bluuebunny/crossref_metadata_2025 huggingface dataset:
Introduction to Compressible Flows
Authors: Drikakis Dimitris
Published: December 2010

This chapter provides a brief introduction to compressible flows, including fundamentals, physical regimes, and associated flow phenomena. It introduces the notion of shock and expansion waves as well as the fundamentals of subsonic, transonic, supersonic, and hypersonic flow regimes. It further presents the governing equations and their simplified forms along with the associated flow and thermodynamic assumptions. The limits of applicability of the various forms of the governing equations are also discussed.

Finally, the chapter briefly presents the equation of state for compressible flows in the form used in aeronautical applications.
High‐Temperature Effects in Hypersonic Flight
Authors: Candler Graham V.
Published: December 2010

The high temperatures encountered at hypersonic speeds trigger complex thermochemical effects in the surrounding medium and have a substantial impact on the vehicle. In addition to the excitation of internal energy modes, chemical reactions such as dissociation and ionization may also occur. The resultant species can then interact with the vehicle surface to produce diverse thermal effects. In this chapter, some of the main concepts are summarized. The notion of nonequilibrium is introduced and related to collisionality. The mechanisms by which chemical reactions occur, the rates at which they proceed, their effect on momentum and energy balance and the coupling between internal energy and chemistry are exposed by deriving the principal conservation equations. Methods of obtaining the equation of state, as well as various transport properties such as viscosity and thermal conductivity are presented. The chapter concludes with an illustrative example of a waverider vehicle traveling at Mach 8.
Spacecraft Thermal Management
Authors: Hurlbert Kathryn M.
Published: December 2010

All spacecraft must include a thermal control system (TCS) to maintain equipment and/or crew within tolerable temperature limits during the mission. This chapter provides an overview of spacecraft thermal control systems design and development, with descriptions of the passive and active subsystems and associated components. The necessary steps in the design process are also provided, including establishing mission and system requirements, characterizing the mission environments, developing the design concept and models, and planning a test program to ensure the system functions as expected.
Computational Magnetohydrodynamics
Authors: Falle Sam A.E.G.
Published: December 2010

This chapter describes computational methods for the equations of ideal compressible magnetohydrodynamics (MHD), which describe the motion of an electrically conducting fluid. These equations are applicable to: laboratory plasmas; the earth's magnetosphere; the sun and other astrophysical objects. The emphasis is on upwind shock capturing methods that can be used for flows containing strong shocks. Although these methods are very similar to those for compressible flow, the MHD equations have certain properties that need to be handled carefully, i.e., degeneracy of the wave system and the constraint that the magnetic field be divergence free.
Shear Stress Measurements
Authors: Chandrasekharan Vijay , Naughton Jonathan , Sheplak Mark
Published: December 2010

Wall shear stress or skin friction causes a significant amount of drag in an aerodynamic system. As a result, measurements are extremely important for efficient and effective aerodynamic design as well as fundamental understanding of the underlying flow physics. This measurement is also important for a wide variety of applications ranging from feedback flow control to drag reduction to wind tunnel design and characterization. It may also be a useful technique for non‐intrusive flow rate measurement. An instrument grade, time accurate sensor with sufficient spatial resolution is required for quantitative time resolved wall shear stress measurement. This chapter gives an overview of relevant measurement scales that depend on the nature of the flow, existing measurement techniques with their strengths and limitations, and a methodology to characterize shear stress sensors, ultimately leading to a fully characterized shear stress measurement tool.
Particle Image Velocimetry
Authors: Scarano Fulvio
Published: December 2010

Particle Image Velocimetry (PIV) is a laser‐based technique to measure the instantaneous velocity distribution within a planar domain. The present chapter introduces the working principle of PIV and discusses its relevance for aerodynamic testing of aerospace vehicles and propulsion systems. The main components of an experiment performed by PIV are the seeding particles, the illumination system, the digital image recording and the algorithms used to analyze the motion of recorded particle images. The chapter closes with a discussion on the accuracy and spatial resolution of PIV measurements and on the data reduction procedures typically applied to post‐process PIV data.
Gas Turbine Engines: Compressors
Authors: Song Bo , Ng Wing F.
Published: December 2010

This chapter introduces important basics of the aerodynamics and thermodynamics of compressors. It starts with a classification of all types of compressors, showing various configuration features, operating principles, and applications. The two basic categories, positive displacement compressors and dynamic compressors, are described, followed by a breakdown of sub‐categories: reciprocating, rotary, axial, centrifugal, and diagonal compressors. Advantage and specialty of each type of compressor are explained. Following the discussion on the entire class of compressor family, the chapter then focuses on dynamic compressors only, since dynamic compressors are of primary use in gas turbine engines. The remaining sections of this chapter are dedicated to axial and centrifugal compressors. The aero‐thermodynamic process of a compressor stage is illustrated, using the one‐dimensional mean line approach, explaining how the gas state varies and how the work/energy conversion takes place through the compression. The definition of the compressor efficiency is derived and three commonly used definitions are discussed. The important concepts and terms usually encountered when dealing with compressor research and application are illustrated: surge, stall, choke, performance curve, performance map, operating range, and specific speed. The chapter closes with explaining the complexity, foreseeing the development trend, and providing reference sources of the subject.
Gas Turbine Engine Combustors
Authors: Chang Clarence T.
Published: December 2010

Aircraft gas turbine engine combustors are designed to generate high‐pressure, high‐temperature burned gas for work extraction in the turbine. The double‐shelled structure design concept evolved to become structurally more robust, aerodynamically more stable over broader operating ranges, much more durable, and produce less pollutants.
Solid Propulsion: Ignition Transients and Combustion Instability
Authors: Schlueter Sam S. , Flandro Gary A.
Published: December 2010

Ignition transients are a critical and complex period of operation in solid rocket motors. During the ignition interval, many factors combine that must be taken into account in the design of the entire system. There are many methods in use to analyze different aspects of the ignition processes, and the level of analysis complexity varies with need and available resources. These methods vary from empirically based sizing rules to complex physics‐based analyses. There are still many aspects of ignition transient behavior that have not been fully characterized, and research is continuing to fully understand all processes that occur during ignition transients in solid rocket motors. Combustion chamber pressure oscillations, often calledcombustion instability, can lead to dangerous vibration loads (“thrust roughness”) and elevation of motor operating pressure (“DC shift”). Frequencies are often associated with the chamber acoustic modes and cover a wide range from 10 Hz (in large solid rocket booster (SRB) motors) to over 30 kHz (in tactical rockets). Successful avoidance of these problems requires comprehensive understanding of a multitude of unsteady energy gain and loss mechanisms. The principal goals of current research are to predict (i) motor stability (tendency for oscillations to grow) and (ii) peak amplitude of the pressure oscillations throughout the motor burn.

This information allows assessment of the threat to system operability and guides selection and application of corrective measures.
Combined‐Cycle Engines
Authors: Kanda Takeshi
Published: December 2010

A combined‐cycle engine has two or more operating modes with a single flowpath. The motivation behind a combined‐cycle engine is to extend the engine's operating envelope and attain higher average performance. Several combined‐cycle engines and a combined engine system are presented. The rocket‐based combined‐cycle (RBCC) engine is a combination of a rocket engine and a ramjet engine. RBCC has wide operating range and structural simplicity, since there are no rotating parts. The drawback is a relatively lower specific impulse in the subsonic and transonic range. RBCC is suitable for the single‐stage‐to‐orbit (SSTO) vehicle due to its operability in low ambient pressure conditions and in space. The liquid air cycle engine (LACE) liquefies air using cryogenic propellants to reduce the onboard oxygen requirement. The advantages of LACE are reduced engine weight and wide operating conditions. However, owing to the low liquefaction efficiency of air, LACE suffers from low specific impulse and high fuel consumption. The turbo‐ramjet (TRE) and the air‐turbo‐rocket (ATR) engines employ turbocompressors to compress the airflow like in turbojet engines. Despite the advantage of increased specific impulse, both engines have low thrust to weight ratios. The dual‐mode scramjet engine like the RBCC has no moving parts. The combustion is subsonic in the ramjet mode and supersonic in the scramjet mode. The combination engine system, which mounts several engines on a vehicle, extends the operating range of the vehicle by operating appropriate engines according to the flight conditions.
Magnetoplasmadynamic Thrusters
Authors: Andrenucci Mariano
Published: December 2010

A brief account is given initially of the origins of the MPD thruster concept. The nature of the Lorentz force, constituting the basic accelerating process exploited in MPD thrusters, is analyzed. A simple model of ideal self‐field MPD thruster is then considered; to illustrate the basic thrust law and the ensuing scaling trends characterizing this class of device. The behavior of real self‐field MPD thrusters is then described with regard to deviations from the ideal electrical characteristics, highlighting the Hall and the back‐EMF effects and the role of Alfvén's critical ionization velocity. Onset phenomenology and the critical onset parameter are then introduced. The main theories proposed to explain onset phenomena are summarized, with particular regard to mass starvation, and instabilities. Applied field MPD thrusters and lithium propellant self‐field and applied‐field devices are then described. The major R&D efforts so far undertaken in this field worldwide are shortly reviewed. Finally, some concluding remarks are made as to the status and prospects of MPD propulsion.
Torsion of Bars and Bending of Beams
Authors: Sun C.T.
Published: December 2010

Governing equations including derivations for structural members under torsion and bending are presented. The emphasis is placed on thin‐walled structures. The formulation for torsion problems is based on the Saint‐Venant torsion displacement assumption and solutions are obtained using the Prandtl stress function. Bi‐directional bending of beams is considered. Methods for calculating shear flows produced by combined bending and torsion loads are presented. The concept of shear center is discussed.
Dynamic Response Computations
Authors: Mignolet Marc P.
Published: December 2010

This chapter focuses on a detailed presentation of the methods available for the determination of the dynamic response of linear structural dynamic systems. Three particular situations are considered: free response, forced harmonic response, and forced response to an arbitrary loading. Approaches to determine these three different responses are presented for both classically and nonclassically damped systems using modal/eigenvector expansions. They transform multi‐degree‐of‐freedom systems into uncoupled second‐order (for classically damped systems) and first‐order (for nonclassically damped systems) differential equations the solution of which is presented and discussed. The determination of the steady‐state response to a harmonic loading through a frequency dependent impedance matrix is also demonstrated and the pros and cons of this method and the modal expansion strategy are discussed. The numerical evaluation of the response to an arbitrary loading from Duhamel's formula and by using step‐by‐step algorithms is discussed in details and some of the key properties of these methods are highlighted. It is finally demonstrated how to extend the previous discussion when the structure is excited by the motion of its supports. The finite element model of a wing is considered to exemplify the above methods and concepts.
Thermal Analysis
Authors: Rolfes Raimund J.
Published: December 2010

Important application areas for thermal analysis of aerospace structures are listed. The modes of heat transfer are described briefly. Starting from the laws of thermo‐dynamics the general heat conduction equation is derived. Fourier's law as the constitutive law for heat conduction is discussed, the appearance of the conductivity tensor for different material classes is described. Special methods for inhomogeneous and anisotropic materials (composites, sandwiches) as homogenization and thermal lamination theories are mentioned. Some typical temperature‐dependent thermo‐physical properties for aerospace materials are provided. Convective as well as radiative boundary conditions are treated. Radiation exchange between different structural parts is also covered. The general finite element equation system for nonlinear transient heat transfer problems is derived. Solution schemes including explicit and implicit time integration are derived and discussed.
Computational Fracture Mechanics
Authors: Brocks Wolfgang
Published: December 2010

A survey of fracture mechanics as an approach to characterise the safety and technical reliability of structures containing defects is given. The classical concepts based upon analytical asymptotic solutions of stress and strain fields at crack tips or, alternatively, on energy balances for cracked bodies are outlined. Characteristic parameters like stress intensity factor, energy release rate,
J
‐integral, CTOD etc. and the respective fracture criteria are presented. An introduction into the application of finite element methods for fracture problems is given. As fracture mechanics concepts find increasing applications for thin‐walled lightweight structures mainly in transportation industries, adapted new concepts like CTOA‐controlled crack extension and cohesive models have been developed, going parallel with improved capabilities and performance of computer codes.
Models for Delamination
Authors: König Manfred , D'Ottavio Michele
Published: December 2010

The chapter reviews some aspects of the broad and complex problem of delamination in composites. The focus is put on computational models for delamination predictions in the framework of a damage tolerance design. Both delamination initiation and its propagation under quasi‐static and cyclic loading are addressed, and their simulation by means of the Finite Element Method (FEM) is discussed. However, dynamic delamination propagation under impact loads, as well as the prediction of the effect of delamination on the ultimate failure, is not considered in this chapter.

Basically, two modelling approaches are reviewed, namely Linear Elastic Fracture Mechanics (LEFM) in the form of the Virtual Crack Closure Technique (VCCT) and Continuum Damage Mechanics (CDM) applied to interface problems, that is, Cohesive Zone Models. Both approaches have recently been implemented in commercially available FE software. A summary of the respective peculiarities and limitations is presented. The significance of 2D laminated plate/shell elements that ensure the capturing of relevant through‐thickness effects is emphasized.
Multiscale Methods
Authors: Ladevèze Pierre , Néron David
Published: December 2010

This contribution deals with the class of techniques called “multiscale computational approaches”, which are capable of analyzing structures in which two or more very different scales can be identified. Here, the focus is on the main emerging approaches, and a brief classification of the multiscale methods most often used in solid mechanics is also presented.
Static Buckling Tests of Aerospace Vehicle Structures
Authors: Hilburger Mark W.
Published: December 2010

Guidelines on the development of a successful test plan for large‐scale, aerospace vehicle shell buckling tests with particular attention given to defining test objectives and requirements are presented. In addition, some of the more challenging aspects of test planning, test operations, test article, and test apparatus design are discussed, and recommendations on instrumentation and control system setup for buckling tests and including state‐of‐the‐art measurement approaches and technologies are provided. In many cases, actual examples are given. This chapter is intended to provide the first time as well as the experienced test engineer or project manager with experiences and lessons learned from recent large‐scale aerospace vehicle development test activities at NASA.
Techniques for Damage Tolerance and Structural Integrity of Composite Structures
Authors: Razi Hamid , Ambur Damodar R.
Published: December 2010

This section discusses the importance of damage tolerance and how different damage conditions are addressed in the structural design process to assure structural integrity and safety of composite aircraft structures. The regulatory requirements from the Federal Aviation Regulations (FAR) and Joint Aviation Regulations (JAR) for damage‐tolerant design of aircraft structures are presented. Analysis and testing methods used for validation and certification are also summarized.
Future Aircraft Structures: From Metal to Composite Structures
Authors: Beukers Adriaan , Bersee Harald E.N. , Bergsma Otto , Koussios Sotiris , van Tooren Michel
Published: December 2010

In the twentieth century mobility became an important part of life. Aircraft and cars have evolved for over 70 years, and the conventional solutions for further improvements are reaching the point of saturation. Since the fifties, aircraft efficiency improvements were mainly based on refinements in aerodynamics (15 %) and propulsion (40 %). Structures on the other hand (concepts, materials, and manufacturing techniques), did not change all that much and relative weight reductions were annulled by comfort, safety and more systems. Even the latest developments in tools for analysis and design did not result in structure weight reduction, which might be an indication that a leap to novel materials and manufacturing techniques, a leap to new technologies, is the only way to achieve the necessary improvements. In this chapter composite materials are presented as a solution to not only reduce structural weight, to a maximum of 12 percent operational empty weight, but also to reduce exploitation costs and emissions for a 30‐year life span. Even though, by today's pricing, fiber reinforced polymers are more expensive per kilogram than most metals, on a life time basis, operational cost can be reduced by a decrease in fuel consumption, maintenance and inspection costs and, last but not least, manufacturing cost, which leads to long term cost savings. Therefore an integral approach for structure development is discussed, from concepts and materials to downstream manufacturing techniques. The emphasis is on structure and material simplicity and, on the reduction of the number of production steps from suppliers to final construction.
Advanced Composites Made by the Layer‐by‐Layer (
LBL
) Assembly of Nanomaterials
Authors: Podsiadlo Paul , Shim Bong Sup , Mamedov Arif A. , Kotov Nicholas A.
Published: December 2010

This chapter focuses on the preparation and applications of layer‐by‐layer (LBL) assembled organic/inorganic films. As model systems we use incorporation of two multifunctional nanomaterials in the LBL: the clay nanosheets and carbon nanotubes. All the aspects of the composite design starting with the structure of the individual nanoscale building blocks and their interactions with polymer matrix, orientation of the inorganic components in the multilayer, origin of record properties, and most likely applications of the resulting materials are given. Special attention is placed on the understanding of the control parameters for key functional properties such as mechanical strength/stiffness/toughness, electrical transport, transparency, and some properties relevant for biological applications.
Titanium Alloys: Processing, Properties, and Applications
Authors: Williams James C.
Published: December 2010

This chapter describes the history of titanium alloy development and production. It also summarizes the current range of applications for aerospace applications. The production of titanium alloys including processing to impart desired, application‐specific properties also is described. The ability to tailor the properties of titanium alloys by processing makes them attractive for a wide range of applications. The matching of properties to requirements is also discussed. Examples of applications are also described including the rationale for selecting titanium alloys even though the initial cost is higher.
Thermal Barrier Coatings
Authors: Paul Shiladitya
Published: December 2010

Modern gas turbine engines, both aircraft and industrial, operate under conditions of high temperature and stresses, and the engine components are also subjected to corrosion, oxidation, and abrasion. The ever‐increasing demand of higher operating temperature for better efficiency has led to researchers being on a constant lookout for new materials. The present operating temperature of gas turbine engines is limited by the onset of melting, creep, or excessive oxidation of the structural parts. Thermal barrier coatings (TBCs), which comprise oxidation‐resistant metallic and insulating ceramic layers, when deposited onto the hot sections of turbine engines improve their durability and efficiency. It is thus recognized that better understanding of TBC materials and their failure mechanisms must be gained to fully exploit the significant performance improvements they can offer.

In this short review, a description is given of the materials' issues involved in the development of TBCs together with a brief overview of the current TBC systems, their anatomy, failure mechanisms, and possible future progress.
Lifing Approaches and Component Classification: Overview of Methods
Authors: Brooks Jeffery W. , Tranter Paul H.
Published: December 2010

The modern gas turbine aeroengine is made up from many parts and these are divided into different categories relating to the safety of the engine and the aircraft to which the engines are fitted. These classifications vary between military and civil applications but the aim of operating an engine “safely” is similar. The drive to lighter and more efficient gas turbines has required advances in many areas, including materials, design methods, and manufacturing processes. These have shown up potential weaknesses in the traditional lifing approach and required new methodologies to be developed, so that the desired safety level is maintained.
Ferroelectric Materials
Authors: Landis Chad M. , Sirohi Jayant
Published: December 2010

Ferroelectrics are a class of materials that possess a spontaneous electrical dipole moment that can be reoriented with the application of a suitable electric field. Perhaps the most significant applications of ferroelectric materials are for sensors and actuators where the electromechanically coupled piezoelectric properties are utilized. However, ferroelectric materials have many other interesting physical behaviors including temperature‐induced phase changes, nonlinear dielectric, and ferroelastic behaviors. This chapter describes the fundamental thermal, electrical, and mechanical behaviors of ferroelectric ceramics. The discussion of these properties attempts to impart some physical intuition of the behaviors by referring to the underlying atomic structure of the material.
Introduction to Aerial Vehicle Flight Mechanics, Stability and Control
Authors: Knowles Kevin
Published: December 2010

This chapter provides an introduction to Volume 5, Part 22. It introduces some basic concepts of flight control, and static and dynamic stability. Some particular features of vertical or short take‐off and landing (V/STOL) aircraft flight control, not covered elsewhere in this part, are discussed briefly. The other chapters in this part are introduced.
Climb and Descent of Fixed‐Wing Aircraft
Authors: Young Trevor M.
Published: December 2010

Methods are presented for the analysis of the climb and descent of fixed‐wing airplanes. The airplane has been treated as a rigid body, and classical techniques applicable to the dynamics of bodies in motion used. General equations are developed for an accelerated flight condition, where the associated unbalanced forces would cause the airplane's speed to either increase or decrease. A simplified flight condition, in which the airplane is assumed to be in a steady state (i.e., equilibrium), has been considered by setting the acceleration factor equal to zero. Expressions for the airplane's angle of climb/descent and for the rate of climb/descent are derived. The adopted approach initially considers flight in still air, and thereafter considers the impact of wind on the airplane's trajectory. A generic climb‐speed schedule, typical of that used by airliners, is presented as an illustration of an accelerated climb. The optimum speeds that would maximize the angle of climb or the rate of climb for jet and piston‐propeller airplane types are explored through the derivation of analytical expressions. A brief discussion on a topic related to climb performance, that is, the airplane's ceiling (i.e., maximum altitude), is included in the chapter.
Static Longitudinal Stability
Authors: Filippone Antonio
Published: December 2010

This chapter deals with the static longitudinal stability of fixed‐wing aircraft having a conventional configuration consisting of a wing and a horizontal tailplane with elevator and trim tab. The aircraft is considered as a rigid body. We provide a definition for the mean aerodynamic chord and show its role in the longitudinal stability problem. Then the pitching moment equations are written for the wing alone and the full aircraft. Trim equations are derived for stick‐fixed and stick‐free conditions; the corresponding stability points are calculated. Finally, the pull‐up up maneuver is described under steady‐state conditions; stick‐free and stick‐fixed maneuver points are derived.
Solar Sail Dynamics and Control
Authors: Dachwald Bernd
Published: December 2010

Solar sails are large and lightweight reflective structures that are propelled by solar radiation pressure. This chapter covers their orbital and attitude dynamics and control. First, the advantages and limitations of solar sails are discussed and their history and development status is outlined. Because the dynamics of solar sails is governed by the (thermo‐)optical properties of the sail film, the basic solar radiation pressure force models have to be described and compared before parameters to measure solar sail performance can be defined. The next part covers the orbital dynamics of solar sails for heliocentric motion, planetocentric motion, and motion at Lagrangian equilibrium points. Afterwards, some advanced solar radiation pressure force models are described, which allow to quantify the thrust force on solar sails of arbitrary shape, the effects of temperature, of light incidence angle, of surface roughness, and the effects of optical degradation of the sail film in the space environment. The orbital motion of a solar sail is strongly coupled to its rotational motion, so that the attitude control of these soft and flexible structures is very challenging, especially for planetocentric orbits that require fast attitude maneuvers. Finally, some potential attitude control methods are sketched and selection criteria are given.
Satellite in Formation Flight
Authors: Alfriend Kyle T.
Published: December 2010

The fundamental aspects of the dynamics, control, and relative navigation of satellite formations are discussed. Types of relative motion orbits about a circular reference orbit and a spherical Earth are developed first and then expanded to relative motion about an eccentric reference orbit. The effects of gravitational perturbations on the formation dynamics are then presented along with some approaches for minimizing their effects. This is followed by a short discussion of control for the establishment, maintenance and reconfiguration of formations. A discussion of relative navigation for formations is then presented.
Active Attitude Control Mechanisms
Authors: Horri Nadjim M. , Palmer Phil , Giffen Alice
Published: December 2010

This section describes the fundamentals, operating principles, and dynamical modeling of the actuators used for active spacecraft attitude control. Magnetic torquers and thrusters are presented as a way of applying external control torques to a spacecraft to alter both attitude and momentum. Momentum exchange devices, consisting of reaction and momentum wheels and control moment gyros are then presented as means of generating internal control torques for the operational attitude control of a spacecraft. The evolution of space applications is putting increasingly stringent requirements on satellite attitude control performance, thence the increasing importance of attitude control hardware.
Aircraft Flight Regimes and Applications
Authors: Howe Denis
Published: December 2010

Having defined an aircraft, consideration is given to the nature of the primary forces that act on a platform in flight. The means of generating lift in the context of lighter‐than‐air craft and fixed and rotating wing platforms are discussed. The development of thrust and the associated propulsion and overall efficiencies are described as they are affected by the type of power plant employed. This enables the many classes of operational aircraft to be placed in flight regimes determined by the speed and altitude at which they fly. Comments are made on some unusual and outstanding designs. The interaction of take‐off and landing with the local environment is considered.
Re‐Entry Vehicle Flight Profiles
Authors: East Robin A.
Published: December 2010

An historical perspective of re‐entry issues is presented, and factors that determine the flight profiles of re‐entry vehicles are considered. An outline is given of the aerothermal environment encountered during re‐entry. Analyses of approximate equations of motion of ballistic and lifting re‐entry trajectories through an atmosphere in which the density varies exponentially are discussed. Results from these analyses demonstrate the importance of the ballistic parameterm/SCD, the lifting parameterW/SCL, and the entry angle and velocity in determining the deceleration and thermal environments during re‐entry. Quantitative results are also presented from numerical integrations of the equations of motion through a more realistic standard atmosphere model. These describe the effect of the entry angle, entry velocity, and the ballistic and lifting parameters on deceleration and maximum stagnation point heating. Outline discussions are given of the entry corridors that are accessible within the constraints of permitted decelerations and allowable heating. Various types of thermal protection systems are described that involve ablation, thermal insulation, heat conduction, and radiation, and their relevance to different types of re‐entry vehicles is considered. Consideration is also given to the effect of the vehicle environments encountered during re‐entry on the vehicle shape and design.
The Interplanetary and Planetary Environments
Authors: Garrett Henry B.
Published: December 2010

This chapter will focus on the interplanetary and planetary environments in which spacecraft, landers, rovers, and aerobots will have to survive as mankind explores and expands out into the solar system. Emphasis is on the expected range of magnetospheric, atmospheric, ionospheric, and dust environments that will be encountered at the planets, comets, asteroids, and the Moon and that can impact spacecraft performance. The discussion includes a description of Solar Wind, which is a primary source of many of these environments and the ‘ocean’ in which all the spacecraft must fly. The surfaces and environments of the terrestrial planets and the Moon will also be discussed.
Airframe Noise – High Lift Device Noise
Authors: Zhang Xin
Published: December 2010

High lift devices, together with landing gears, are the main sources of airframe noise during the approach‐and‐landing phase of aircraft flight. Typical high lift devices include leading edge slats and trailing edge flaps. Other high‐lift‐related noise‐generating devices include spoilers if deployed during a steep approach operation. All the above aerodynamic devices are retracted during the cruise phase of aircraft operation. A slat, when deployed, forms a cove region between the slat and the central main element of the aircraft wing. Flow separation, flow recirculation, an unsteady shear layer, and slat settings together generate noise of mainly broadband content. For a flap, the outboard flap side edge and vortex system associated with it are the main sources of noise. The intensity of high lift device noise generally follows a power law of flow velocity. The main sources of noise are identified and described in this chapter. Introduction is provided concerning main semi‐empirical and computational fluid dynamics methods. Noise attenuation methods are also described.
Atmospheric Modelling
Authors: Braesicke Peter
Published: December 2010

This chapter describes the fundamentals of atmospheric modeling. It begins with introducing general concepts and develops these concepts in the context of numerical atmospheric models. The chapter will highlight the elementary building blocks of such models and will introduce fundamental ideas of forecast and climate models in use today. Concluding remarks looking at transport problems and how to model chemistry and aerosol physics in the atmospheric environment will close the chapter.
Aircraft Disposal and Recycling
Authors: van Heerden Derk‐Jan , Curran Ricky
Published: December 2010

This chapter addresses the issues surrounding the end‐of‐life for aircraft and their components, including disposal and recycling. Firstly, some definitions are considered in order to clarify the range of terminology, which is often used in an ad‐hoc manner, for example, reuse, recycling, recovery, disposal, disassembly, and dismantling. Performance measurement is also considered with indexes presented to show how recyclability and recoverability can be quantified. Subsequently, the end‐of‐life process is considered in terms of either the disassembly, dismantling, or recycling processes. This in turn leads to consideration of the treatment of the associated aircraft components, in terms of classification, commonality, component end‐of‐life, and piece parts. Finally, this chapter considers the economic aspects associated with end‐of‐life, from the point of view of the aircraft, the operator, and the market; with some attention also on aircraft parking. The conclusion summarizes some of the current and future challenges, and also considers the role of legislation and learning from other industries that are more advanced in how to cope with disposal and recycling.
Aircraft Design for Manufacture and Assembly
Authors: Eakin David
Published: December 2010

This chapter introduces a short review of the background to product design for manufacture and the emergence of the design for manufacture and assembly (DFMA) methodology. Experience and results from specific aircraft DFMA improvement projects are presented along with development of the synergy between DFMA, six sigma quality, and lean manufacturing for competitive aircraft production. Concluding comments describe the experience gained from these DFMA applications and the synergy with quality and lean.
Value‐Driven Manufacture: Digital Lean Manufacture
Authors: Curran R. , Butterfield J. , Jin Y. , Collins R. , Burke R.
Published: December 2010

The chapter presents the utilization of digital manufacture with a value‐driven Manufacture context, including the development of digital manufacturing capability for integration into the Integrated Product Process Development process. As part of the business process the key phase being addressed is the concurrent integration of manufacturing requirements at the stage when design geometry has been released. The digital manufacturing platform is used to provide simulations of the assembly process that have been developed in order provide simultaneous estimation of the associated learning curves, cycle time, recurring cost, and throughput. The integration of Lean principles at the program and functional levels will also be addressed as the Lean approach underwrites the entire program. Fundamentally, the compression of lead time, increase in value‐added effort, and reduction in waste and inefficiency are the key Lean challenges being addressed. Consequently, a Lean Implementation Methodology will be presented while the Lean characteristics of the functional development will also be highlighted. The latter also includes the Lean Flow Accounting Methodology that addresses the Lean flow of work through a plant in order to maximize value‐added effort according to a top‐down assessment of financial value and optimal throughput, thereby reducing Work In Progress.
Evolution of the Lean Enterprise System
Authors: Bozdogan Kirkor
Published: December 2010

Many aerospace enterprises and other organizations have adopted a variety of management approaches to achieve continuous process improvement, enterprise change and transformation, such as thelean enterprise system, total quality management (TQM), theory of constraints (TOC), agile manufacturing, and business process re‐engineering (BPR). Among them, thelean enterprise system, with its origins in the Toyota Production System (TPS), comes closest to providing a holistic view of enterprises as complex socio‐technical systems embodying a mutually supportive set of precepts and practices driving enterprise operations at all levels (i.e., strategic, tactical, operational) and throughout the enterprise value stream encompassing both upstream supplier networks and downstream customer‐focused activities. Lean enterprise principles and practices have evolved over many decades through a process of experimentation, learning and adaptation. A distinction is made between thebasic lean enterprise system(BLES), capturing salient developments over the period between the late 1940s and mid‐1990s, and thecontemporary lean enterprise system(CLES), capturing major conceptual and implementation‐related extensions of the basic model since the mid‐1990s. Thelean enterprise system, as a viable framework for explaining the structure and dynamics of modern networked enterprises, for managing them, and for improving their performance through either continuous process improvement or planned systemic change and transformation, remains a work‐in‐progress.
Seaplanes and Amphibians
Authors: La Rocca Gianfranco
Published: December 2010

Seaplanes are fixed‐wing aircraft able to takeoff and land from water. Two main types exist, floatplanes and flying boats, the first being conventional aircraft fitted with floats instead of wheels, and the second aircraft with the fuselage partially submerged in the water to provide the main source of buoyancy, as well as pilot and payload accommodation. Floatplanes and flying boats exist in amphibian versions, fitted with landing gears for ground operations. This chapter describes this special class of aircraft, addressing both their versatility and limitations with respect to conventional ground planes. The history of seaplanes and amphibians is summarized. The most relevant aircraft and technological developments from the pioneering days up to date are highlighted. A technical section is provided addressing the main design aspects related to buoyancy and static stability, hydrodynamic efficiency and dynamic stability, water spray and loads handling. Preliminary design rules and reference to specific certification rules are provided. A brief section on seaplanes and amphibians operation is included. An overview on wing‐in‐ground effect craft is provided as well, where the peculiarities and similarities of these vehicles with respect to seaplanes and amphibians are addressed.
Airplane Performance Optimization
Authors: Visser Hendrikus.G.
Published: December 2010

The considerable analytical foundation and theoretical body of knowledge as well as powerful practical computer codes for flight trajectory optimization that exist today cover a hierarchy of modeling fidelity level and rigor of optimization from the very approximate and computationally inexpensive to the rigorous high‐fidelity detailed mathematical models of flight vehicles and the robust optimization techniques used to obtain the optimal trajectories such vehicles can fly. This chapter complements another chapter in the encyclopedia on general trajectory optimization (see Trajectory Optimization) by reviewing this hierarchy as applied to airplane performance optimization and by presenting examples of those techniques in approximate airplane performance optimization that have influenced operation and design over the years, including techniques based on closed form expressions for different mission segments and techniques based on transformation of state variables and associated model order reduction.
Space Stations
Authors: Messerschmid Ernst W. , Renk Florian
Published: December 2010

The chapter describes the history of American and Russian space stations as well as early space station concepts and the development of the ISS. The technical discussion comprises the space station configuration, the characteristic subsystems and possible utilization scenarios. It aims at outlining the differences of a large manned space system compared to unmanned satellites with respect to assembly, operation, and utilization. An emphasis will be on the treatment of the Environmental Control and Life Support System (ECLSS), since this is a subsystem specific for manned space systems. Due to the diverse products to be handled by the ECLSS the advantages of synergisms with other subsystems are discussed. The outlook will treat requirements for space stations beyond the low Earth orbit.
The Survivability Balance
Authors: MacDiarmid Ian
Published: December 2010

The survivability of a platform in the battlefield is based on three issues – damage avoidance, damage tolerance, and damage repair. The design of a platform, in this case an aircraft, must consider in a balanced manner all three elements in order to reduce the chances of loss of the aircraft from the battle (attrition).

Damage avoidance is in itself a balance between observability, defensive aids performance, and maneuverability and mission planning endeavors to maximize avoidance given these three performance characteristics.

There are three levels of damage of concern – fatal damage resulting in loss of the aircraft, significant damage resulting in loss of performance and possible mission abort, and slight damage amenable to rapid repair, not impacting on availability.

Systems and structures are of concern, and highly critical and integrated designs require careful consideration.

Finally, damage repair (and repairability) is a vital consideration to enable rapid but effective repairs to maintain valuable combat assets in theatre.

This chapter introduces the considerations that need to be made when considering the overall topic as a means of introducing the more detailed
Chapters of 7.6.
Life‐Cycle Engineering: Economic Theory
Authors: Hartley Keith
Published: December 2010

Life‐cycle engineering involves costs, which is where economists have a role. The focus is on defense aerospace projects. The phrase “life cycle” is defined, and available cost data are reviewed. There is considerable published data on development and production costs but much less on ownership costs. Sensible informed choices require accurate data on life‐cycle costs and not solely on development and production costs. Economists stress both costs and trade‐offs. The implications for procurement policy are explained including the sources of cost growth and its future impact on both defense forces and defense industries.
Modern Aircraft Flight Management Systems
Authors: Cramer Michael R. , Herndon Albert , Steinbach Daniela , Mayer Ralf H.
Published: December 2010

This chapter describes the components, functions, and uses of Flight Management Systems (FMS) in current day air transport, regional and business aircraft. The integrated avionics components & functionality that provide flight crews with the ability to operate an aircraft efficiently and in compliance with the requirements of the Air Navigation Service Provider (ANSP) are listed and their integration is described. The FMS functions are defined in an operational context within the airspace system to provide a better level of understanding of system functionality relative to the purpose for which the FMS was designed.
Vehicle Systems Management
Authors: Moir Ian , Seabridge Allan
Published: December 2010

Most, if not all, of the vehicle systems need some means of measuring and monitoring of their performance, as well as the implementation of control functions. This chapter will describe how this function evolved from many individual control units, often based on relay logic into integrated software‐driven architectures, performing many sophisticated and safety critical functions. The development of the system through a range of military and commercial aircraft types will be described and the examples given. Descriptions of the input output interfacing, data bus types, processing and memory architectures, and total system architectures will also be provided.
Transport Aircraft Aerodynamic Integration: Subsonic
Authors: Smyth Richard
Published: December 2010

The aerodynamic integration of the propulsion system is a key activity to ensure that the engine/aircraft combination meets the objectives and commercial guarantees of performance, economics and noise reduction of a given aircraft program. The scope of application is for externally installed propulsion systems, typical for current subsonic transport aircraft. A reliable assessment of thrust and external drag of the engine and nacelle configuration is essential early in the development phase. Methodologies, computational tools, and model tests with powered exhaust flow are available for early evaluation and later reference to flight test.
Trajectory Optimization
Authors: Rao Anil V.
Published: December 2010

A general overview of the topic of trajectory optimization is presented. The general trajectory optimization problem is posed, and the two broad classes of indirect and direct methods for solving trajectory optimization problems are discussed. A brief discussion is then given of well‐known software tools to solve trajectory optimization problems. Finally, a brief survey is given of famous trajectory optimization problems that have been solved in aerospace engineering.