bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incompressible Flow Over Finite Wings
Authors: Katz Joseph 
Published: December 2010

Abstract
In this chapter, the aerodynamics of finite wings is analyzed using the classical lifting line model. This simple model allows a closed‐form solution that captures most of the physical effects applicable to finite wings. The model is based on the horseshoe‐shaped vortex that introduces the concept of a vortex wake and wing tip vortices. The downwash induced by the wake creates an induced drag that did not exist in the two‐dimensional analysis. Furthermore, as wingspan is reduced, the wing lift slope decreases, and the induced drag increases, reducing overall efficiency. To complement the high aspect ratio wing case, a slender wing model is formulated so that the lift and drag can be estimated for this limiting case as well. Finally, a brief survey of panel methods is presented. These methods are capable of solving the potential flow over complex (and thick) lifting configurations. The solution, however, can be obtained by using numerical methods only.
ImplicitCFDMethods and Unstructured Grids
Authors: Mavriplis Dimitri J. 
Published: December 2010

AbstractThis chapter provides an overview of the various implicit solution strategies developed for use with unstructured mesh CFD calculations. For time‐dependent simulations, implicit methods are appealing because they enable the use of arbitrarily large time steps, while for steady‐state problems implicit methods are imperative for enabling the practical solution of large problems. The key aspect of implicit solvers on unstructured meshes is the requirement to form and invert a large sparse matrix either directly or approximately. This chapter examines the structure of the implicit matrix and covers various approaches for approximating and inverting the matrix either directly or iteratively. The combination of these basic techniques with other convergence acceleration strategies such as multigrid and Krylov methods is also discussed. The performance of these methods is illustrated through a series of sample calculations.
Thermodynamics
Authors: Borgnakke Claus 
Published: December 2010

Abstract
The basic general laws of thermal science are presented and discussed for the application to finite control volume analyses. These are conservation laws for mass, momentum, and energy and a balance law for entropy. Applications to fixed mass systems and to steady flow devices are shown together with the additional special laws governing the behavior of pure substances as equations of state. Further auxiliary laws are indicated as necessary information from the fields of fluid mechanics and heat transfer. Reversible and irreversible processes are discussed, and limitations imposed by the general laws on processes and device behavior are shown. Special attention is given to the possible work that can be extracted from a proposed system or process as the theoretical limit used as a reference for actual systems. The general theory is used to present an ideal heat engine exemplified by a Carnot cycle and relate that to actual heat engines and their efficiencies.
Gas Turbine Engines: Inlets
Authors: Benson Thomas J. , Seidel Jonathan A. 
Published: December 2010

AbstractThe inlet is the part of the aircraft that brings air into the propulsion system. The inlet design affects the performance of the propulsion system. In turn, the varying airflow demands of the engine affect the performance of the inlet and the flight envelope of the aircraft. A “good” inlet design allows the engine to produce high thrust and low fuel usage over a wide range of flight conditions and throttle conditions. A “poor” inlet design limits the operating range of the engine and aircraft. The chapter discusses the fundamental parameters of performance, compatibility, and integration that characterize an inlet, and then presents some of the recent trends and future directions in inlet design.
Gas Turbine Engines: Nozzles
Authors: DeBonis James R. 
Published: December 2010

AbstractThis chapter describes the exhaust nozzle and its application to aircraft gas turbine engines. The nozzle's two primary functions are to generate thrust and to act as a control valve for the engine. Nozzle performance parameters, discharge coefficient, and thrust coefficient are defined. The basic fluid dynamics and performance of convergent and convergent‐divergent nozzles are discussed. Types of nozzles for subsonic, supersonic, and hypersonic vehicles are described. Secondary nozzle functions thrust reversing, thrust vectoring, noise suppression, and infrared signature suppression are described. Finally nozzle design, analysis, and testing methods are described.
Liquid Propulsion: Engine Production and Operation
Authors: Leahy Joseph C. , Hanna Stephen G. , Malchi Jonathan Y. , Kim Eun S. 
Published: December 2010

AbstractLaunch success involves detailed multi‐disciplined engineering during all phases of a liquid rocket engine – development, production, and operation. The development phase starts with system requirements and involves extensive testing and evaluation to characterize and qualify engine design and operation. Upon completion of development, an engine goes into full‐scale production. Each production engine must meet its requirements within allowable engine‐to‐engine variations, typically during acceptance testing. Every risk must be understood, accepted or mitigated. Numerous reviews, tests and inspections are performed to verify compliance with requirements throughout the entire production process, from component fabrication to vehicle integration. The overall operation of a liquid rocket engine is divided into four distinct stages: (i) start‐up transient, (ii) steady state, (iii) throttling (if throttleable), and (iv) shutdown transient. Start and shutdown transients expose engine components to extreme gradients in operating conditions, while steady‐state and throttling operations occur for a majority of flight and involve fairly moderate changes in operating conditions. This chapter will provide a general overview of the production and operation of liquid rocket engines. Manufacturing and acceptance testing will be discussed as well as vehicle integration and flight operation. Examples of three actual operational engines will also be provided.
Resistojets and Arcjets
Authors: Hoskins Andrew 
Published: December 2010

AbstractThe simplest forms of electrically augmented propulsion for spacecraft are resistance‐heated and arc‐heated thrusters, generally called resistojets and arcjets, respectively. As with all forms of electric propulsion, electric energy added from the spacecraft increases the specific impulse over that achievable with a chemical reaction and expansion through a nozzle. With electrothermal devices, the added energy is imparted to the propellant as thermal energy. In the specific case of the resistojet, energy is added to the propellant with a resistance heater. In the case of an arcjet, an arc is drawn directly through the propellant between a cathode and an anode. The augmented specific impulse is limited by the maximum temperature tolerable by key components over the necessary life of the thruster. The maximum thrust as a function of input electrical power is limited by the efficiency with which the electrical energy is coupled into and contained within the flow and by the efficiency with which the flow enthalpy is converted to axial kinetic energy in the expansion. Resistojets and arcjets have been in development since the late 1950s and have been used on well over 200 spacecraft. This chapter describes the basic construction of these devices, illustrates relationships governing their performance, and surveys the performance demonstrated by a range of laboratory and flight qualified models.
Turbomachinery Aeroelasticity
Authors: Bendiksen Oddvar , Kielb Robert E. , Hall Kenneth C. 
Published: December 2010

AbstractIn this chapter, we describe the range of aeroelastic problems found in modern turbomachinery, and briefly describe the nondimensional parameters that govern these phenomena and the analytical methods used to model them. We classify types of flutter and forced respsone in compressors and fans by location on the compressor map and on the so‐called Campbell diagram. We also present the fundamental equations of motion that govern the aeromechanical behavior of turbomachinery, describe the effect of mistuning on forced response, and give an overview of the computational methods currently used to compute the unsteady aerodynamics associated with the aeroelasticity of turbomachinery.
Thermal Protection Systems (TPSs
Authors: Hurwitz Frances I. 
Published: December 2010

AbstractThermal protection systems (TPSs) for space and hypersonic vehicles encompass a wide range of materials and design designs. In any particular vehicle, a variety of materials may be used. The choice of materials and thermal protection concepts is based upon thermal environment and exposure times, as well as whether the application requires single use or multiuse. This chapter provides an overview of materials and concepts, including tile, blankets, metallic systems, structurally integrated concepts, ceramic matrix composites (CMCs), used primarily in hot structures, ultra‐high temperature ceremics (UHTCs), and ablators. It is based upon a review of publicly available literature and includes a historical perspective, as well as some newer developments as of 2009.
Nickel‐Based Superalloys for Blade Application: Production, Performance and Application
Authors: Tin Sammy , Pollock Tresa M. 
Published: December 2010

Abstract
The continuing drive for improvements in the performance, operating temperatures, and emissions in advanced aircraft engines has driven the development of nickel‐based superalloys for decades. Nickel base superalloys are an unusual class of metallic materials with an exceptional combination of high temperature strength, toughness, and resistance to degradation in corrosive or oxidizing environments. Their performance in severe combustion and chemical environments materials has led to their widespread use in aircraft and power generation turbines, rocket engines, nuclear power plant components, marine engines, and a variety of chemical processing operations. Intensive alloy and process development activities over the past few decades have resulted in single crystal Ni‐based superalloys that can tolerate average temperatures of 1050°C with occasional excursions (or local hot spots near airfoil tips) to temperatures as high as 1200°C which is ∼90% of the melting point of the material. The fundamental aspects of the composition and structure that result in these exceptional properties are briefly reviewed. Single crystal Ni‐superalloys that are utilized in gas turbine engines and the advanced manufacturing processes used for their production are outlined along with characteristic mechanical and physical properties.
Active Materials in Aerospace Applications
Authors: Martin Christopher A. , Sater Janet M. , Crowe C. Robert , Obal Michael W. 
Published: December 2010

AbstractThe demonstration and integration of active materials such as electroactive ceramics, shape memory alloys, electroactive polymers, magnetostrictive materials, and electro and magnetorheological fluids into aerospace vehicles has experienced rapid growth in the last two decades. The application and demonstration of active materials and structures has focused on spacecraft, aircraft, and rotorcraft to solve vibration suppression problems and fixed geometry limitations. Illustrative examples of and references for this dynamic and rich area of technology applications are provided.
Corrosion in Space
Authors: de Rooij Antonius 
Published: December 2010

Abstract
The corrosion in space is described by the effect of atomic oxygen on several materials. The metal which was most affected is silver. Silver oxidizes according to a linear‐parabolic law and due to the thermal stresses the oxide layer continuously breaks up, resulting in a linear degradation. Atomic oxygen not only attacks materials in the line of sight of the ram flux, but also by reflected atomic oxygen. Many materials form an adherent oxide layer, such as Cu, Al, and stainless steel and are as such protected once this oxide layer is formed. Some materials have a volatile oxide such as Osmium and many polymers materials. They show a linear behavior.
Takeoff and Landing of Fixed‐Wing Aircraft
Authors: Poole Richard J. 
Published: December 2010

AbstractThis section describes aircraft takeoff and landing maneuvers and the effects of factors such as ambient wind strength and direction involved their execution. Formal requirements of the Western airworthiness authorities for commercial aircraft operations and the necessary safety margins demanded by them are introduced and their interaction with performance scheduling is also addressed. This includes the consideration of the specification of takeoff, landing, acceleration and stopping distances, the accommodation of engine failures, and the specific speeds scheduled when flight planning for these operations. The differing requirements for the operation of naval aircraft from aircraft carriers are presented and the innovative ski‐jump take‐off technique and its performance advantages are described. Special features that allow some aircraft to achieve short take‐off and landing performance are also briefly considered. Finally, simple equations that can be used for trade studies of the various parameters that contribute to take‐off and landing performance are developed and presented.These should not be used for operational flight planning purposes for any particular aircraft.
Fixed‐Wing Lateral and Directional Dynamic Stability
Authors: Lowenberg Mark 
Published: December 2010

AbstractStability and control are fundamental properties of an aircraft's dynamic characteristics, influencing flying qualities and hence pilot workload and safety. They are closely linked to other fundamental aspects of aircraft design, including aerodynamics, performance, systems, structure, and operating cost factors. This chapter discusses the governing equations of motion for a rigid‐body aircraft and their linearized form, the latter facilitating the decoupling of lateral–directional stability and control from its longitudinal counterparts for conventional aircraft. The consideration of flight responses in terms of their constituent modes of motion is introduced, using the linear state‐space form of the equations and a stability‐and‐control‐derivative representation of the aerodynamic loads. Thereafter, the stability and response associated with each lateral–directional mode is described in some detail for standard aircraft configurations, with reference to the aerodynamic parameters governing the behavior. The chapter concludes with a brief comment on nonlinearity and how it may modify the linear system stability and control characteristics.
Fly‐by‐Wire Flight Control Systems
Authors: Fielding Chris 
Published: December 2010

AbstractThe early generation of flight control systems were entirely mechanical and used rods and levers, or cables and pulleys, to provide direct mechanical linkages between the pilot's cockpit controls and the control surfaces that maneuver the aircraft. As technologies developed and aircraft evolved in size and speed, the mechanical systems were developed to include fully power‐operated controls. The desire for improved aircraft handling and the need to automate some phases of flight, made it necessary to add signals from the stability augmentation systems and autopilot, to the basic manual control circuits. Eventually, the direct mechanical linkages between the cockpit controls and the actuators were replaced with electrical signalling and computers, leading to the term “fly‐by‐wire”. This arrangement allows the pilot to directly command the aircraft's motion, rather than by commanding the control surface angles needed to achieve the motion. This chapter provides an overview of some of the technologies and processes used for the design and qualification of fly‐by‐wire systems, including aerodynamics and flight control, system hardware and implementation, flight control laws, piloted simulation and aircraft handling, ground and flight testing, the benefits of fly‐by‐wire and future system developments.
Adaptive Control Design Technique for Nonlinear Flight Systems
Authors: Unnikrishnan Nishant , Balakrishnan Sivasubramanya. N. 
Published: December 2010

Abstract

This chapter proposes a new model‐following adaptive control design technique for nonlinear systems that are nonaffine in control. This adaptive controller uses online neural networks that guarantee stability in the presence of unmodeled dynamics (neglected nonlinear terms in the mathematical model) and/or parameter uncertainties present in the system model. In order to ensure stable behavior, an online control adaptation procedure is proposed. The controller design is carried out in two steps:

synthesis of a set of neural networks that capture the unmodeled (neglected) dynamics or model uncertainties due to parametric variations and

synthesis of a controller that drives the state of the actual plant to that of a reference model.

The neural network weight update rule is derived using Lyapunov theory, which guarantees both stability of the error dynamics and boundedness of the weights of the neural networks. This method is tested using a three‐degree‐of‐freedom model of a unmanned aerial vehicle (UAV). Numerical results that demonstrate these features and clearly bring out the potential of the proposed approach are presented in this chapter.
Reconfigurable Flight Control
Authors: Kim Youdan , Kim Sungwan 
Published: December 2010

Abstract

A reconfigurable
flight control system
(
FCS
) is a flight control system that can accommodate the effects of faults by modifying the control system when faults occur during flight. The reconfigurable flight control system provides a significant enhancement to flight safety and performance in the event of a system fault. In this chapter, various approaches for fault tolerant flight control are introduced: passive approaches utilizing robust control schemes and active approaches (control reconfiguration) utilizing
fault detection and diagnosis
(
FDD
), system identification, and adaptive control schemes. The active approach is classified into two methods: a fault detection and diagnosis‐based approach, and an adaptive control‐based approach. In the FDD‐based approach, an efficient and accurate FDD algorithm is required. An appropriate controller is pre‐designed for each fault model, and a switching mechanism is used in selecting the corresponding controller when a particular fault mode is declared by the FDD process. In the adaptive control‐based approach, the FDD process is eliminated to make the fault tolerant control algorithm simple and allow it to adapt quickly to unknown faults. To compensate for the effects of faults in the adaptive control‐based approach,

the changed system parameters due to the faults are estimated or identified online and the controller is adjusted based on the estimated system, or

the changed system model is parameterized in terms of the controller parameters that are directly updated without calculating the plant parameters.
Electro‐optic Sensor Principles
Authors: Richardson Mark A. , James David B. 
Published: December 2010

Abstract
In this chapter the origins and physics of electromagnetic infrared radiation emitted from objects will be presented and discussed; both in terms of the theoretical ideal blackbody, and as applied to more realistic emitters. The wavelength of the emitted radiation is dependent upon the temperature of the object. The suitability of detector systems and configurations will be presented as applied to the detection of objects at different temperatures, and so emitting different wavelengths. Finally, laser action will be explained; covering the origins of laser light, and it's properties which differentiate it from conventional light sources.
Target Tracking
Authors: Ralph Jason F. 
Published: December 2010

AbstractRadar and electro‐optical systems are used to detect aircraft, missiles, and other vehicles. They measure aspects of the positions and velocities of the objects (targets) that they detect. However, it is only when these measurements are combined to form consistent trajectories or tracks that the sensor can present an intelligible picture of the world around it. Modern target tracking algorithms allow sequences of noisy, erratic measurements to be combined to form reliable tracks. Tracking consists of several stages: measurement‐track association, state estimation, and track creation/deletion. State estimation lies at the heart of all tracking algorithms. It provides accurate estimates of the position and motion of multiple targets and allows their subsequent motion to be predicted, but ancillary track management functions are essential to ensure that the tracks produced are robust and computationally efficient. This section gives an overview of tracking systems and describes how a simple approach (based on linear Kalman and steady‐state filters) can be expanded to deal with more complicated environments and to include advanced algorithms, including nonlinear filters and multiple hypothesis trackers.
Orbital Mechanics Fundamentals
Authors: Vallado David A. 
Published: December 2010

Abstract
Reviews basic statements of the equations of motion, including Kepler's and Newton's laws and the constants of orbital motion. Orbital elements are introduced and the two‐body problem is shown along with conic sections. These relations form the basis for astrodynamic applications and permit many useful studies to be accomplished. Perturbation theory and the major forces affecting satellite motion are discussed, along with the variability of those forces. Graphs are included to show the effect of perturbing forces on typical satellite orbits. The distinction is made between mean and osculating elements, fast and slow variables, and periodic forces. Discussion about the main problems in astrodynamics is included – orbit propagation and orbit estimation – along with definitions of analytical, numerical, and semianalytical propagation. The broad concept of orbit determination is introduced. Some relevant problems in astrodynamics are introduced noting the tie to propagation and orbit estimation. A summary concludes the remarks.
Mission Design and Trajectory Optimization
Authors: Ocampo Cesar A. , Byrnes Dennis V. 
Published: December 2010

AbstractThe fundamental concepts associated with designing spacecraft missions and optimizing trajectories with impulsive and/or finite thrust maneuvers are discussed. The description of ballistic motion for the central two‐body force field and a more realistic force field used in interplanetary mission design is presented. Basic orbital transfer maneuvers are discussed which form the basis for more complex transfers. The rocket equation is used to relate velocity impulses to propellent mass consumption and finite thrust maneuvers. The gravity assist maneuver is described to illustrate its use in the design of multi‐body trajectories. The state transition matrix and its applications to the trajectory design process is discussed. The trajectory design and optimization process is discussed in the context of solving nonlinear root finding or constrained optimization problems. A complex interplanetary trajectory problem is posed and solved to illustrate some of the concepts and ideas presented.