Blade faults diagnosis in multi stage rotor system by means of wavelet analysis

Thesis (PhD. (Mechanical Engineering))

Bibliographic Details
Main Author: Abdelrhman Ahmed, Ahmed Mohammed
Format: Thesis
Language:English
Published: Universiti Teknologi Malaysia 2024
Subjects:
Online Access:https://openscience.utm.my/handle/123456789/1463
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author Abdelrhman Ahmed, Ahmed Mohammed
author_facet Abdelrhman Ahmed, Ahmed Mohammed
author_sort Abdelrhman Ahmed, Ahmed Mohammed
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description Thesis (PhD. (Mechanical Engineering))
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institution Universiti Teknologi Malaysia - OpenScience
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spelling oai:openscience.utm.my:123456789/14632024-12-16T13:00:32Z Blade faults diagnosis in multi stage rotor system by means of wavelet analysis Abdelrhman Ahmed, Ahmed Mohammed Blades Thesis (PhD. (Mechanical Engineering)) Blade fault is one of the most causes of gas turbine failures. Vibration spectral analysis and blade pass frequency (BPF) monitoring are the most widely used methods for blade fault diagnosis. These methods however have limitations in the detection of incipient faults due to weak and/or transient signals, as well as inability to diagnose the blade faults types. This study investigates the applications of wavelet analysis in blade fault diagnosis of a multi stage rotor system, as an extension of previous works which involved a single stage only. Results showed that conventional wavelet analysis has limitations in segregating the BPFs and locating the faults. An improvement in Morlet wavelet was made to achieve high resolution in both time and frequency domains. Two new wavelets for high time-frequency resolutions were formulated and added to the standard MATLAB Wavelet Toolbox. The optimal parameters for the high frequency resolution wavelet were found at the centre of frequency, ????=4 and bandwidth, ??=0.5. For high time resolution wavelet, the optimal parameters were ????=4 and ??=10. A novel algorithm was formulated by combining the two newly developed wavelets. A variety of blade faults including blade creep rubbing, blade tip rubbing, stage rubbing, blade loss of part and blade twisting were tested and their vibration responses measured in a laboratory test facility. The proposed method showed potential in segregating closely spaced BPFs components and identifying the faulty stage and fault location. The method demonstrated the ability in differentiating various blade faults based on a unique pattern (“fingerprint”) of each fault produced by the newly added wavelet. The formulated algorithm was demonstrated to be suitable in monitoring rotor systems with multiple blade stages Faculty of Mechanical Engineering 2024-12-16T04:48:22Z 2024-12-16T04:48:22Z 2014 Thesis Dataset https://openscience.utm.my/handle/123456789/1463 en application/pdf application/pdf application/pdf Universiti Teknologi Malaysia
spellingShingle Blades
Abdelrhman Ahmed, Ahmed Mohammed
Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title_full Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title_fullStr Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title_full_unstemmed Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title_short Blade faults diagnosis in multi stage rotor system by means of wavelet analysis
title_sort blade faults diagnosis in multi stage rotor system by means of wavelet analysis
topic Blades
url https://openscience.utm.my/handle/123456789/1463
work_keys_str_mv AT abdelrhmanahmedahmedmohammed bladefaultsdiagnosisinmultistagerotorsystembymeansofwaveletanalysis