Systematic review for fluid pipeline leakage monitoring: present status and challenges of acoustic emission technique

Acoustic emission (AE) technique stands as a cutting-edge, real-time, and exquisitely sensitive method for structural health monitoring, offering unparalleled insight into the operational status of pipeline integrity. It vigilantly tracks the lifecycle of cracks within pipelines, from their nascent stages to their eventual leakage, and even catastrophic double-end shear failures. By swiftly detecting strain energy release and correlating the data with relevant physical events that occur within the monitored structure, the AE technique acts as a sentinel for a safe, stable, and efficient operation of large complex systems under full-load and high-quality conditions. Despite a wealth of scientific inquiries into AE signatures of pipeline leakage, it is still lacking in providing a systematic and comprehensive compilation of the works that contribute to advancing the specific area of research. Therefore, this paper aims to address the gap by delving into the genesis of jet formation in pipeline leakage. It provides a thorough overview of the current numerical and experimental methodologies for pipeline leakage, and meticulously outlines the state-of-the-art in applying AE-based techniques for detection, localization, and quantification of fluid pipeline leakage. Through rigorous evaluation of the strengths and weaknesses of the prevalent AE signal processing techniques and analysis methods for the featured AE parameters, this review not only maps out the existing landscape but also forecasts future trajectories and challenges associated with effective implementation of AE monitoring technique. The goal of this review is to equip practitioners with the essential theoretical and analytical frameworks, as well as technical strategies necessary for advancing the frontiers of on-site fluid pipeline leakage monitoring.