Fatigue failure of centrifugal compressor impellers: A comprehensive review

Fatigue failure can be considered as the main failure mode of impellers in various kinds of turbomachinery, especially centrifugal compressors. Studying and understanding the fatigue failure mechanism is a milestone in the structural design and optimization of centrifugal compressor impellers. Having a sound knowledge of fatigue failure mechanism, and how it starts, develops and leads to fracture, equips turbomachinery engineers and researchers with new reliable design criteria, enabling them to predict and prevent future potential failures. This paper presents a comprehensive review of fatigue failure of centrifugal compressor impellers considering numerous case studies and research papers. Different factors contributing to fatigue failure of centrifugal compressor impellers are first classified as internal and external factors and then investigated separately by reviewing extensive failure case reports and research papers. High cycle fatigue (HFC) is the most prevalent failure mode in centrifugal impellers which occurs as a result of high-frequency, low-amplitude vibration due to impeller-diffuser interaction or upstream flow distortions. Low cycle fatigue (LCF), having the second rank, happens mainly because of high mechanical stress and/or primary resonant vibration which are due to improper design or successive loading, unbalanced operation, installation error, or variation in the operating condition of the compressor. On the other hand, corrosive medium, high temperature, and microstructural and manufacturing defects degrade material properties and fatigue resistance, facilitating and precipitating fatigue failure. The current study aims to bring up an encyclopedic, yet detailed review of fatigue failure of centrifugal compressor impellers suitable for both academic and industrial research.