Numerical Research of Pipeline Leakage Sound Field Based on Acoustic Emission Technique

Pipeline leak is an important factor for affecting the safe operation of the oil and gas gathering and transportation system. Acoustic Emission (AE) technique is an effective means of pipeline leak detection. Analysis of the characteristics of the sound source and the transmission mechanism of AE signals caused by leakage can be one of the important conditions that ensure the efficiency and accuracy of detection. The paper was based on the Lighthill aeroacoustic theory, combined the numerical simulation with experimental study, used computational fluid dynamics software Fluent and acoustic software LMS Virtual Lab to simulate the flow field and the sound field of pipeline leakage, and analyzed them in time domain and frequency domain to provide guidance for the acoustic emission pipeline leak detection. First of all, the dipole and quadrupole source at the pipe leak hole were respectively selected. The pipeline leak fluid velocity and noise directivity pattern were analyzed to determine the sound source type. And then the comparative analysis of pipeline leak sound field distribution with pipe wall vibration and no pipe wall vibration was conducted. The AE experiment data verified the necessity of acoustic vibration coupling on the calculation model. Finally, taking the pipe wall as a boundary, the inside and outside pipe acoustic model was established to study the pipeline leakage sound field distribution when the medium outside the pipe was respectively air, water and soil. The AE technique was used to detect pipeline leakage to verify simulation results.