Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




Rotordynamics


Book Description

As the most important parts of rotating machinery, rotors are also the most prone to mechanical vibrations, which may lead to machine failure. Correction is only possible when proper and accurate diagnosis is obtained through understanding of rotor operation and all of the potential malfunctions that may occur. Mathematical modeling, in particular




Monthly Catalog of United States Government Publications


Book Description

February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index




Limits, Modeling and Design of High-Speed Permanent Magnet Machines


Book Description

There is a growing number of applications that require fast-rotating machines; motivation for this thesis comes from a project in which downsized spindles for micro-machining have been researched. The thesis focuses on analysis and design of high-speed PM machines and uses a practical design of a high-speed spindle drive as a test case. Phenomena, both mechanical and electromagnetic, that take precedence in high-speed permanent magnet machines are identified and systematized. The thesis identifies inherent speed limits of permanent magnet machines and correlates those limits with the basic parameters of the machines. The analytical expression of the limiting quantities does not only impose solid constraints on the machine design, but also creates the way for design optimization leading to the maximum mechanical and/or electromagnetic utilization of the machine. The models and electric-drive concepts developed in the thesis are evaluated in a practical setup.




Paper


Book Description




Rotating Machinery Vibration


Book Description

Diagnosis and correction are critical tasks for the vibrations engineer. Many causes of rotor vibration are so subtle and pervasive that excessive vibration continues to occur despite the use of usually effective design practices and methods of avoidance. Rotating Machinery Vibration: From Analysis to Troubleshooting provides a comprehensive, consolidated overview of the fundamentals of rotating machinery vibration and addresses computer model building, sources and types of vibration, and machine vibration signal analysis. This reference is a powerful tool to strengthen vital in-house competency on the subject for professionals in a variety of fields. After presenting governing fundamental principles and background on modern measurement, computational tools, and troubleshooting methods, the author provides practical instruction and demonstration on how to diagnose vibration problems and formulate solutions. The topic is covered in four sequential sections: Primer on Rotor Vibration, Use of Rotor Dynamic Analyses, Monitoring and Diagnostics, and Troubleshooting Case Studies. This book includes comprehensive descriptions of vibration symptoms for rotor unbalance, dynamic instability, rotor-stator rubs, misalignment, loose parts, cracked shafts, and rub-induced thermal bows. It is an essential reference for mechanical, chemical, design, manufacturing, materials, aerospace, and reliability engineers. Particularly useful as a reference for specialists in vibration, rotating machinery, and turbomachinery, it also makes an ideal text for upper-level undergraduate and graduate students in these disciplines.




Air Bearings


Book Description

Comprehensive treatise on gas bearing theory, design and application This book treats the fundamental aspects of gas bearings of different configurations (thrust, radial, circular, conical) and operating principles (externally pressurized, self-acting, hybrid, squeeze), guiding the reader throughout the design process from theoretical modelling, design parameters, numerical formulation, through experimental characterisation and practical design and fabrication. The book devotes a substantial part to the dynamic stability issues (pneumatic hammering, sub-synchronous whirling, active dynamic compensation and control), treating them comprehensively from theoretical and experimental points of view. Key features: Systematic and thorough treatment of the topic. Summarizes relevant previous knowledge with extensive references. Includes numerical modelling and solutions useful for practical application. Thorough treatment of the gas-film dynamics problem including active control. Discusses high-speed bearings and applications. Air Bearings: Theory, Design and Applications is a useful reference for academics, researchers, instructors, and design engineers. The contents will help readers to formulate a gas-bearing problem correctly, set up the basic equations, solve them establishing the static and dynamic characteristics, utilise these to examine the scope of the design space of a given problem, and evaluate practical issues, be they in design, construction or testing.




Turbomachinery Rotordynamics


Book Description

Imparts the theory and analysis regarding the dynamics of rotating machinery in order to design such rotating devices as turbines, jet engines, pumps and power-transmission shafts. Takes into account the forces acting upon machine structures, bearings and related components. Provides numerical techniques for analyzing and understanding rotor systems with examples of actual designs. Features an excellent treatment of numerical methods available to obtain computer solutions for authentic design problems.