输气管道泄漏音波产生机理研究

为研究输气管道音波法泄漏检测技术的基本原理和应用方法，对输气管道中泄漏音波的产生机理进行了研究。首先从理论上确定输气管道气动噪声的产生机理；其次将仿真模拟得到四极子声源和偶极子声源产生的泄漏音波进行分析并总结规律；再次将音波传感器测得泄漏音波与仿真模拟得到的泄漏音波进行对比验证；然后对比分析多工况条件下仿真模拟和实验方法得到的泄漏音波；最后通过分析仿真模拟中泄漏音波产生机理和实验中所用的音波传感器的工作机理总结输气管道音波法泄漏检测技术的基本原理。研究结果表明：输气管道泄漏音波产生的根本原因是气体泄漏时产生的湍流脉动导致的四极子声源和偶极子声源；实验中音波传感器测得的压力波动主要成分为声源产生的音波波动；仿真模拟和实验的方法可以研究输气管道泄漏音波的产生机理。

Study on Leak-Acoustics Generation Mechanism for Natural Gas Pipelines

In order to study the law and the use of leak detection and location for gas pipelines based on acoustic method, a research is made on leak-acoustics generation mechanism for natural gas pipelines. First the aero-acoustics generation mechanism is ensured in theory so that the wave equation of sources can be concluded when gas pipelines are leaking. Secondly, the leak-acoustics which are generated by the quadrupole sonic sources and the dipole sonic sources are simulated to analyze the law of their characteristics. Thirdly the leak-acoustics are acquired by experiments as the same conditions as the simulation after which the leak-acoustics simulated are compared with the experimental leak-acoustics to testify the simulation method. And then the comparative analyses are accomplished between the leak-acoustics simulated and the leak-acoustics acquired by experiments under variable operating conditions. At last the law and the use of leak detection and location for gas pipelines based on acoustic method are concluded after analyzing the leak-acoustics generation mechanism and the working principle of dynamic pressure sensors. The results indicate that it is the quadrupoles and the dipoles generated by turbulent fluctuations that causes the leak-acoustics. And the main part of pressure perturbations acquired by dynamic pressure sensors is acoustic perturbations. And both the simulation method and the experiment method can be applied to study the leak-acoustics generation mechanism for natural gas pipelines.