bluuebunny/crossref_metadata_2025_split huggingface dataset:
Propulsion System Cycles
Authors: Dahm Werner J.A. 
Published: December 2010

Abstract
The most important cycles used for practical air vehicle propulsion systems are discussed and analyzed, including their relative thermal efficiencies and various other attributes that determine their suitability for specific propulsion applications. This includes the fundamental thermodynamic performance of the most widely used heat engine cycles, such as the Otto and Diesel cycles, which are widely used in reciprocating engines, the Brayton cycle, which is used in continuous‐flow systems such as gas turbines and ramjet engines, and the Humphrey cycle, which is relevant to various wave‐driven propulsion systems including pulse jets and pulse detonation engines. Classical ideal cycle results are obtained for each case, and discussion of real cycle effects shows where the performance of practical systems departs from the ideal cycles. Performance metrics for the various cycles are compared, and realistic values for modern systems are used to assess the relative merits of practical propulsion systems based on each these heat engine cycles.
Chemical Equilibrium, Kinetics, and Combustion
Authors: Driscoll James F. 
Published: December 2010

Abstract
The combustion of fuel and air, which occurs in jet engines and in other devices, is one example of an important set of chemical reactions. To understand and to model this complex process, the basic laws of chemical equilibrium and chemical kinetics are applied. First, the Law of Mass Action is described for a system that is in chemical equilibrium, and then the Arrhenius law is applied to unsteady systems that are changing due to chemical kinetics. Some basic information is presented about the properties of premixed flames, non‐premixed flames, and detonations.
Multiphase Dynamics and Pollutant Formation
Authors: McDonell Vincent G. , Dunn‐Rankin Derek 
Published: December 2010

AbstractThis chapter discusses the controlling phenomena associated with the combustion of liquid and solid fuels for aerospace applications. The key physical processes and governing factors are reviewed within the context of the fluid mechanical devices and systems that are generally utilized in aerospace power and propulsion systems. A general discussion of the role of fuels in terms of pollutant formation as well as combustion system operability is provided. Finally, some comments are made to summarize the material discussed.
A Brief History of Positive Displacement Aviation Engines
Authors: Schock Harold J. 
Published: December 2010

Abstract
The positive displacement internal combustion engine was the engine used for the first successful powered manned flight by the Wright Brothers in North Carolina, United States, 1903. Positive displacement engines differ from turbine engines in that their work is generally obtained by the products of combustion expanding against a sealed piston. The aircraft engine has stringent operating requirements, and these are outlined. From 1900–1950 the primary types of positive displacement engines were: in‐line, rotary radial, static radial, vee engines, opposed cylinder engines, and diesel engines. Piston engines can be turbocharged to maintain engine output at high altitudes.
Gas Turbine Engines: Turbines
Authors: Bohn Dieter , Kusterer Karsten 
Published: December 2010

Abstract
The working principle of the turbine in a gas turbine engine is to convert the energy from the fluid into mechanical energy of the shaft. Thus, the power derived from the shaft can be used to drive a compressor, fan, or for the electrical power supply. The chapter introduces the reader to the basic characteristics of typical turbine designs and gives an overview of the different design approaches. Furthermore, it explains major aerodynamic loss mechanisms in axial turbines. As the front stages consist typically of cooled blades, the chapter describes the different design approaches for cooled turbine blades.
Gas Turbine Engines: Turbine Cooling
Authors: Bunker Ronald S. 
Published: December 2010

AbstractThe advancement of gas turbine cooling has allowed engine design to greatly exceed normal material temperature limits. Cooled component design and development has consistently trended in the direction of higher heat loads, and higher through‐wall and in‐plane thermal gradients. The ultimate goals in gas turbine cooling are consistent with the thermodynamics of isentropic energy transfer in that (1) the component or some portion of it is desired to be isothermal to eliminate all internal thermal stresses, (2) the component is desired to be as hot as allowable to minimize coolant usage and inefficient energy transfers, and (3) thermal gradients from the component to the support and containment structure are desired to be minimized. In terms of the turbine system, the goal of turbine cooling is to achieve the longest component life with the least impact on engine efficiency and cost. This summary describes the means and methods, as well as the constraints, concerning the cooling of gas turbine components.
Commercial Engine Noise
Authors: Benzakein Mike J. 
Published: December 2010

AbstractThe source of commercial engine noise is briefly discussed for the legacy fleet, as well as for the new products being introduced into the field. While considerable progress has been done over the last fifty years, there is more to be done. Fan and jet noise are the very components requiring attention as we go forward. New regulations reflecting the public needs are putting pressure on the industry to lower the noise levels for new upcoming products. Intensive research is underway in industry, academia, and government to meet these challenges.
Solid Propellants
Authors: Thakre Piyush , Yang Vigor 
Published: December 2010

AbstractSolid propellants are widely used in rocket propulsion applications. They are often tailored by specific applications such as space launchers, missiles, and guns. Solid propellants are typically classified as homogeneous or heterogeneous (composite propellants), according to their chemical composition and physical structures. The former contains fuels and oxidizers, which are chemically linked at the molecular level. The latter include fuel and oxidizers, which are mixed physically. Typical examples of homogeneous propellants are single‐base (NC and additives), double‐base (NC, NG and additives), and triple‐base (NC, NG, NQ, and additives) propellants. For composite propellants, the ingredients often used as oxidizers are AP, AN, ADN, RDX, and HMX. Some of the commonly employed binders are HTPB, CTPB, and GAP. Metal fuel additives such as aluminum particles are widely employed in propellant mixtures to enhance motor performance and stability characteristics. This section details the composition and classification of solid propellants, along with their combustion behaviors.
Solid Rocket Motor Failure
Authors: McDonald Allan J. 
Published: December 2010

Abstract

An overview of solid rocket motor (SRM) failures is presented in this chapter. The historical context of large rocket motor development is introduced, along with the strategic and financial motivations for the great efforts toward failure prevention. Several historically significant US and international failures, including that of the space shuttle
Challenger
, are presented in order to identify the primary modes of failure of most modern rocket systems. The overall rates of failure of liquid and solid rockets are compared. A summary of failure analysis tools and methods is given, and common sources of information used to facilitate the determination of rockets' modes of failure are identified. Recommendations are made regarding a prudent approach to post‐flight or post‐test investigations of motors exhibiting anomalous conditions. To illustrate such an approach, the response to the
Challenger
explosion is examined in detail. Evidence of
Challenger's
abnormal SRM operation is presented, and subsequent subscale and full‐scale testing and engineering analysis is described. Finally, the overarching lessons learned over many years of SRM failure analysis are summarized.
Liquid Propellants and Combustion: Fundamentals and Classifications
Authors: Chehroudi Bruce , Talley Doug , Yang Vigor 
Published: December 2010

Abstract
Relevant properties of propellants such as physical properties, specific impulse, specific gravity, material compatibility, and others are briefly described. Various kinds and classifications of liquid propellants are reviewed, and common ones are briefly described. The ignition properties of these propellants are divided into hypergolic and nonhypergolic classes, and methods of igniting nonhypergolic propellants are discussed. The steps and stages of the subsequent combustion process are described generally, and the problem of combustion instabilities is introduced and briefly described, along with methods for testing for them and eliminating them.
Liquid Propulsion: Propellant Feed System Design
Authors: Cannon James L. 
Published: December 2010

Abstract
The propellant feed system of a liquid rocket engine determines how the propellants are delivered from the tanks to the thrust chamber. They are generally classified as either pressure fed or pump fed. The pressure‐fed system is simple and relies on tank pressures to feed the propellants into the thrust chamber. This type of system is typically used for space propulsion applications and auxiliary propulsion applications requiring low system pressures and small quantities of propellants. In contrast, the pump‐fed system is used for high‐pressure, high‐performance applications. The selection of one propellant feed system over another is determined based on design trade studies at both the engine and vehicle levels. This chapter first provides a brief overview of the basic configurations of pressure‐fed systems. Pump‐fed systems are then discussed with greater detail given to the turbomachinery design. Selected design requirements and configurations are provided.
Liquid Propulsion: Systems Engineering, Design Trades, and Testing
Authors: Emdee Jeffery L. 
Published: December 2010

AbstractLiquid rocket engine design, manufacturing, and testing require implementation of a robust systems engineering process to be successful. In addition to propulsion, there are multiple disciplines involved, including thermal, structures, structural dynamics, electrical engineering, and fluid dynamics. There are also significant interface challenges when integrating the engine system with the launch vehicle. The overall process requires a balance of often competing requirements, including cost, schedule, performance, and reliability. Application of the systems engineering process to liquid rocket engine system design and test evaluation is described in this chapter. Considerations for several system design requirements are covered, including human rating and reliability. After an engine is designed and manufactured, extensive testing and evaluation are required to confirm analytical model predictions and assumptions. Engine testing processes are described to provide an overview of test objectives and requirements. Development testing is used to characterize engine operation and to identify failure modes before qualification begins. Qualification test requirements and flight test demonstration goals will also be reviewed. Finally, systems engineering tools, which are available to prevent and resolve failures, are summarized with specific application to liquid rocket propulsion systems described.
Hybrid Propulsion
Authors: Chiaverini Martin J. 
Published: December 2010

AbstractHybrid rocket propulsion systems have several inherent safety and operational features that make them attractive choices for a broad range of applications, including primary propulsion for launch vehicles, upper stage propulsion, tactical and strategic missile systems, and the emerging field of commercial space transportation. Although hybrid rocket motors as we know them today have been investigated for more than six decades, their development and maturation has not been as actively pursued as that of liquid bipropellant engines or solid rocket motors. Historically, military applications have favored the storability and launch‐readiness capabilities of solid rocket motors, while high specific impulse and controllability made liquid engines the system of choice for civil applications. Nevertheless, emphasis on greater propulsion safety, reduced development and recurring costs, insensitive munitions, environmentally benign propellants, propulsion system robustness and reliability, and a high degree of operability have heightened interest in hybrid propulsion systems for commercial space applications and some military propulsion programs. In response to this, hybrid rocket research and development efforts have, within the past decade, led to significant state‐of‐the‐art advancements in hybrid rocket propulsion. The purpose of this chapter is to introduce the reader to the operating principles and characteristics of hybrid rocket motors.
Ion Thrusters
Authors: Goebel Dan M. , Foster John E. 
Published: December 2010

AbstractIon thrusters utilize high‐voltage grids to electrostatically accelerate ions to high velocity to produce thrust. Efficient ionization of the propellant carried onboard the spacecraft is achieved by optimized hollow cathode, RF or microwave discharge chambers, and electrons from an external hollow cathode are injected into the ion beam to provide charge neutralization in order to avoid spacecraft charging. The ion thruster propulsion subsystem also contains a power processor, a propellant control system and a gimbal mechanism. The high exhaust velocities produced in present flight thrusters by acceleration of the ions to energies in the range of 1–2 keV produces a specific impulse that exceeds 3000 s, and energies of over 10 keV have been demonstrated. The low thrust produced by these devices of typically a fraction of a Newton requires that thruster lifetimes measured in years are needed for most deep space prime propulsion and earth‐orbiting station‐keeping applications. Ion thrusters feature the highest efficiency (60 to < 80%) and very high specific impulse (2000 to over 10000 s) compared to other thruster types.
Pulsed Plasma Thrusters
Authors: Burton Rodney L. 
Published: December 2010

AbstractPulsed plasma thrusters comprise a large class of electric space thrusters, using an electric discharge to accelerate solid, liquid, or gaseous propellant. Each pulse provides a small velocity increment to a spacecraft. Repeating the pulses at a constant rate over 103–109pulses creates significant spacecraft velocity change and also permits highly accurate spacecraft control. The thruster propellant is accelerated either by discharge pressure heating, or by high current electromagnetic forces. The chapter discusses the basic pulsed thruster concept, the measurement of thruster propulsion performance, and describes the distinguishing features of a large number of pulsed thrusters, including those that have achieved space application and those that have experienced advanced development in the laboratory.
Electrospray Propulsion
Authors: Lozano Paulo C. , Martínez‐Sánchez Manuel , Hruby Vlad 
Published: December 2010

Abstract“Electrospray thrusters” are electrostatic accelerators of charged droplets or of ions extracted directly from a liquid. The best known of these devices are those based on droplets, for which the term “colloid propulsion” has been used. Colloid propulsion development was initiated in the 1960s and 1970s, but this development was halted after reaching near flight status, due to perceived complexity and risks associated with high voltages. More recent developments include the pure ionic regime using ionic liquids, which opens up access to high specific impulses at low voltage, and the use of micro‐fabrication to build compact arrays of hundreds or thousands of emitters. A new factor favoring electrospray propulsion is the emergence of micro‐propulsion missions, especially those requiring high precision and repeatability. However, research work underway indicates that massive arraying can also open the way to practical, highly efficient, high specific impulse main propulsion. This chapter reviews the pertinent physics and the status of the technology, including examples from the older generation and from recent applications.
Power Management and Distribution
Authors: Lenertz Brian A. 
Published: December 2010

AbstractThe topic of Power Management and Distribution (PMAD) for spacecraft Electrical Power Systems (EPS) is presented. Various PMAD architectures are shown, followed by a discussion of the PMAD elements, and then moving into power distribution and fusing. Design requirements such as power quality and stability are covered, as well as command and telemetry, fault tolerance, and design verification.
Linear Elasticity
Authors: Mal Ajit 
Published: December 2010

Abstract
A brief exposition of the theory of linear elastostatics is presented in this chapter. The equations of elasticity are written in compact forms using the index notation and coordinate‐independent direct vector notation when convenient. The chapter is divided into three sections dealing with kinematics, balance laws, and constitutive relations. The concepts of displacement, strain, and stress are developed and the relationships between them are derived under the assumption of linearity. The equations of equilibrium are derived based on the application of Newton's laws to deformable solids. Solutions of a few typical linear elastostatic problems of interest in aerospace engineering applications are presented.
Plates and Shells
Authors: Birman Victor 
Published: December 2010

Abstract
The chapter outlines the foundations of the theory of plates and shells. The general approach employed in all versions of the relevant theories leads to particular cases including the classical (technical) theory of isotropic and composite plates and shells. Examples of solutions of linear bending and buckling problems are illustrated. The effect of large nonlinear deformations on the response of plates and shells is reviewed. The analysis of stiffened plates and shells is discussed, including the method modeling discrete reinforcements and the smeared stiffeners technique applicable to closely spaced identical stringers. It is shown that openings and cut‐outs influence the behavior and strength of plates and shells, both locally through the stress concentration as well as globally through their effect on the stiffness. The concepts of composite and sandwich plates and shells are elucidated, providing insight on the peculiarities of mechanics of these structures.
Fatigue and Fracture Mechanics in Aerospace Structures
Authors: Kardomateas George A. , Geubelle Philippe H. 
Published: December 2010

Abstract
The usage history of aerospace structures may include cyclic loads of either constant or varying amplitude, fluctuations in temperature, or a corrosive environment. This section deals with the effects of cyclic loads, which lead to material degradation over time, due to the initiation and growth of cracks; this degradation can eventually result in failure (fatigue). Thus, a reliable prediction of component fatigue life is critical to aircraft safety. This is even more important as the average age of the world's transport fleet continues to rise. This section provides a general overview of the approaches, based on fracture mechanics, which have been developed to arrive at an estimate of fatigue life or at an inspection interval (damage tolerance) with the goal of ensuring component safety.
Structural Stability
Authors: Simitses George J. , Hodges Dewey H. 
Published: December 2010

AbstractThe behavior of structures can be classified in terms of response and stability. Structural stability can, in turn, be further classified in terms of the rate at which the structure is loaded. Structures that are very slowly loaded may be analyzed with static principles; otherwise, dynamic behavior must be taken into account. In the first part of this chapter basic principles of static structural stability are discussed. The main part of the discussion is presented in the framework of analyses that are linearized about an equilibrium state, which may be governed by nonlinear equations. The discussion also distinguishes conservative from nonconservative loading; outlines the uses of classical, kinetic, and imperfection methodologies; and illustrates bifurcation buckling, finite disturbance buckling, and snap‐through. A brief buckling analysis example and a discussion of the role of experiments are presented. In the second part an overview of dynamic stability is presented. Dynamic stability analyses for structures subjected to aperiodic time‐dependent loads are distinguished from those subjected to periodic time‐dependent loads. An example analysis is presented for stability of a system subjected to a periodic force, leading to parametric resonance. Finally, an overview is given of the application of structural stability to the aerospace field.
Damping in Structural Dynamics
Authors: Lesieutre George A. 
Published: December 2010

AbstractDamping is an important aspect of aerospace structural dynamics. Passive damping is caused by numerous physical mechanisms, only some of which can be exploited by design. The most effective methods of designing materials‐based passive damping into structures involve the use of: high damping viscoelastic polymers in layered damping treatments; elastomers; shunted piezoelectrics; and damped composites. To consider damping during the design process, accurate models are needed—these must capture the general effects of damping, while also enabling the detailed design of damping treatments. Strain‐based viscous damping models yield modal damping that increases monotonically with frequency, a result inconsistent with observations. More general proportional damping is best regarded as a mathematical curiosity. Complex stiffness models, although capable of accommodating frequency‐dependent damping and stiffness in frequency response analysis, cannot directly predict structural response to arbitrary loading. The combination of either the complex stiffness or the modal strain energy method with a modal damping model, however, often yields acceptable results. The need for better accuracy in some applications has motivated the development of improved time‐domain models that capture the frequency‐, temperature‐, and amplitude dependence of damping and stiffness exhibited by the high‐loss materials that are frequently used to effect significant damping.
The Evolution of Analytic and Computational Methods for Fixed‐Wing Flight Vehicle Aeroelasticity
Authors: Livne Eli 
Published: December 2010

Abstract
The development of analysis and computational methods used to design and certify fixed‐wing flight vehicles is presented in this chapter from the early work following World War I and up to recent development in computational fluid dynamics/finite element‐based computational aeroelasticity and from flight vehicles operating in the low subsonic flow regime to vehicles that fly transonically, supersonically, and hypersonically, representing flight vehicle technology developed over more than a hundred years of flight. The professional literature on aeroelasticity is vast, and only key references are included in the bibliography at the end of this chapter. These references contain substantial references lists of their own that can serve as appoint of departure for further searches.