Download or read book Measurements of the Aerodynamic Forces on Small Oscillating Wing Models combined Flapping and Twist written by E. V. Holst and published by . This book was released on 1943 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Swimming and Flying in Nature written by Theodore Wu and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Symposium on Swimming and Flying in Nature which was held at the California Institute of Technology, Pasadena, California from July 8-12, 1974 was conceived with the objective of providing an interdisciplinary forum for the discussion of funda mental biological and fluid mechanical aspects of these forms of natura110comotion. It was the earnest hope of all concerned in the organization of the Symposium that the exchange of knowledge and interaction of ideas from the disciplines involved would stimu late new research in this developing field. If the liveliness of the discussion generated among the 250 or so participants is any measure, then this objective was fulfilled to a significant degree. These two companion volumes contain the manuscripts of the papers presented during the Symposium. It is hoped that this permanent record will serve to perpetuate the enthusiasm and active thought generated during those days in Pasadena. The first volume contains the proceedings of the first two days of the confer ence (Sessions I to IV) which concentrated on the locomotion of micro-organisms. The second volume (Sessions V to VIII) deals with the propulsion of larger fish, insects and birds. Professor Sir James Lighthill's Special Invited Lecture which opened the Symposium is contained in the second volume, rather than the first, since it deals with natural flight.
Download or read book An Introduction to Flapping Wing Aerodynamics written by Wei Shyy and published by Cambridge University Press. This book was released on 2013-08-19 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an ideal book for graduate students and researchers interested in the aerodynamics, structural dynamics and flight dynamics of small birds, bats and insects, as well as of micro air vehicles (MAVs), which present some of the richest problems intersecting science and engineering. The agility and spectacular flight performance of natural flyers, thanks to their flexible, deformable wing structures, as well as to outstanding wing, tail and body coordination, is particularly significant. To design and build MAVs with performance comparable to natural flyers, it is essential that natural flyers' combined flexible structural dynamics and aerodynamics are adequately understood. The primary focus of this book is to address the recent developments in flapping wing aerodynamics. This book extends the work presented in Aerodynamics of Low Reynolds Number Flyers (Shyy et al. 2008).
Download or read book The Aerodynamics of Flexible Flapping Flight written by Liang Zhao and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I used a dynamically scaled mechanical model of flapping flight 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 center 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. I also investigated inertial and aerodynamic power consumption during hovering flight of the hawk moth Manduca sexta. The aerodynamic power was estimated based on the aerodynamic torques measured on model hawk-moth wings and hovering kinematics. The inertial power was estimated based on the measured wing mass distribution and hovering kinematics. The results suggest that wing inertial power (without consideration of muscle efficiency and elastic energy storage) consumes about half of the total power expenditure. Wing areal mass density was measured to decrease sharply from the leading edge toward the trailing edge and from the wing base to the wing tip. Such a structural property helps to minimize the wing moment of inertia given a fixed amount of mass. We measured the aerodynamic forces on the rigid and flexible wings, which were made to approximate the flexural stiffness (EI) distribution and deformation of moth wings. It has been found that wings with the characteristic spanwise and chordwise decreasing EI (and mass density) are beneficial for power efficiency while generating aerodynamic forces comparative to rigid wings. Furthermore, negative work to aid pitching in stroke reversals from aerodynamic forces was found, and it showed that the aerodynamic force contributes partially to passive pitching of the wing. Wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout 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 as discussed in the first experiment. Model tests on flexible and rigid wings show that the leading edge vortex can be greatly affected by the flexural stiffness. Rigid wings are coupled with strong leading edge and higher net force at the angle of attack tested. Flexible wings, due to the trailing edge bending, can easily meet the Kutta condition. Hence the strength of the leading edge vortex is weakened. The strong correlation among the wing flexion, leading edge vortex and the forces generation were found during the test. The aerodynamic force was substantially enhanced by adding a single carbon fiber vein on flexible wings. Both the force and leading edge vortex were increased dramatically.
Download or read book Measurement of Aerodynamic Forces for Various Mean Angles of Attach on an Airfoil Oscillating in Pitch and on Two Finite Span Wings Oscillating in Bending with Emphasis on Damping in the Stall written by and published by . This book was released on 1956 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number from 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 5-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Download or read book Index of NACA Technical Publications written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1959 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerodynamic Force Measurements and Flow Visualizations of Flapping Wings written by D. M. McRobert and published by . This book was released on 1980 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aerodynamics of Flapping Wings written by Sanjay Prafullachandra Sane and published by . This book was released on 2001 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Tip Effects on the Aerodynamic Forces on an Oscillating Wing written by Garabed Zartarian and published by . This book was released on 1949 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Flapping Wing Aerodynamics and Flight Dynamics Analysis Using Computational Methods written by Alok Ashok Rege and published by . This book was released on 2016 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insect flight comes with a lot of intricacies that cannot be explained by conventional aerodynamics. Even with their small-size, insects have the ability to generate the required aerodynamic forces using high frequency apping motion of their wings to perform different maneuvers. The maneuverability obtained by these flyers using apping motion belies the classical aerodynamics theory and calls for a new approach to study this highly unsteady aerodynamics. Research is on to find new ways to realize the flight capabilities of these insects and engineer a micro- flyer which would have wide range of applications, including but not limited to Autonomous Pollination of crop fields; High Resolution Weather and Climate Mapping; Traffic Monitoring; Oil & Gas Exploration; and Area Surveillance, Detection & Rescue Missions In this research, a parametric study of apping trajectories is performed using a two-dimensional wing to identify the factors that affect the force production. These factors are then non-dimensionalized and used in a design of experiments set-up to conduct sensitivity analysis. A procedure to determine an aerodynamic model comprising cycle-averaged force coefficients is described. This aerodynamic model is then used in a nonlinear dynamics framework to perform flight dynamics analysis using a micro- flyer with model properties based on Drosophila. Stability analysis is conducted to determine different steady state flight conditions that could achieved by the micro- flyer with the given model properties. The effect of scaling the mass properties is discussed. An LQR design is used for closed-loop control. Open and closed-loop simulations are performed. The results show that nonlinear dynamics framework can be used to determine values for model properties of a micro-flyer that would enable it to perform different flight maneuvers.
Download or read book A Selected Listing of NASA Scientific and Technical Reports for written by and published by . This book was released on 1957 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Aerodynamic Forces for Various Mean Angles of Attack on an Airfoil Oscillating in Pitch and on Two Finite span Wings Oscillating in Bending with Emphasis on Damping in the Stall written by A. Gerald Rainey and published by . This book was released on 1957 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the aerodynamic damping of a 10-percent-thick and of a 3-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Download or read book Measurement of the Aerodynamic Forces on Oscillating Aerofoils written by and published by . This book was released on 1956 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various techniques for oscillatory force measurements are considered in relation to their application to the measurement of the aerodynamic coefficients for a rectangular wing oscillating in modes of vertical translation and uniform pitch. It is shown that eight relevant coefficients are obtainable by any of the techniques described. The various corrections that must be applied to oscillatory aerodynamic force measurements are also discussed. The paper provides a basis for comparison of the various force-measuring techniques and should assist investigators in this field in determining the particular technique most likely to meet their requirements. (Author).
Download or read book Aerodynamic forces on a combination of a wing and a fin oscillating in subsonic flow written by Valter J. E. Stark and published by . This book was released on 1964 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Order Modeling of the Unsteady Aerodynamics in Flapping Wings written by Juan Carlos Gomez and published by . This book was released on 2015 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The investigation of unsteady aerodynamics is becoming a more attractive topic of research in enhancing flight capabilities. Natural flyers such as birds and insects can undergo flight maneuvers that are very difficult or not possible with current aerodynamic understanding. Modeling the unsteady phenomena produced by flapping wings is important to the understanding of these maneuvers, with possible applications to aircraft flight. We investigate reduced-order modeling of the unsteady aerodynamics generated by flapping wings using the two separate approaches of rotational lift and dynamic stall. A low order quasi steady model based on rotational lift and a revised version incorporating dynamic stall are presented. Both concepts are analyzed using simulated results, with experimental data measured with matching kinematics as a basis of comparison. This combined model is then used to conduct parametric studies of the time averaged aerodynamic forces over varying kinematic variables.
Download or read book An Introduction to Flapping Wing Aerodynamics written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an ideal book for graduate students and researchers interested in the aerodynamics, structural dynamics and flight dynamics of small birds, bats and insects, as well as of micro air vehicles (MAVs), which present some of the richest problems intersecting science and engineering. The agility and spectacular flight performance of natural flyers, thanks to their flexible, deformable wing structures, as well as to outstanding wing, tail and body coordination, is particularly significant. To design and build MAVs with performance comparable to natural flyers, it is essential that natural flyers' combined flexible structural dynamics and aerodynamics are adequately understood. The primary focus of this book is to address the recent developments in flapping wing aerodynamics. This book extends the work presented in Aerodynamics of Low Reynolds Number Flyers (Shyy et al. 2008).
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1951 with total page 1364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
