Vibration Analysis of Elastic Uniform Cantilever Rotor Blades in Unsteady Aerodynamics Modeling

2010 ◽  
Vol 47 (4) ◽  
pp. 1430-1435 ◽  
Author(s):  
Mir Y. Ziabari ◽  
Behzad Ghadiri
Keyword(s):  
Vibration Analysis ◽  
Unsteady Aerodynamics ◽  
Rotor Blades

Deformation and vibration analysis of compressor rotor blades based on fluid-structure coupling

2021 ◽  
Vol 122 ◽  
pp. 105216
Author(s):  
Hai'ou Sun ◽  
Aoyu Ren ◽  
Yanhua Wang ◽  
Mingfei Zhang ◽  
Tao Sun
Keyword(s):  
Vibration Analysis ◽  
Rotor Blades ◽  
Fluid Structure ◽  
Compressor Rotor

Vibration Analysis of Rotor Blades with Pendulum Absorbers

1981 ◽  
Vol 18 (1) ◽  
pp. 23-29 ◽  
Author(s):  
V. R. Murthy ◽  
C. E. Hammond
Keyword(s):  
Vibration Analysis ◽  
Rotor Blades

Influence of the Blade Count Ratio on Aerodynamic Forcing: Part II—High Pressure Transonic Turbine

2011 ◽  
Author(s):  
Florian Fruth ◽  
Damian M. Vogt ◽  
Torsten H. Fransson
Keyword(s):  
High Pressure ◽  
Rotor Blade ◽  
Linear Time ◽  
Unsteady Aerodynamics ◽  
Rotor Blades ◽  
Mode Shapes ◽  
Monotonic Trend ◽  
Count Ratio ◽  
Mode Excitation ◽  
Transonic Turbine

The influence of the Blade Count Ratio (BCR) on the aerodynamic forcing of a transonic high pressure turbine has been investigated numerically. Main focus here was put on the change in unsteady aerodynamics, modal properties and the mode excitation. Using a scaling technique, six different transonic turbine stages with different numbers of scaled blades but maintained steady aerodynamics were generated and further analyzed. In the analysis a non-linear, time marching CFD solver was used and the unsteady, harmonic forces projected onto the mode shapes. For this transonic turbine the unsteady pressure at the rotor blade decreases in amplitude and spanwise distribution from low to high blade count ratios. In chordwise direction a local minimum for intermediate blade count ratios was found for the rotor and stator blades. Mode frequencies decreased monotonically with an increasing BCR. Significant mode changes for modes 5 and 6 of the different BCRs were captured using the Modal Assurance Criteria. It was found that for these transonic turbines the blade count ratio and reduced frequency are amongst others key parameters for a reduction in aerodynamic forcing. Even though an almost monotonic trend was found for the stator blade excitation, the rotor blade excitation behaves highly non-monotonic. A maximum value in excitation potential was found close to reported blade count ratio values. Optimization of certain modes is possible but case dependent, due to the non-monotonic nature. Moreover it was found that for a minor increase in upstream blade count the mean unsteady forces on the rotor blades is reduced, but the mode excitation not necessarily has to decrease.

Unsteady Aerodynamics on Multi-Passage LP Last Stage Induced by Flow Separation Under Low Load Flow

2019 ◽  
Author(s):  
Jing Zhang ◽  
Danmei Xie ◽  
Fan Wu ◽  
Haifen Du ◽  
Wei Chen
Keyword(s):  
Flow Separation ◽  
Optimization Design ◽  
Rapid Development ◽  
Unsteady Aerodynamics ◽  
Load Flow ◽  
Rotor Blades ◽  
Time Step ◽  
Unsteady Pressure ◽  
Low Load ◽  
Last Stage

Abstract With the rapid development of renewable energy generation, the requirement for operational flexibility of power plants has increased. This has led to steam turbine operating frequently at low load flow conditions. This paper focuses on the investigation of unsteady aerodynamic excitation in the last stage of LP under low load flow, which was conducted by assuming one single passage, to provide detailed flow information for optimization design. We present a numerical investigation of unsteady pressure forces on Multi-passage LP last blade rows caused by flow separation under low load flow. The flow field of the turbine was calculated by transient 3D computational fluid dynamic (ANSYS CFX16.0). The results indicate the vortex strength induced by high incidence angle under low load flow having the characteristic of spatial non-uniformity and time non-uniformity. We found that the unsteady pressure forces on the rotor are significantly influenced by the separation vortex and have different phase pressure fluctuation between neighboring two rotor blades. The variation in the forces indicates that the neighboring rotor blades experience a load imbalance at every time step which may results in oscillation in the last long moving blades. In particular, the tip vortex plays a crucial part in unsteady aerodynamics.

Rotor Blade Unsteady Aerodynamic Gust Response to Inlet Guide Vane Wakes

1993 ◽  
Vol 115 (1) ◽  
pp. 197-206 ◽  
Author(s):  
S. R. Manwaring ◽  
S. Fleeter
Keyword(s):  
Rotor Blade ◽  
Guide Vane ◽  
Axial Flow ◽  
Unsteady Aerodynamics ◽  
Rotor Blades ◽  
Inlet Guide Vane ◽  
Unsteady Aerodynamic ◽  
Forcing Function ◽  
Reduced Frequency ◽  
Flow Compressor

A series of experiments is performed in an extensively instrumented axial flow research compressor to investigate the fundamental flow physics of wake-generated periodic rotor blade row unsteady aerodynamics at realistic values of the reduced frequency. Unique unsteady data are obtained that describe the fundamental unsteady aerodynamic gust interaction phenomena on the first-stage rotor blades of a research axial flow compressor generated by the wakes from the inlet guide vanes. In these experiments, the effects of steady blade aerodynamic loading and the aerodynamic forcing function, including both the transverse and chordwise gust components, and the amplitude of the gusts, are investigated and quantified.

Multistage Coupling of Eight Mistuned Bladed Disk on a Solid Shaft: Part 1—Free Vibration Analysis

2012 ◽  
Author(s):  
Romuald Rzadkowski ◽  
Artur Maurin
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Free Vibrations ◽  
Rotor Blades ◽  
Mode Shapes ◽  
Bladed Disk ◽  
Centrifugal Stiffening

Considered here was the effect of multistage coupling on the dynamics of a rotor consisting of eight mistuned bladed discs on a solid shaft. Each bladed disc had a different number of rotor blades. Free vibrations were examined using finite element representations of rotating single blades, bladed discs, and the entire rotor. In this study the global rotating mode shapes of eight flexible mistuned bladed discs on shaft assemblies were calculated, taking into account rotational effects such as centrifugal stiffening. The thus obtained natural frequencies of the blade, shaft, bladed disc and entire shaft with discs were carefully examined to discover resonance conditions and coupling effects. This study found that mistuned systems cause far more intensive multistage coupling than tuned ones. The greater the mistuning, the more intense the multistage coupling.

scholarly journals Numerical and Experimental Vibration Analysis of a Steam Turbine Rotor Blade

2021 ◽  
Vol 15 (4) ◽  
pp. 462-466
Author(s):  
Marko Katinić ◽  
Marko Ljubičić
Keyword(s):  
Numerical Model ◽  
Modal Analysis ◽  
Steam Turbine ◽  
Vibration Analysis ◽  
Rotor Blade ◽  
High Reliability ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Turbine Rotor Blade ◽  
Computer Environment

Damage to the rotor blade of a steam turbine is a relatively common problem and is one of the leading causes of sudden and unplanned shutdowns of a steam turbine. Therefore, the high reliability of the rotor blades is very important for the safe and economical operation of the steam turbine. To ensure high reliability, it is necessary to perform a vibration analysis of the rotor blades experimentally and in a computer environment. In this paper, a modal analysis was performed on the twisted blade of the last stage of the turbine in the Ansys software. The results of the modal analysis of the stationary rotor blade were compared with the results obtained by the bump test, which confirmed the numerical model of the blade. A modal analysis of a rotating rotor blade was performed on the same numerical model, and Campbell diagrams were plotted to determine the critical speed

scholarly journals Vibration Analysis of Rotor Blades of a Farm Wind-Power Plant

2012 ◽  
Vol 17 (2) ◽  
pp. 164-175 ◽  
Author(s):  
K. Gürsel ◽  
Tufan Çoban ◽  
Aydogan Özdamar
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Vibration Analysis ◽  
Rotor Blades ◽  
Wind Power Plant
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