Ensuring the integrity and safe operation of gas pipelines and distribution networks is of paramount importance, as leaks can lead to significant economic losses, environmental harm, and safety hazards. Reliable leak detection is therefore a critical component of pipeline operation and monitoring strategies. Among the different approaches, acoustic leak detection techniques have attracted considerable attention due to their non-intrusive nature and potential for real-time implementation. These methods exploit the characteristic noise generated by leakage discharge flow.
This study presents an experimental investigation into the spectral properties of acoustic noise generated by gas leakage through apertures in pressurized pipelines. Emphasis is placed on the dependence of the spectral features on aperture geometric parameters including size, shape, and orientation, as well as on flow hydrodynamic conditions such as discharge flow velocity and internal pipe pressure. The experimental design posed unique challenges, particularly in isolating leak-induced acoustic signals from background flow noise originating upstream of the test section. To address this, a hybrid pipe flow silencer was developed to effectively attenuate unwanted upstream flow noise while preserving the fidelity of the leakage-generated acoustic signals propagating inside the pipe. Furthermore, a precise fabrication methodology was established to create leakage apertures in the pipe wall with high geometric accuracy, ensuring close resemblance to real-life leakage scenarios.
The findings from this study contribute to a more fundamental understanding of the mechanisms governing acoustic noise generation during gas leakage. By elucidating the relationships between leakage geometry, flow conditions, and acoustic spectral characteristics, the work provides a foundation for improving the detection sensitivity and localization accuracy, thereby advancing acoustic leak detection capabilities in gas pipelines.