Numerical simulation study on flow field and sound field characteristics of pipeline leakage

Pipeline leakage, a prevalent failure mode in pipeline systems, poses substantial detection challenges due to the limited sensitivity of conventional pressure monitoring techniques in identifying minor leaks (especially leak apertures <1 % pipe diameter), particularly under extreme operating conditions (elevated pressure, low temperature, multiphase flow). The detection signals from such micro-leakages exhibit weak energy and strong interference susceptibility, making accurate recognition difficult. The dependency on experimental approaches or empirical formulations frequently proves inadequate in meeting requirements for early warning of micro-leakages, precise localization, or quantitative risk evaluation. This research employs fluid dynamics and aeroacoustic theories to investigate acoustic signature extraction methods for minor gas pipeline leaks, examining pressure differentials, aperture-scale turbulence effects, and flow-acoustic interactions. A comprehensive multi-physics simulation model was developed to characterize micro-leakage-induced acoustic fields, thereby validating high-sensitivity acoustic-based detection methodologies for subtle leak signals. Experimental findings revealed the predominance of quadrupole sources in micro-leak scenarios, demonstrating significant correlations between instantaneous pressure fluctuations, sound pressure levels (SPL), flow velocities, leakage aperture dimensions, and operational pressures. The established sound pressure attenuation pattern along the leakage axis offers critical parameters for identifying faint micro-leak signatures, providing a scientific basis for high-precision monitoring of minor pipeline leaks.