Multi-modal identification of leakage-induced acoustic vibration in gas-filled pipelines by selection of coherent frequency band

Abstract

Leak location using correlation-based acoustic method is a common practice in gas-filled pipelines, which will be extremely effective when the leakage-induced acoustic wave has a constant propagation speed. This premise is often not satisfied as result of multi-modal and dispersive nature which will cause acoustic speed to vary with frequency and modal type. In this work, the multi-modal identification based on selection of coherent frequency band is proposed for improving leak location in gas pipelines. The dispersive and multi-modal characteristics are studied by theory analysis and experimental validation to give understanding of the reason that correlation-based leak location has a larger error at times. The results demonstrate that the multi-modal type can be identified from law of acoustic speed variation by selection of coherent frequency band and multi-modal and dispersive characteristics are the main cause of a larger leak location error.