AIRCRAFT DESIGN - .e-bookshelf.de

xivContents12.5.4Longitudinal Trim Requirement12.5.5Elevator Design ProcedureRudder Design12.6.1Introduction to Rudder Design12.6.2Fundamentals of Rudder Design12.6.3Rudder Design StepsAerodynamic Balance and Mass Balance12.7.1Aerodynamic Balance12.7.2Mass BalanceChapter Examples12.8.1Aileron Design Example12.8.2Elevator Design Example12.8.3Rudder Design 22723723729738745752AppendicesAppendix A: Standard Atmosphere, SI UnitsAppendix B: Standard Atmosphere, British Units755755756Index75712.612.712.8

PrefaceObjectivesThe objective of this book is to provide a basic text for courses in the design of heavierthan-air vehicles at both the upper division undergraduate and beginning graduate levels.Aircraft design is a special topic in the aeronautical/aerospace engineering discipline.The academic major of aeronautical/aerospace engineering traditionally tends to havefour main areas of expertise: aerodynamics, flight dynamics, propulsion, and structure.A qualified aircraft designer employs all these four scientific concepts and principles andintegrates them using special design techniques to design a coordinated unique system;an aircraft. Design is a combination of science, art, and techniques. A designer not onlymust have sufficient level of knowledge in these four areas, but also needs to employmathematics, skills, experiences, creativity, art, and system design techniques. It is truethat aircraft design is not completely teachable in classrooms, but combining class lectureswith a semester-long aircraft design project provides the best opportunity for students tolearn and experience aircraft design.Every aeronautical engineering discipline offers at least one course in aircraftdesign or aerospace system design. The lack of an aircraft design textbook withacademic features – such as full coverage of all aspects of an air vehicle, aeronauticalconcepts, design methods, design flowcharts, design examples, and end-of-chapterproblems – combined with the newly developed systems engineering techniques was themain motivation to write this book.In the past several years, I have talked to various aircraft design instructors and students at conferences and AIAA Design/Build/Fly design competitions. I came to theconclusion that the great design books published by such pioneers as Roskam, Torenbeek, Nicolai, Stinton, and Raymer need more development and expansion. This is tomeet the ever-increasing need of universities and colleges for aircraft design education,and of industries for design implementation. The new text should possess significantfeatures such as systems engineering approaches, design procedures, solved examples,and end-of-chapter problems. This book was written with the aim of filling the gap foraeronautical/aerospace engineering students and also for practicing engineers.

xviPrefaceApproachThe process of air vehicle design is a complex combination of numerous disciplineswhich have to be blended together to yield the optimum design to meet a given setof requirements. The systems engineering approach is defined as an interdisciplinaryapproach encompassing the entire technical effort to evolve and verify an integratedand lifecycle-balanced set of system people, products, and process solutions that satisfycustomer needs. Multi-discipline system engineering design involves the application of asystems engineering process and requires engineers with substantive knowledge of designacross multiple technical areas and improved tools and methods for doing it. Complexaircraft systems, due to the high cost and the risks associated with their development,become a prime candidate for the adoption of systems engineering methodologies. Thesystems engineering technique has been applied in the development of many mannedairplanes. An aircraft is a system composed of a set of interrelated components workingtogether toward some common objective or purpose. Primary objectives include safeflight achieved at a low cost. Every system is made up of components or subsystems,and any subsystem can be broken down into smaller components. For example, in an airtransportation system, the aircraft, terminal, ground support equipment, and controls areall subsystems.Throughout the text, the systems engineering approach is examined and implemented.The book has been arranged to facilitate the student’s gradual understanding of designtechniques. Statement proofs are provided whenever they contribute to the understandingof the subject matter presented. Special effort has been made to provide example problemsso that the reader will have a clear understanding of the topic discussed. The reader isencouraged to study all such solved problems carefully; this will allow the interestedreader to obtain a deeper understanding of the materials and tools.FeaturesSome of the unique features of this textbook are as follows. It: follows a systems engineering approach; is organized based on components design (e.g., wing design, tail design, and fuselagedesign); provides design steps and procedures in each chapter; derives a number of design equations that are unique to the book; provides several fully solved design examples at the component level; has many end-of-chapter problems for readers to practice; includes a lot of aircraft figures/images to emphasize the application of the concepts; describes some real design stories that stress the significance of safety in aircraft design; provides various aircraft configurations, geometries, and weights data to demonstratereal-world applications and examples; covers a variety of design techniques/processes so that the designer has freedom andflexibility to satisfy the design requirements in several ways; encourages and promotes the creativity of the reader.

PrefacexviiFor these reasons, as aeronautical/aerospace engineering students transit to practicingengineers, they will find that this text is indispensable as a reference text. Some materials,such as “design optimization” and “design of control surfaces,” may be taught at thegraduate level. The reader is expected to have a basic knowledge of the fundamentalsand concepts of aerodynamics, propulsion, aero-structure, aircraft performance, and flightdynamics (stability and control) at aeronautical/aerospace engineering senior level.The following is a true statement: “design techniques are not understood unless practiced.” Therefore, the reader is strongly encouraged to experience the design techniquesand concepts through applied projects. Instructors are also encouraged to define an openended semester/year-long aircraft design project to help the students to practice and learnthrough application and experiencing the iterative nature of the design technique. It is mysincere wish that this book will help aspiring students and design engineers to learn andcreate more efficient and safer aircraft.OutlineThe text consists of 12 chapters and is organized in a standard fashion according to thesystems engineering discipline: conceptual design, preliminary design, and detail design.In summary, Chapter 3 presents the aircraft conceptual design; Chapter 4 introduces theaircraft preliminary design; and Chapters 5–12 cover the aircraft detail design. The outlineof this book is as follows.Chapter 1 is an introduction to design fundamentals and covers such topics as engineering design principles, design project planning, decision-making processes, feasibilityanalysis, and tort of negligence. Design standards and requirements such as Federal Aviation Regulations (FARs) and Military Standards are reviewed in this chapter, and addressedfurther throughout the text.Chapter 2 deals with the systems engineering approach. Major design phases according to systems engineering are introduced: conceptual system design, preliminary systemdesign, and detail system design. In this chapter, several concepts and fundamental definitions such as technical performance measures, functional analysis, system trade-offanalysis, design review, and design requirements are reviewed. Implementations of systems engineering into aircraft design via aircraft design phases, aircraft design flowcharts,aircraft design groups, and design evaluation and feedback loops are explained. At the endof the chapter, the overall aircraft design procedure in terms of design steps is outlined.Chapter 3 covers aircraft conceptual design, and examines the aircraft configurationselection. The primary function of each aircraft component such as wing, fuselage, tail,landing gear, and engine is introduced. Furthermore, various configuration alternatives foreach component are reviewed. In addition, the aircraft classification and design constraintsare addressed. In this chapter the design optimization and its mathematical tools are brieflyreviewed. The chapter ends with a configuration selection process and methodology, andalso a trade-off analysis technique.Chapter 4 discusses the topic of aircraft preliminary design. In this chapter, the technique to determine three aircraft fundamental parameters is presented. These parametersare: maximum take-off weight, wing area, and engine thrust/power. The weight buildup technique is examined for estimation of the aircraft maximum take-off weight. The

xviiiPrefacematching plot technique is utilized in the calculation of wing area, and engine thrust/power.These three parameters are computed based on the aircraft performance requirements suchas range, endurance, maximum speed, take-off run, rate-of-climb, and ceiling. Two fullysolved examples illustrate the application of the two techniques.Chapters 5–9 and 12 present detail design of the aircraft components of wing, tail, fuselage, propulsion system, landing gear, and control surfaces respectively. In these chapters,the techniques to calculate all aircraft components parameters such as wing/tail span,chord, airfoil, incidence, sweep angle, tail arm, tail area, landing gear height, wheel base,wheel track, fuselage diameter, fuselage length, cabin design, cockpit design, number ofengines, and engine selection are examined. Furthermore, the features of various component configurations and their relationship with the design requirements (e.g., performance,stability, control, and cost) are addressed. Chapter 12 introduces the detail design of theconventional control surfaces of aileron, elevator, and rudder. In each chapter, the designflowchart and design step for each component is also presented. Each chapter is accompanied by several examples, including a fully solved chapter example to demonstrate theapplications of design techniques and methods.Chapter 10 introduces the technique to calculate the weight of the aircraft components,equipment, and subsystems. The technique is derived mainly based on past aircraft weightdata and statistics.Chapter 11 addresses the topic of aircraft weight distribution, and weight and balance.The aircraft center of gravity (cg) calculation, aircraft most aft and most forward cg, andcg range are also covered in this chapter. In addition, the technique to determine theaircraft mass moment of inertia about three axes (i.e., x , y, and z ) is examined.Unit SystemsIn this text, the emphasis is on SI units or the metric system, which employs the meter(m) as the unit of length, the kilogram (kg) as the unit of mass, and the second (s) as theunit of time. It is true that metric units are more universal and technically consistent thanBritish units. However, currently, many FARs are published in British units, where thefoot (ft) is the unit of length, the slug is the unit of mass, the pound (lb) is the unit offorce (weight), and the second (s) is the unit of time. In FARs, the pound is used as theunit for force and weight, the knot for airspeed, and the foot for altitude. Thus, in variouslocations, the knot is mainly used as the unit of airspeed, the pound for weight and force,and the foot for altitude. Therefore, in this text, a combination of SI and British unitsystems is utilized. A common mistake in the literature (even in the Jane’s publications)is the application of kg for the unit of aircraft weight. Throughout the text, wheneverthe unit of kg is used, the term “aircraft mass” is employed. Some texts have created thepound-mass (lbm) as the unit of mass, and the pound-force (lbf) as the unit of weight. Thisinitiative may generate some confusion; so in this text, only one pound (lb) is employedas the unit of weight and force.

Series PrefaceThe field of aerospace is wide ranging and multi-disciplinary, covering a large varietyof products, disciplines and domains, not merely in engineering but in many relatedsupporting activities. These combine to enable the aerospace industry to produce excitingand technologically advanced vehicles. The wealth of knowledge and experience that hasbeen gained by expert practitionersin the various aerospace fields needs to be passed ontoothers working in the industry, including those just entering from University.The Aerospace Series aims to be a practical and topical series of books aimed atengineering professionals, operators, users and allied professions such as commercial andlegal executives in the aerospace industry. The range of topics is intended to be wideranging, covering design and development, manufacture, operation and support of aircraftas well as topics such as infrastructure operations and developments in research andtechnology. The intention is to provide a source of relevant information that will be ofinterest and benefit to all those people working in aerospace.Aircraft design brings together the key aeronautical engineering disciplines: aerodynamics, flight dynamics, propulsion and structures, which must be combined to producedesigns that meet today’s stringent performance, economic and environmental demands.As such, aircraft designis a key component of all undergraduate aerospace engineeringcourses, and all aerospace students usually tackle some form of aircraft design project.This book, Aircraft Design: A Systems Engineering Approach, extends the classicalaircraft design approaches through the implementation of systems engineering techniquesfor the conceptual, preliminary and detailed design of heavier-than-air vehicles. As a veryreadable and informative text reference, with plenty of examples from a wide range ofcontemporary aircraft designs, and solved examples at the end of each chapter, it is aworthy addition to the Wiley Aerospace Series.Peter Belobaba, Jonathan Cooper, Roy Langton and Allan Seabridge

AcknowledgmentsI am enormously grateful to the Almighty for the opportunity to serve the aerospacecommunity by writing this text. The author would like to acknowledge the many contributors and photographers who have contributed to this text. I am especially grateful to those who provided great aircraft photographs: Anne Deus (Germany); JenneyCoffey (UK); Anthony Osborne (UK); A J Best (UK); Vlamidir Mikitarenko (Germany); Rainer Bexten (Germany); Hideki Nakamura (Japan); Akira Uekawa (Japan); LuisDavid Sanchez (Puerto Rico); Tom Houquet (Belgium); Toshi Aoki (Japan); MiloslavStoroska (Slovakia); Tom Otley (Panacea Publishing International, UK); Jonas Lövgren(SAAB, Sweden); Jeff Miller (Gulfstream Aerospace Corporation, USA); Michael deBoer (Netherland); Konstantin von Wedelstaedt (Germany); Augusto G. Gomez R. (Mexico); Randy Crew (Singapore); Robert Domandl; Serghei Podlesnii (Moldova); Orlando J.Junior (Brazil); Balázs Farkas (Hungary); and Christopher Huber and www.airliners.net.In addition, the efforts of the author were helped immeasurably by the many insightsand constructive suggestions provided by students and instructors over the past 16 years.Unattributed figures are held in the public domain and are from either the US GovernmentDepartments and Agencies, or Wikipedia.Putting a book together requires the talents of many people, and talented people aboundat John Wiley & Sons, Inc. My sincere gratitude goes to Paul Petralia, commissioningeditor, for coordinating the whole publication process; Clarissa Lim for coordinating theproduction project; Sarah Lewis for editing the manuscript; Jayashree Saishankar fortypesetting; and Sandra Grayson for helping in the copyright process. I am particularlygrateful to my editors, Liz Wingett and Sophia Travis, for their comments and guidance.My special thanks go to the outstanding copyeditors and proofreaders who are essentialin creating an error-free text. I especially owe a large debt of gratitude to the reviewersof this text. Their ideas, suggestions, and criticisms have helped me to write more clearlyand accurately and have influenced the evolution of this book markedly.

Symbols and AcronymsSymbolsSymbolNameUnitaaAARbBCCCD , CL , CyCl , Cm , CnSpeed of soundAccelerationAreaAspect ratioLifting surface/control surface spanWheel baseSpecific fuel consumptionMean aerodynamic chordDrag, lift, and side-force coefficientsRolling, pitching, and yawing momentcoefficientsHinge moment coefficientAircraft side drag coefficientRate of change of drag coefficient w.r.t.sidesli

2.3.2 Conceptual Design Flowchart 24 2.3.3 Technical Performance Measures 25 2.3.4 Functional Analysis 26 2.3.5 System Trade-Off Analysis 27 2.3.6 Conceptual Design Review 28 2.4 Preliminary System Design 29 2.5 Detail System Design 30 2.6 Design Requirements 33 2.7 Design Review, Evaluation