Next-Generation Modeling, Analysis, and Testing of the Vibration of Mistuned Bladed Disks

Next-Generation Modeling, Analysis, and Testing of the Vibration of Mistuned Bladed Disks

Author:

Publisher:

Published: 2007

Total Pages: 27

ISBN-13:

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Turbomachinery rotors, or bladed disks, are known to suffer from severe vibration problems due to small, random deviations (mistuning) of the blade properties. Mistuning can lead to dramatic increases in the maximum blade stress and cause high cycle fatigue (HCF), which is a major cost, readiness, and safety concern for the U.S. Air Force. The primary objective of this research was to provide significantly improved understanding, modeling, and prediction of the vibration response of mis-tuned bladed disk systems by including the effects of important phenomena that had been largely neglected in previous mistuning models. The models developed in this research program were used to investigate the interaction of blade mistuning with aerodynamic coupling, stage-to-stage connections for multistage rotors, blade damage, and nonlinearities. In addition, key mistuning phenomena were examined through vibration testing of blisks (single-piece bladed disks). New methods were developed for identifying blade mistuning parameters from test data and for running experimental Monte Carlo assessments of the effects of mistuning on the system forced response.


Turbomachine Blade Vibration

Turbomachine Blade Vibration

Author: J. S. Rao

Publisher: New Age International

Published: 1991

Total Pages: 466

ISBN-13: 9788122403046

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Fatigue Failures Of Blades Is One Of The Most Vexing Problems Of Turbomachine Manufacturers, Ever Since The Steam Turbine Became The Main Stay For Power Generating Equipment And Gas Turbines Are Increasingly Used In The Air Transport. The Problem Is Very Complex, Involving The Excitation Due To Aerodynamic Stage Interaction; Damping Due To Material Deformation, Friction At Slip Surfaces And Aerodynamic Damping; Vibration Of An Asymmetric Aerofoil Tapered Along Its Length And Mounted On A Rotating Disc At A Stagger Angle. The Problem Is Also Governed By Heat Transfer Analysis And Thermal Stresses.His Book Deals With A Basic Understanding Of Free Vibratory Behaviour Of Turbine Blades- Free Standing, Packetted, And Bladed-Discs. The Analysis Is Based On Continuous And Discrete Models Using Energy Principles And Finite Element Techniques. A Clear Understanding Of The Interference Phenomenon In A Thin Cambered Airfoil Stage In Subsonic Flow Is Presented To Determine The Nonsteady Excitation Forces Acting On The Blades. A Comprehensive Treatment On The Blade Damping Phenomenon That Occurs In Turbines Is Given. The Nonlinear Damping Models Account For Material Damping And Friction Damping As A Function Of Rotational Speed For Each Mode. Resonant Response Calculation Procedures For The Steadily Running As Well As Accelerating Blades Are Given.Cumulative Damage Calculations Are Then Outlined For Fatigue Life Estimation Of Turbomachine Blades. The Book Also Deals With Heat Transfer Analysis And Thermal Stress Calculations Which Help In A Comprehensive Understanding Of The Blade Problems.


Blade Design and Analysis for Steam Turbines

Blade Design and Analysis for Steam Turbines

Author: Murari P. Singh

Publisher: McGraw Hill Professional

Published: 2011-03-22

Total Pages: 384

ISBN-13: 0071635734

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THE LATEST STEAM TURBINE BLADE DESIGN AND ANALYTICAL TECHNIQUES Blade Design and Analysis for Steam Turbines provides a concise reference for practicing engineers involved in the design, specification, and evaluation of industrial steam turbines, particularly critical process compressor drivers. A unified view of blade design concepts and techniques is presented. The book covers advances in modal analysis, fatigue and creep analysis, and aerodynamic theories, along with an overview of commonly used materials and manufacturing processes. This authoritative guide will aid in the design of powerful, efficient, and reliable turbines. COVERAGE INCLUDES: Performance fundamentals and blade loading determination Turbine blade construction, materials, and manufacture System of stress and damage mechanisms Fundamentals of vibration Damping concepts applicable to turbine blades Bladed disk systems Reliability evaluation for blade design Blade life assessment aspects Estimation of risk