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Keywords: vibrations
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Journal Articles
Article Type: Research Papers
J. Turbomach. July 2012, 134(4): 041001.
Published Online: July 19, 2011
... finite element analysis Monte Carlo methods reduced order systems rotors statistical distributions vibrations Substituting Eq. 3 into Eq. 1 and premultiplying by Φ H , the reduced order model is obtained as follows: 5 M r y ̈ + K r y = 0 where 6 M r...
Journal Articles
Article Type: Technical Briefs
J. Turbomach. July 2012, 134(4): 044501.
Published Online: July 19, 2011
...Y.-J. Chan; D. J. Ewins Integral bladed disks (also known as blisks) are more widely used in modern aeroengine compressor designs because of the potential weight savings, but there are challenges in controlling the extreme vibration response levels in mistuned blisks, which are blisks with blades...
Journal Articles
Article Type: Research Papers
J. Turbomach. October 2011, 133(4): 041030.
Published Online: April 27, 2011
...Jean Thomassin; Huu Duc Vo; Njuki W. Mureithi Nonsynchronous vibration (NSV) is a particular type of aero-elastic phenomenon, where the rotor blades vibrate at nonintegral multiples of the shaft rotational frequencies. NSV behavior appears similar to off-design stall flutter but with a particular...
Journal Articles
Article Type: Research Papers
J. Turbomach. April 2011, 133(2): 021016.
Published Online: October 22, 2010
... on the blade vibrations observed in the first rotor of a multistage high pressure compressor. The cause of vibrations, whose frequencies were “not in resonance with the engine speed,” was referred to as a “rotating instability,” in which a sound source, which propagates relative to the rotor “is presumably...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2011, 133(1): 011016.
Published Online: September 22, 2010
... temperature measurement vibrations Contemporary gas turbines rely on complex blade-casing rub-in-systems to improve the tip clearance behavior during operation from initial service to maximum lifetime ( 1 2 ). The rather complex endwall flow field region associated with the compression system...
Journal Articles
Article Type: Research Papers
J. Turbomach. July 2009, 131(3): 031007.
Published Online: April 8, 2009
... for an academic rotor are presented to establish the validity of the technique. 22 07 2007 22 02 2008 08 04 2009 blades discs (structures) geometry reduced order systems rotors vibrations Mistuning refers to inevitable variations in blades’ properties, which arise during...
Journal Articles
Article Type: Research Papers
J. Turbomach. July 2009, 131(3): 031002.
Published Online: April 2, 2009
...T. Klauke; A. Kühhorn; B. Beirow; M. Golze Blade-to-blade variations of bladed disk assemblies result in local zoning of vibration modes as well as amplitude magnifications, which primarily reduces the high cycle fatigue life of aeroengines. Criteria were introduced to determine the level...
Journal Articles
Article Type: Research Papers
J. Turbomach. April 2009, 131(2): 021016.
Published Online: January 29, 2009
... sensible to the addition of small perturbations such as the aerodynamic forces. Since the determination of the aerodynamic vibrational correction (damping and frequency) requires knowing the mode shape, the aerodynamic corrections of the N a − 1 cluster modes are now unavoidably coupled together. Moreover...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2009, 131(1): 011013.
Published Online: October 28, 2008
...Jean Thomassin; Huu Duc Vo; Njuki W. Mureithi This paper investigates the role of tip clearance flow in the occurrence of nonsynchronous vibrations (NSVs) observed in the first axial rotor of a high-speed high-pressure compressor in an aeroengine. NSV is an aeroelastic phenomenon where the rotor...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2009, 131(1): 011009.
Published Online: October 17, 2008
... during vibration, causing the first axial bending mode to carry an increased, out of phase, torsional component. It is shown that this change in mode shape, compared to an unshrouded LSMB, can lead to destabilizing aerodynamic forces during vibration. At a sufficiently high mass flow, the destabilizing...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2009, 131(1): 011011.
Published Online: October 17, 2008
... and ( b ) blade-by-blade damping breakdown, − 4 ND mode, lightly damped, ABM Rotor X 20 06 2007 19 07 2007 17 10 2008 aerodynamics blades computational fluid dynamics discs (structures) elasticity flexible structures rotors vibrations The object of any...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2008, 130(1): 011013.
Published Online: January 25, 2008
... with ANSYS and experimental results as well. In Fig. 17 , statistics of natural frequencies are presented. Standard deviations predicted by the POD method compare very well with experimental results for few modes of vibration. For many modes of vibration, standard deviations of natural frequencies...
Journal Articles
Article Type: Research Papers
J. Turbomach. January 2008, 130(1): 011002.
Published Online: December 14, 2007
...J. Szwedowicz; R. Visser; W. Sextro; P. A. Masserey Numerical predictions of the forced vibration of a disk assembly including frictional effects between the shrouds are presented concerning engineering needs for the blade design process. Assuming a tuned disk assembly, numerical static, free...
Journal Articles
Article Type: Research Papers
J. Turbomach. October 2007, 129(4): 730–739.
Published Online: August 15, 2006
...M. Nikolic; E. P. Petrov; D. J. Ewins The problem of estimating the mutual interaction of the effects of Coriolis forces and of blade mistuning on the vibration characteristics of bladed disks is addressed in this paper. The influence of different degrees of mistuning on forced response...
Journal Articles
Article Type: Technical Papers
J. Turbomach. July 2007, 129(3): 495–502.
Published Online: July 25, 2006
...E. P. Petrov A method has been developed to calculate directly resonance frequencies and resonance amplitudes as functions of design parameters or as a function of excitation levels. The method provides, for the first time, this capability for analysis of strongly nonlinear periodic vibrations...
Journal Articles
Article Type: Technical Briefs
J. Turbomach. January 2006, 128(1): 206–210.
Published Online: August 1, 2005
...Sang-Ho Lim; Christophe Pierre; Matthew P. Castanier The forced vibration response of bladed disks can increase dramatically due to blade mistuning, which can cause major durability and reliability problems in turbine engines. To predict the mistuned forced response efficiently, several reduced...
Journal Articles
Article Type: Technical Papers
J. Turbomach. April 2007, 129(2): 412–420.
Published Online: June 3, 2005
... into account by including all stator bladerows of interest. The low engine-order excitation that could arise from a blocked passage was investigated next. It was shown that high vibration response could arise in such cases. 11 02 2004 03 06 2005 compressors turbomachinery Navier-Stokes...
Journal Articles
Article Type: Technical Papers
J. Turbomach. April 2005, 127(2): 412–421.
Published Online: May 5, 2005
...A. J. Sanders This paper describes the identification and prediction of a new class of nonsynchronous vibration (NSV) problem encountered during the development of an advanced design composite fan stator for an aircraft engine application. Variable exhaust nozzle testing on an instrumented engine...
Journal Articles
Article Type: Technical Papers
J. Turbomach. January 2005, 127(1): 128–136.
Published Online: February 9, 2005
...E. P. Petrov; D. J. Ewins An efficient method for analysis of nonlinear vibrations of mistuned bladed disk assemblies has been developed. This development has facilitated the use of large-scale finite element models for realistic bladed disks, used hitherto in analysis of linear vibration...
Journal Articles
Article Type: Technical Papers
J. Turbomach. July 2006, 128(3): 528–535.
Published Online: February 1, 2005
... between the observed structures and those from vortex shedding in some other physical situations, such as the vortex wakes shed from cylinders and airfoils in sinusoidal heaving motion in low-speed flow. The established field of vortex-induced vibration has provided a developed classification scheme...