scholarly journals Erratum: “Analysis of an Axial Compressor Blade Vibration Based on Wave Reflection Theory” (Journal of Engineering for Gas Turbines and Power, 1984, 106, pp. 57–64)

1984 ◽  
Vol 106 (4) ◽  
pp. 919-919 ◽  
Author(s):  
J. A. Owczarek
Keyword(s):  
Gas Turbines ◽  
Wave Reflection ◽  
Axial Compressor ◽  
Compressor Blade ◽  
Blade Vibration ◽  
Reflection Theory

Analysis of an Axial Compressor Blade Vibration Based on Wave Reflection Theory

1984 ◽  
Vol 106 (1) ◽  
pp. 57-64 ◽  
Author(s):  
J. A. Owczarek
Keyword(s):  
Rotor Blade ◽  
Wave Reflection ◽  
Axial Compressor ◽  
Compressor Blade ◽  
Rotor Blades ◽  
Wave Reflections ◽  
Blade Vibration ◽  
Blade Vibrations ◽  
Reflection Theory ◽  
Prediction Techniques

The paper describes application of the theory of wave reflection in turbomachines to rotor blade vibrations measured in an axial compressor stage. The blade vibrations analyzed could not be explained using various flutter prediction techniques. The wave reflection theory, first advanced in 1966, is expanded, and more general equations for the rotor blade excitation frequencies are derived. The results of the analysis indicate that all examined rotor blade vibrations can be explained by forced excitations caused by reflecting waves (pressure pulses). Wave reflections between the rotor blades and both the upstream and downstream stator vanes had to be considered.

scholarly journals Detection of Rotor Forced Response Vibrations Using Stationary Pressure Transducers in a Multistage Axial Compressor

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
William L. Murray ◽  
Nicole L. Key
Keyword(s):  
Gas Turbines ◽  
Axial Compressor ◽  
Fast Response ◽  
Forced Response ◽  
Vibration Monitoring ◽  
Blade Vibration ◽  
Response Condition ◽  
Pressure Transducers ◽  
Forcing Function ◽  
Cross Covariance

Blade row interactions in turbomachinery can lead to blade vibrations and even high cycle fatigue. Forced response conditions occur when a forcing function (such as impingement of stator wakes) occurs at a frequency that matches the natural frequency of a blade. The objective of this research is to develop the data processing techniques needed to detect rotor blade vibration in a forced response condition from stationary fast-response pressure transducers to allow for detection of rotor vibration from transient data and lead to techniques for vibration monitoring in gas turbines. This paper marks the first time in the open literature that engine-order resonant response of an embedded bladed disk in a 3-stage intermediate-speed axial compressor was detected using stationary pressure transducers. Experiments were performed in a stage axial research compressor focusing on the embedded rotor of blisk construction. Fourier waterfall graphs from a laser tip timing system were used to detect the vibrations after applying signal processing methods to uncover these pressure waves associated with blade vibration. Individual blade response was investigated using cross covariance to compare blade passage pressure signatures through resonance. Both methods agree with NSMS data that provide a measure of the exact compressor speeds at which individual blades enter resonance.

Compressor Blade Vibration Measurements Using Blade Image Velocimetry

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Paul L. Mikrut ◽  
Scott C. Morris ◽  
Joshua D. Cameron
Keyword(s):  
Mass Flow Rate ◽  
Flow Rate ◽  
Measurement Technique ◽  
Vibration Amplitude ◽  
Axial Compressor ◽  
Compressor Blade ◽  
Shaft Speed ◽  
Blade Vibration ◽  
Air Mass ◽  
Image Velocimetry

This paper discusses the application of a novel vibration measurement technique, termed blade image velocimetry (BIV), to a high-speed axial compressor. Measurements of compressor blade vibration can be difficult to obtain and are critical to aeromechanical design validation. The measurement technique discussed in this paper used a commercial particle image velocimetry (PIV) system and was developed as an alternative to conventional measurement techniques such as strain gages and blade tip timing (BTT). The measurement principles and error analysis are reviewed. Methods for estimating the magnitude of random noise corrupting the measurement and validating the vibration amplitude estimates are presented. The technique was validated using a 1.5 stage axial compressor operating at low shaft speed, where it measured the tip velocity to within 0.02% of the true value. The technique was then used to investigate blade vibration at high shaft speed. Low amplitude vibrations in first bending and first torsion were discovered when the compressor was operated at design air-mass flow rate. These vibrations had a maximum tip deflection of 15μm for bending and 7μm for torsion. The vibration amplitude for first bending and first torsion tripled when the compressor was operated at low air mass-flow rate, corresponding to deep stall. Furthermore, excitation of the third eigenmode was also measured. The maximum tip deflections of the first three eigenmodes when the compressor was operated at deep stall were 47μm, 27μm, and 15μm, respectively.

Fouling on a Multistage Axial Compressor in the Presence of a Third Substance at the Particle/Surface Interface

2018 ◽  
Author(s):  
Nicola Aldi ◽  
Nicola Casari ◽  
Devid Dainese ◽  
Mirko Morini ◽  
Michele Pinelli ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Fluid Dynamic ◽  
Particle Surface ◽  
Axial Compressor ◽  
Micro Particles ◽  
Multistage Compressor ◽  
Particle Ingestion ◽  
The Impact

Solid particle ingestion is one of the principal degradation mechanisms in the compressor and turbine sections of gas turbines. In particular, in industrial applications, the micro-particles not captured by the air filtration system can cause deposits on blades and, consequently, can result in a decrease in compressor performance. It is of great interest to the industry to determine which zones of the compressor blades are impacted by these small particles. However, this information often refers to single stage analysis. This paper presents three-dimensional numerical simulations of the micro-particle ingestion (0.15 μm – 1.50 μm) in a multistage (i.e. eight stage) subsonic axial compressor, carried out by means of a commercial CFD code. Particle trajectory simulations use a stochastic Lagrangian tracking method that solves the equations of motion separately from the continuous phase. The effects of humidity, or more generally, the effects of a third substance at the particle/surface interface (which is considered one of the major promoters of fouling) is then studied. The behavior of wet and oiled particles, in addition to the usual dry particles, is taken into consideration. In the dry case, the particle deposition is established only by using the sticking probability. This quantity links the kinematic characteristics of particle impact on the blade with the fouling phenomenon. In the other two cases, the effect of the presence of a third substance at the particle/surface interface is considered by means of an energy-based model. Moreover, the influence of the tangential impact velocity on particle deposition is analyzed. Introducing the effect of a third substance, such as humidity or oil, the phenomenon of fouling concerns the same areas of the multistage compressor. The most significant results are obtained by combining the effect of the third substance with the effect of the tangential component of the impact velocity of the particles. The deposition trends obtained with these conditions are comparable with those reported in literature, highlighting how the deposits are mainly concentrated in the early stages of a multistage compressor. Particular fluid dynamic phenomena, such as corner separations and clearance vortices, strongly influence the location of particle deposits.

scholarly journals The methodology for measuring the vibration amplitude of the blade of the aircraft engine compressor in the fatigue test

Mechanik ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 230-232
Author(s):  
Leszek Bielenda ◽  
Wojciech Obrocki ◽  
Maciej Masłyk ◽  
Jan Sieniawski
Keyword(s):  
Fatigue Test ◽  
Eddy Current ◽  
Vibration Amplitude ◽  
Aircraft Engine ◽  
Fatigue Tests ◽  
Compressor Blade ◽  
Additional Test ◽  
Blade Vibration ◽  
Comparison Research ◽  
Engine Compressor

Results of comparison research of various sensors types used in the fatigue tests for aircraft engine compressor blade vibration amplitude measurement were analysed. Sensors under tests: inductive, capacitive, eddy-current, laser and vibration. Presented were sensors characteristics and their faults. Additional test stand instrumentation was designed and performed, including mounting bracket.

scholarly journals Observations of Wake-Induced Turbulent Spots on an Axial Compressor Blade

1993 ◽  
Author(s):  
G. J. Walker ◽  
W. J. Solomon ◽  
J. P. Gostelow
Keyword(s):  
Surface Film ◽  
Axial Compressor ◽  
Adverse Pressure Gradient ◽  
Shear Layers ◽  
Compressor Blade ◽  
Ensemble Average ◽  
Transitional Flow ◽  
Instability Wave ◽  
Random Disturbance ◽  
Turbulent Spots

Measurements of transitional flow in regions of strong adverse pressure gradient on an axial compressor stator are reported. The range of observations covers separating laminar flow at transition onset, and reattachment of intermittently turbulent periodically separated shear layers. Transition was characterised by the regular appearance of turbulent spots in association with the rotor blade wake disturbances. However, the initial breakdown did not coincide with the wake passage as has usually been observed by other workers. The spots rather evolved from the growth of instability wave packets which lagged the wake passage. Data presented from the compressor blade measurements include: mean and ensemble-average velocities and associated integral parameters; distributions of total, periodic and random disturbance components; typical individual velocity fluctuation records; contours of ensemble-average random disturbance level; and boundary layer intermittency distributions. Measurements of turbulent intermittency showed a significant fall in this quantity near the wall in the reattaching flow. This has significant implications for the interpretation of transition data from surface film gage observations.

Structural Analysis of a Gas Turbine Axial Compressor Blade Eroded by Online Water Washing

2021 ◽  
Author(s):  
Rossella Cinelli ◽  
Gianluca Maggiani ◽  
Serena Gabriele ◽  
Alessio Castorrini ◽  
Giuliano Agati ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Gas Turbine ◽  
Axial Compressor ◽  
Compressor Blade ◽  
Water Washing

CTV: A New Method for Mapping a Full Scale Prototype of an Axial Compressor

1996 ◽  
Author(s):  
Vasco Mezzedimi ◽  
Pierluigi Nava ◽  
Dave Hamilla
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Theoretical Basis ◽  
Axial Compressor ◽  
Heavy Duty ◽  
Test Vehicle ◽  
Testing Method ◽  
Area Reduction ◽  
Speed Range ◽  
Compressor Inlet

The full mapping of a new gas turbine axial compressor at different speeds, IGV settings and pressure ratios (from choking to surge) has been performed utilizing a complete gas turbine with a suitable set of modifications. The main additions and modifications, necessary to transform the turbine into the Compressor Test Vehicle (CTV), are: - Compressor inlet throttling valve addition - Compressor discharge bleed valve addition - Turbine 1st stage nozzle area reduction - Starting engine change (increase in output and speed range). This method has been successfully employed on two different single shaft heavy-duty gas turbines (with a power rating of 11MW and 170 MW respectively). The paper describes the theoretical basis of this testing method and a specific application with the above mentioned 170 MW machine.

Sign in / Sign up

Export Citation Format

Share Document