanisms for central digit loss invite consideration of new alternative possibilities (I-II-IV or I-III-IV) for the homologies of avian wing digits. While much progress has been made, some advances point to the complexity of the problem and a final resolution to this ongoing debate demands additional work from both paleontological and developmental perspectives, which will surely yield new insights on mechanisms of evolutionary adaptation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Unsteady fluid dynamics around a hovering wing

    Science.gov (United States)

    Krishna, Swathi; Green, Melissa; Mulleners, Karen

    2017-11-01

    The unsteady flow around a hovering flat plate wing has been investigated experimentally using particle image velocimetry and direct force measurements. The measurements are conducted on a wing that rotates symmetrically about the stroke reversal at a reduced frequency of k = 0.32 and Reynolds number of Re = 220 . The Lagrangian finite-time Lyapunov exponent method is used to analyse the unsteady flow fields by identifying dynamically relevant flow features such as the primary leading edge vortex (LEV), secondary vortices, and topological saddles, and their evolution within a flapping cycle. The flow evolution is divided into four stages that are characterised by the LEV (a)emergence, (b)growth, (c)lift-off, and (d)breakdown and decay. Tracking saddle points is shown to be helpful in defining the LEV lift-off which occurs at the maximum stroke velocity. The flow fields are correlated with the aerodynamic forces revealing that the maximum lift and drag are observed just before LEV lift-off. The end of wing rotation in the beginning of the stroke stimulates a change in the direction of the LEV growth and the start of rotation at the end of the stroke triggers the breakdown of the LEV.

  18. A Systems Engineering Approach in Providing Air Defense Support to Ground Combat Vehicle Maneuver Forces

    Science.gov (United States)

    2015-03-01

    SLAMRAAM surface launched advanced medium range air-to-air missile SME subject matter expert SOS system of systems UAV unmanned aerial vehicle UCAV ...threats of fixed wing aircraft and attack helicopters, unmanned aerial vehicles (UAVs) and unmanned combat aerial vehicles ( UCAVs ) are fast becoming a... UCAVs and capable of conducting offensive attacks. UAVs/ UCAVs are physically smaller in size compared to fixed wing aircraft or attack helicopters and

  19. Golden Legacy, Boundless Future: Essays on the United States Air Force and the Rise of Aerospace Power

    Science.gov (United States)

    2000-01-01

    Charles A. Ravenstein , The Organization and Lineage of the United States Air Force (D.C.: Office of Air Force History, 1986), 17. 13. James L... Ravenstein , Air Force Combat Wings: Lineage and Honors, 1947-1977 (Washington, D.C: Office of Air Force History, 1984), pp. 47-48, 88-89. 14. Monograph, "H 0

  20. Wing geometry of Triatoma sordida (Hemiptera: Reduviidae) populations from Brazil.

    Science.gov (United States)

    Vendrami, Daniel Pagotto; Obara, Marcos Takashi; Gurgel-Gonçalves, Rodrigo; Ceretti-Junior, Walter; Marrelli, Mauro Toledo

    2017-04-01

    Triatoma sordida has a widespread distribution in Argentina, Bolivia, Brazil, Paraguay, and Uruguay and is frequently found in peridomestic environments. We investigated size and shape variability of T. sordida wings across Brazil. Field-collected adults from twelve populations were studied. For each individual female, seven landmarks on the right wing were digitalized. Shape variables derived from Procrustes superimposition were used in Principal Component Analysis (PCA). Wing size and shape variations among populations was explored by means of ANOVA. Wing centroid size was significantly different among T. sordida populations; specimens from Bahia (East) were larger than those of Mato Grosso do Sul (West). PCA based on wing shape variables showed low wing shape variability. These results reinforce previous data showing low genetic variability among T. sordida populations from Brazil. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Free vibration analysis of dragonfly wings using finite element method

    OpenAIRE

    M Darvizeh; A Darvizeh; H Rajabi; A Rezaei

    2016-01-01

    In the present work, investigations on the microstructure and mechanicalproperties of the dragonfly wing are carried out and numerical modelingbased on Finite Element Method (FEM) is developed to predict Flightcharacteristics of dragonfly wings. Vibrational behavior of wings typestructures is immensely important in analysis, design and manufacturing ofsimilar engineering structures. For this purpose natural frequencies andmode shapes are calculated. In addition, the kind of deformation in eac...

  2. Poster Puzzler Solution: Taking in Air | Poster

    Science.gov (United States)

    The current Poster Puzzler image shows the top of Building 560, where a new supply air handler was recently installed by Facilities Maintenance and Engineering (FME) staff, as part of lab renovations in wing 1, floor 1. FME staff enlarged the attic of the building to make space for the air handler. Building 560, the largest building at the NCI at Frederick campus, houses about 120 labs and has 19 air handlers. A supply air handler draws in outside air, filters it, cools or heats it, and adjusts the humidity to provide clean conditioned air to the laboratories. The Building 560 air handler weighs approximately 22,500 pounds and moves 22,000 cubic feet of air per minute.

  3. Investigation and design of a C-Wing passenger aircraft

    Directory of Open Access Journals (Sweden)

    Karan BIKKANNAVAR

    2016-06-01

    Full Text Available A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in a reduction of required fuel mass by 16%. Also take-off mass savings were obtained for the aircraft with C-Wing configuration. The effect of a variations of height to span ratio (h/b of C-Wings on induced drag factor k, is formulated from a vortex lattice method and literature based equations. Finally the DOC costing methods used by the Association of European Airlines (AEA was applied to the existing A320 aircraft and to the C-Wing configuration obtaining a reduction of 6% in Direct Operating Costs (DOC for the novel concept resulted. From overall outcomes, the C-Wing concept suggests interesting aerodynamic efficiency and stability benefits.

  4. Effects of Canard on the Flowfield over a Wing

    Science.gov (United States)

    Nayebzadeh, Arash

    2015-11-01

    Surface and flowfield pressure measurements have been done over delta wing/canard configuration in a variety of canard vertical and horizontal locations and angles of attack. The experimental model consisted of wing, canard and a body to accommodate pressure tubing and canard rotation mechanism. All the tests have been performed at subsonic velocities and the effect of canard were analyzed through comparison between surface and flowfield pressure distributions. It was found that vortex flow pattern over the wing is dominated mainly by canard vertical position and in some cases, by merging of canard and wing vortices. In addition, the pressure loss induced by canard vortex on the wing surface moves the wing vortex toward the leading edge. In the mid canard configuration, canard and wing vortices merge at x/c greater than 0.5 and as a result of this phenomenon, abrupt pressure loss induces more stable vortex flow over the wing. It is also shown that canard plays a vital role in vortex break down over the wing.

  5. Improvement of the aerodynamic performance by wing flexibility and elytra–hind wing interaction of a beetle during forward flight

    Science.gov (United States)

    Le, Tuyen Quang; Truong, Tien Van; Park, Soo Hyung; Quang Truong, Tri; Ko, Jin Hwan; Park, Hoon Cheol; Byun, Doyoung

    2013-01-01

    In this work, the aerodynamic performance of beetle wing in free-forward flight was explored by a three-dimensional computational fluid dynamics (CFDs) simulation with measured wing kinematics. It is shown from the CFD results that twist and camber variation, which represent the wing flexibility, are most important when determining the aerodynamic performance. Twisting wing significantly increased the mean lift and camber variation enhanced the mean thrust while the required power was lower than the case when neither was considered. Thus, in a comparison of the power economy among rigid, twisting and flexible models, the flexible model showed the best performance. When the positive effect of wing interaction was added to that of wing flexibility, we found that the elytron created enough lift to support its weight, and the total lift (48.4 mN) generated from the simulation exceeded the gravity force of the beetle (47.5 mN) during forward flight. PMID:23740486

  6. 76 FR 75453 - Restricted Areas and Danger Zones at Eglin Air Force Base, FL

    Science.gov (United States)

    2011-12-02

    ... and Danger Zones at Eglin Air Force Base, FL AGENCY: U.S. Army Corps of Engineers, Department of... within the Eglin Air Force Base (AFB) facilities and along the Eglin AFB facility shoreline in Florida... have the permission of the Commander, 96 Air Base Wing, Eglin AFB or his/her authorized representative...

  7. Folding wings like a cockroach: a review of transverse wing folding ensign wasps (Hymenoptera: Evaniidae: Afrevania and Trissevania.

    Directory of Open Access Journals (Sweden)

    István Mikó

    Full Text Available We revise two relatively rare ensign wasp genera, whose species are restricted to Sub-Saharan Africa: Afrevania and Trissevania. Afrevania longipetiolata sp. nov., Trissevania heatherae sp. nov., T. hugoi sp. nov., T. mrimaensis sp. nov. and T. slideri sp. nov. are described, males and females of T. anemotis and Afrevania leroyi are redescribed, and an identification key for Trissevaniini is provided. We argue that Trissevania mrimaensis sp. nov. and T. heatherae sp. nov. populations are vulnerable, given their limited distributions and threats from mining activities in Kenya. We hypothesize that these taxa together comprise a monophyletic lineage, Trissevaniini, tr. nov., the members of which share the ability to fold their fore wings along two intersecting fold lines. Although wing folding of this type has been described for the hind wing of some insects four-plane wing folding of the fore wing has never been documented. The wing folding mechanism and the pattern of wing folds of Trissevaniini is shared only with some cockroach species (Blattodea. It is an interesting coincidence that all evaniids are predators of cockroach eggs. The major wing fold lines of Trissevaniini likely are not homologous to any known longitudinal anatomical structures on the wings of other Evaniidae. Members of the new tribe share the presence of a coupling mechanism between the fore wing and the mesosoma that is composed of a setal patch on the mesosoma and the retinaculum of the fore wing. While the setal patch is an evolutionary novelty, the retinaculum, which originally evolved to facilitate fore and hind wing coupling in Hymenoptera, exemplifies morphological exaptation. We also refine and clarify the Semantic Phenotype approach used in previous taxonomic revisions and explore the consequences of merging new with existing data. The way that semantic statements are formulated can evolve in parallel, alongside improvements to the ontologies themselves.

  8. Cantilever Wings for Modern Aircraft: Some Aspects of Cantilever Wing Construction with Special Reference to Weight and Torsional Stiffness

    Science.gov (United States)

    Stieger, H J

    1929-01-01

    In the foregoing remarks I have made an attempt to touch on some of the structural problems met with in cantilever wings, and dealt rather fully with a certain type of single-spar construction. The experimental test wing was a first attempt to demonstrate the principles of this departure from orthodox methods. The result was a wing both torsionally stiff and of light weight - lighter than a corresponding biplane construction.

  9. Variable multilayer reflection together with long-pass filtering pigment determines the wing coloration of papilionid butterflies of the nireus group

    NARCIS (Netherlands)

    Trzeciak, Tomasz M.; Wilts, Bodo D.; Stavenga, Doekele G.; Vukusic, Peter; Sterke, C. Martijn de

    2012-01-01

    The dorsal wing surfaces of papilionid butterflies of the nireus group are marked by bands of brilliant blue-green-colored cover scales. The thin, cuticular lower lamina of the scales acts as a blue reflector. The thick upper lamina forms a dense two-dimensional cuticular lattice of air cavities

  10. Demonstration of an in situ morphing hyperelliptical cambered span wing mechanism

    International Nuclear Information System (INIS)

    Manzo, Justin; Garcia, Ephrahim

    2010-01-01

    Research on efficient shore bird morphology inspired the hyperelliptical cambered span (HECS) wing, a crescent-shaped, aft-swept wing with vertically oriented wingtips. The wing reduces vorticity-induced circulation loss and outperforms an elliptical baseline when planar. Designed initially as a rigid wing, the HECS wing makes use of morphing to transition from a planar to a furled configuration, similar to that of a continuously curved winglet, in flight. A morphing wing concept mechanism is presented, employing shape memory alloy actuators to create a discretized curvature approximation. The aerodynamics for continuous wing shapes is validated quasi-statically through wind tunnel testing, showing enhanced planar HECS wing lift-to-drag performance over an elliptical wing, with the furled HECS wing showing minimal enhancements beyond this point. Wind tunnel tests of the active morphing wing prove the mechanism capable of overcoming realistic loading, while further testing may be required to establish aerodynamic merits of the HECS wing morphing maneuver

  11. A novel hovering type of fixed wing aircraft with stealth capability

    Directory of Open Access Journals (Sweden)

    Valeriu DRĂGAN

    2010-12-01

    Full Text Available The tactical need for fixed wing aircraft with hovering capably has long been recognized bythe military for two reasons: increased safety when landing on aircraft carriers and higher velocitiesthat the ones obtainable with rotary wing aircraft.Thus far, the only concept governing the field of vertical flight was to use thrust either from a liftfan-F35, puffer ducts –Harrier or smaller jet engines-D0 31 or Yak-141, i.e. direct lift thrust.In this paper we will look at the prospect of using a combination of the Coanda effect with theVenturi effect to generate lift by so- called “supercirculation”. This novel approach can yield manyadvantages to conventional vertical lifting by providing a more stable platform and requiring lowerpower settings – and thus lower fuel consumption.The aircraft has a fixed, negatively sweped wing that uses circulation control to achieve lift atzero air speed. The fluid used for supercirculation will come from the fan thrust reversers – which, ifcorrectly managed, can give a sufficient flow for lifting the craft and also a negative thrust componentto compensate for the positive thrust of the primary flow (not diverted.

  12. Flight dynamic investigations of flying wing with winglet configured unmanned aerial vehicle

    Science.gov (United States)

    Ro, Kapseong

    2006-05-01

    A swept wing tailless vehicle platform is well known in the radio control (RC) and sailing aircraft community for excellent spiral stability during soaring or thermaling, while exhibiting no Dutch roll behavior at high speed. When an unmanned aerial vehicle (UAV) is subjected to fly a mission in a rugged mountainous terrain where air current or thermal up-drift is frequently present, this is great aerodynamic benefit over the conventional cross-tailed aircraft which requires careful balance between lateral and directional stability. Such dynamic characteristics can be studied through vehicle dynamic modeling and simulation, but it requires configuration aerodynamic data through wind tunnel experiments. Obtaining such data is very costly and time consuming, and it is not feasible especially for low cost and dispensable UAVs. On the other hand, the vehicle autonomy is quite demanding which requires substantial understanding of aircraft dynamic characteristics. In this study, flight dynamics of an UAV platform based on flying wing with a large winglet was investigated through analytical modeling and numerical simulation. Flight dynamic modeling software and experimental formulae were used to obtain essential configuration aerodynamic characteristics, and linear flight dynamic analysis was carried out to understand the effect of wing sweep angle and winglet size on the vehicle dynamic characteristics.

  13. Measurement of circulation around wing-tip vortices and estimation of lift forces using stereo PIV

    Science.gov (United States)

    Asano, Shinichiro; Sato, Haru; Sakakibara, Jun

    2017-11-01

    Applying the flapping flight to the development of an aircraft as Mars space probe and a small aircraft called MAV (Micro Air Vehicle) is considered. This is because Reynolds number assumed as the condition of these aircrafts is low and similar to of insects and small birds flapping on the earth. However, it is difficult to measure the flow around the airfoil in flapping flight directly because of its three-dimensional and unsteady characteristics. Hence, there is an attempt to estimate the flow field and aerodynamics by measuring the wake of the airfoil using PIV, for example the lift estimation method based on a wing-tip vortex. In this study, at the angle of attack including the angle after stall, we measured the wing-tip vortex of a NACA 0015 cross-sectional and rectangular planform airfoil using stereo PIV. The circulation of the wing-tip vortex was calculated from the obtained velocity field, and the lift force was estimated based on Kutta-Joukowski theorem. Then, the validity of this estimation method was examined by comparing the estimated lift force and the force balance data at various angles of attack. The experiment results are going to be presented in the conference.

  14. Control of wing-tip vortex using winglets at low Reynolds number

    Science.gov (United States)

    Cho, Seunghyun; Choi, Haecheon

    2014-11-01

    Winglets are considered as one of the effective devices for reducing induced drag, and thus many studies have been conducted, but mainly at high Reynolds numbers (Re ~106 ~107) for commercial airplanes. However, small-size unmanned air vehicles (UAV), operating at low Reynolds numbers (Re PIV measurements are conducted at several cross-flow planes for a few different angles of attack (α) . At high angles of attack (7° ~13°) , the winglets with the cant angle of 70° increase the aerodynamic performance, whereas at low angles of attack (2° ~6°) , the wing-tip extension (cant angle of 0°) shows better performances. The velocity fields measured from PIV indicate that, with the winglet, the wing-tip vortex moves away from the wing surface at α =12° , and the downwash motion in the wake behind the trailing edge is decreased, reducing the magnitude of the induced drag. A concept of changing the cant angle during flight is also suggested at this talk. Supported by 2011-0028032.

  15. Biomechanics of smart wings in a bat robot: morphing wings using SMA actuators

    International Nuclear Information System (INIS)

    Colorado, J; Barrientos, A; Rossi, C; Breuer, K S

    2012-01-01

    This paper presents the design of a bat-like micro aerial vehicle with actuated morphing wings. NiTi shape memory alloys (SMAs) acting as artificial biceps and triceps muscles are used for mimicking the morphing wing mechanism of the bat flight apparatus. Our objective is twofold. Firstly, we have implemented a control architecture that allows an accurate and fast SMA actuation. This control makes use of the electrical resistance measurements of SMAs to adjust morphing wing motions. Secondly, the feasibility of using SMA actuation technology is evaluated for the application at hand. To this purpose, experiments are conducted to analyze the control performance in terms of nominal and overloaded operation modes of the SMAs. This analysis includes: (i) inertial forces regarding the stretchable wing membrane and aerodynamic loads, and (ii) uncertainties due to impact of airflow conditions over the resistance–motion relationship of SMAs. With the proposed control, morphing actuation speed can be increased up to 2.5 Hz, being sufficient to generate lift forces at a cruising speed of 5 m s −1 . (paper)

  16. Biomechanics of smart wings in a bat robot: morphing wings using SMA actuators.

    Science.gov (United States)

    Colorado, J; Barrientos, A; Rossi, C; Bahlman, J W; Breuer, K S

    2012-09-01

    This paper presents the design of a bat-like micro aerial vehicle with actuated morphing wings. NiTi shape memory alloys (SMAs) acting as artificial biceps and triceps muscles are used for mimicking the morphing wing mechanism of the bat flight apparatus. Our objective is twofold. Firstly, we have implemented a control architecture that allows an accurate and fast SMA actuation. This control makes use of the electrical resistance measurements of SMAs to adjust morphing wing motions. Secondly, the feasibility of using SMA actuation technology is evaluated for the application at hand. To this purpose, experiments are conducted to analyze the control performance in terms of nominal and overloaded operation modes of the SMAs. This analysis includes: (i) inertial forces regarding the stretchable wing membrane and aerodynamic loads, and (ii) uncertainties due to impact of airflow conditions over the resistance-motion relationship of SMAs. With the proposed control, morphing actuation speed can be increased up to 2.5 Hz, being sufficient to generate lift forces at a cruising speed of 5 m s(-1).

  17. A parametric wing design study for a modern laminar flow wing

    Science.gov (United States)

    Koegler, J. A., Jr.

    1979-01-01

    The results of a parametric wing design study using a modern laminar flow airfoil designed to exhibit desirable stall characteristics while maintaining high cruise performance are presented. It was found that little is sacrificed in cruise performance when satisfying the stall margin requirements if a taper ratio of 0.65 or greater is used.

  18. SUPERDENSE MASSIVE GALAXIES IN WINGS LOCAL CLUSTERS

    International Nuclear Information System (INIS)

    Valentinuzzi, T.; D'Onofrio, M.; Fritz, J.; Poggianti, B. M.; Bettoni, D.; Fasano, G.; Moretti, A.; Omizzolo, A.; Varela, J.; Cava, A.; Couch, W. J.; Dressler, A.; Moles, M.; Kjaergaard, P.; Vanzella, E.

    2010-01-01

    Massive quiescent galaxies at z > 1 have been found to have small physical sizes, and hence to be superdense. Several mechanisms, including minor mergers, have been proposed for increasing galaxy sizes from high- to low-z. We search for superdense massive galaxies in the WIde-field Nearby Galaxy-cluster Survey (WINGS) of X-ray selected galaxy clusters at 0.04 10 M sun , are mostly S0 galaxies, have a median effective radius (R e ) = 1.61 ± 0.29 kpc, a median Sersic index (n) = 3.0 ± 0.6, and very old stellar populations with a median mass-weighted age of 12.1 ± 1.3 Gyr. We calculate a number density of 2.9 x 10 -2 Mpc -3 for superdense galaxies in local clusters, and a hard lower limit of 1.3 x 10 -5 Mpc -3 in the whole comoving volume between z = 0.04 and z = 0.07. We find a relation between mass, effective radius, and luminosity-weighted age in our cluster galaxies, which can mimic the claimed evolution of the radius with redshift, if not properly taken into account. We compare our data with spectroscopic high-z surveys and find that-when stellar masses are considered-there is consistency with the local WINGS galaxy sizes out to z ∼ 2, while a discrepancy of a factor of 3 exists with the only spectroscopic z > 2 study. In contrast, there is strong evidence for a large evolution in radius for the most massive galaxies with M * > 4 x 10 11 M sun compared to similarly massive galaxies in WINGS, i.e., the brightest cluster galaxies.

  19. Effects of boundary layer forcing on wing-tip vortices

    Science.gov (United States)

    Shaw-Ward, Samantha

    The nature of turbulence within wing-tip vortices has been a topic of research for decades, yet accurate measurements of Reynolds stresses within the core are inherently difficult due to the bulk motion wandering caused by initial and boundary conditions in wind tunnels. As a result, characterization of a vortex as laminar or turbulent is inconclusive and highly contradicting. This research uses several experimental techniques to study the effects of broadband turbulence, introduced within the wing boundary layer, on the development of wing-tip vortices. Two rectangular wings with a NACA 0012 profile were fabricated for the use of this research. One wing had a smooth finish and the other rough, introduced by P80 grade sandpaper. Force balance measurements showed a small reduction in wing performance due to surface roughness for both 2D and 3D configurations, although stall characteristics remained relatively unchanged. Seven-hole probes were purpose-built and used to assess the mean velocity profiles of the vortices five chord lengths downstream of the wing at multiple angles of attack. Above an incidence of 4 degrees, the vortices were nearly axisymmetric, and the wing roughness reduced both velocity gradients and peak velocity magnitudes within the vortex. Laser Doppler velocimetry was used to further assess the time-resolved vortex at an incidence of 5 degrees. Evidence of wake shedding frequencies and wing shear layer instabilities at higher frequencies were seen in power spectra within the vortex. Unlike the introduction of freestream turbulence, wing surface roughness did not appear to increase wandering amplitude. A new method for removing the effects of vortex wandering is proposed with the use of carefully selected high-pass filters. The filtered data revealed that the Reynolds stress profiles of the vortex produced by the smooth and rough wing were similar in shape, with a peak occurring away from the vortex centre but inside of the core. Single hot

  20. Folding in and out: passive morphing in flapping wings.

    Science.gov (United States)

    Stowers, Amanda K; Lentink, David

    2015-03-25

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  1. Spatial perturbation of a wing-tip vortex using pulsed span-wise jets

    Science.gov (United States)

    Heyes, A. L.; Smith, D. A. R.

    The separation distance required between transport aircraft to avoid wake vortices remains a limiting factor on airport capacity. The dissipation of the wake can be accelerated by perturbing co-operative instabilities between multiple pairs of vortices. This paper presents the results of a preliminary experimental investigation into the use of pulsed span-wise air jets in the wing tip to perturb a single tip vortex in the very near field. Velocity measurements were made using PIV and hot-wire anemometry. The results demonstrate that the vortex position can be modulated at frequencies up to 50 Hz and, as such, the method shows promise for forcing instability in multiple vortex wakes.

  2. Video change detection for fixed wing UAVs

    Science.gov (United States)

    Bartelsen, Jan; Müller, Thomas; Ring, Jochen; Mück, Klaus; Brüstle, Stefan; Erdnüß, Bastian; Lutz, Bastian; Herbst, Theresa

    2017-10-01

    In this paper we proceed the work of Bartelsen et al.1 We present the draft of a process chain for an image based change detection which is designed for videos acquired by fixed wing unmanned aerial vehicles (UAVs). From our point of view, automatic video change detection for aerial images can be useful to recognize functional activities which are typically caused by the deployment of improvised explosive devices (IEDs), e.g. excavations, skid marks, footprints, left-behind tooling equipment, and marker stones. Furthermore, in case of natural disasters, like flooding, imminent danger can be recognized quickly. Due to the necessary flight range, we concentrate on fixed wing UAVs. Automatic change detection can be reduced to a comparatively simple photogrammetric problem when the perspective change between the "before" and "after" image sets is kept as small as possible. Therefore, the aerial image acquisition demands a mission planning with a clear purpose including flight path and sensor configuration. While the latter can be enabled simply by a fixed and meaningful adjustment of the camera, ensuring a small perspective change for "before" and "after" videos acquired by fixed wing UAVs is a challenging problem. Concerning this matter, we have performed tests with an advanced commercial off the shelf (COTS) system which comprises a differential GPS and autopilot system estimating the repetition accuracy of its trajectory. Although several similar approaches have been presented,23 as far as we are able to judge, the limits for this important issue are not estimated so far. Furthermore, we design a process chain to enable the practical utilization of video change detection. It consists of a front-end of a database to handle large amounts of video data, an image processing and change detection implementation, and the visualization of the results. We apply our process chain on the real video data acquired by the advanced COTS fixed wing UAV and synthetic data. For the

  3. How wing kinematics affect power requirements and aerodynamic force production in a robotic bat wing

    International Nuclear Information System (INIS)

    Bahlman, Joseph W; Swartz, Sharon M; Breuer, Kenneth S

    2014-01-01

    Bats display a wide variety of behaviors that require different amounts of aerodynamic force. To control and modulate aerodynamic force, bats change wing kinematics, which, in turn, may change the power required for wing motion. There are many kinematic mechanisms that bats, and other flapping animals, can use to increase aerodynamic force, e.g. increasing wingbeat frequency or amplitude. However, we do not know if there is a difference in energetic cost between these different kinematic mechanisms. To assess the relationship between mechanical power input and aerodynamic force output across different isolated kinematic parameters, we programmed a robotic bat wing to flap over a range of kinematic parameters and measured aerodynamic force and mechanical power. We systematically varied five kinematic parameters: wingbeat frequency, wingbeat amplitude, stroke plane angle, downstroke ratio, and wing folding. Kinematic values were based on observed values from free flying Cynopterus brachyotis, the species on which the robot was based. We describe how lift, thrust, and power change with increases in each kinematic variable. We compare the power costs associated with generating additional force through the four kinematic mechanisms controlled at the shoulder, and show that all four mechanisms require approximately the same power to generate a given force. This result suggests that no single parameter offers an energetic advantage over the others. Finally, we show that retracting the wing during upstroke reduces power requirements for flapping and increases net lift production, but decreases net thrust production. These results compare well with studies performed on C. brachyotis, offering insight into natural flight kinematics. (paper)

  4. Preliminary wing model tests in the variable density wind tunnel of the National Advisory Committee for Aeronautics

    Science.gov (United States)

    Munk, Max M

    1926-01-01

    This report contains the results of a series of tests with three wing models. By changing the section of one of the models and painting the surface of another, the number of models tested was increased to five. The tests were made in order to obtain some general information on the air forces on wing sections at a high Reynolds number and in particular to make sure that the Reynolds number is really the important factor, and not other things like the roughness of the surface and the sharpness of the trailing edge. The few tests described in this report seem to indicate that the air forces at a high Reynolds number are not equivalent to respective air forces at a low Reynolds number (as in an ordinary atmospheric wind tunnel). The drag appears smaller at a high Reynolds number and the maximum lift is increased in some cases. The roughness of the surface and the sharpness of the trailing edge do not materially change the results, so that we feel confident that tests with systematic series of different wing sections will bring consistent results, important and highly useful to the designer.

  5. Blended Wing Body Concept Development with Open Rotor Engine Intergration

    Science.gov (United States)

    Pitera, David M.; DeHaan, Mark; Brown, Derrell; Kawai, Ronald T.; Hollowell, Steve; Camacho, Peter; Bruns, David; Rawden, Blaine K.

    2011-01-01

    The purpose of this study is to perform a systems analysis of a Blended Wing Body (BWB) open rotor concept at the conceptual design level. This concept will be utilized to estimate overall noise and fuel burn performance, leveraging recent test data. This study will also investigate the challenge of propulsion airframe installation of an open rotor engine on a BWB configuration. Open rotor engines have unique problems relative to turbofans. The rotors are open, exposed to flow conditions outside of the engine. The flow field that the rotors are immersed in may be higher than the free stream flow and it may not be uniform, both of these characteristics could increase noise and decrease performance. The rotors sometimes cause changes in the flow conditions imposed on aircraft surfaces. At high power conditions such as takeoff and climb out, the stream tube of air that goes through the rotors contracts rapidly causing the boundary layer on the body upper surface to go through an adverse pressure gradient which could result with separated airflow. The BWB / Open Rotor configuration must be designed to mitigate these problems.

  6. Small-scale fixed wing airplane software verification flight test

    Science.gov (United States)

    Miller, Natasha R.

    The increased demand for micro Unmanned Air Vehicles (UAV) driven by military requirements, commercial use, and academia is creating a need for the ability to quickly and accurately conduct low Reynolds Number aircraft design. There exist several open source software programs that are free or inexpensive that can be used for large scale aircraft design, but few software programs target the realm of low Reynolds Number flight. XFLR5 is an open source, free to download, software program that attempts to take into consideration viscous effects that occur at low Reynolds Number in airfoil design, 3D wing design, and 3D airplane design. An off the shelf, remote control airplane was used as a test bed to model in XFLR5 and then compared to flight test collected data. Flight test focused on the stability modes of the 3D plane, specifically the phugoid mode. Design and execution of the flight tests were accomplished for the RC airplane using methodology from full scale military airplane test procedures. Results from flight test were not conclusive in determining the accuracy of the XFLR5 software program. There were several sources of uncertainty that did not allow for a full analysis of the flight test results. An off the shelf drone autopilot was used as a data collection device for flight testing. The precision and accuracy of the autopilot is unknown. Potential future work should investigate flight test methods for small scale UAV flight.

  7. Design and Performance of Insect-Scale Flapping-Wing Vehicles

    Science.gov (United States)

    Whitney, John Peter

    Micro-air vehicles (MAVs)---small versions of full-scale aircraft---are the product of a continued path of miniaturization which extends across many fields of engineering. Increasingly, MAVs approach the scale of small birds, and most recently, their sizes have dipped into the realm of hummingbirds and flying insects. However, these non-traditional biologically-inspired designs are without well-established design methods, and manufacturing complex devices at these tiny scales is not feasible using conventional manufacturing methods. This thesis presents a comprehensive investigation of new MAV design and manufacturing methods, as applicable to insect-scale hovering flight. New design methods combine an energy-based accounting of propulsion and aerodynamics with a one degree-of-freedom dynamic flapping model. Important results include analytical expressions for maximum flight endurance and range, and predictions for maximum feasible wing size and body mass. To meet manufacturing constraints, the use of passive wing dynamics to simplify vehicle design and control was investigated; supporting tests included the first synchronized measurements of real-time forces and three-dimensional kinematics generated by insect-scale flapping wings. These experimental methods were then expanded to study optimal wing shapes and high-efficiency flapping kinematics. To support the development of high-fidelity test devices and fully-functional flight hardware, a new class of manufacturing methods was developed, combining elements of rigid-flex printed circuit board fabrication with "pop-up book" folding mechanisms. In addition to their current and future support of insect-scale MAV development, these new manufacturing techniques are likely to prove an essential element to future advances in micro-optomechanics, micro-surgery, and many other fields.

  8. Morphing Wing Design with an Innovative Three-Dimensional Warping Actuation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced wing configurations where traditional control surfaces are replaced by dynamically controlled distribution of wing twist and/or camber can provide...

  9. Variable Geometry Aircraft Wing Supported by Struts And/Or Trusses

    Science.gov (United States)

    Melton, John E. (Inventor); Dudley, Michael R. (Inventor)

    2016-01-01

    The present invention provides an aircraft having variable airframe geometry for accommodating efficient flight. The aircraft includes an elongated fuselage, an oblique wing pivotally connected with said fuselage, a wing pivoting mechanism connected with said oblique wing and said fuselage, and a brace operably connected between said oblique wing and said fuselage. The present invention also provides an aircraft having an elongated fuselage, an oblique wing pivotally connected with said fuselage, a wing pivoting mechanism connected with said oblique wing and said fuselage, a propulsion system pivotally connected with said oblique wing, and a brace operably connected between said propulsion system and said fuselage.

  10. Numerical simulation of X-wing type biplane flapping wings in 3D using the immersed boundary method

    International Nuclear Information System (INIS)

    Tay, W B; Van Oudheusden, B W; Bijl, H

    2014-01-01

    The numerical simulation of an insect-sized ‘X-wing’ type biplane flapping wing configuration is performed in 3D using an immersed boundary method solver at Reynolds numbers equal to 1000 (1 k) and 5 k, based on the wing's root chord length. This X-wing type flapping configuration draws its inspiration from Delfly, a bio-inspired ornithopter MAV which has two pairs of wings flapping in anti-phase in a biplane configuration. The objective of the present investigation is to assess the aerodynamic performance when the original Delfly flapping wing micro-aerial vehicle (FMAV) is reduced to the size of an insect. Results show that the X-wing configuration gives more than twice the average thrust compared with only flapping the upper pair of wings of the X-wing. However, the X-wing's average thrust is only 40% that of the upper wing flapping at twice the stroke angle. Despite this, the increased stability which results from the smaller lift and moment variation of the X-wing configuration makes it more suited for sharp image capture and recognition. These advantages make the X-wing configuration an attractive alternative design for insect-sized FMAVS compared to the single wing configuration. In the Reynolds number comparison, the vorticity iso-surface plot at a Reynolds number of 5 k revealed smaller, finer vortical structures compared to the simulation at 1 k, due to vortices’ breakup. In comparison, the force output difference is much smaller between Re = 1 k and 5 k. Increasing the body inclination angle generates a uniform leading edge vortex instead of a conical one along the wingspan, giving higher lift. Understanding the force variation as the body inclination angle increases will allow FMAV designers to optimize the thrust and lift ratio for higher efficiency under different operational requirements. Lastly, increasing the spanwise flexibility of the wings increases the thrust slightly but decreases the efficiency. The thrust result is similar

  11. Air Research

    Science.gov (United States)

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  12. Wing design for light transport aircraft with improved fuel economy

    Energy Technology Data Exchange (ETDEWEB)

    Welte, D.; Birrenbach, R.; Haberland, W.

    An advanced technology wing has been designed for a light utility and commuter service aircraft with the requirements for economy, safety and flexibility. Trade-off studies give optimum area and aspect-ratio of the wing. A new airfoil was developed to fulfill the performance requirements. Wing planform and twist were chosen to give high maximum lift, low drag and good stall characteristics. Preset ailerons were optimized for wheel forces and lateral control. The applied aerodynamic methods, including two- and three-dimensional wind tunnel tests are shown. Various structural configurations of the wing and various flap systems are evaluated. The cantilever tapered wing and a Fowler-flap with a two-lever mechanism were found to be the most economic ones. The wing was constructed and flight-tested with a modified Dornier Do 28 Skyservant as a test bed. The new wing is being applied to a family of light transport aircraft. Finally, aircraft with the new wing are compared performancewise with contemporary aircraft.

  13. Design and Testing of Aeroelastically Tailored Wings Under Maneuver Loading

    NARCIS (Netherlands)

    Werter, N.P.M.; Sodja, J.; De Breuker, R.

    2016-01-01

    The goal of the present paper is to provide experimental validation data for the aeroelastic analysis of composite aeroelastically tailored wings with a closed-cell cross-sectional structure. Several rectangular wings with differ- ent skin thicknesses and composite layups are designed in order to

  14. Optimisation of the Sekwa blended-wing-Body research UAV

    CSIR Research Space (South Africa)

    Broughton, BA

    2008-10-01

    Full Text Available A variable stability, blended-wing-body research mini-UAV was developed at the CSIR in South Africa. The purpose of the UAV was to study some of the aerodynamic design and control issues associated with flying wing geometries and to develop a...

  15. Flapping-wing mechanical butterfly on a wheel

    Science.gov (United States)

    Godoy-Diana, Ramiro; Thiria, Benjamin; Pradal, Daniel

    2009-11-01

    We examine the propulsive performance of a flapping-wing device turning on a ``merry-go-round'' type base. The two-wing flapper is attached to a mast that is ball-bearing mounted to a central shaft in such a way that the thrust force produced by the wings makes the flapper turn around this shaft. The oscillating lift force produced by the flapping wings is aligned with the mast to avoid vibration of the system. A turning contact allows to power the motor that drives the wings. We measure power consumption and cruising speed as a function of flapping frequency and amplitude as well as wing flexibility. The design of the wings permits to change independently their flexibility in the span-wise and chord-wise directions and PIV measurements in various planes let us examine the vorticity field around the device. A complete study of the effect of wing flexibility on the propulsive performance of the system will be presented at the conference.

  16. Use of wing morphometry for the discrimination of some Cerceris ...

    African Journals Online (AJOL)

    The outline analysis, in which geometric and traditional morphometry potentials are insufficient, was performed by using the Fourier transformation. As a result of the comprehensive wing morphometry study, it was found that both Cerceris species can be distinguished according to their wing structures and the metric ...

  17. Energy-based Aeroelastic Analysis and Optimisation of Morphing Wings

    NARCIS (Netherlands)

    De Breuker, R.

    2011-01-01

    Morphing aircraft can change their shape radically when confronted with a variety of conflicting flight conditions throughout their mission. For instance the F-14 Tomcat fighter aircraft, known from the movie Top Gun, was able to sweep its wings from a straight wing configuration to a highly swept

  18. COLIBRI : A hovering flapping twin-wing robot

    NARCIS (Netherlands)

    Roshanbin, A.; Altartouri, H.; Karasek, M.; Preumont, André

    2017-01-01

    This paper describes the results of a six-year project aiming at designing and constructing a flapping twin-wing robot of the size of hummingbird (Colibri in French) capable of hovering. Our prototype has a total mass of 22 g, a wing span of 21 cm and a flapping frequency of 22 Hz; it is actively

  19. Design, Development and Testing of Shape Shifting Wing Model

    Directory of Open Access Journals (Sweden)

    Dean Ninian

    2017-11-01

    Full Text Available The design and development of morphing (shape shifting aircraft wings—an innovative technology that has the potential to increase the aerodynamic efficiency and reduce noise signatures of aircrafts—was carried out. This research was focused on reducing lift-induced drag at the flaps of the aerofoil and to improve the design to achieve the optimum aerodynamic efficiency. Simulation revealed a 10.8% coefficient of lift increase for the initial morphing wing and 15.4% for the optimized morphing wing as compared to conventional wing design. At angles of attack of 0, 5, 10 and 15 degrees, the optimized wing has an increase in lift-to-drag ratio of 18.3%, 10.5%, 10.6% and 4% respectively when compared with the conventional wing. Simulations also showed that there is a significant improvement on pressure distribution over the lower surface of the morphing wing aerofoil. The increase in flow smoothness and reduction in vortex size reduced pressure drag along the trailing edge of the wing as a result an increase in pressure on the lower surface was experienced. A morphing wing reduced the size of the vortices and therefore the noise levels measured were reduced by up to 50%.

  20. Temporal variation of wing geometry in Aedes albopictus

    Directory of Open Access Journals (Sweden)

    Paloma Oliveira Vidal

    2012-12-01

    Full Text Available Although native to the tropical and subtropical areas of Southeast Asia, Aedes albopictus is now found on five continents, primarily due to its great capacity to adapt to different environments. This species is considered a secondary vector of dengue virus in several countries. Wing geometric morphometrics is widely used to furnish morphological markers for the characterisation and identification of species of medical importance and for the assessment of population dynamics. In this work, we investigated the metric differentiation of the wings of Ae. albopictus samples collected over a four-year period (2007-2010 in São Paulo, Brazil. Wing size significantly decreased during this period for both sexes and the wing shape also changed over time, with the wing shapes of males showing greater differences after 2008 and those of females differing more after 2009. Given that the wings play sex-specific roles, these findings suggest that the males and females could be affected by differential evolutionary pressures. Consistent with this hypothesis, a sexually dimorphic pattern was detected and quantified: the females were larger than the males (with respect to the mean and had a distinct wing shape, regardless of allometric effects. In conclusion, wing alterations, particularly those involving shape, are a sensitive indicator of microevolutionary processes in this species.

  1. Temporal variation of wing geometry in Aedes albopictus.

    Science.gov (United States)

    Vidal, Paloma Oliveira; Carvalho, Eneas; Suesdek, Lincoln

    2012-12-01

    Although native to the tropical and subtropical areas of Southeast Asia, Aedes albopictus is now found on five continents, primarily due to its great capacity to adapt to different environments. This species is considered a secondary vector of dengue virus in several countries. Wing geometric morphometrics is widely used to furnish morphological markers for the characterisation and identification of species of medical importance and for the assessment of population dynamics. In this work, we investigated the metric differentiation of the wings of Ae. albopictus samples collected over a four-year period (2007-2010) in São Paulo, Brazil. Wing size significantly decreased during this period for both sexes and the wing shape also changed over time, with the wing shapes of males showing greater differences after 2008 and those of females differing more after 2009. Given that the wings play sex-specific roles, these findings suggest that the males and females could be affected by differential evolutionary pressures. Consistent with this hypothesis, a sexually dimorphic pattern was detected and quantified: the females were larger than the males (with respect to the mean) and had a distinct wing shape, regardless of allometric effects. In conclusion, wing alterations, particularly those involving shape, are a sensitive indicator of microevolutionary processes in this species.

  2. Stable structural color patterns displayed on transparent insect wings.

    Science.gov (United States)

    Shevtsova, Ekaterina; Hansson, Christer; Janzen, Daniel H; Kjærandsen, Jostein

    2011-01-11

    Color patterns play central roles in the behavior of insects, and are important traits for taxonomic studies. Here we report striking and stable structural color patterns--wing interference patterns (WIPs)--in the transparent wings of small Hymenoptera and Diptera, patterns that have been largely overlooked by biologists. These extremely thin wings reflect vivid color patterns caused by thin film interference. The visibility of these patterns is affected by the way the insects display their wings against various backgrounds with different light properties. The specific color sequence displayed lacks pure red and matches the color vision of most insects, strongly suggesting that the biological significance of WIPs lies in visual signaling. Taxon-specific color patterns are formed by uneven membrane thickness, pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by microstructures of the wing such as membrane corrugations and spherical cell structures that reinforce the pattern and make it essentially noniridescent over a large range of light incidences. WIPs can be applied to map the micromorphology of wings through direct observation and are useful in several fields of biology. We demonstrate their usefulness as identification patterns to solve cases of cryptic species complexes in tiny parasitic wasps, and indicate their potentials for research on the genetic control of wing development through direct links between the transregulatory wing landscape and interference patterns we observe in Drosophila model species. Some species display sexually dimorphic WIPs, suggesting sexual selection as one of the driving forces for their evolution.

  3. Hydraulic Evaluation of the Crest Wing Wave Energy Converter

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC). The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave to generate power. Model tests have been performed using a scal...

  4. Unsteady Aerodynamics of Flapping Wing of a Bird

    Directory of Open Access Journals (Sweden)

    M. Agoes Moelyadi

    2013-04-01

    Full Text Available The unsteady flow behavior and time-dependent aerodynamic characteristics of the flapping motion of a bird’s wing were investigated using a computational method. During flapping, aerodynamic interactions between bird wing surfaces and surrounding flow may occur, generating local time-dependent flow changes in the flow field and aerodynamic load of birds. To study the effect of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely a quasi-steady and an unsteady simulation. To mimic the movement of the down-stroke and the upstroke of a bird, the flapping path accorded to a sinus function, with the wing attitude changing in dihedral angle and time. The computations of time-dependent viscous flow were based on the solution of the Reynolds Averaged Navier-Stokes equations by applying the k-e turbulence model. In addition, the discretization for the computational domain around the model used multi-block structured grid to provide more accuracy in capturing viscous flow, especially in the vicinity of the wing and body surfaces, to obtain a proper wing-body geometry model. For this research, the seagull bird was chosen, which has high aspect ratio wings with pointed wing-tips and a high camber wing section. The results include mesh movement, velocity contours as well as aerodynamic coefficients of the flapping motion of the bird at various flapping frequencies.

  5. Vortex coupling in trailing vortex-wing interactions

    Science.gov (United States)

    Chen, C.; Wang, Z.; Gursul, I.

    2018-03-01

    The interaction of trailing vortices of an upstream wing with rigid and flexible downstream wings has been investigated experimentally in a wind tunnel, using particle image velocimetry, hot-wire, force, and deformation measurements. Counter-rotating upstream vortices exhibit increased meandering when they are close to the tip of the downstream wing. The upstream vortex forms a pair with the vortex shed from the downstream wing and then exhibits large displacements around the wing tip. This coupled motion of the pair has been found to cause large lift fluctuations on the downstream wing. The meandering of the vortex pair occurs at the natural meandering frequency of the isolated vortex, with a low Strouhal number, and is not affected by the frequency of the large-amplitude wing oscillations if the downstream wing is flexible. The displacement of the leading vortex is larger than that of the trailing vortex; however, it causes highly correlated variations of the core radius, core vorticity, and circulation of the trailing vortex with the coupled meandering motion. In contrast, co-rotating vortices do not exhibit any increased meandering.

  6. Closed-type wing for drones: positive and negative characteristics

    Directory of Open Access Journals (Sweden)

    Leonid I. Gretchihin

    2014-02-01

    Full Text Available The paper presents the aerodynamics of a wing of a closed oval ellipsoidal shape, designed with the use of the molecular-kinetic theory. The positive and negative characteristics of aircraft - drones with an oval wing are described. The theoretical calculations have been experimentally checked.

  7. DETERMINATION OF COMMERCIAL AIRCRAFT WING GEOMETRY DURING THE FLIGHT

    Directory of Open Access Journals (Sweden)

    V. I. Shevyakov

    2015-01-01

    Full Text Available The article deals with the task of determination of wing shape for sub-sonic commercial aircraft by photogrammetric method. It provides the procedure for measurements taken on ground and in flight. It also provides the outcome of wing twist for commercial aircraft at cruise.

  8. Global Local Structural Optimization of Transportation Aircraft Wings

    NARCIS (Netherlands)

    Ciampa, P.D.; Nagel, B.; Van Tooren, M.J.L.

    2010-01-01

    The study presents a multilevel optimization methodology for the preliminary structural design of transportation aircraft wings. A global level is defined by taking into account the primary wing structural components (i.e., ribs, spars and skin) which are explicitly modeled by shell layered finite

  9. Wing flexibility effects in clap-and-fling

    NARCIS (Netherlands)

    Percin, M.; Hu, Y.; Van Oudheusden, B.W.; Remes, B.; Scarano, F.

    2011-01-01

    The work explores the use of time-resolved tomographic PIV measurements to study a flapping-wing model, the related vortex generation mechanisms and the effect of wing flexibility on the clap-and-fling movement in particular. An experimental setup is designed and realized in a water tank by use of a

  10. 14 CFR 23.302 - Canard or tandem wing configurations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Canard or tandem wing configurations. 23.302 Section 23.302 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure General § 23.302 Canard or tandem wing...

  11. Quantitative-genetic analysis of wing form and bilateral asymmetry ...

    Indian Academy of Sciences (India)

    Unknown

    Overall wing size was analysed here using centroid size. (defined as the square root of the sum .... For those isochromosomal lines that were common to both experimental temperatures .... subobscura reared at 18ºC. CS refers to centroid size (values in pixels2; 1 mm = 144 pixels), and WS to wing shape (all values ×. 104).

  12. Mixed ice accretion on aircraft wings

    Science.gov (United States)

    Janjua, Zaid A.; Turnbull, Barbara; Hibberd, Stephen; Choi, Kwing-So

    2018-02-01

    Ice accretion is a problematic natural phenomenon that affects a wide range of engineering applications including power cables, radio masts, and wind turbines. Accretion on aircraft wings occurs when supercooled water droplets freeze instantaneously on impact to form rime ice or runback as water along the wing to form glaze ice. Most models to date have ignored the accretion of mixed ice, which is a combination of rime and glaze. A parameter we term the "freezing fraction" is defined as the fraction of a supercooled droplet that freezes on impact with the top surface of the accretion ice to explore the concept of mixed ice accretion. Additionally we consider different "packing densities" of rime ice, mimicking the different bulk rime densities observed in nature. Ice accretion is considered in four stages: rime, primary mixed, secondary mixed, and glaze ice. Predictions match with existing models and experimental data in the limiting rime and glaze cases. The mixed ice formulation however provides additional insight into the composition of the overall ice structure, which ultimately influences adhesion and ice thickness, and shows that for similar atmospheric parameter ranges, this simple mixed ice description leads to very different accretion rates. A simple one-dimensional energy balance was solved to show how this freezing fraction parameter increases with decrease in atmospheric temperature, with lower freezing fraction promoting glaze ice accretion.

  13. Computation of Lifting Wing-Flap Configurations

    Science.gov (United States)

    Cantwell, Brian; Kwak, Dochan

    1996-01-01

    Research has been carried out on the computation of lifting wing-flap configurations. The long term goal of the research is to develop improved computational tools for the analysis and design of high lift systems. Results show that state-of-the-art computational methods are sufficient to predict time-averaged lift and overall flow field characteristics on simple high-lift configurations. Recently there has been an increased interest in the problem of airframe generated noise and experiments carried out in the 7 x 10 wind tunnel at NASA Ames have identified the flap edge as an important source of noise. A follow-on set of experiments will be conducted toward the end of 1995. The computations being carried out under this project are coordinated with these experiments. In particular, the model geometry being used in the computations is the same as that in the experiments. The geometry consists of a NACA 63-215 Mod B airfoil section which spans the 7 x lO tunnel. The wing is unswept and has an aspect ratio of two. A 30% chord Fowler flap is deployed modifications of the flap edge geometry have been shown to be effective in reducing noise and the existing code is currently being used to compute the effect of a modified geometry on the edge flow.

  14. New aeroelastic studies for a morphing wing

    Directory of Open Access Journals (Sweden)

    Ruxandra Mihaela BOTEZ*

    2012-06-01

    Full Text Available For this study, the upper surface of a rectangular finite aspect ratio wing, with a laminar airfoil cross-section, was made of a carbon-Kevlar composite material flexible skin. This flexible skin was morphed by use of Shape Memory Alloy actuators for 35 test cases characterized by combinations of Mach numbers, Reynolds numbers and angles of attack. The Mach numbers varied from 0.2 to 0.3 and the angles of attack ranged between -1° and 2°. The optimized airfoils were determined by use of the CFD XFoil code. The purpose of this aeroelastic study was to determine the flutter conditions to be avoided during wind tunnel tests. These studies show that aeroelastic instabilities for the morphing configurations considered appeared at Mach number 0.55, which was higher than the wind tunnel Mach number limit speed of 0.3. The wind tunnel tests could thus be performed safely in the 6’×9’ wind tunnel at the Institute for Aerospace Research at the National Research Council Canada (IAR/NRC, where the new aeroelastic studies, applied on morphing wings, were validated.

  15. A flight investigation of oscillating air forces: Equipment and technique

    Science.gov (United States)

    Reed, W. H., III

    1975-01-01

    The equipment and techniques are described which are to be used in a project aimed at measuring oscillating air forces and dynamic aeroelastic response of a swept wing airplane at high subsonic speeds. Electro-hydraulic inertia type shakers installed in the wing tips will excite various elastic airplane modes while the related oscillating chordwise pressures at two spanwise wing stations and the wing mode shapes are recorded on magnetic tape. The data reduction technique, following the principle of a wattmeter harmonic analyzer employed by Bratt, Wight, and Tilly, utilizes magnetic tape and high speed electronic multipliers to record directly the real and imaginary components of oscillatory data signals relative to a simple harmonic reference signal. Through an extension of this technique an automatic flight-flutter-test data analyzer is suggested in which vector plots of mechanical admittance or impedance would be plotted during the flight test.

  16. COMPARISON OF A FIXED-WING AND MULTI-ROTOR UAV FOR ENVIRONMENTAL MAPPING APPLICATIONS: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    M. A. Boon

    2017-08-01

    Full Text Available The advent and evolution of Unmanned Aerial Vehicles (UAVs and photogrammetric techniques has provided the possibility for on-demand high-resolution environmental mapping. Orthoimages and three dimensional products such as Digital Surface Models (DSMs are derived from the UAV imagery which is amongst the most important spatial information tools for environmental planning. The two main types of UAVs in the commercial market are fixed-wing and multi-rotor. Both have their advantages and disadvantages including their suitability for certain applications. Fixed-wing UAVs normally have longer flight endurance capabilities while multi-rotors can provide for stable image capturing and easy vertical take-off and landing. Therefore, the objective of this study is to assess the performance of a fixed-wing versus a multi-rotor UAV for environmental mapping applications by conducting a specific case study. The aerial mapping of the Cors-Air model aircraft field which includes a wetland ecosystem was undertaken on the same day with a Skywalker fixed-wing UAV and a Raven X8 multi-rotor UAV equipped with similar sensor specifications (digital RGB camera under the same weather conditions. We compared the derived datasets by applying the DTMs for basic environmental mapping purposes such as slope and contour mapping including utilising the orthoimages for identification of anthropogenic disturbances. The ground spatial resolution obtained was slightly higher for the multi-rotor probably due to a slower flight speed and more images. The results in terms of the overall precision of the data was noticeably less accurate for the fixed-wing. In contrast, orthoimages derived from the two systems showed small variations. The multi-rotor imagery provided better representation of vegetation although the fixed-wing data was sufficient for the identification of environmental factors such as anthropogenic disturbances. Differences were observed utilising the respective DTMs

  17. Comparison of a Fixed-Wing and Multi-Rotor Uav for Environmental Mapping Applications: a Case Study

    Science.gov (United States)

    Boon, M. A.; Drijfhout, A. P.; Tesfamichael, S.

    2017-08-01

    The advent and evolution of Unmanned Aerial Vehicles (UAVs) and photogrammetric techniques has provided the possibility for on-demand high-resolution environmental mapping. Orthoimages and three dimensional products such as Digital Surface Models (DSMs) are derived from the UAV imagery which is amongst the most important spatial information tools for environmental planning. The two main types of UAVs in the commercial market are fixed-wing and multi-rotor. Both have their advantages and disadvantages including their suitability for certain applications. Fixed-wing UAVs normally have longer flight endurance capabilities while multi-rotors can provide for stable image capturing and easy vertical take-off and landing. Therefore, the objective of this study is to assess the performance of a fixed-wing versus a multi-rotor UAV for environmental mapping applications by conducting a specific case study. The aerial mapping of the Cors-Air model aircraft field which includes a wetland ecosystem was undertaken on the same day with a Skywalker fixed-wing UAV and a Raven X8 multi-rotor UAV equipped with similar sensor specifications (digital RGB camera) under the same weather conditions. We compared the derived datasets by applying the DTMs for basic environmental mapping purposes such as slope and contour mapping including utilising the orthoimages for identification of anthropogenic disturbances. The ground spatial resolution obtained was slightly higher for the multi-rotor probably due to a slower flight speed and more images. The results in terms of the overall precision of the data was noticeably less accurate for the fixed-wing. In contrast, orthoimages derived from the two systems showed small variations. The multi-rotor imagery provided better representation of vegetation although the fixed-wing data was sufficient for the identification of environmental factors such as anthropogenic disturbances. Differences were observed utilising the respective DTMs for the mapping

  18. Effects of Wing-Cuff on NACA 23015 Aerodynamic Performances

    Directory of Open Access Journals (Sweden)

    Meftah S.M.A

    2014-03-01

    Full Text Available The main subject of this work is the numerical study control of flow separation on a NACA 23015 airfoil by using wing cuff. This last is a leading edge modification done to the wing. The modification consists of a slight extension of the chord on the outboard section of the wings. Different numerical cases are considered for the baseline and modified airfoil NACA 23015 according at different angle of incidence. The turbulence is modeled by two equations k-epsilon model. The results of this numerical investigation showed several benefits of the wing cuff compared with a conventional airfoil and an agreement is observed between the experimental data and the present study. The most intriguing result of this research is the capability for wing cuff to perform short take-offs and landings.

  19. Experimental Investigation of a Wing-in-Ground Effect Craft

    Directory of Open Access Journals (Sweden)

    M. Mobassher Tofa

    2014-01-01

    Full Text Available The aerodynamic characteristics of the wing-in-ground effect (WIG craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

  20. Computational wing design studies relating to natural laminar flow

    Science.gov (United States)

    Waggoner, Edgar G.

    1986-01-01

    Two research studies are described which directly relate to the application of natural laminar flow (NLF) technology to transonic transport-type wing planforms. Each involved using state-of-the-art computational methods to design three-dimensional wing contours which generate significant runs of favorable pressure gradients. The first study supported the Variable Sweep Transition Flight Experiment and involves design of a full-span glove which extends from the leading edge to the spoiler hinge line on the upper surface of an F-14 outer wing panel. A wing was designed computationally for a corporate transport aircraft in the second study. The resulting wing design generated favorable pressure gradients from the leading edge aft to the mid-chord on both upper and lower surfaces at the cruise design point. Detailed descriptions of the computational design approach are presented along with the various constraints imposed on each of the designs.

  1. Experimental investigation of a wing-in-ground effect craft.

    Science.gov (United States)

    Tofa, M Mobassher; Maimun, Adi; Ahmed, Yasser M; Jamei, Saeed; Priyanto, Agoes; Rahimuddin

    2014-01-01

    The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

  2. Experimental Investigation of a Wing-in-Ground Effect Craft

    Science.gov (United States)

    Tofa, M. Mobassher; Ahmed, Yasser M.; Jamei, Saeed; Priyanto, Agoes; Rahimuddin

    2014-01-01

    The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future. PMID:24701170

  3. A Short History of The Air University, Maxwell AFB, and the 42nd Air Base Wing

    Science.gov (United States)

    2014-07-31

    bombers in 1956. Operated out of Ramey AFB, Puerto Rico (bombers), and Goose AB, Labrador (tankers), while runway repairs were made at Loring, 10 Jul–5...November 2011. In 2006-2007, AU’s structure and program effectiveness underwent an in-depth review that led to major changes in AU’s structure. In... hurricane Katrina devastated New Orleans, Maxwell-Gunter served as an evacuation center for over 1,000 displaced evacuees from the Gulf coast and as a

  4. Association between unemployment, income, education level, population size and air pollution in Czech cities: evidence for environmental inequality? A pilot national scale analysis.

    Science.gov (United States)

    Branis, Martin; Linhartova, Martina

    2012-09-01

    We analyzed differentials in exposure to SO(2), PM(10) and NO(2) among Czech urban populations categorized according to education level, unemployment rate, population size and average annual salary. Altogether 39 cities were included in the analysis. The principal component analysis revealed two factors explaining 72.8% of the data variability. The first factor explaining 44.7% of the data variability included SO(2), PM(10), low education level and high unemployment, documenting that inhabitants with unfavorable socioeconomic status mainly reside in smaller cities with higher concentration levels of combustion-related air pollutants. The second factor explaining 28.1% of the data variability included NO(2), high salary, high education level and large population, suggesting that large cities with residents with higher socioeconomic status are exposed to higher levels of traffic-related air pollution. We conclude that, after more than a decade of free-market economy, the Czech Republic, a former Soviet satellite with a centrally planned economy, displays signs of a certain kind of environmental inequality, since environmental hazards are unevenly distributed among the Czech urban populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Aerodynamic performance of a hovering hawkmoth with flexible wings: a computational approach.

    Science.gov (United States)

    Nakata, Toshiyuki; Liu, Hao

    2012-02-22

    Insect wings are deformable structures that change shape passively and dynamically owing to inertial and aerodynamic forces during flight. It is still unclear how the three-dimensional and passive change of wing kinematics owing to inherent wing flexibility contributes to unsteady aerodynamics and energetics in insect flapping flight. Here, we perform a systematic fluid-structure interaction based analysis on the aerodynamic performance of a hovering hawkmoth, Manduca, with an integrated computational model of a hovering insect with rigid and flexible wings. Aerodynamic performance of flapping wings with passive deformation or prescribed deformation is evaluated in terms of aerodynamic force, power and efficiency. Our results reveal that wing flexibility can increase downwash in wake and hence aerodynamic force: first, a dynamic wing bending is observed, which delays the breakdown of leading edge vortex near the wing tip, responsible for augmenting the aerodynamic force-production; second, a combination of the dynamic change of wing bending and twist favourably modifies the wing kinematics in the distal area, which leads to the aerodynamic force enhancement immediately before stroke reversal. Moreover, an increase in hovering efficiency of the flexible wing is achieved as a result of the wing twist. An extensive study of wing stiffness effect on aerodynamic performance is further conducted through a tuning of Young's modulus and thickness, indicating that insect wing structures may be optimized not only in terms of aerodynamic performance but also dependent on many factors, such as the wing strength, the circulation capability of wing veins and the control of wing movements.

  6. Micro- and Nano-Air Vehicles: State of the Art

    Directory of Open Access Journals (Sweden)

    Luca Petricca

    2011-01-01

    Full Text Available Micro- and nano air vehicles are defined as “extremely small and ultra-lightweight air vehicle systems” with a maximum wingspan length of 15 cm and a weight less than 20 grams. Here, we provide a review of the current state of the art and identify the challenges of design and fabrication. Different configurations are evaluated, such as fixed wings, rotary wings, and flapping wings. The main advantages and drawbacks for each typology are identified and discussed. Special attention is given to rotary-wing vehicles (helicopter concept; including a review of their main structures, such as the airframe, energy storage, controls, and communications systems. In addition, a review of relevant sensors is also included. Examples of existing and future systems are also included. Micro- and nano-vehicles with rotary wings and rechargeable batteries are dominating. The flight times of current systems are typically around 1 hour or less due to the limited energy storage capabilities of the used rechargeable batteries. Fuel cells and ultra capacitors are promising alternative energy supply technologies for the future. Technology improvements, mainly based on micro- and nanotechnologies, are expected to continue in an evolutionary way to improve the capabilities of future micro- and nano air vehicles, giving improved flight times and payload capabilities.

  7. Pegasus Rocket Wing and PHYSX Glove Being Prepared for Stress Loads Testing

    Science.gov (United States)

    1997-01-01

    A technician adjusts the Pegasus Hypersonic Experiment (PHYSX) Project's Pegasus rocket wing with attached PHYSX glove before a loads-test at Scaled Composites, Inc., in Mojave, California, in January 1997. For the test, technicians slowly filled water bags beneath the wing to create the pressure, or 'wing-loading,' required to determine whether the wing could withstand its design limit for stress. The wing sits in a wooden triangular frame which serves as the test-rig, mounted to the floor atop the waterbags. PHYSX was launched aboard a Pegasus rocket on October 22, 1998. Pegasus is an air-launched space booster produced by Orbital Sciences Corporation and Hercules Aerospace Company (initially; later, Alliant Tech Systems) to provide small satellite users with a cost-effective, flexible, and reliable method for placing payloads into low earth orbit. Pegasus has been used to launch a number of satellites and the PHYSX experiment. That experiment consisted of a smooth glove installed on the first-stage delta wing of the Pegasus. The glove was used to gather data at speeds of up to Mach 8 and at altitudes approaching 200,000 feet. The flight took place on October 22, 1998. The PHYSX experiment focused on determining where boundary-layer transition occurs on the glove and on identifying the flow mechanism causing transition over the glove. Data from this flight-research effort included temperature, heat transfer, pressure measurements, airflow, and trajectory reconstruction. Hypersonic flight-research programs are an approach to validate design methods for hypersonic vehicles (those that fly more than five times the speed of sound, or Mach 5). Dryden Flight Research Center, Edwards, California, provided overall management of the glove experiment, glove design, and buildup. Dryden also was responsible for conducting the flight tests. Langley Research Center, Hampton, Virginia, was responsible for the design of the aerodynamic glove as well as development of sensor and

  8. Digital Morphing Wing: Active Wing Shaping Concept Using Composite Lattice-Based Cellular Structures.

    Science.gov (United States)

    Jenett, Benjamin; Calisch, Sam; Cellucci, Daniel; Cramer, Nick; Gershenfeld, Neil; Swei, Sean; Cheung, Kenneth C

    2017-03-01

    We describe an approach for the discrete and reversible assembly of tunable and actively deformable structures using modular building block parts for robotic applications. The primary technical challenge addressed by this work is the use of this method to design and fabricate low density, highly compliant robotic structures with spatially tuned stiffness. This approach offers a number of potential advantages over more conventional methods for constructing compliant robots. The discrete assembly reduces manufacturing complexity, as relatively simple parts can be batch-produced and joined to make complex structures. Global mechanical properties can be tuned based on sub-part ordering and geometry, because local stiffness and density can be independently set to a wide range of values and varied spatially. The structure's intrinsic modularity can significantly simplify analysis and simulation. Simple analytical models for the behavior of each building block type can be calibrated with empirical testing and synthesized into a highly accurate and computationally efficient model of the full compliant system. As a case study, we describe a modular and reversibly assembled wing that performs continuous span-wise twist deformation. It exhibits high performance aerodynamic characteristics, is lightweight and simple to fabricate and repair. The wing is constructed from discrete lattice elements, wherein the geometric and mechanical attributes of the building blocks determine the global mechanical properties of the wing. We describe the mechanical design and structural performance of the digital morphing wing, including their relationship to wind tunnel tests that suggest the ability to increase roll efficiency compared to a conventional rigid aileron system. We focus here on describing the approach to design, modeling, and construction as a generalizable approach for robotics that require very lightweight, tunable, and actively deformable structures.

  9. Control Power Optimization using Artificial Intelligence for Forward Swept Wing and Hybrid Wing Body Aircraft

    OpenAIRE

    Adegbindin, Moustaine Kolawole Agnide

    2017-01-01

    Many futuristic aircraft such as the Hybrid Wing Body have numerous control surfaces that can result in large hinge moments, high actuation power demands, and large actuator forces/moments. Also, there is no unique relationship between control inputs and the aircraft response. Distinct sets of control surface deflections may result in the same aircraft response, but with large differences in actuation power. An Artificial Neural Network and a Genetic Algorithm were used here for the control a...

  10. Prediction of Wing Downwash Using CFD

    Directory of Open Access Journals (Sweden)

    Mohammed MAHDI

    2015-06-01

    Full Text Available Wing downwash study and estimation of downwash effect on the tail plane is an important task during the aircraft design process, although a lot of papers and works has been done, but the experimental work is the most important, the progress in CFD simulation has reached to the point it is able to reduce the number of runs in the wind tunnel. In this work CFD has been utilized to calculate the downwash angle and downwash gradient with respect to the angle of attack over a high aspect ratio of a typical UAV. The results of the simulation shall be used in the estimation and calculation of the longitudinal static stability analysis of the UAV.

  11. Static Aeroelastic Effects of Formation Flight for Slender Unswept Wings

    Science.gov (United States)

    Hanson, Curtis E.

    2009-01-01

    The static aeroelastic equilibrium equations for slender, straight wings are modified to incorporate the effects of aerodynamically-coupled formation flight. A system of equations is developed by applying trim constraints and is solved for component lift distribution, trim angle-of-attack, and trim aileron deflection. The trim values are then used to calculate the elastic twist distribution of the wing box. This system of equations is applied to a formation of two gliders in trimmed flight. Structural and aerodynamic properties are assumed for the gliders, and solutions are calculated for flexible and rigid wings in solo and formation flight. It is shown for a sample application of two gliders in formation flight, that formation disturbances produce greater twist in the wingtip immersed in the vortex than for either the opposing wingtip or the wings of a similar airplane in solo flight. Changes in the lift distribution, resulting from wing twist, increase the performance benefits of formation flight. A flexible wing in formation flight will require greater aileron deflection to achieve roll trim than a rigid wing.

  12. Antibiotics, primary symbionts and wing polyphenism in three aphid species.

    Science.gov (United States)

    Hardie, Jim; Leckstein, Peter

    2007-08-01

    The possible role of the primary Buchnera symbionts in wing polyphenism is examined in three aphid species. Presumptive winged aphids were fed on antibiotic-treated beans to destroy these symbionts. As previously reported, this leads to inhibited growth and low/zero fecundity. When such treatment is applied to the short-day-induced gynoparae (the winged autumn migrant) of the black bean aphid, Aphis fabae, it also causes many insects to develop as wingless or winged/wingless intermediate adult forms (apterisation). However, whilst antibiotic treatment of crowd-induced, long-day winged forms of the pea aphid, Acyrthosiphon pisum (a green and a pink clone) and the vetch aphid, Megoura viciae has similar effects on size and fecundity, it does not affect wing development. Food deprivation also promotes apterisation in A. fabae gynoparae but not in the crowd-induced winged morphs of the other two species. Thus, it appears that apterisation in A. fabae is not a direct effect of antibiotic treatment or a novel role for symbionts but is most likely related to impaired nutrition induced by the loss of the symbiont population.

  13. Computational Optimization of a Natural Laminar Flow Experimental Wing Glove

    Science.gov (United States)

    Hartshom, Fletcher

    2012-01-01

    Computational optimization of a natural laminar flow experimental wing glove that is mounted on a business jet is presented and discussed. The process of designing a laminar flow wing glove starts with creating a two-dimensional optimized airfoil and then lofting it into a three-dimensional wing glove section. The airfoil design process does not consider the three dimensional flow effects such as cross flow due wing sweep as well as engine and body interference. Therefore, once an initial glove geometry is created from the airfoil, the three dimensional wing glove has to be optimized to ensure that the desired extent of laminar flow is maintained over the entire glove. TRANAIR, a non-linear full potential solver with a coupled boundary layer code was used as the main tool in the design and optimization process of the three-dimensional glove shape. The optimization process uses the Class-Shape-Transformation method to perturb the geometry with geometric constraints that allow for a 2-in clearance from the main wing. The three-dimensional glove shape was optimized with the objective of having a spanwise uniform pressure distribution that matches the optimized two-dimensional pressure distribution as closely as possible. Results show that with the appropriate inputs, the optimizer is able to match the two dimensional pressure distributions practically across the entire span of the wing glove. This allows for the experiment to have a much higher probability of having a large extent of natural laminar flow in flight.

  14. Sexual selection on wing interference patterns in Drosophila melanogaster.

    Science.gov (United States)

    Katayama, Natsu; Abbott, Jessica K; Kjærandsen, Jostein; Takahashi, Yuma; Svensson, Erik I

    2014-10-21

    Animals with color vision use color information in intra- and interspecific communication, which in turn may drive the evolution of conspicuous colored body traits via natural and sexual selection. A recent study found that the transparent wings of small flies and wasps in lower-reflectance light environments display vivid and stable structural color patterns, called "wing interference patterns" (WIPs). Such WIPs were hypothesized to function in sexual selection among small insects with wing displays, but this has not been experimentally verified. Here, to our knowledge we present the first experimental evidence that WIPs in males of Drosophila melanogaster are targets of mate choice from females, and that two different color traits--saturation and hue--experience directional and stabilizing sexual selection, respectively. Using isogenic lines from the D. melanogaster Genetic Reference Panel, we compare attractiveness of different male WIPs against black and white visual backgrounds. We show that males with more vivid wings are more attractive to females than are males with dull wings. Wings with a large magenta area (i.e., intermediate trait values) were also preferred over those with a large blue or yellow area. These experimental results add a visual element to the Drosophila mating array, integrating sexual selection with elements of genetics and evo-devo, potentially applicable to a wide array of small insects with hyaline wings. Our results further underscore that the mode of sexual selection on such visual signals can differ profoundly between different color components, in this case hue and saturation.

  15. The design and testing of subscale smart aircraft wing bolts

    International Nuclear Information System (INIS)

    Vugampore, J M V; Bemont, C

    2012-01-01

    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers. (paper)

  16. NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

    Science.gov (United States)

    Nguyen, Nhan

    2010-01-01

    This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

  17. Calidad del aire interior

    Science.gov (United States)

    This web site will educate the public about indoor environmental issues including health risks and means by which human exposures can be reduced. Content on this site will be focused on Spanish translated resources for information about indoor air quality.

  18. X-38 on B-52 Wing Pylon - View from Observation Window

    Science.gov (United States)

    1997-01-01

    A unique, close-up view of the X-38 under the wing of NASA's B-52 mothership prior to launch of the lifting-body research vehicle. The photo was taken from the observation window of the B-52 bomber as it banked in flight. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In

  19. Free vibration analysis of dragonfly wings using finite element method

    Directory of Open Access Journals (Sweden)

    M Darvizeh

    2016-04-01

    Full Text Available In the present work, investigations on the microstructure and mechanicalproperties of the dragonfly wing are carried out and numerical modelingbased on Finite Element Method (FEM is developed to predict Flightcharacteristics of dragonfly wings. Vibrational behavior of wings typestructures is immensely important in analysis, design and manufacturing ofsimilar engineering structures. For this purpose natural frequencies andmode shapes are calculated. In addition, the kind of deformation in eachmode shape evaluated and the ratio between numerical natural frequencyand experimental natural frequency presented as damping ratio. Theresults obtain from present method are in good agreement with sameexperimental methods.

  20. A Video-Based Experimental Investigation of Wing Rock

    Science.gov (United States)

    1989-08-01

    maintained a negative damping in roll (Fig. 6b). Ross concluded that wing tanks act like an aerodynamic fence, controlling flow separation over the wing...to Ross that wing rock was initiated by a nonlinear yawing moment due to sideslip, which caused a divergent Dutch roll oscillation to grow into the...20 30 40 50 e) (p (D EG) * Fig. 128 Continued S * 158 (Fig. 128a) and cycle B (Fig. 128b ) both occurred early in the 0 build-up and consisted of

  1. Dynamics and control of robotic aircraft with articulated wings

    Science.gov (United States)

    Paranjape, Aditya Avinash

    There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control

  2. Aeroelastic Tailoring of Transport Wings Including Transonic Flutter Constraints

    Science.gov (United States)

    Stanford, Bret K.; Wieseman, Carol D.; Jutte, Christine V.

    2015-01-01

    Several minimum-mass optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic stress and panel buckling constraints are imposed across several trimmed static maneuver loads, in addition to a transonic flutter margin constraint, captured with aerodynamic influence coefficient-based tools. Tailoring with metallic thickness variations, functionally graded materials, balanced or unbalanced composite laminates, curvilinear tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

  3. Winging of scapula due to serratus anterior tear

    Directory of Open Access Journals (Sweden)

    Varun Singh Kumar

    2014-10-01

    Full Text Available 【Abstract】Winging of scapula occurs most commonly due to injury to long thoracic nerve supplying serratus anterior muscle. Traumatic injury to serratus anterior muscle itself is very rare. We reported a case of traumatic winging of scapula due to tear of serratus anterior muscle in a 19-year-old male. Winging was present in neutral position and in extension of right shoulder joint but not on "push on wall" test. Patient was managed conservatively and achieved satisfactory result. Key words: Serratus anterior tear; Scapula; Wounds and injuries

  4. Program for establishing long-time flight service performance of composite materials in the center wing structure of C-130 aircraft. Phase 5: flight service and inspection. Final report

    International Nuclear Information System (INIS)

    Kizer, J.A.

    1981-10-01

    Inspections of the C-130 composite-reinforced center wings were conducted over the flight service monitoring period of more than six years. Twelve inspections were conducted on each of the two C-130H airplanes having composite reinforced center wing boxes. Each inspection consisted of visual and ultrasonic inspection of the selective boron-epoxy reinforced center wings which included the inspection of the boron-epoxy laminates and the boron-epoxy reinforcement/aluminum structure adhesive bondlines. During the flight service monitoring period, the two C-130H aircraft accumulated more than 10,000 flight hours and no defects were detected in the inspections over this period. The successful performance of the C-130H aircraft with composite-reinforced center wings allowed the transfer of the responsibilities of inspecting and maintaining these two aircraft to the U. S. Air Force

  5. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  6. Waiting in the wings: what can we learn about gene co-option from the diversification of butterfly wing patterns?

    Science.gov (United States)

    Jiggins, Chris D; Wallbank, Richard W R; Hanly, Joseph J

    2017-02-05

    A major challenge is to understand how conserved gene regulatory networks control the wonderful diversity of form that we see among animals and plants. Butterfly wing patterns are an excellent example of this diversity. Butterfly wings form as imaginal discs in the caterpillar and are constructed by a gene regulatory network, much of which is conserved across the holometabolous insects. Recent work in Heliconius butterflies takes advantage of genomic approaches and offers insights into how the diversification of wing patterns is overlaid onto this conserved network. WntA is a patterning morphogen that alters spatial information in the wing. Optix is a transcription factor that acts later in development to paint specific wing regions red. Both of these loci fit the paradigm of conserved protein-coding loci with diverse regulatory elements and developmental roles that have taken on novel derived functions in patterning wings. These discoveries offer insights into the 'Nymphalid Ground Plan', which offers a unifying hypothesis for pattern formation across nymphalid butterflies. These loci also represent 'hotspots' for morphological change that have been targeted repeatedly during evolution. Both convergent and divergent evolution of a great diversity of patterns is controlled by complex alleles at just a few genes. We suggest that evolutionary change has become focused on one or a few genetic loci for two reasons. First, pre-existing complex cis-regulatory loci that already interact with potentially relevant transcription factors are more likely to acquire novel functions in wing patterning. Second, the shape of wing regulatory networks may constrain evolutionary change to one or a few loci. Overall, genomic approaches that have identified wing patterning loci in these butterflies offer broad insight into how gene regulatory networks evolve to produce diversity.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological

  7. Manufacturing and Evaluation of a Biologically Inspired Engineered MAV Wing Compared to the Manduca Sexta Wing Under Simulated Flapping Conditions

    Science.gov (United States)

    2011-03-24

    thorax to the wings will continue for a short period of time, preserving the integrity of these wings. This small window was considered in order to...PromasterTM Digital XR EDO Aspherical LD (IF) 17-50 mm 1:2.8 Macro φ 67. Photomodeler provides the means to calibrate a camera via subroutine within...36. 20. DeLeón, N., O’Hara, R., and Palazotto, A., “Manufacturing of Engineering Bio- logically Inspired Flapping Wings,” 25th Annual US- Japan

  8. Silent and Efficient Supersonic Bi-Directional Flying Wing

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a Phase I study for a novel concept of a supersonic bi-directional (SBiDir) flying wing (FW) that has the potential to revolutionize supersonic flight...

  9. Toward Wing Aerostructural Optimization Using Simultaneous Analysis and Design Strategy

    NARCIS (Netherlands)

    Elham, A.; van Tooren, M.J.L.

    2017-01-01

    The application and computational efficiency of wing aerostructural optimization us- ing simultaneous analysis and design (SAND) strategy is investigated. A coupled adjoint aerostructural analysis method based on quasi-three-dimensional aerodynamic analysis is used for this research. Two different

  10. Supercritical Wing Technology: A Progress Report on Flight Evaluations

    Science.gov (United States)

    1972-01-01

    The papers in this compilation were presented at the NASA Symposium on "Supercritical Wing Technology: A Progress Report on Flight Evaluation" held at the NASA Flight Research Center, Edwards, Calif., on February 29, 1972. The purpose of the symposium was to present timely information on flight results obtained with the F-8 and T-2C supercritical wing configurations, discuss comparisons with wind-tunnel predictions, and project [ ] flight programs planned for the F-8 and F-III (TACT) airplanes.

  11. Wing sexual dimorphism of pathogen-vector culicids.

    Science.gov (United States)

    Virginio, Flávia; Oliveira Vidal, Paloma; Suesdek, Lincoln

    2015-03-14

    Sexual dimorphism in animals has been studied from different perspectives for decades. In 1874 Darwin hypothesized that it was related to sexual selection, and even after nearly 140 years, when additional empirical data has become available and the subject has been investigated from a contemporary viewpoint, this idea is still supported. Although mosquito (Culicidae) wings are of great importance as they play a sex-specific role, little is known about wing sexual dimorphism in these pathogen-vector insects. Detection and characterization of wing sexual dimorphism in culicids may indirectly enhance our knowledge of their epidemiology or reveal sex-linked genes, aspects that have been discussed by vector control initiatives and developers of genetically modified mosquitoes. Using geometric morphometrics, we carried out a comparative assessment of wing sexual dimorphism in ten culicid species of medical/veterinary importance from genera Culex, Aedes, Anopheles and Ochlerotatus collected in Brazil. Discriminant analysis revealed significant sexual dimorphism in all the species studied, indicating that phenotypic expression of wing shape in mosquitoes is indeed sex-specific. A cross-validated test performed to reclassify the sexes with and without allometry yielded very similar results. Mahalanobis distances among the ten species showed that the species had different patterns of shape sexual dimorphism and that females are larger than males in some species. Wing morphology differed significantly between species. The finding of sexual dimorphism in all the species would suggest that the wing geometry of Culicidae is canalized. Although sexual dimorphism is prevalent, species-specific patterns occur. Allometry was not the main determinant of sexual dimorphism, which suggests that sexual selection or other evolutionary mechanisms underlie wing sexual dimorphism in these insects.

  12. Simulating Bird Strike on Aircraft Composite Wing Leading Edge.

    OpenAIRE

    Ericsson, Max

    2012-01-01

    In this master thesis project the possibility to model the response of a wing when subjected to bird strike using finite elements is analyzed. Since this transient event lasts only a few milliseconds the used solution method is explicit time integration. The wing is manufactured using carbon fiber laminate. Carbon fiber laminates have orthotropic material properties with different stiffness in different directions. Accordingly, there are damage mechanisms not considered when using metal that ...

  13. Humidification and perceived indoor air quality in the office environment.

    Science.gov (United States)

    Reinikainen, L M; Aunela-Tapola, L; Jaakkola, J J

    1997-01-01

    OBJECTIVE: To evaluate the effect of humidification on the odour, acceptability, and stuffiness of indoor air. METHODS: In a six period cross over trial at the Pasila Office Center, Helsinki, the air of two wings of the building in turn were ventilated with air of 30%-40% humidity. A third wing served as a non-humidified control area. The quality of indoor air was assessed weekly by a panel containing 18 to 23 members. The intraindividual differences in the ratings for odour, stuffiness, and acceptability between humidified and non-humidified wings were used to assess the effect of humidification. The roles of sex, current smoking, and age as potential effect modifiers were assessed by comparing the mean intraindividual differences in ratings between the groups. RESULTS: Humidified air was found to be more odorous and stuffy (paired t test P = 0.0001) and less acceptable than the non-humidified air (McNemar's test P humidification decreases the perceived air quality. This effect is strongest in women and young subjects. PMID:9196454

  14. Shock/shock interactions between bodies and wings

    Directory of Open Access Journals (Sweden)

    Gaoxiang XIANG

    2018-02-01

    Full Text Available This paper examines the Shock/Shock Interactions (SSI between the body and wing of aircraft in supersonic flows. The body is simplified to a flat wedge and the wing is assumed to be a sharp wing. The theoretical spatial dimension reduction method, which transforms the 3D problem into a 2D one, is used to analyze the SSI between the body and wing. The temperature and pressure behind the Mach stem induced by the wing and body are obtained, and the wave configurations in the corner are determined. Numerical validations are conducted by solving the inviscid Euler equations in 3D with a Non-oscillatory and Non-free-parameters Dissipative (NND finite difference scheme. Good agreements between the theoretical and numerical results are obtained. Additionally, the effects of the wedge angle and sweep angle on wave configurations and flow field are considered numerically and theoretically. The influences of wedge angle are significant, whereas the effects of sweep angle on wave configurations are negligible. This paper provides useful information for the design and thermal protection of aircraft in supersonic and hypersonic flows. Keywords: Body and wing, Flow field, Hypersonic flow, Shock/shock interaction, Wave configurations

  15. Unsteady flow over flexible wings at different low Reynolds numbers

    Directory of Open Access Journals (Sweden)

    Genç Mustafa Serdar

    2016-01-01

    Full Text Available In this study, unsteady flow around flexible membrane wing which had aspect ratio of 1 (AR=1 was investigated experimentally at various Reynolds numbers (Re = 25000 and Re = 50000. Smoke-wire technique for flow visualization over the flexible membrane wing was utilized in the experiments. Digital Image Correlation system (DIC was used for measuring deformation of AR = 1 flexible membrane wing. Instantaneous deformation measurements of membrane wing were combined with the flow field measurements. In low aspect ratio flexible membrane wings, unsteadiness includes tip vortices and vortex shedding, and the combination of tip vortices. In these types of wings, complex unsteady deformations occurred due to vortex shedding. The results showed that the increasing angle of attack results in increase of membrane deformation. Moreover, it was concluded that analysis of the instantaneous deformation revealed chordwise and spanwise, modes which were due to the shedding of leading-edge vortices as well as tip vortices. Consequently, vibrational mode decreased and maximum standard deviation location approached to the trailing edge by reason of increasing angle of attack.

  16. Effect of flexibility on flapping wing characteristics under forward flight

    International Nuclear Information System (INIS)

    Zhu, Jianyang; Jiang, Lin; Zhou, Chaoying; Wang, Chao

    2014-01-01

    Through two-dimensional numerical simulation and by solving the unsteady incompressible Navier–Stokes (NS) equations, coupled with the structural dynamic equation for the motion of the wing, the effect of flexibility on flapping wing characteristics during forward flight is systematically studied. The flapping wing is considered as a cantilever, which performs the translational and rotational motion at its leading edge, and the other part is passively deformed by the aerodynamic force. The frequency ratio ω* and mass ratio m* are defined and used to characterize the flexibility of the flapping wing. It has been found that an optimal range of the frequency ratio exists in which the flexible wing possesses both a larger propulsive efficiency and lifting efficiency than their rigid counterpart. Also, the flexible wing with the smaller mass ratio may be of benefit to generate thrust, while the larger mass ratio may be of benefit to generate lift. In addition, a stronger leading edge vortex and reattachment vortex are observed around the appropriate flexibility wing’s surface, which therefore leads to better aerodynamic characteristics. (paper)

  17. Flow structure on a rotating wing undergoing deceleration to rest

    Science.gov (United States)

    Tudball Smith, Daniel; Rockwell, Donald; Sheridan, John

    2013-11-01

    Inspired by the behavior of small biological flyers and micro aerial Vehicles, this study experimentally addresses the flow structure on a low aspect ratio rotating wing at low Reynolds number. The study focuses on a wing decelerating to rest after rotating at constant velocity. The wing was set to a constant 45° angle of attack and, during the initial phase of the motion, accelerated to a constant velocity at its radius of gyration, which resulted in a Reynolds number of 1400 based on the chord length. Stereoscopic PIV was used to construct phase-averaged three-dimensional (volumetric) velocity fields that develop and relax throughout the deceleration and cessation of the wing motion. During gradual deceleration, the flow structure is maintained when normalised by the instantaneous velocity; the distinguishing feature is shedding of a trailing edge vortex that develops due to the deceleration. At higher deceleration rates to rest, the flow structure quickly degrades. Induced flow in the upstream direction along the surface of the wing causes detachment of the previously stable leading edge vortex; simultaneously, a trailing-edge vortex and the reoriented tip vortex form a co-rotating vortex pair, drawing flow downward away from the wing.

  18. Structure design of an innovative adaptive variable camber wing

    Directory of Open Access Journals (Sweden)

    Zhao An-Min

    2018-01-01

    Full Text Available In this paper, an innovative double rib sheet structure is proposed, which can replace the traditional rigid hinge joint with the surface contact. On the one hand, the variable camber wing structural design not only can improve the capacity to sustain more load but also will not increase the overall weight of the wing. On the other hand, it is a simple mechanical structure design to achieve the total wing camber change. Then the numerical simulation results show that the maximum stress at the connect of the wing rib is 88.2MPa, and the double ribs sheet engineering design meet the structural strength requirements. In addition, to make a fair comparison, the parameters of variable camber are fully referenced to the Talon Unmanned Aerial Vehicle (UAV. The results reveal that the total variable camber wing can further enhance aircraft flight efficiency by 29.4%. The design of the whole variable camber wing structure proposed in this paper has high engineering value and feasibility.

  19. Flying Wings. A New Paradigm for Civil Aviation?

    Directory of Open Access Journals (Sweden)

    R. Martinez-Val

    2007-01-01

    Full Text Available Over the last 50 years, commercial aviation has been mainly based what is currently called the conventional layout, characterized by a slender fuselage mated to a high aspect ratio wing, with aft-tail planes and pod-mounted engines under the wing. However, it seems that this primary configuration is approaching an asymptote in its productivity and performance characteristics. One of the most promising configurations for the future is the flying wing in its distinct arrangements: blended-wing-body, C-wing, tail-less aircraft, etc. These layouts might provide significant fuel savings and, hence, a decrease in pollution. This configuration would also reduce noise in take-off and landing. All this explains the great deal of activity carried out by the aircraft industry and by numerous investigators to perform feasibility and conceptual design studies of this aircraft layout to gain better knowledge of its main characteristics: productivity, airport compatibility, passenger acceptance, internal architecture, emergency evacuation, etc. The present paper discusses the main features of flying wings, their advantages over conventional competitors, and some key operational issues, such as evacuation and vortex wake intensity. 

  20. Wing-pitching mechanism of hovering Ruby-throated hummingbirds.

    Science.gov (United States)

    Song, Jialei; Luo, Haoxiang; Hedrick, Tyson L

    2015-01-19

    In hovering flight, hummingbirds reverse the angle of attack of their wings through pitch reversal in order to generate aerodynamic lift during both downstroke and upstroke. In addition, the wings may pitch during translation to further enhance lift production. It is not yet clear whether these pitching motions are caused by the wing inertia or actuated through the musculoskeletal system. Here we perform a computational analysis of the pitching dynamics by incorporating the realistic wing kinematics to determine the inertial effects. The aerodynamic effect is also included using the pressure data from a previous three-dimensional computational fluid dynamics simulation of a hovering hummingbird. The results show that like many insects, pitch reversal of the hummingbird is, to a large degree, caused by the wing inertia. However, actuation power input at the root is needed in the beginning of pronation to initiate a fast pitch reversal and also in mid-downstroke to enable a nose-up pitching motion for lift enhancement. The muscles on the wing may not necessarily be activated for pitching of the distal section. Finally, power analysis of the flapping motion shows that there is no requirement for substantial elastic energy storage or energy absorption at the shoulder joint.

  1. Wing-pitching mechanism of hovering Ruby-throated hummingbirds

    International Nuclear Information System (INIS)

    Song, Jialei; Luo, Haoxiang; Hedrick, Tyson L

    2015-01-01

    In hovering flight, hummingbirds reverse the angle of attack of their wings through pitch reversal in order to generate aerodynamic lift during both downstroke and upstroke. In addition, the wings may pitch during translation to further enhance lift production. It is not yet clear whether these pitching motions are caused by the wing inertia or actuated through the musculoskeletal system. Here we perform a computational analysis of the pitching dynamics by incorporating the realistic wing kinematics to determine the inertial effects. The aerodynamic effect is also included using the pressure data from a previous three-dimensional computational fluid dynamics simulation of a hovering hummingbird. The results show that like many insects, pitch reversal of the hummingbird is, to a large degree, caused by the wing inertia. However, actuation power input at the root is needed in the beginning of pronation to initiate a fast pitch reversal and also in mid-downstroke to enable a nose-up pitching motion for lift enhancement. The muscles on the wing may not necessarily be activated for pitching of the distal section. Finally, power analysis of the flapping motion shows that there is no requirement for substantial elastic energy storage or energy absorption at the shoulder joint. (paper)

  2. The Rural Wings Project: Bridging the Digital Divide with Satellite-Provided Internet. Phase I--Identifying and Analysing the Learning Needs of 31 Communities in 10 Countries

    Science.gov (United States)

    Hansson, Henrik; Mihailidis, Paul; Larsson, Ken; Sotiriou, Menelaos; Sotiriou, Sofoklis; Uzunoglu, Nikolaos; Gargalakos, Michail

    2007-01-01

    The digitally marginalised communities are in focus in the EU-funded Rural Wings project 2006-2008. The aim is to identify and analyse the user learning needs in non-connected communities and to meet these needs by providing satellite Internet broadband connections, education and tools. This article reports the findings of the user needs…

  3. Reassessment of the wing feathers of Archaeopteryx lithographica suggests no robust evidence for the presence of elongated dorsal wing coverts.

    Directory of Open Access Journals (Sweden)

    Robert L Nudds

    Full Text Available Recently it was proposed that the primary feathers of Archaeopteryx lithographica (HMN1880 were overlaid by long covert feathers, and that a multilayered feathered wing was a feature of early fossils with feathered forelimbs. The proposed long covert feathers of Archaeopteryx were previously interpreted as dorsally displaced remiges or a second set of impressions made by the wing. The following study shows that the qualitative arguments forwarded in support of the elongated covert hypothesis are neither robust nor supported quantitatively. The idea that the extant bird wing with its single layer of overlapping primaries evolved from an earlier multilayered heavily coveted feathered forelimb as seen in Anchiornis huxleyi is reasonable. At this juncture, however, it is premature to conclude unequivocally that the wing of Archaeopteryx consisted of primary feathers overlaid with elongated coverts.

  4. Environmental Assessment for Proposed Utility Corridors at Edwards Air Force Base, California

    Science.gov (United States)

    2016-07-01

    Air Force Base, California Figure 3-6 Los Angeles County Significant Ecological Areas 76 Environmental Assessment for Proposed Utility... Ecological Areas designated by Los Angeles County (refer to Section 3.7.2);  Potential wildlife movement corridors; and 81 Environmental Assessment...412th Test Wing Civil Engineer Group Environmental Management Division Edwards Air Force Base, California ENVIRONMENTAL ASSESSMENT FOR PROPOSED

  5. The Secret Air War Over France USAAF Special Operations Units in the French Campaign of 1944

    Science.gov (United States)

    1992-05-01

    Alfred H. Paddock, Jr. US Army Special Warfare (Washington, D.C.: National Defense University Press, 1982), 118- 129. 161. Charles A. Ravenstein ...1954. Ravenstein , Charles A. Air Force Combat Wings. Washington, D.C.: Office of Air Force History, 1984. Rositzke, Harry The CIA�s Secret

  6. Conceptual Design Tool for Fuel-Cell Powered Micro Air Vehicles

    Science.gov (United States)

    2010-03-01

    fsID=10469&page=1, accessed 11 Jan 10, Nov 09. 39 Stewart, K., Wagener , J., Abate, G., and Salichon, M., ―Design of the Air Force Research... Wagener , J., Czabaranek, J., and Abate, G., ―Development and Initial Flight Tests of a Single-Jointed Articulated-Wing Micro Air Vehicle,‖ AIAA 2008-6708

  7. Quantification of hood effectiveness and entrained subsurface air in a Seattle Hospital

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, R.N.; Goodrich, R.W.

    1994-05-01

    An underground 3-story wing of a hospital having problems with sewer air odors was tested with perfluorocarbon tracer (PFI) technology to quantify the performance of the mechanical ventilation system and determine the extent of sewer air entrainment and chemical hood effectiveness.

  8. UNDERGRADUATE AIR BATTLE MANAGER TRAINING: PREPARED TO ACHIEVE COMBAT MISSION READY

    Science.gov (United States)

    2016-04-01

    weapons directing practice with MU-2 and F-15C aircraft.”xxii The MU-2 aircraft is a high wing, turbo -prop aircraft that was used to provide air-to-air...most dynamic AWO position on the jet , more live training was required. The second most dynamic position on the crew was Tanker AWO, or more commonly

  9. Fuzzy Model-based Pitch Stabilization and Wing Vibration Suppression of Flexible Wing Aircraft.

    Science.gov (United States)

    Ayoubi, Mohammad A.; Swei, Sean Shan-Min; Nguyen, Nhan T.

    2014-01-01

    This paper presents a fuzzy nonlinear controller to regulate the longitudinal dynamics of an aircraft and suppress the bending and torsional vibrations of its flexible wings. The fuzzy controller utilizes full-state feedback with input constraint. First, the Takagi-Sugeno fuzzy linear model is developed which approximates the coupled aeroelastic aircraft model. Then, based on the fuzzy linear model, a fuzzy controller is developed to utilize a full-state feedback and stabilize the system while it satisfies the control input constraint. Linear matrix inequality (LMI) techniques are employed to solve the fuzzy control problem. Finally, the performance of the proposed controller is demonstrated on the NASA Generic Transport Model (GTM).

  10. The Effect of Height, Wing Length, and Wing Symmetry on Tabebuia rosea Seed Dispersal

    Directory of Open Access Journals (Sweden)

    Yasmeen Moussa

    2014-12-01

    Full Text Available The relationship between the vertical drop height and the horizontal distance traveled (dispersal ratio was investigated for a sample of fifty Tabebuia rosea seeds by dropping the seeds from five heights ranging from 1.00 to 2.00 meters. The dispersal ratio was found to be a constant 0.16 m/m for these heights. The effects of total seed length and asymmetry of seed wings on dispersal ratio were also measured using separate samples of fifty Tabebuia rosea seeds. It was found that neither seed length nor asymmetry had a significant effect on the dispersal ratio.

  11. Aerodynamic effects of corrugation and deformation in flapping wings of hovering hoverflies.

    Science.gov (United States)

    Du, Gang; Sun, Mao

    2012-05-07

    We investigated the aerodynamic effects of wing deformation and corrugation of a three-dimensional model hoverfly wing at a hovering condition by solving the Navier-Stokes equations on a dynamically deforming grid. Various corrugated wing models were tested. Insight into whether or not there existed significant aerodynamic coupling between wing deformation (camber and twist) and wing corrugation was obtained by comparing aerodynamic forces of four cases: a smooth-plate wing in flapping motion without deformation (i.e. a rigid flat-plate wing in flapping motion); a smooth-plate wing in flapping motion with deformation; a corrugated wing in flapping motion without deformation (i.e. a rigid corrugated wing in flapping motion); a corrugated wing in flapping motion with deformation. There was little aerodynamic coupling between wing deformation and corrugation: the aerodynamic effect of wing deformation and corrugation acting together was approximately a superposition of those of deformation and corrugation acting separately. When acting alone, the effect of wing deformation was to increase the lift by 9.7% and decrease the torque (or aerodynamic power) by 5.2%, and that of wing corrugation was to decrease the lift by 6.5% and increase the torque by 2.2%. But when acting together, the wing deformation and corrugation only increased the lift by ~3% and decreased the torque by ~3%. That is, the combined aerodynamic effect of deformation and corrugation is rather small. Thus, wing corrugation is mainly for structural, not aerodynamic, purpose, and in computing or measuring the aerodynamic forces, using a rigid flat-plate wing to model the corrugated deforming wing at hovering condition can be a good approximation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Butterfly wing colors : glass scales of Graphium sarpedon cause polarized iridescence and enhance blue/green pigment coloration of the wing membrane

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Giraldo, Marco A.; Leertouwer, Hein L.

    2010-01-01

    The wings of the swordtail butterfly Graphium sarpedon nipponum contain the bile pigment sarpedobilin, which causes blue/green colored wing patches. Locally the bile pigment is combined with the strongly blue-absorbing carotenoid lutein, resulting in green wing patches and thus improving camouflage.

  13. Observations and Measurements of Wing Parameters of the Selected Beetle Species and the Design of a Mechanism Structure Implementing a Complex Wing Movement

    Science.gov (United States)

    Geisler, T.

    2016-12-01

    Beetle wings perform a flapping movement, consisting of the rotation relative to the two axes. This paper presents the results of observations and measurements of wings operating parameters in different planes of some beetle species. High speed photos and videos were used. The concept of the mechanism performing a complex wing movement was proposed and developed.

  14. Observations and Measurements of Wing Parameters of the Selected Beetle Species and the Design of a Mechanism Structure Implementing a Complex Wing Movement

    Directory of Open Access Journals (Sweden)

    Geisler T.

    2016-12-01

    Full Text Available Beetle wings perform a flapping movement, consisting of the rotation relative to the two axes. This paper presents the results of observations and measurements of wings operating parameters in different planes of some beetle species. High speed photos and videos were used. The concept of the mechanism performing a complex wing movement was proposed and developed.

  15. Real-time in vivo imaging of butterfly wing development: revealing the cellular dynamics of the pupal wing tissue.

    Directory of Open Access Journals (Sweden)

    Masaki Iwata

    Full Text Available Butterfly wings are covered with regularly arranged single-colored scales that are formed at the pupal stage. Understanding pupal wing development is therefore crucial to understand wing color pattern formation. Here, we successfully employed real-time in vivo imaging techniques to observe pupal hindwing development over time in the blue pansy butterfly, Junonia orithya. A transparent sheet of epithelial cells that were not yet regularly arranged was observed immediately after pupation. Bright-field imaging and autofluorescent imaging revealed free-moving hemocytes and tracheal branches of a crinoid-like structure underneath the epithelium. The wing tissue gradually became gray-white, epithelial cells were arranged regularly, and hemocytes disappeared, except in the bordering lacuna, after which scales grew. The dynamics of the epithelial cells and scale growth were also confirmed by fluorescent imaging. Fluorescent in vivo staining further revealed that these cells harbored many mitochondria at the surface of the epithelium. Organizing centers for the border symmetry system were apparent immediately after pupation, exhibiting a relatively dark optical character following treatment with fluorescent dyes, as well as in autofluorescent images. The wing tissue exhibited slow and low-frequency contraction pulses with a cycle of approximately 10 to 20 minutes, mainly occurring at 2 to 3 days postpupation. The pulses gradually became slower and weaker and eventually stopped. The wing tissue area became larger after contraction, which also coincided with an increase in the autofluorescence intensity that might have been caused by scale growth. Examination of the pattern of color development revealed that the black pigment was first deposited in patches in the central areas of an eyespot black ring and a parafocal element. These results of live in vivo imaging that covered wide wing area for a long time can serve as a foundation for studying the

  16. Induced mutations of winged bean in Ghana

    International Nuclear Information System (INIS)

    Klu, G.Y.P.; Quaynor-Addy, M.; Dinku, E.; Dikumwin, E.

    1989-01-01

    Winged bean (Psophocarpus tetragonolobus (L.) D.C.) was introduced into Ghana about two decades ago and not long after a high quality baby food was compounded from it. Germplasm collections are established at the Kade Agricultural Research Station of the University of Ghana and the University of Cape Coast. In 1980 a mutation breeding project was initiated at the University of Cape Coast under FAO/IAEA research contract and among various mutants a single erect stem mutant, a multiple branched bush type and a mutant with extra long pods were obtained. A similar programme was started at the National Nuclear Research Centre Kwabenya in 1982. Seeds of accessions UPS 122 and Kade 6/16 were gamma irradiated (100-400 Gy). In M 2 a mutant was obtained that did not flower throughout a growing period of five months. This mutant had very few leaves but developed an underground tuber weighing ca. 100 g. The parent, UPS 122, although normally tuber producing did not form tubers at Kwabenya within the period studied. In M 3 , mutants with variations in seed size and seed coat colour have been detected

  17. Vortex Lattice Simulations of Attached and Separated Flows around Flapping Wings

    Directory of Open Access Journals (Sweden)

    Thomas Lambert

    2017-04-01

    Full Text Available Flapping flight is an increasingly popular area of research, with applications to micro-unmanned air vehicles and animal flight biomechanics. Fast, but accurate methods for predicting the aerodynamic loads acting on flapping wings are of interest for designing such aircraft and optimizing thrust production. In this work, the unsteady vortex lattice method is used in conjunction with three load estimation techniques in order to predict the aerodynamic lift and drag time histories produced by flapping rectangular wings. The load estimation approaches are the Katz, Joukowski and simplified Leishman–Beddoes techniques. The simulations’ predictions are compared to experimental measurements from wind tunnel tests of a flapping and pitching wing. Three types of kinematics are investigated, pitch-leading, pure flapping and pitch lagging. It is found that pitch-leading tests can be simulated quite accurately using either the Katz or Joukowski approaches as no measurable flow separation occurs. For the pure flapping tests, the Katz and Joukowski techniques are accurate as long as the static pitch angle is greater than zero. For zero or negative static pitch angles, these methods underestimate the amplitude of the drag. The Leishman–Beddoes approach yields better drag amplitudes, but can introduce a constant negative drag offset. Finally, for the pitch-lagging tests the Leishman–Beddoes technique is again more representative of the experimental results, as long as flow separation is not too extensive. Considering the complexity of the phenomena involved, in the vast majority of cases, the lift time history is predicted with reasonable accuracy. The drag (or thrust time history is more challenging.

  18. Experiments on a low aspect ratio wing at low Reynolds numbers

    Science.gov (United States)

    Morse, Daniel R.

    At the start of the 21st century much of the focus of aircraft design has been turned to unmanned aerial vehicles (UAVs) which generally operate at much lower speeds in higher risk areas than manned aircraft. One subset of UAVs are Micro Air Vehicles (MAVs) which usually are no larger than 20cm and rely on non-traditional shapes to generate lift at very low velocities. This purpose of this work is to describe, in detail with experimental methods, the flow field around a low aspect ratio wing operating at low Reynolds numbers and at high angles of attack. Quantitative measurements are obtained by Three Component Time Resolved Particle Image Velocimetry (3C TR PIV) which describe the mean and turbulent flow field. This research focuses on the leading edge separation zone and the vortex shedding process which occurs at the leading edge. Streamwise wing tip vortices which dominate the lift characteristics are described with flow visualization and 3C TR PIV measurements. Turbulent Kinetic Energy (TKE) is described at the leading edge over several angles of attack. Turbulent Reynolds stresses in all three directions are described over the wing span and several Reynolds numbers. Two primary cyclic processes are observed within the flow field; one low frequency oscillation in the separated region and one high frequency event associated with leading edge vortex formation and convection. Two length scales are proposed and are shown to match well with each other, one based on leading edge vortex shedding frequency and convective velocity and the other based on mean vortex separation distance. A new method of rendering velocity frequency content over large data sets is proposed and used to illustrate the different frequencies observed at the leading edge.

  19. A new technique for investigating the induced and profile drag coefficients of a smooth wing and a tubercled wing

    Directory of Open Access Journals (Sweden)

    Bolzon Michael

    2016-01-01

    Full Text Available The induced and profile drag coefficients of a wing are typically determined through a complex experimental technique, such as wake surveying. Such a technique requires measurement of all three orthogonal components of the downstream velocity to find the components of drag, which results in the necessary usage of a sophisticated and costly measurement device, such as multi-hole pressure probe. However, in this paper data is presented which demonstrate that the relative changes in the induced and profile drag coefficients can largely be determined through the sole measurement of the downstream, streamwise velocity. To demonstrate this, the induced and profile drags of two NACA 0021 wings, one with a smooth leading edge and the other wing a tubercled leading edge for comparison, are determined through the measurement of the three orthogonal velocities. The downstream, streamwise velocity distribution of each wing is then constructed and relationships can be determined. The wings were surveyed at 3°, 9°, and 12°. It has been found that the relative magnitude of the profile drag coefficient can be found for all considered angles of attack, while the relative magnitude of the induced drag coefficient can be found at 9° and 12°. These findings produce an innovative, simpler, and more cost effective experimental technique in determining the components of drag of a wing, and reduces the burdensome requirement of a sophisticated measurement device for such an experiment. Further investigation is required to determine the induced drag at 3°.

  20. Assessing genotoxicity of diuron on Drosophila melanogaster by the wing-spot test and the wing imaginal disk comet assay.

    Science.gov (United States)

    Peraza-Vega, Ricardo I; Castañeda-Sortibrán, América N; Valverde, Mahara; Rojas, Emilio; Rodríguez-Arnaiz, Rosario

    2017-05-01

    The aim of this study was to evaluate the genotoxicity of the herbicide diuron in the wing-spot test and a novel wing imaginal disk comet assay in Drosophila melanogaster. The wing-spot test was performed with standard (ST) and high-bioactivation (HB) crosses after providing chronic 48 h treatment to third instar larvae. A positive dose-response effect was observed in both crosses, but statistically reduced spot frequencies were registered for the HB cross compared with the ST. This latter finding suggests that metabolism differences play an important role in the genotoxic effect of diuron. To verify diuron's ability to produce DNA damage, a wing imaginal disk comet assay was performed after providing 24 h diuron treatment to ST and HB third instar larvae. DNA damage induced by the herbicide had a significantly positive dose-response effect even at very low concentrations in both strains. However, as noted for the wing-spot test, a significant difference between strains was not observed that could be related to the duration of exposure between both assays. A positive correlation between the comet assay and the wing-spot test was found with regard to diuron genotoxicity.

  1. MicroRNAs of the mesothorax in Qinlingacris elaeodes, an alpine grasshopper showing a wing polymorphism with unilateral wing form.

    Science.gov (United States)

    Li, R; Jiang, G F; Ren, Q P; Wang, Y T; Zhou, X M; Zhou, C F; Qin, D Z

    2016-04-01

    MicroRNAs (miRNAs) are now recognized as key post-transcriptional regulators in regulation of phenotypic diversity. Qinlingacris elaeodes is a species of the alpine grasshopper, which is endemic to China. Adult individuals have three wing forms: wingless, unilateral-winged and short-winged. This is an ideal species to investigate the phenotypic plasticity, development and evolution of insect wings because of its case of unilateral wing form in both the sexes. We sequenced a small RNA library prepared from mesothoraxes of the adult grasshoppers using the Illumina deep sequencing technology. Approximately 12,792,458 raw reads were generated, of which the 854,580 high-quality reads were used only for miRNA identification. In this study, we identified 49 conserved miRNAs belonging to 41 families and 69 species-specific miRNAs. Moreover, seven miRNA*s were detected both for conserved miRNAs and species-specific miRNAs, which were supported by hairpin forming precursors based on polymerase chain reaction. This is the first description of miRNAs in alpine grasshoppers. The results provide a useful resource for further studies on molecular regulation and evolution of miRNAs in grasshoppers. These findings not only enrich the miRNAs for insects but also lay the groundwork for the study of post-transcriptional regulation of wing forms.

  2. Physiological trade-off between cellular immunity and flight capability in the wing-dimorphic cricket, Gryllus firmus

    Science.gov (United States)

    The sand cricket, Gryllus firmus, is a wing-dimorphic species with long-wing (LW) and short wing (LW) morphs. The LW forms have very well developed wings and flight muscles and their SW counterparts have reduced wings and flight muscles, coupled with greater resource allocations to reproduction. Thi...

  3. Investigation of asymmetry of vortex flow over slender delta wings

    Science.gov (United States)

    Atashbaz, Ghasem

    Vortex flow, a major area of interest in fluid mechanics, is widespread in nature and in many man-made fluid mechanical devices. It can create havoc as cyclones or tornadoes or have significant implications in the performance of turbo-fluid machines or supersonic vehicles and so forth. Asymmetric vortices can cause a loss of lift and increase in rolling moment which can significantly affect wing stability and control. Up until the early nineties, it was generally believed that vortex asymmetry was the result of vortex interactions due to the close proximity of vortices over slender delta wings. However, some recent studies have thrown considerable doubt on the validity of this hypothesis. As a result, wind tunnel investigations were conducted on a series of nine delta wing planforms with sharp and round leading edges to examine the occurrence of vortex asymmetry at different angles of attack and sideslip. The study included surface oil and laser light sheet flow visualization in addition to surface pressure and hot-wire velocity measurements under static conditions. The effects of incidence, sideslip and sweep angles as well as Reynolds number variations were investigated. In this study, it was found that the effect of apex and leading edge shape played an important role in vortex asymmetry generation at high angle of attack. Vortex asymmetry was not observed over slender sharp leading edge delta wings due to the separation point being fixed at the sharp leading edge. Experimental results for these wings showed that the vortices do not impinge on one another because they do not get any closer beyond a certain value of angle of attack. Thus vortex asymmetry was not generated. However, significant vortex asymmetry was observed for round leading-edged delta wings. Asymmetric separation positions over the round leading edge was the result of laminar/turbulent transition which caused vortex asymmetry on these delta wing configurations. Sideslip angle and vortex

  4. Study of Passive Flow Control for Ship Air Wakes

    Science.gov (United States)

    2013-05-10

    and Kestrel , a Department of Defense CFD code. Simulations have been performed for various wind over deck velocities and starboard crosswind angles...Burks, J.S., “Comparison of Experimental and Computational Ship Air Wakes for YP Class Patrol Craft,” American Society of Naval Engineers...and Investigation of Ship Air Wake Impact on Rotary Wing Aircraft,” American Society of Naval Engineers Launch and Recovery Symposium, Linthicum, MD

  5. Performance Assessment in a Heat Exchanger Tube with Opposite/Parallel Wing Twisted Tapes

    Directory of Open Access Journals (Sweden)

    S. Eiamsa-ard

    2015-02-01

    Full Text Available The thermohydraulic performance in a tube containing a modified twisted tape with alternate-axes and wing arrangements is reported. This work aims to investigate the effects of wing arrangements (opposite (O and parallel (P wings at different wing shapes (triangle (Tri, rectangular (Rec, and trapezoidal (Tra wings and on the thermohydraulic performance characteristics. The obtained results show that wing twisted tapes with all wing shape arrangements (O-Tri/O-Rec/O-Tra/P-Tri/P-Rec/P-Tra give superior thermohydraulic performance and heat transfer rate to the typical twisted tape. In addition, the tapes with opposite wing arrangement of O-Tra, O-Rec, and O-Tri give superior thermohydraulic performances to those with parallel wing arrangement of P-Tra, P-Rec, and P-Tri around 2.7%, 3.5%, and 3.2%, respectively.

  6. Analysis of Low Speed Stall Aerodynamics of a Swept Wing with Laminar Flow Glove

    Science.gov (United States)

    Bui, Trong T.

    2014-01-01

    Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) analysis was conducted to study the low-speed stall aerodynamics of a GIII aircraft's swept wing modified with a laminar-flow wing glove. The stall aerodynamics of the gloved wing were analyzed and compared with the unmodified wing for the flight speed of 120 knots and altitude of 2300 ft above mean sea level (MSL). The Star-CCM+ polyhedral unstructured CFD code was first validated for wing stall predictions using the wing-body geometry from the First American Institute of Aeronautics and Astronautics (AIAA) CFD High-Lift Prediction Workshop. It was found that the Star-CCM+ CFD code can produce results that are within the scattering of other CFD codes considered at the workshop. In particular, the Star-CCM+ CFD code was able to predict wing stall for the AIAA wing-body geometry to within 1 degree of angle of attack as compared to benchmark wind-tunnel test data. Current results show that the addition of the laminar-flow wing glove causes the gloved wing to stall much earlier than the unmodified wing. Furthermore, the gloved wing has a different stall characteristic than the clean wing, with no sharp lift drop-off at stall for the gloved wing.

  7. Analysis of Low-Speed Stall Aerodynamics of a Swept Wing with Laminar-Flow Glove

    Science.gov (United States)

    Bui, Trong T.

    2014-01-01

    Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) analysis was conducted to study the low-speed stall aerodynamics of a GIII aircraft's swept wing modified with a laminar-flow wing glove. The stall aerodynamics of the gloved wing were analyzed and compared with the unmodified wing for the flight speed of 120 knots and altitude of 2300 ft above mean sea level (MSL). The Star-CCM+ polyhedral unstructured CFD code was first validated for wing stall predictions using the wing-body geometry from the First American Institute of Aeronautics and Astronautics (AIAA) CFD High-Lift Prediction Workshop. It was found that the Star-CCM+ CFD code can produce results that are within the scattering of other CFD codes considered at the workshop. In particular, the Star-CCM+ CFD code was able to predict wing stall for the AIAA wing-body geometry to within 1 degree of angle of attack as compared to benchmark wind-tunnel test data. Current results show that the addition of the laminar-flow wing glove causes the gloved wing to stall much earlier than the unmodified wing. Furthermore, the gloved wing has a different stall characteristic than the clean wing, with no sharp lift drop-off at stall for the gloved wing.

  8. Effects of flexibility and aspect ratio on the aerodynamic performance of flapping wings.

    Science.gov (United States)

    Fu, Junjiang; Liu, Xiaohui; Shyy, Wei; Qiu, Huihe

    2018-01-26

    In the current study, we experimentally investigated the flexibility effects on the aerodynamic performance of flapping wings and the correlation with aspect ratio at angle of attack α = 45o. The Reynolds number based on the chord length and the wing tip velocity is maintained at Re = 5.3x103. Our result for compliant wings with an aspect ratio of 4 shows that wing flexibility can offer improved aerodynamic performance compared to that of a rigid wing. Flexible wings are found to offer higher lift-to-drag ratios; in particular, there is significant reduction in drag with little compromise in lift. The mechanism of the flexibility effects on the aerodynamic performance is addressed by quantifying the aerodynamic lift and drag forces, the transverse displacement on the wings and the flow field around the wings. The regime of the effective stiffness that offers improved aerodynamic performance is quantified in a range of about 0.5~10 and it matches the stiffness of insect wings with similar aspect ratios. Furthermore, we find that the aspect ratio of the wing is the predominant parameter determining the flexibility effects of compliant wings. Compliant wings with an aspect ratio of two do not demonstrate improved performance compared to their rigid counterparts throughout the entire stiffness regime investigated. The correlation between wing flexibility effects and the aspect ratio is supported by the stiffness of real insect wings. © 2018 IOP Publishing Ltd.

  9. Hybrid Wing-Body Pressurized Fuselage and Bulkhead, Design and Optimization

    Science.gov (United States)

    Mukhopadhyay, Vivek

    2013-01-01

    The structural weight reduction of a pressurized Hybrid Wing-Body (HWB) fuselage is a serious challenge. Hence, research and development are presently being continued at NASA under the Environmentally Responsible Aviation (ERA) and Subsonic Fixed Wing (SFW) projects in collaboration with the Boeing Company, Huntington Beach and Air Force Research Laboratory (AFRL). In this paper, a structural analysis of the HWB fuselage and bulkhead panels is presented, with the objectives of design improvement and structural weight reduction. First, orthotropic plate theories for sizing, and equivalent plate analysis with appropriate simplification are considered. Then parametric finite-element analysis of a fuselage section and bulkhead are conducted using advanced stitched composite structural concepts, which are presently being developed at Boeing for pressurized HWB flight vehicles. With this advanced stiffened-shell design, structural weights are computed and compared to the thick sandwich, vaulted-ribbed-shell, and multi-bubble stiffened-shell structural concepts that had been studied previously. The analytical and numerical results are discussed to assess the overall weight/strength advantages.

  10. Air Pollution

    OpenAIRE

    Appleton, Bonnie Lee, 1948-2012; Koci, Joel; Harris, Roger; Sevebeck, Kathryn P.; Alleman, Dawn; Swanson, Lynette

    2009-01-01

    This publication reviews the major phytotoxic air pollutants, in decreasing order of severity, they include oxidants, sulfur dioxide, and particulates. Topics also include the connection between weather and air pollution and a section on diagnosing air pollution damage to trees.

  11. Air Abrasion

    Science.gov (United States)

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  12. Assessment of the correlation between wing size and body weight in captive Culex quinquefasciatus

    Directory of Open Access Journals (Sweden)

    Vivian Petersen

    Full Text Available Abstract: INTRODUCTION: Mass production of mosquitoes under laboratory conditions allows implementing methods to control vector mosquitoes. Colony development depends on mosquito size and weight. Body size can be estimated from its correlation with wing size, whereas weight is more difficult to determine. Our goal was to test whether wing size can predict the weight. METHODS: We compared dry weight and wing centroid size of Culex quinquefasciatus reared at different temperatures and four diets. RESULTS: Weight and wing size were strongly correlated. The diets did not influence wing size. CONCLUSIONS: Wing centroid size is a good predictor of Cx. quinquefasciatus body weight.

  13. Analysis of Low-Speed Stall Aerodynamics of a Business Jets Wing Using STAR-CCM+

    Science.gov (United States)

    Bui, Trong

    2016-01-01

    Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) analysis was conducted: to study the low-speed stall aerodynamics of a GIII aircrafts swept wing modified with (1) a laminar-flow wing glove, or (2) a seamless flap. The stall aerodynamics of these two different wing configurations were analyzed and compared with the unmodified baseline wing for low-speed flight. The Star-CCM+ polyhedral unstructured CFD code was first validated for wing stall predictions using the wing-body geometry from the First AIAA CFD High-Lift Prediction Workshop.

  14. Assessment of the correlation between wing size and body weight in captive Culex quinquefasciatus.

    Science.gov (United States)

    Petersen, Vivian; Marchi, Marco Jacometto; Natal, Delsio; Marrelli, Mauro Toledo; Barbosa, Admilson Clayton; Suesdek, Lincoln

    2016-01-01

    Mass production of mosquitoes under laboratory conditions allows implementing methods to control vector mosquitoes. Colony development depends on mosquito size and weight. Body size can be estimated from its correlation with wing size, whereas weight is more difficult to determine. Our goal was to test whether wing size can predict the weight. We compared dry weight and wing centroid size of Culex quinquefasciatus reared at different temperatures and four diets. Weight and wing size were strongly correlated. The diets did not influence wing size. Wing centroid size is a good predictor of Cx. quinquefasciatus body weight.

  15. Aeroelasticity Benchmark Assessment: Subsonic Fixed Wing Program

    Science.gov (United States)

    Florance, Jennifer P.; Chwalowski, Pawel; Wieseman, Carol D.

    2010-01-01

    Aeroelasticity Branch will examine other experimental efforts within the Subsonic Fixed Wing (SFW) program (such as testing of the NASA Common Research Model (CRM)) and other NASA programs and assess aeroelasticity issues and research topics.

  16. Age-class separation of blue-winged ducks

    Science.gov (United States)

    Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

    1995-01-01

    Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

  17. Education

    NARCIS (Netherlands)

    de Valk, H.; Crul, M.; Crul, M.; Heering, L.

    2008-01-01

    Education is of crucial importance in the lives of young adults. Attending school is not only a major part of everyday life, but education is a decisive factor for the future. In literature, educational attainment has been tied to a host of outcomes in adult life. Education is perceived as the key

  18. Unsteady Flow Interactions Between Pitching Wings In Schooling Arrangements

    Science.gov (United States)

    Kurt, Melike; Moored, Keith

    2017-11-01

    In nature, many fish aggregate into large groups or schools for protection against predators, for social interactions and to save energy during migrations. Regardless of their prime motivation, fish experience three-dimensional flow interactions amongst themselves that can improve or hamper swimming performance and give rise to fluid-mediated forces between individuals. To date, the unsteady, three-dimensional flow interactions among schooling fish remains relatively unexplored. In order to study these interactions, the caudal fins of two interacting fish are idealized as two finite span pitching wings arranged in mixtures of canonical in-line and side-by-side arrangements. The forces and moments acting on the wings in the streamwise and cross-stream directions are quantified as the arrangement and the phase delay between the wings is altered. Particle image velocimetry is employed to characterize the flow physics during high efficiency locomotion. Finally, the forces and flowfields of two-dimensional pitching wings are compared with three-dimensional wings to distinguish how three-dimensionality alters the flow interactions in schools of fish.

  19. Imaging optical scattering of butterfly wing scales with a microscope.

    Science.gov (United States)

    Fu, Jinxin; Yoon, Beom-Jin; Park, Jung Ok; Srinivasarao, Mohan

    2017-08-06

    A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as Morpho butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of Morpho butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of Morpho rhetenor by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of Morpho cypris . In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.

  20. Multidisciplinary Shape Optimization of a Composite Blended Wing Body Aircraft

    Science.gov (United States)

    Boozer, Charles Maxwell

    A multidisciplinary shape optimization tool coupling aerodynamics, structure, and performance was developed for battery powered aircraft. Utilizing high-fidelity computational fluid dynamics analysis tools and a structural wing weight tool, coupled based on the multidisciplinary feasible optimization architecture; aircraft geometry is modified in the optimization of the aircraft's range or endurance. The developed tool is applied to three geometries: a hybrid blended wing body, delta wing UAS, the ONERA M6 wing, and a modified ONERA M6 wing. First, the optimization problem is presented with the objective function, constraints, and design vector. Next, the tool's architecture and the analysis tools that are utilized are described. Finally, various optimizations are described and their results analyzed for all test subjects. Results show that less computationally expensive inviscid optimizations yield positive performance improvements using planform, airfoil, and three-dimensional degrees of freedom. From the results obtained through a series of optimizations, it is concluded that the newly developed tool is both effective at improving performance and serves as a platform ready to receive additional performance modules, further improving its computational design support potential.

  1. Evaluation of Aircraft Wing-Tip Vortex Using PIV

    Science.gov (United States)

    Alsayed, Omer A.; Asrar, Waqar; Omar, Ashraf A.

    2010-06-01

    The formation and development of a wing-tip vortex in a near and extended near filed were studied experimentally. Particle image velocimetry was used in a wind tunnel to measure the tip vortex velocity field and hence investigate the flow structure in a wake of aircraft half-wing model. The purpose of this investigation is to evaluate the main features of the lift generated vortices in order to find ways to alleviate hazardous wake vortex encounters for follower airplanes during start and approach such that the increase in airport capacity can be achieved. First the wake structure at successive downstream planes crosswise to the axis of the wake vortices was investigated by measuring parameters such as core radius, maximum tangential velocities, vorticities and circulation distributions. The effect of different angles of attack setting on vortex parameters was examined at one downstream location. In very early stages the vortex sheet evolution makes the tip vortex to move inward and to the suction side of the wing. While the core radius and circulation distributions hardly vary with the downstream distance, noticeable differences for the same vortex parameters at different angles of attack settings were observed. The center of the wing tip vortices scatter in a circle of radius nearly equal to 1% of the mean wing chord and wandering amplitudes shows no direct dependence on the vortex strength but linearly increase with the downstream distance.

  2. Investigation of the Three-Dimensional Hinge Moment Characteristics Generated by the ONERA-M6 Wing with an Aileron

    Directory of Open Access Journals (Sweden)

    G. Q. Zhang

    2013-01-01

    Full Text Available The hinge moment characteristics for ONERA-M6 wing with aileron configuration have been investigated numerically based on the different gaps and deflecting angles. The results show that the effects on the wing made by the deflecting aileron are notable. Comparing with the nonaileron case, the chordwise pressure coefficient distribution for the wing with aileron has shown the totally different trends. The small gap can force the air flow through and form the extremely strong spraying flow. It can directly destroy the previously formed leading edge vortex (LEV. Due to the presence of the positive deflecting angle, the trailing edge vortex (TEV will begin to generate at the trailing edge of the aileron. The induced secondary LEV will be mixed with the developing TEVs and form the stronger TEVs at the downstream position. Comparing with the subsonic flow, the curve for the supersonic flow has shown a good linear. The corresponding hinge moments are also extremely sensitive to the changing angle of attack, and the slope of curves is also bigger than that of the subsonic flow. The bigger gap and deflecting angle can result in the curve of hinge moment bending upward at high angle of attack. The corresponding pressure cloud and streamlines have also been obtained computationally and analyzed in detail.

  3. Forewings match the formation of leading-edge vortices and dominate aerodynamic force production in revolving insect wings.

    Science.gov (United States)

    Chen, Di; Kolomenskiy, Dmitry; Nakata, Toshiyuki; Liu, Hao

    2017-10-20

    In many flying insects, forewings and hindwings are coupled mechanically to achieve flapping flight synchronously while being driven by action of the forewings. How the forewings and hindwings as well as their morphologies contribute to aerodynamic force production and flight control remains unclear yet. Here we demonstrate that the forewings can produce most of the aerodynamic forces even with the hindwings removed through a computational fluid dynamic study of three revolving insect wing models, which are identical to the wing morphologies and Reynolds numbers of hawkmoth (Manduca sexta), bumblebee (Bombus ignitus) and fruitfly (Drosophila melanogaster). We find that the forewing morphologies match the formation of leading-edge vortices (LEV) and are responsible for generating sufficient lift forces at the mean angles of attack and the Reynolds numbers where the three representative insects fly. The LEV formation and pressure loading keep almost unchanged with the hindwing removed, and even lead to some improvement in power factor and aerodynamic efficiency. Moreover, our results indicate that the size and strength of the LEVs can be well quantified with introduction of a conical LEV angle, which varies remarkably with angles of attack and Reynolds numbers but within the forewing region while showing less sensitivity to the wing morphologies. This implies that the forewing morphology very likely plays a dominant role in achieving low-Reynolds number aerodynamic performance in natural flyers as well as in revolving and/or flapping micro air vehicles. © 2017 IOP Publishing Ltd.

  4. Toward the bi-modal camber morphing of large aircraft wing flaps: the CleanSky experience

    Science.gov (United States)

    Pecora, R.; Amoroso, F.; Magnifico, M.

    2016-04-01

    The Green Regional Aircraft (GRA), one of the six CleanSky platforms, represents the largest European effort toward the greening of next generation air transportation through the implementation of advanced aircraft technologies. In this framework researches were carried out to develop an innovative wing flap enabling airfoil morphing according to two different modes depending on aircraft flight condition and flap setting: - Camber morphing mode. Morphing of the flap camber to enhance high-lift performances during take-off and landing (flap deployed); - Tab-like morphing mode. Upwards and downwards deflection of the flap tip during cruise (flap stowed) for load control at high speed and consequent optimization of aerodynamic efficiency. A true-scale flap segment of a reference aircraft (EASA CS25 category) was selected as investigation domain for the new architecture in order to duly face the challenges posed by real wing installation issues especially with reference to the tapered geometrical layout and 3D aerodynamic loads distributions. The investigation domain covered the flap region spanning 3.6 m from the wing kink and resulted characterized by a taper ratio equal to 0.75 with a root chord of 1.2 m. High TRL solutions for the adaptive structure, actuation and control system were duly analyzed and integrated while assuring overall device compliance with industrial standards and applicable airworthiness requirements.

  5. Aerodynamic performance of a hovering hawkmoth with flexible wings: a computational approach

    Science.gov (United States)

    Nakata, Toshiyuki; Liu, Hao

    2012-01-01

    Insect wings are deformable structures that change shape passively and dynamically owing to inertial and aerodynamic forces during flight. It is still unclear how the three-dimensional and passive change of wing kinematics owing to inherent wing flexibility contributes to unsteady aerodynamics and energetics in insect flapping flight. Here, we perform a systematic fluid-structure interaction based analysis on the aerodynamic performance of a hovering hawkmoth, Manduca, with an integrated computational model of a hovering insect with rigid and flexible wings. Aerodynamic performance of flapping wings with passive deformation or prescribed deformation is evaluated in terms of aerodynamic force, power and efficiency. Our results reveal that wing flexibility can increase downwash in wake and hence aerodynamic force: first, a dynamic wing bending is observed, which delays the breakdown of leading edge vortex near the wing tip, responsible for augmenting the aerodynamic force-production; second, a combination of the dynamic change of wing bending and twist favourably modifies the wing kinematics in the distal area, which leads to the aerodynamic force enhancement immediately before stroke reversal. Moreover, an increase in hovering efficiency of the flexible wing is achieved as a result of the wing twist. An extensive study of wing stiffness effect on aerodynamic performance is further conducted through a tuning of Young's modulus and thickness, indicating that insect wing structures may be optimized not only in terms of aerodynamic performance but also dependent on many factors, such as the wing strength, the circulation capability of wing veins and the control of wing movements. PMID:21831896

  6. Do hummingbirds use a different mechanism than insects to flip and twist their wings?

    Science.gov (United States)

    Song, Jialei; Luo, Haoxiang; Hedrick, Tyson

    2014-11-01

    Hovering hummingbirds flap their wings in an almost horizontal stroke plane and flip the wings to invert the angle of attack after stroke reversal, a strategy also utilized by many hovering insects such as fruit flies. However, unlike insects whose wing actuation mechanism is only located at the base, hummingbirds have a vertebrate musculoskeletal system and their wings contain bones and muscles and thus, they may be capable of both actively flipping and twisting their wings. To investigate this issue, we constructed a hummingbird wing model and study its pitching dynamics. The wing kinematics are reconstructed from high-speed imaging data, and the inertial torques are calculated in a rotating frame of reference using mass distribution data measured from dissections of hummingbird wings. Pressure data from a previous CFD study of the same wing kinematics are used to calculate the aerodynamic torque. The results show that like insect wings, the hummingbird wing pitching is driven by its own inertia during reversal, and the aerodynamic torque is responsible for wing twist during mid-stroke. In conclusion, our study suggests that their wing dynamics are very similar even though their actuation systems are entirely different. This research was supported by the NSF.

  7. Short revolving wings enable hovering animals to avoid stall and reduce drag

    Science.gov (United States)

    Lentink, David; Kruyt, Jan W.; Heijst, Gertjan F.; Altshuler, Douglas L.

    2014-11-01

    Long and slender wings reduce the drag of airplanes, helicopters, and gliding animals, which operate at low angle of attack (incidence). Remarkably, there is no evidence for such influence of wing aspect ratio on the energetics of hovering animals that operate their wings at much higher incidence. High incidence causes aircraft wings to stall, hovering animals avoid stall by generating an attached vortex along the leading edge of their wings that elevates lift. Hypotheses that explain this capability include the necessity for a short radial distance between the shoulder joint and wing tip, measured in chord lengths, instead of the long tip-to-tip distance that elevates aircraft performance. This stems from how hovering animals revolve their wings around a joint, a condition for which the precise effect of aspect ratio on stall performance is unknown. Here we show that the attachment of the leading edge vortex is determined by wing aspect ratio with respect to the center of rotation-for a suite of aspect ratios that represent both animal and aircraft wings. The vortex remains attached when the local radius is shorter than 4 chord lengths, and separates outboard on more slender wings. Like most other hovering animals, hummingbirds have wing aspect ratios between 3 and 4, much stubbier than helicopters. Our results show this makes their wings robust against flow separation, which reduces drag below values obtained with more slender wings. This revises our understanding of how aspect ratio improves performance at low Reynolds numbers.

  8. Effect of leading- and trailing-edge flaps on clipped delta wings with and without wing camber at supersonic speeds

    Science.gov (United States)

    Hernandez, Gloria; Wood, Richard M.; Covell, Peter F.

    1994-01-01

    An experimental investigation of the aerodynamic characteristics of thin, moderately swept fighter wings has been conducted to evaluate the effect of camber and twist on the effectiveness of leading- and trailing-edge flaps at supersonic speeds in the Langley Unitary Plan Wind Tunnel. The study geometry consisted of a generic fuselage with camber typical of advanced fighter designs without inlets, canopy, or vertical tail. The model was tested with two wing configurations an uncambered (flat) wing and a cambered and twisted wing. Each wing had an identical clipped delta planform with an inboard leading edge swept back 65 deg and an outboard leading edge swept back 50 deg. The trailing edge was swept forward 25 deg. The leading-edge flaps were deflected 4 deg to 15 deg, and the trailing-edge flaps were deflected from -30 deg to 10 deg. Longitudinal force and moment data were obtained at Mach numbers of 1.60, 1.80, 2.00, and 2.16 for an angle-of-attack range 4 deg to 20 deg at a Reynolds number of 2.16 x 10(exp 6) per foot and for an angle-of-attack range 4 deg to 20 deg at a Reynolds number of 2.0 x 10(exp 6) per foot. Vapor screen, tuft, and oil flow visualization data are also included.

  9. Longer wings for faster springs - wing length relates to spring phenology in a long-distance migrant across its range.

    Science.gov (United States)

    Hahn, Steffen; Korner-Nievergelt, Fränzi; Emmenegger, Tamara; Amrhein, Valentin; Csörgő, Tibor; Gursoy, Arzu; Ilieva, Mihaela; Kverek, Pavel; Pérez-Tris, Javier; Pirrello, Simone; Zehtindjiev, Pavel; Salewski, Volker

    2016-01-01

    In migratory birds, morphological adaptations for efficient migratory flight often oppose morphological adaptations for efficient behavior during resident periods. This includes adaptations in wing shape for either flying long distances or foraging in the vegetation and in climate-driven variation of body size. In addition, the timing of migratory flights and particularly the timely arrival at local breeding sites is crucial because fitness prospects depend on site-specific phenology. Thus, adaptations for efficient long-distance flights might be also related to conditions at destination areas. For an obligatory long-distance migrant, the common nightingale, we verified that wing length as the aerodynamically important trait, but not structural body size increased from the western to the eastern parts of the species range. In contrast with expectation from aerodynamic theory, however, wing length did not increase with increasing migration distances. Instead, wing length was associated with the phenology at breeding destinations, namely the speed of local spring green-up. We argue that longer wings are beneficial for adjusting migration speed to local conditions for birds breeding in habitats with fast spring green-up and thus short optimal arrival periods. We suggest that the speed of spring green-up at breeding sites is a fundamental variable determining the timing of migration that fine tune phenotypes in migrants across their range.

  10. Leading-edge vortex shedding from rotating wings

    Energy Technology Data Exchange (ETDEWEB)

    Kolomenskiy, Dmitry [Centre de Recherches Mathématiques (CRM), Department of Mathematics and Statistics, McGill University, 805 Sherbrooke W., Montreal, QC H3A 0B9 (Canada); Elimelech, Yossef [Faculty of Aerospace Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Schneider, Kai, E-mail: dkolom@gmail.com [M2P2–CNRS, Université d' Aix-Marseille, 39, rue Frédéric Joliot-Curie, F-13453 Marseille Cedex 13 (France)

    2014-06-01

    This paper presents a numerical investigation of the leading-edge vortices generated by rotating triangular wings at Reynolds number Re = 250. A series of three-dimensional numerical simulations have been carried out using a Fourier pseudo-spectral method with volume penalization. The transition from stable attachment of the leading-edge vortex to periodic vortex shedding is explored, as a function of the wing aspect ratio and the angle of attack. It is found that, in a stable configuration, the spanwise flow in the recirculation bubble past the wing is due to the centrifugal force, incompressibility and viscous stresses. For the flow outside of the bubble, an inviscid model of spanwise flow is presented. (papers)

  11. An overview of two nonlinear supersonic wing design studies

    Science.gov (United States)

    Miller, D. S.; Pittman, J. L.; Wood, R. M.

    1983-01-01

    The progress of two studies which apply nonlinear aerodynamics to supersonic wing design is reviewed. The first study employed a nonlinear potential flow code to design wings for high lift and low drag due to lift by employing a controlled leading-edge expansion in which the crossflow accelerates to supercritical conditions and decelerates through a weak shock. The second study utilized a modified linearized theory code to explore the concept of using 'attainable' leading-edge thrust as a guide for selecting a wing leading-edge shape (planform and radius) for maintaining attached flow and maximizing leading-edge thrust. Experimental and theoretical results obtained during the course of these two studies are discussed.

  12. Aeroelastic Flutter of Subsonic Aircraft Wing Section with Control Surface

    Directory of Open Access Journals (Sweden)

    Aeroelastic Flutter of Subsonic Aircraft Wing Section with Control Surface

    2015-12-01

    Full Text Available Aeroelastic flutter in aircraft mechanisms is unavoidable, essentially in the wing and control surface. In this work a three degree-of-freedom aeroelastic wing section with trailing edge flap is modeled numerically and theoretically. FLUENT code based on the steady finite volume is used for the prediction of the steady aerodynamic characteristics (lift, drag, pitching moment, velocity, and pressure distribution as well as the Duhamel formulation is used to model the aerodynamic loads theoretically. The system response (pitch, flap pitch and plunge was determined by integration the governing equations using MATLAB with a standard Runge–Kutta algorithm in conjunction with Henon’s method. The results are compared with previous experimental data. The results show that the aerodynamic loads and wing-flap system response are increased when increasing the flow speed. On the other hand the aeroelastic response led up to limit cycle oscillation when the flow equals or more than flutter speed.

  13. Surface Roughness Measurement on a Wing Aircraft by Speckle Correlation

    Directory of Open Access Journals (Sweden)

    Alberto Barrientos

    2013-09-01

    Full Text Available The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given.

  14. Surface roughness measurement on a wing aircraft by speckle correlation.

    Science.gov (United States)

    Salazar, Félix; Barrientos, Alberto

    2013-09-05

    The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given.

  15. Effects of external influences in subsonic delta wing vortices

    Science.gov (United States)

    Washburn, Anthony E.

    1992-01-01

    An experimental investigation was conducted to examine inconsistencies in reported studies for the vortical flow over highly-swept delta wings. A 76-deg swept delta wing was tested in three facilities with open and closed test sections and different model-support systems. The results obtained include surface oil-flow patterns, off-body laser-light-sheet flow visualization, and aerodynamic load measurements. Parameters such as the wall boundaries and model-support systems can drastically alter the loads. The effect of a high level of free-stream turbulence on the delta-wing flowfield was also examined and found to be significant. The increase in free-stream turbulence caused boundary-layer transition, unsteadiness in the vortex core positions, and altered the loads and moments.

  16. Shape matters: improved flight in tapered auto-rotating wings

    Science.gov (United States)

    Liu, Yucen; Vincent, Lionel; Kanso, Eva

    2017-11-01

    Many plants use gravity and wind to disperse their seeds. The shape of seed pods influence their aerodynamics. For example, Liana seeds form aerodynamic gliders and Sycamore trees release airborne ``helicopters.'' Here, we use carefully-controlled experiments and high-speed photography to examine dispersion by tumbling (auto-rotation) and we focus on the effect of geometry on flight characteristics. We consider four families of shapes: rectangular, elliptic, tapered, and sharp-tip wings, and we vary the span-to-chord ratio. We find that tapered wings exhibit extended flight time and range, that is, better performance. A quasi-steady two-dimensional model is used to highlight the mechanisms by which shape affects flight performance. These findings could have significant implications on linking seedpod designs to seed dispersion patterns as well as on optimizing wing design in active flight problems.

  17. Development and experiments of the Sea-Wing underwater glider

    Science.gov (United States)

    Yu, Jian-Cheng; Zhang, Ai-Qun; Jin, Wen-Ming; Chen, Qi; Tian, Yu; Liu, Chong-Jie

    2011-12-01

    Underwater gliders, which glide through water columns by use of a pair of wings, are efficient long-distance, long-duration marine environment observatory platforms. The Sea-Wing underwater glider, developed by the Shenyang Institute of Automation, CAS, is designed for the application of deep-sea environment variables observation. The system components, the mechanical design, and the control system design of the Sea-Wing underwater glider are described in this paper. The pitch and roll adjusting models are derived based on the mechanical design, and the adjusting capabilities for the pitch and roll are analyzed according to the models. Field experiments have been carried out for validating the gliding motion and the ability of measuring ocean environment variables. Experimental results of the motion performances of the glider are presented.

  18. HYDRODYNAMICS OF OSCILLATING WING ON THE PITCH ANGLE

    Directory of Open Access Journals (Sweden)

    Vitalii Korobov

    2017-07-01

    Full Text Available Purpose: research of the hydrodynamic characteristics of a wing in a nonstationary stream. Methods: The experimental studies of the hydrodynamic load acting on the wing of 1.5 elongation, wich harmonically oscillated respect to the transversal axis in the frequency range of 0.2-2.5 Hz. The flow speed in the hydrodynamic tunnel ranged of 0.2-1.5 m/s. Results: The instantaneous values of the coefficients of lift and drag / thrust on the pitch angle at unsteady flow depends on the Strouhal number.Discussion: with increasing oscillation frequency coefficients of hydrodynamic force components significantly higher than the data for the stationary blowing out of the wing.

  19. Spanwise drag variation on low Re wings -- revisited

    Science.gov (United States)

    Yang, Shanling; Spedding, Geoffrey

    2011-11-01

    Aerodynamic performance measurement and prediction of airfoils and wings at chord Reynolds numbers below 105 is both difficult and increasingly important in application to small-scale aircraft. Not only are the aerodynamics strongly affected by the dynamics of the unstable laminar boundary layer but the flow is decreasingly likely to be two-dimensional as Re decreases. The spanwise variation of the flow along a two-dimensional geometry is often held to be responsible for the large variations in measured profile drag coefficient. Here we measure local two-dimensional drag coefficients along a finite wing using non-intrusive PIV methods. Variations in Cd (y) can be related to local flow variations on the wing itself. Integrated values can be compared with force balance data, and the proper description of drag components at low Re will be discussed.

  20. Flow Measurements of a Plunging Wing in Unsteady Environment

    Science.gov (United States)

    Wengel, Jesse; Nathan, Rungun; Cheng, Bo; Eslam-Panah, Azar

    2017-11-01

    Despite the great progress in their design and control, Unmanned Aerial Vehicles (UAVs) are tremendously troubled while flying in turbulent environments, which are common in the lower atmospheric boundary layer (ABL). A nominally 2D plunging wing was developed and tested in the presence of unsteady wake to investigate the effect of the flow disturbances on vorticity fields. The experiments were conducted in a water channel facility with test section width of 0.76 m, and a water depth of 0.6 m. The unsteady wake in the form of von Kármán Vortex Street was generated by a cylinder located upstream of the plunging wing. The plunge amplitude and frequency of the oscillation were adjusted to bracket the range of Strouhal numbers relevant to the biological locomotion (0.25PIV) was employed to quantitatively study the effect of unsteady wake on the flow measurements of the plunging wing.