An Investigation on Failure Analysis of Titanium Gas Turbine Compressor Blades

Several premature failures were occurred in the high-pressure section of an industrial gas turbine compressor due to the fracture of Titanium blade roots. In this work, the failure process of the compressor blades was investigated based on the experimental characterisation. Macro/microfractographic studies were carried out on the fracture surfaces. Optical and scanning electron microscopy of the blade airfoil and root were performed. Mechanical properties of the blade alloy were also evaluated and compared with the standard specifications. The experimental results showed no metallurgical and mechanical defects for the blade materials. Microstructures of the blade root and airfoil as well as the hardness and tensile properties were all comparable with those reported in the standard specification AMS 4928Q. Fractography experiments showed clearly multiple crack initiation sites and fatigue beach marks. Debris particles were observed on the fracture surface of samples and in the mouth of initiated cracks. The blade surface in contact to the disc in the dovetail region showed a higher surface roughness than the other surfaces. Based on the results obtained, the fretting fatigue mechanism was proposed for the premature failures. It was concluded that the stress concentration has been caused by either unsuitable curvature ratio of the disk dovetail, incorrect design of the blade or insufficient distance between the blade root and the disk in dovetail region.

Download Full-text

Study of Wash Fluid Cleaning Effectiveness on Industrial Gas Turbine Compressor Foulants

Volume 5A: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine; Microturbines, Turbochargers, and Small Turbomachines ◽

10.1115/gt2013-94510 ◽

2013 ◽

Cited By ~ 3

Author(s):

Agbadede Roupa ◽

Pericles Pilidis ◽

Isaiah Allison ◽

Paul Lambart

Keyword(s):

Wind Tunnel ◽

Crude Oil ◽

Gas Turbine ◽

Compressor Cascade ◽

Compressor Blades ◽

Advanced Method ◽

Full Speed ◽

Gas Turbine Compressor ◽

Industrial Gas Turbine

Online compressor washing is an advanced method of mitigating the effects of fouling as well as to increase the interval between offline washes. The major concern with online compressor washing has been its cleaning effectiveness, since it is carried out when the engine is running at full or near full speed. Hence, injecting wash fluid into the compressor to achieve an efficient cleaning is a challenge. This work investigates the most appropriate wash fluid for cleaning a particular type of foulant. Contaminants found on the surface of the compressor blades are of different composition; if the correct wash fluid is not selected, efficient cleaning cannot be achieved. In this study, wash fluids are applied to different compositions of foulants in a wind tunnel compressor cascade to ascertain their effectiveness in removing foulants. The research demonstrates that aqueous surfactant wash fluid is more effective for removing foulants composed of crude oil and carborundum particles.

Download Full-text

A Statistical Study on HCF Validation Data for Axial Gas Turbine Compressor Blades

10.1115/1.0002506v ◽

2021 ◽

Author(s):

Lukas Schuchard ◽

Stefano Cerutti ◽

Matthias Voigt ◽

Ronald Mailach

Keyword(s):

Gas Turbine ◽

Statistical Study ◽

Compressor Blades ◽

Validation Data ◽

Gas Turbine Compressor

Download Full-text

Failure Investigation of Frame 6FA Gas Turbine Compressor Blades

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-015-0775-6 ◽

2015 ◽

Vol 69 (2) ◽

pp. 647-651 ◽

Cited By ~ 1

Author(s):

M. Swamy ◽

Kulvir Singh ◽

A. H. V. Pavan ◽

Antony Harison M. C. ◽

G. Jayaraman

Keyword(s):

Gas Turbine ◽

Compressor Blades ◽

Failure Investigation ◽

Gas Turbine Compressor

Download Full-text

Numerical Simulation of Blade Fault Signatures From Unsteady Wall Pressure Signals

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2815583 ◽

1997 ◽

Vol 119 (2) ◽

pp. 362-369 ◽

Cited By ~ 4

Author(s):

V. Dedoussis ◽

K. Mathioudakis ◽

K. D. Papailiou

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Gas Turbine ◽

Wall Pressure ◽

Operating Point ◽

Calculation Time ◽

Rotating Blades ◽

Time Signals ◽

Gas Turbine Compressor ◽

Industrial Gas Turbine

A method for establishing signatures of faults in the rotating blades of a gas turbine compressor is presented. The method employs a panel technique for the calculation of the flow field around blade cascades, with disrupted periodicity, a situation encountered when a blade fault has occurred. From this calculation, time signals of the pressure at a location on the casing wall, facing the rotating blades, are constituted. Processing these signals, in combination with “healthy” pressure signals, allows the constitution of fault signatures. The proposed method employs geometric data, as well as data about the operating point of the engine. It gives the possibility of establishing the fault signatures without the need of performing experiments with implanted faults. The successful application of the method is demonstrated by comparison of signatures obtained by simulation to signatures derived from experiments with implanted blade faults, in an industrial gas turbine.

Download Full-text

Optimizing Automated Gas Turbine Fault Detection Using Statistical Pattern Recognition

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education ◽

10.1115/92-gt-029 ◽

1992 ◽

Author(s):

E. Loukis ◽

K. Mathioudakis ◽

K. Papailiou

Keyword(s):

Decision Making ◽

Pattern Recognition ◽

Gas Turbine ◽

Statistical Pattern Recognition ◽

Dynamic Measurements ◽

Statistical Pattern ◽

Gas Turbine Compressor ◽

Industrial Gas Turbine ◽

Spectral Patterns ◽

Automated Decision Making

A method enabling the automated diagnosis of Gas Turbine Compressor blade faults, based on the principles of statistical pattern recognition is initially presented. The decision making is based on the derivation of spectral patterns from dynamic measurements data and then the calculation of discriminants with respect to reference spectral patterns of the faults while it takes into account their statistical properties. A method of optimizing the selection of discriminants using dynamic measurements data is also presented. A few scalar discriminants are derived, in such a way that the maximum available discrimination potential is exploited. In this way the success rate of automated decision making is further improved, while the need for intuitive discriminant selection is eliminated. The effectiveness of the proposed methods is demonstrated by application to data coming from an Industrial Gas Turbine while extension to other aspects of Fault Diagnosis is discussed.

Download Full-text

Determination of Vibration Amplitudes and Stresses Using the Holography Interference Techniques and Finite Element Method

Journal of Vibration and Acoustics ◽

10.1115/1.3269132 ◽

1983 ◽

Vol 105 (4) ◽

pp. 484-488 ◽

Cited By ~ 1

Author(s):

Z. F. Fu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Gas Turbine ◽

Strain Gage ◽

Present Method ◽

The Finite Element Method ◽

Compressor Blades ◽

Gas Turbine Compressor ◽

Element Method

A new method which combines the holography interference technique with the finite element method for determining the distribution of vibration amplitudes and stresses of gas turbine compressor blades is presented in this paper. In comparison with the ordinary electrical strain gage method, the present method has the advantage that there is no limitation to the number of measuring points and good results can be obtained even at high order modes.

Download Full-text

Vibration Amplitudes of Compressor Blades Resulting From Scatter in Blade Natural Frequencies

Journal of Engineering for Power ◽

10.1115/1.3574726 ◽

1969 ◽

Vol 91 (3) ◽

pp. 182-187 ◽

Cited By ~ 75

Author(s):

R. C. F. Dye ◽

T. A. Henry

Keyword(s):

Gas Turbine ◽

Natural Frequency ◽

Natural Frequencies ◽

Model Analysis ◽

Lumped Parameter Model ◽

Compressor Blades ◽

Lumped Parameter ◽

Gas Turbine Compressor ◽

Flexible Disk

Intercoupling between blades mounted on a flexible disk is examined employing a lumped-parameter model incorporating damping. Tests carried out on a gas turbine compressor and blades provide frequency and mass parameters for the model. Analysis of the model shows that vibration, and hence stress, in one or more blades, can be magnified if the distribution of blade natural frequency around the disk is suitably chosen. Feasible distributions are examined, leading to stress increases of up to 180 percent.

Download Full-text