Jet noise characterization for advanced pipeline leak detection

The detection of leaks in pipeline transportation systems is a matter of serious concern for operators, who pursue the integrity of their assets, the reduction of losses and the prevention of environmental hazards. Whenever a hole occurs in a pressurized pipeline, the corresponding fluid leakage is characterized by a turbulent flow and a peculiar acoustic noise, whose characteristics depend also on the size of the hole itself. This study shows that both the presence and the size of such a leaking hole can be successfully detected, by exploiting the acoustic noise (pressure transients) generated by the fluid exiting the pipe and recorded internally by hydrophones, or by considering the corresponding vibrations (e.g., acceleration signals) propagating along the external shell of the conduit. To this purpose, several experimental campaigns of acoustic noise generation have been performed using multiple calibrated nozzles on a 16 ID connection pipeline in a fuel tanks area. Detection and classification procedures are proposed to control the presence of leakages and to estimate the size of the hole, using pressure and vibration signals.