Aerodynamics Of Low Reynolds Number Flyers
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationAerodynamics of Low Reynolds Number FlyersLow Reynolds number aerodynamics is important to a number of natural and manmade flyers. Birds, bats, and insects have been investigated by biologists for years, andactive study in the aerospace engineering community, motivated by interest in microair vehicles (MAVs), has been increasing rapidly. The primary focus of this book isthe aerodynamics associated with fixed and flapping wings. The book considers bothbiological flyers and MAVs, including a summary of the scaling laws that relate theaerodynamics and flight characteristics to a flyer’s sizing on the basis of simple geometric and dynamics analyses, structural flexibility, laminar–turbulent transition, airfoil shapes, and unsteady flapping-wing aerodynamics. The interplay between flappingkinematics and key dimensionless parameters such as the Reynolds number, Strouhalnumber, and reduced frequency is highlighted. The various unsteady lift-enhancementmechanisms are also addressed.Wei Shyy is the Clarence L. “Kelly” Johnson Collegiate Professor and Chairman of theDepartment of Aerospace Engineering at the University of Michigan. He also taught atthe University of Florida, as Distinguished Professor and Department Chair. He is theauthor and coauthor of books and articles dealing with computational and modelingtechniques involving fluid flow, aerodynamics, propulsion, interfacial dynamics, andmoving-boundary problems. He is the General Editor of the Cambridge AerospaceSeries (Cambridge University Press), and is a Fellow of the American Institute ofAeronautics and Astronautics and the American Society of Mechanical Engineers.Yongsheng Lian, Jian Tang, and Dragos Viieru are research scientists at the Universityof Michigan. They have done original research in flexible-wing and aerodynamicsinteractions: flapping-wing aerodynamics; laminar–turbulent transition; and unsteady,low Reynolds number fluid physics.Hao Liu is a Professor of Biomechanical Engineering at Chiba University in Japan.He is well known for his contributions to biological, flapping-flight research, includingoriginal publications on insect aerodynamics simulations. in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationCambridge Aerospace SeriesEditors: Wei Shyy and Michael J. 8.19.20.21.22.23.J. M. Rolfe and K. J. Staples (eds.): Flight SimulationP. Berlin: The Geostationary Applications SatelliteM. J. T. Smith: Aircraft NoiseN. X. Vinh: Flight Mechanics of High-Performance AircraftW. A. Mair and D. L. Birdsall: Aircraft PerformanceM. J. Abzug and E. E. Larrabee: Airplane Stability and ControlM. J. Sidi: Spacecraft Dynamics and ControlJ. D. Anderson: A History of AerodynamicsA. M. Cruise, J. A. Bowles, C. V. Goodall, and T. J. Patrick: Principles of SpaceInstrument DesignG. A. Khoury and J. D. Gillett (eds.): Airship TechnologyJ. Fielding: Introduction to Aircraft DesignJ. G. Leishman: Principles of Helicopter Aerodynamics, 2nd EditionJ. Katz and A. Plotkin: Low Speed Aerodynamics, 2nd EditionM. J. Abzug and E. E. Larrabee: Airplane Stability and Control: A History of theTechnologies that Made Aviation Possible, 2nd EditionD. H. Hodges and G. A Pierce: Introduction to Structural Dynamics andAeroelasticityW. Fehse: Automatic Rendezvous and Docking of SpacecraftR. D. Flack: Fundamentals of Jet Propulsion with ApplicationsE. A. Baskharone: Principles of Turbomachinery in Air-Breathing EnginesDoyle D. Knight: Numerical Methods for High-Speed FlowsC. Wagner, T. Huettl, and P. Sagaut: Large-Eddy Simulation for AcousticsD. Joseph, T. Funada, and J. Wang: Potential Flows of Viscous and ViscoelasticFluidsW. Shyy, Y. Lian, J. Tang, D. Viieru, and H. Liu: Aerodynamics of Low ReynoldsNumber FlyersJ. Saleh: Analyses for System Design Lifetime: With Applications to SateliteUtility Models, Reliability, and Optimal Design Lifetime in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationAerodynamics ofLow Reynolds Number FlyersWEI SHYYUniversity of MichiganYONGSHENG LIANUniversity of MichiganJIAN TANGUniversity of MichiganDRAGOS VIIERUUniversity of MichiganHAO LIUChiba University in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationCAMBRIDGE UNIVERSITY PRESSCambridge, New York, Melbourne, Madrid, Cape Town,Singapore, São Paulo, Delhi, Tokyo, Mexico CityCambridge University Press32 Avenue of the Americas, New York, NY 10013-2473, USAwww.cambridge.orgInformation on this title: www.cambridge.org/9780521204019 Wei Shyy 2008This publication is in copyright. Subject to statutory exceptionand to the provisions of relevant collective licensing agreements,no reproduction of any part may take place without the writtenpermission of Cambridge University Press.First published 2008Reprinted 2009First paperback edition 2011A catalog record for this publication is available from the British LibraryLibrary of Congress Cataloging in Publication dataShyy, Wei.Aerodynamics of low reynolds number flyers : wei shyy . . . [et al.].p. cm. – (Cambridge aerospace series)Includes bibliographical references and index.ISBN 978-0-521-88278-1 (hardback)1. Aerodynamics. i. Title. ii. Series.TL570.S4882007629.132'3 – dc222007019227ISBNISBN978-0-521-88278-1 Hardback978-0-521-20401-9 PaperbackAdditional resources for this publication at www.cambridge.org/9780521204019Cambridge University Press has no responsibility for the persistence oraccuracy of URLs for external or third-party internet websites referred to inthis publication, and does not guarantee that any content on such websites is,or will remain, accurate or appropriate. in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationContentsNomenclatureList of AbbreviationsPreface12Introductionpage xixvxvii11.1 Flapping Flight in Nature1.1.1 Unpowered Flight: Gliding and Soaring1.1.2 Powered Flight: Flapping1.1.3 Hovering1.1.4 Forward Flight1.2 Scaling1.2.1 Geometric Similarity1.2.2 Wingspan1.2.3 Wing Area1.2.4 Wing Loading1.2.5 Aspect Ratio1.2.6 Wing-Beat Frequency1.3 Power Implication of a Flapping Wing1.3.1 Upper and Lower Limits1.3.2 Drag and Power1.4 Concluding Remarks6789101416171718181920212326Fixed, Rigid-Wing Aerodynamics282.1 Laminar Separation and Transition to Turbulence2.1.1 Navier–Stokes Equation and the Transition Model2.1.2 The e N Method2.1.3 Case Study: SD70032.2 Factors Influencing Low Reynolds Number Aerodynamics2.2.1 Re 103 –1042.2.2 Re 104 –1062.2.3 Effect of Free-Stream Turbulence2.2.4 Effect of Unsteady Free-Stream293537394445475054vii in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationviiiContents342.3 Three-Dimensional Wing Aerodynamics2.3.1 Unsteady Phenomena at High Angles of Attack2.3.2 Aspect Ratio and Tip Vortices2.3.3 Wingtip Effect2.3.4 Unsteady Tip Vortices2.4 Concluding Remarks576163707376Flexible-Wing Aerodynamics783.1 General Background of Flexible-Wing Flyers3.2 Flexible-Wing Models3.2.1 Linear Membrane Model3.2.2 Hyperelastic Membrane Model3.2.3 Combined Fluid–Structural Dynamics Computation3.3 Coupled Elastic Structures and Aerodynamics3.3.1 Flexible Airfoils3.3.2 Membrane-Wing Aerodynamics3.4 Concluding Remarks7885858991929294100Flapping-Wing Aerodynamics1014.1 Scaling, Kinematics, and Governing Equations4.1.1 Flapping Motion4.1.2 Reynolds Number4.1.3 Strouhal Number and Reduced Frequency4.2 Nonstationary Airfoil Aerodynamics4.2.1 Dynamic Stall4.2.2 Thrust Generation of a Pitching/Plunging Airfoil4.3 Simplified Flapping-Wing Aerodynamics Model4.4 Lift-Enhancement Mechanisms in Flapping Wings4.4.1 Leading-Edge Vortex4.4.2 Rapid Pitch-Up4.4.3 Wake Capture4.4.4 Clap-and-Fling Mechanism4.4.5 Wing Structural Flexibility4.5 Effects of Reynolds Number, Reduced Frequency, andKinematics on Hovering Aerodynamics4.5.1 Hovering Kinematics4.5.2 Scaling Effect on Force Generation for HoveringAirfoils4.6 Aerodynamics of a Hovering Hawkmoth4.6.1 Downstroke4.6.2 Supination4.6.3 Upstroke4.6.4 8 in this web service Cambridge University Press144144148151152153155155www.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationContents4.6.5 Evaluation of Aerodynamic Forces4.6.6 Aerodynamic and Inertial Powers of Flapping Wings4.7 Concluding Remarksix155156157References159Index175 in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationNomenclatureFirst oDweEFmff,maxf,minghah0h(t)h(t)hHHTIJJTaspect ratio b /Sangle of attackwingspanchord length Llift coefficient CL 0.5 U2S Ddrag coefficient CD 0.5 U2Sdrag coefficient due to skin frictiondrag coefficient due to pressurePpressure coefficient (C P 0.5 U2)tension coefficient of a membrane sailright Cauchy–Green deformation tensortotal aerodynamic draginduced dragparasite drag (drag on the body)profile dragdrag on a finite wingspan efficiency factorelastic modulusforce exerted by a musclewing-beat frequencymaximum flapping frequencyminimum flapping frequencygravitational accelerationflapping amplitudemembrane thickness in nondeformed configurationsdeformed membrane thicknesstime-dependent flapping displacementmembrane thicknessshape factorshape factor at the transition pointmoment of inertiaadvance ratiotorque2Eq. (1.9)Eq. (1.9)Eq. (1.1)Eq. (1.3)Eq. (2.22)Eq. (2.22)Eq. (2.22)Eq. (3.1)Eq. (3.23)Eq. (1.27)Eq. (1.26)Eq. (1.27)Eq. (1.26)Eq. (1.26)Eq. (2.22)Eq. (3.7)Eq. (1.10)Eq. (1.14)Eq. (1.15)Eq. (1.18)Eq. (1.5)Eq. (4.4)Eq. (3.27)Eq. (3.27)Eq. (4.4)Eq. (3.7)Eq. (2.2)Eq. (2.19)Eq. (1.12)Eq. (4.15)Eq. (1.11)xi in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore eropcenterPindPinerPproreduced frequencyturbulent kinetic energycharacteristic lengthliftunstrained membrane lengthlift-to-drag ratio, or glide ratio ( CL /CD )body massmass of a limbmass of the pectoral musclesmass of the supracoracoideus musclesamplification factorthreshold value that triggers turbulent flow in eN methodstatic pressurenormalized static pressuretotal aerodynamic powerpressure at the center of a vortex core rotating as a rigid bodyinduced power (required for generating lift and thrust)inertial power (required for moving the wings)profile power (required for overcomingform and friction drag of the wings)parasite power (required for overcoming formand friction drag of the body)total power required for flightfar-field dynamic pressureradius of the vortex core rotating as a rigid bodywing lengthReynolds numberReynolds number for 2D flapping airfoilsReynolds number for 3D flapping wingturbulent Reynolds numbermomentum-thickness Reynolds numbercritical Reynolds numbermomentum-thickness Reynolds number at transition pointwing areasecond Piola–Kirchoff stress tensormembrane prestressStrouhal numberwing-stroke time scalethrust (for hovering)free-stream turbulence intensitytimeforward-flight velocity (free-stream velocity)reference velocityedge velocityvelocity vector in Cartesian coordinatesPparPtotq r1RReRef 2Ref 3ReTRe Re 0Re TSSS0StTTTitUUrefueui in this web service Cambridge University PressEq. (1.1)Eq. (2.6)Eq. (1.6)Eq. (1.3)Eq. (3.2)Eq. (2.20)Eq. (1.5)Eq. (1.12)Eq. (1.24)Eq. (1.25)Eq. (2.12)Eq. (2.17)Eq. (2.5)Eq. (4.19)Eq. (1.28)Eq. (2.23)Eq. (1.30)Eq. (1.31)Eq. (1.30)Eq. (1.30)Eq. (1.31)Eq. (3.12)Eq. (2.23)Eq. (4.20)Eq. (4.7)Eq. (4.8)Eq. (2.10)Eq. (2.12)Eq. (2.12)Eq. (2.19)Eq. (1.3)Eq. (3.23)Eq. (3.7)Eq. (4.9)Eq. (1.14)Eq. (1.29)Eq. (2.17)Eq. (2.5)Eq. (1.2)Eq. (1.1)Eq. (2.2)Eq. (2.4)www.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationNomenclatureuiUfUmpUMrUrwwiWWW/SxixlxT (t) 0 a ˆ ε (t) , Te T 1 2 (t) i j normalized velocity vector in Cartesian coordinatesflapping velocityvelocity for minimum power (forward flight)velocity for maximum range (forward flight)relative flow velocityvertical velocity in the far wakedownwash (induced) velocityweightout-of-plane membrane displacementwing loadingspatial coordinate vectorleg lengthtransition onset positionangle of attackfeathering angle (pitch angle) of a flapping winginitial pitch angle at the beginning of the strokepitch amplitudestroke-plane anglemembrane tensiondimensionless membrane tensioncirculationboundary-layer displacement thicknessnominal membrane straindimensionless excess length of a membraneboundary-layer momentum thicknesselevation angle of a flapping wingcurvilinear coordinates along the membrane airfoilkinematic viscosityeffective eddy viscosityturbulent eddy viscosityaeroelastic parameter (elastic-strain-dominatedmembrane tension)aeroelastic parameter (pretension-dominatedmembrane tension)positional angle of a flapping wingstroke angular amplitudephase difference between plunging and pitching motion(air) densityReynolds stress tensortangential surface traction for 2D membraneangular velocity of a flapping wing 2 fdissipation rate for k– turbulence modelfrequencyangular acceleration in this web service Cambridge University PressxiiiEq. (4.19)Eq. (1.2)Eq. (1.33)Eq. (1.33)Eq. (1.2)Eq. (4.22)Eq. (1.2)Eq. (1.3)Eq. (3.20)Eq. (1.7)Eq. (2.4)Eq. (1.19)Eq. (2.19)Eq. (3.1)Eq. (4.3)Eq. (4.5)Eq. (4.5)Eq. (4.21)Eq. (3.3)Eq. (3.7)Eq. (2.23)Eq. (2.3)Eq. (3.8)Eq. (3.2)Eq. (2.1)Eq. (4.2)Eq. (3.3)Eq. (2.5)Eq. (2.18)Eq. (2.6)Eq.(3.16)Eq. (3.18)Eq. (4.1)Eq. (4.7)Eq. (4.4)Eq. (1.3)Eq. (2.6)Eq. (3.4)Eq. (1.1)Eq. (2.7)Eq. (2.21)Eq. (1.13)www.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationList of ee-dimensionalangle of attackaspect ratiocomputational fluid dynamicscomputational structural dynamicsdirect numerical simulationdigital particle-image velocimetrylarge-eddy simulationleading-edge vortexlaminar separation bubblemicro air vehicleReynolds-averaged Navier–Stokestrailing-edge vortexTollmien–Schlichtingwingtip vortexxv in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationPrefaceLow Reynolds number aerodynamics is important to a number of naturaland manmade flyers. Birds, bats, and insects have been of interest to biologists foryears, and active study in the aerospace engineering community has been increasingrapidly. Part of the reason is the advent of micro air vehicles (MAVs). With a maximaldimension of 15 cm and nominal flight speeds of around 10 m/s, MAVs are capable ofperforming missions such as environmental monitoring, survelliance, and assessmentin hostile environments. In contrast to civilian transport and many military flight vehicles, these small flyers operate in the low Reynolds number regime of 105 or lower. Itis well established that the aerodynamic characteristics, such as the lift-to-drag ratioof a flight vehicle, change considerably between the low and high Reynolds numberregimes. In particular, flow separation and laminar–turbulent transition can result insubstantial change in effective airfoil shape and reduce aerodynamic performance.Because these flyers are lightweight and operate at low speeds, they are sensitive towind gusts. Furthermore, their wing structures are flexible and tend to deform duringflight. Consequently, the aero/fluid and structural dynamics of these flyers are closelylinked to each other, making the entire flight vehicle difficult to analyze.The primary focus of this book is on the aerodynamics associated with fixed andflapping wings. Chapter 1 offers a general introduction to low Reynolds numberflight vehicles, considering both biological flyers and MAVs, followed by a summaryof the scaling laws, which relate the aerodynamics and flight characteristics to aflyer’s size on the basis of simple geometric and dynamics analyses. In Chapter 2,we discuss the aerodynamics of fixed, rigid wings. Both two- and three-dimensionalairfoils with typically low-aspect-ratio wings are considered. Chapter 3 examinesstructural flexibility within the context of fixed-wing aerodynamics. The implicationsof laminar–turbulent transition, multiple time scales, airfoil shapes, angles of attack,stall margin, and the structural flexibility and time-dependent fluid and structuraldynamics are highlighted.Unsteady flapping-wing aerodynamics is presented in Chapter 4, in particular,the interplay between flapping kinematics and key dimensionless parameters suchas the Reynolds number, Strouhal number, and reduced frequency. The variousunsteady lift-enhancement mechanisms are also addressed, including leading-edgevortex, rapid pitch-up, wake capture, and clap-and-fling.The materials presented in this book are based on our own research, existing literature, and communications with colleagues. At different stages, we have benefitedxvii in this web service Cambridge University Presswww.cambridge.org
Cambridge University Press978-0-521-20401-9 - Aerodynamics of Low Reynolds Number FlyersWei Shyy, Yongsheng Lian, Jian Tang, Dragos Viieru and Hao LiuFrontmatterMore informationxviiiPrefacefrom collaborations and interactions with Peter Ifju, David Jenkins, Rick Lind,Raphael Haftka, Richard Fearn, Roberto Albertani, and Bruce Carroll of the University of Florida; Luis Bernal, Carlos Cesnik, and Peretz Friedmann of the Universityof Michigan; Michael Ol, Miguel Visbal, and Gregg Abate, and Johnny Evers ofthe Air Force Research Laboratory; Ismet Gursul of the University of Bath; CharlesEllington of Cambridge University; Keiji Kawachi of the University of Tokyo; HikaruAono of Chiba University; Max Platzer of Naval Postgraduate School; and Mao Sunof the Beijing University of Aeronautics and Astronautics. In particular, we have followed the flight vehicle development efforts of Peter Ifju and his group and enjoyedthe synergy between us.MAVs and biological flight is now an active and well-integrated research area,attracting participation from a wide range of talents. The complementary perspectives of researchers with different training and background enable us to developnew biological insight, mathematical models, physical interpretation, experimentaltechniques, and design concepts.Thinking back to the time we started our own endeavor a l
Aerodynamics of Low Reynolds Number Flyers Low Reynolds number aerodynamics is important to a number of natural and man-made flyers. Birds, bats, and insects have been investigated by biologists for years, and active study in the aerospace engineering community, motivated by interest i
Aerodynamics is the study of the dynamics of gases, or the interaction between moving object and atmosphere causing an airflow around a body. As first a movement of a body (ship) in a water was studies, it is not a surprise that some aviation terms are the same as naval ones rudder, water line, –File Size: 942KBPage Count: 16Explore furtherIntroduction to Aerodynamics - Aerospace Lectures for .www.aerospacelectures.comBeginner's Guide to Aerodynamicswww.grc.nasa.govA basic introduction to aerodynamics - SlideSharewww.slideshare.netBASIC AERODYNAMICS - MilitaryNewbie.comwww.militarynewbie.comBasic aerodynamics - [PPT Powerpoint] - VDOCUMENTSvdocuments.netRecommended to you b
Alonzo Carlton Reynolds, better known as A.C. Reynolds, was born on October 19, 1870 in the Sandy Mush township, a rural community of Buncombe County. The fifth child of seven by John Haskew Reynolds and Sara Ann Ferguson Reynolds, A.C. learned about responsibility
Low Reynolds Number Aerodynamics of Low-Aspect-Ratio, Thin/Flat/Cambered-Plate Wings Alain Pelletier and Thomas J. Mueller† University of Notre Dame, Notre Dame, Indiana 46556 The design of micro aerial vehicles requires a better understanding
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Chapter 13: Aerodynamics of Wind Turbines. Chapter 13: Aerodynamics of Wind Turbines. Chapter 13: Aerodynamics of Wind Turbines. Time accurate predictions for a 2-bladed HAWT are shown in the next figure (13.22) At high tip speed ratio (low wind speeds) vortex ring state (part a)
results indicate that experimental evolution of the clean wing performance coefficients were . Aerodynamic performance testing was conducted in angle of attack sweeps over a Reynolds number range of 0.8 106 to 2.4 106 and a corresponding Mach number range of 0.09 to 0.27. Force-balance and surface-pressure data were acquired.
Initial Counseling . If you are accidentally placed on guard, weekend duty, or special duties that contradict your team orders, it is incumbent upon you to let your chain of command know IMMEDIATELY so that they can find a replacement in time. If you do not inform them within 48 hours of the duty, it is your responsibility to find a replacement. ***A change from past years: Leadership .
