Aerodynamics for Engineers

by Bertin, John J.; Cummings, Russell M.

• ISBN13: 9780130646330
• ISBN10: 0130646334
• Edition: 4th
• Format: Hardcover
• Copyright: 2009-01-01
• Publisher: Pearson College Div

Summary

KEY BENEFIT From low-speed through hypersonic flight, this book merges fundamental fluid mechanics, experimental techniques, and computational fluid dynamics techniques to build a solid foundation in aerodynamic applications. Many references are recent publications by the world's finest aerodynamicists with expertise in subsonic, transonic, supersonic, and hypersonic aerodynamics. KEY TOPICS Starts the new edition with a fun, readable, and motivational presentation on aircraft performance using material on Specific Excess Power (taught to all cadets at the U.S. Air Force Academy). Adds new sections to later chapters, presenting new real-world applications. Includes a CD-ROMwith Excel spreadsheets to solve a wide range of problems showing simple CFD applications, experimental correlations, and more. A useful reference for professionals in the aeronautics industry.

Table of Contents

Preface	xiii
Fluid Properties	1	(16)
Concept of a Fluid	1	(1)
Fluid as a Continuum	2	(1)
Fluid Properties	2	(6)
Temperature	3	(1)
Pressure	3	(1)
Density	3	(2)
Viscosity	5	(1)
Kinematic Viscosity	6	(2)
Speed of Sound	8	(1)
Pressure Variation in a Static Fluid Medium	8	(4)
The Standard Atmosphere	12	(2)
Summary	14	(3)
Problems	14	(2)
References	16	(1)
Fundamentals of Fluid Mechanics	17	(39)
Introduction to Fluid Dynamics	17	(2)
Conservation of Mass	19	(3)
Conservation of Linear Momentum	22	(5)
Applications to Constant-Property Flows	27	(5)
Reynolds Number and Mach Number as Similarity Parameters	32	(4)
Concept of the Boundary Layer	36	(2)
Conservation of Energy	38	(1)
First Law of Thermodynamics	38	(2)
Derivation of the Energy Equation	40	(6)
Integral Form of the Energy Equation	43	(1)
Energy of the System	43	(1)
Flow Work	44	(1)
Viscous Work	44	(1)
Shaft Work	45	(1)
Application of the Integral Form of the Energy Equation	45	(1)
Summary	46	(10)
Problems	47	(8)
References	55	(1)
Dynamics of an Incompressible, Inviscid Flow Field	56	(53)
Inviscid Flows	56	(1)
Bernoulli's Equation	57	(3)
Use of Bernoulli's Equation to Determine Airspeed	60	(2)
The Pressure Coefficient	62	(2)
Circulation	64	(2)
Irrotational Flow	66	(1)
Kelvin's Theorem	67	(1)
Implication of Kelvin's Theorem	67	(1)
Incompressible, Irrotational Flow	68	(1)
Boundary Conditions	68	(1)
Stream Function in a Two-Dimensional, Incompressible Flow	68	(2)
Relation Between Streamlines and Equipotential Lines	70	(2)
Superposition of Flows	72	(1)
Elementary Flows	73	(6)
Uniform Flow	73	(1)
Source or Sink	73	(2)
Doublet	75	(1)
Potential Vortex	75	(3)
Summary of Stream Functions and of Potential Functions	78	(1)
Adding Elementary Flows to Describe Flow Around a Cylinder	79	(6)
Velocity Field	79	(1)
Pressure Distribution	80	(3)
Lift and Drag	83	(2)
Lift and Drag Coefficients as Dimensionless Flow-Field Parameters	85	(4)
Flow Around a Cylinder with Circulation	89	(3)
Velocity Field	89	(1)
Lift and Drag	90	(2)
Source Density Distribution on the Body Surface	92	(4)
Incompressible, Axisymmetric Flow	96	(3)
Flow Around a Sphere	96	(3)
Summary	99	(10)
Problems	99	(9)
References	108	(1)
Viscous Boundary Layers	109	(47)
Equations Governing the Boundary Layer for a Steady, Two-Dimensional, Incompressible Flow	110	(3)
Boundary Conditions	113	(1)
Incompressible, Laminar Boundary Layer	113	(15)
Numerical Solutions for the Falkner-Skan Problem	116	(12)
Boundary-Layer Transition	128	(2)
Incompressible, Turbulent Boundary Layer	130	(7)
Derivation of the Momentum Equation for Turbulent Boundary Layer	131	(2)
Approaches to Turbulence Modeling	133	(1)
Turbulent Boundary Layer for a Flat Plate	134	(3)
Eddy Viscosity and Mixing Length Concepts	137	(3)
Integral Equations for a Flat-Plate Boundary Layer	140	(6)
Application of the Integral Equations to a Turbulent, Flat-Plate Boundary Layer	141	(4)
Integral Solutions for a Turbulent Boundary Layer with a Pressure Gradient	145	(1)
Thermal Boundary Layer for Constant-Property Flows	146	(5)
Reynolds Analogy	147	(1)
Thermal Boundary Layer for Pr 1	148	(3)
Summary	151	(5)
Problems	151	(4)
References	155	(1)
Characteristic Parameters for Airfoil and Wing Aerodynamics	156	(42)
Characterization of Aerodynamic Forces and Moments	156	(3)
General Comments	156	(2)
Parameters That Govern Aerodynamic Forces	158	(1)
Airfoil Geometry Parameters	159	(3)
Airfoil-Section Nomenclature	159	(1)
Leading-Edge Radius and Chord Line	160	(1)
Mean Camber Line	161	(1)
Maximum Thickness and Thickness Distribution	161	(1)
Trailing-Edge Angle	162	(1)
Wing-Geometry Parameters	162	(7)
Aerodynamic Force and Moment Coefficients	169	(14)
Lift Coefficient	169	(4)
Moment Coefficient	173	(2)
Drag Coefficient	175	(3)
Boundary-Layer Transition	178	(3)
Effect of Surface Roughness on the Aerodynamic Forces	181	(2)
Wings of Finite Span	183	(15)
Lift	183	(3)
Drag	186	(4)
Lift/Drag Ratio	190	(3)
Problems	193	(4)
References	197	(1)
Incompressible Flows around Airfoils of Infinite Span	198	(32)
General Comments	198	(1)
Circulation and the Generation of Lift	199	(2)
Starting Vortex	200	(1)
General Thin-Airfoil Theory	201	(2)
Thin, Flat-Plate Airfoil (Symmetric Airfoil)	203	(4)
Thin, Cambered Airfoil	207	(9)
Vorticity Distribution	207	(2)
Aerodynamic Coefficients for a Cambered Airfoil	209	(7)
High-Lift Airfoil Sections	216	(5)
Multielement Airfoil Sections for Generating High Lift	221	(5)
High-Lift Military Airfoils	226	(4)
Problems	227	(2)
References	229	(1)
Incompressible Flow About Wings of Finite Span	230	(73)
General Comments	230	(3)
Vortex System	233	(1)
Lifting-line Theory For Unswept Wings	233	(23)
Trailing Vortices and Downwash	236	(3)
Case of Elliptic Spanwise Circulation Distribution	239	(5)
Technique for General Spanwise Circulation Distribution	244	(4)
Lift on the Wing	248	(1)
Vortex-Induced Drag	248	(6)
Some Final Comments on Lifting-Line Theory	254	(2)
Panel Methods	256	(4)
Boundary Conditions	257	(1)
Methods	258	(2)
Vortex Lattice Method	260	(18)
Velocity Induced by a General Horseshoe Vortex	263	(3)
Application of the Boundary Conditions	266	(2)
Relations for a Planar Wing	268	(10)
Factors Affecting Drag Due-to-Lift at Subsonic Speeds	278	(3)
Delta Wings	281	(9)
Leading-Edge Extensions	290	(3)
Asymmetric Loads on the Fuselage at High Angles of Attack	293	(4)
Asymmetric Vortex Shedding	294	(3)
Wakelike Flows	297	(1)
Flow Fields for Aircraft at High Angles of Attack	297	(1)
Summary	298	(5)
Problems	299	(1)
References	300	(3)
Dynamics of a Compressible Flow Field	303	(46)
Thermodynamic Concepts	304	(6)
Specific Heats	304	(2)
Additional Relations	306	(1)
Second Law of Thermodynamics and Reversibility	306	(2)
Speed of Sound	308	(2)
Adiabatic Flow in a Variable-Area Streamtube	310	(4)
Isentropic Flow in a Variable-Area Streamtube	314	(7)
Characteristic Equations and Prandtl-Meyer Flow	321	(7)
Shock Waves	328	(9)
Viscous Boundary Layer	337	(12)
Effects of Compressibility	338	(5)
Shock-Wave/Boundary-Layer Interactions	343	(1)
Problems	344	(4)
References	348	(1)
Compressible, Subsonic Flows and Transonic Flows	349	(34)
Compressible, Subsonic Flow	350	(4)
Linearized Theory for Compressible Subsonic Flow About a Thin Wing at Relatively Small Angles of Attack	350	(4)
Transonic Flow Past Unswept Airfoils	354	(10)
Supercritical Airfoil Sections	362	(2)
Swept Wings at Transonic Speeds	364	(11)
Wing--Body Interactions and the ``Area Rule,''	366	(9)
Forward Swept Wing	375	(2)
Transonic Aircraft	377	(3)
Summary	380	(3)
Problems	380	(1)
References	380	(3)
Two-Dimensional, Supersonic Flows Around Thin Airfoils	383	(18)
Linear Theory	384	(7)
Lift	385	(2)
Drag	387	(1)
Pitching Moment	388	(3)
Second-Order Theory (Busemann's Theory)	391	(2)
Shock-Expansion Technique	393	(8)
Problems	398	(2)
References	400	(1)
Supersonic Flows over Wings and Airplane Configurations	401	(56)
General Remarks About Lift and Drag	402	(2)
General Remarks About Supersonic Wings	404	(2)
Governing Equation and Boundary Conditions	406	(1)
Consequences of Linearity	407	(1)
Solution Methods	407	(1)
Conical-Flow Method	408	(11)
Rectangular Wings	408	(5)
Swept Wings	413	(4)
Delta and Arrow Wings	417	(2)
Singularity-Distribution Method	419	(24)
Find the Pressure Distribution Given the Configuration	420	(8)
Numerical Method for Calculating the Pressure Distribution Given the Configuration	428	(12)
Numerical Method for the Determination of Camber Distribution	440	(3)
Design Considerations for Supersonic Aircraft	443	(3)
Some Comments About the Design of the SST and of the HSCT	446	(2)
The Supersonic Transport (SST), the Concorde	446	(1)
The High-Speed Civil Transport (HSCT)	446	(1)
Classifying High-Speed Aircraft Designs	447	(1)
Aerodynamic Interaction	448	(4)
Aerodynamic Analysis for Complete Configurations in a Supersonic Stream	452	(5)
Problems	453	(1)
References	454	(3)
Hypersonic Flows	457	(43)
Newtonian Flow Model	458	(2)
Stagnation Region Flow-Field Properties	460	(5)
Modified Newtonian Flow	465	(14)
High L/D Hypersonic Configurations---Waveriders	479	(6)
Aerodynamic Heating	485	(5)
Similarity Solutions for Heat Transfer	488	(2)
A Hypersonic Cruiser for the Twenty-First Century?	490	(4)
Importance of Interrelating CFD, Ground-Test Data, and Flight-Test Data	494	(6)
Problems	496	(1)
References	497	(3)
Aerodynamic Design Considerations	500	(47)
High-Lift Configurations	500	(13)
Increasing the Area	500	(2)
Increasing the Lift Coefficient	502	(2)
Flap Systems	504	(2)
Multielement Airfoils	506	(3)
Power-Augmented Lift	509	(4)
Circulation Control Wing	513	(1)
Design Considerations For Tactical Military Aircraft	514	(3)
Drag Reduction	517	(5)
Variable-Twist, Variable-Camber Wings	517	(2)
Laminar-Flow Control	519	(1)
Winglets	520	(2)
Development of an Airframe Modification to Improve the Mission Effectiveness of an Existing Airplane	522	(15)
The EA-6B	522	(4)
The Evolution of the F-16	526	(5)
External Carriage of Stores	531	(6)
Additional Comments	537	(1)
Considerations for Wing/Canard, Wing/Tail, and Tailless Configurations	537	(4)
Comments on the F-15 Design	541	(1)
The Design of the F-22	542	(5)
Problems	545	(1)
References	545	(2)
Tools for Defining the Aerodynamic Environment	547	(15)
CFD Tools	548	(5)
Semiempirical Methods	549	(1)
Surface Panel Methods for Inviscid Flows	549	(1)
Euler Codes for Inviscid Flow Fields	550	(1)
Two-Layer Flow Models	551	(1)
Computational Techniques that Treat the Entire Flow Field in a Unified Fashion	551	(1)
Integrating the Diverse CFD Tools	552	(1)
Establishing the Credibility of CFD Simulations	553	(2)
Ground-Based Test Programs	555	(3)
Flight-Test Programs	558	(1)
Integration of Experimental and Computational Tools: The Aerodynamic Design Philosophy	559	(3)
References	560	(2)
Appendix A The Equations of Motion Written in Conservation Form	562	(6)
Appendix B A Collection of often used Tables	568	(8)
Index	576

Excerpts

This text is designed for use by undergraduate students in intermediate and advanced classes in aerodynamics and by graduate students in mechanical engineering and aerospace engineering. Basic fluid mechanic principles are presented in the first four chapters. Fluid properties and a model for the standard atmosphere are discussed in Chapter 1, "Fluid Properties." The equations governing fluid motion are presented in Chapter 2, "Fundamentals of Fluid Mechanics." Differential and integral forms of the continuity equation (based on the conservation of mass), the linear momentum equation (based on Newton's law of motion), and the energy equation (based on the first law of thermodynamics) are presented. Modeling inviscid, incompressible flows is the subject of Chapter 3, "Dynamics of an Incompressible, Inviscid Flow Field." Modeling viscous boundary layers, with emphasis on incompressible flows, is the subject of Chapter 4, "Viscous Boundary Layers." Thus, Chapters 1 through 4 present material that covers the principles upon which the aerodynamic applications are based. For the reader who already has had a course (or courses) in fluid mechanics, these four chapters provide a comprehensive review of fluid mechanics and an introduction to the nomenclature and style of the present text. At this point, the reader is ready to begin material focused on aerodynamic applications. Parameters that characterize the geometry of aerodynamic configurations and parameters that characterize aerodynamic performance are presented in Chapter 5, "Characteristic Parameters for Airfoil and Wing Aerodynamics." Techniques for modeling the aerodynamic performance of two-dimensional airfoils and, of finite-span wings at low speeds (where variations in density are negligible) are presented in Chapters 6 and 7, respectively. Chapter 6 is titled "Incompressible Flows around Wings of Infinite Span," and Chapter 7 is titled "Incompressible Flow about Wings of Finite Span." The next five chapters deal with compressible flow fields. To provide the reader with the necessary background for high-speed aerodynamics, the basic fluid mechanic principles for compressible flows are discussed in Chapter 8, "Dynamics of a Compressible Flow Field." Thus, from a pedagogical point of view, the material presented in Chapter 8 complements the material presented in Chapters 1 through 4. Techniques for modeling high-speed flows (where density variations cannot be neglected) are presented in Chapters 9 through 12. Aerodynamic performance for compressible, subsonic flows through transonic speeds is the subject of Chapter 9, "Compressible Subsonic Flows and Transonic Flows." Supersonic aerodynamics for two-dimensional airfoils is the subject of Chapter 10, "Two-Dimensional Supersonic Flows about Thin Airfoils" and for finite-span wings in Chapter 11, "Supersonic Flows over Wings and Airplane Configurations." Hypersonic flows are the subject of Chapter 12. At this point, chapters have been dedicated to the development of basic models for calculating the aerodynamic performance parameters for each of the possible speed ranges. The assumptions and, therefore, the restrictions incorporated into the development of the theory are carefully noted. The applications of the theory are illustrated by working one or more problems. Solutions are obtained using numerical techniques in order to apply the theory for those flows where closed-form solutions are impractical or impossible. In each of the chapters, the computed aerodynamic parameters are compared with experimental data from the open literature to illustrate both the validity of the theoretical analysis and its limitations (or, equivalently, the range of conditions for which the theory is applicable). One objective is to use the experimental data to determine the limits of applicability for the proposed models. Extensive discussions of the effects of viscosity, compressibility, shock/boundary-layer interactions,