Influence of convective amplification on aeroacoustics oscillations in main gas pipeline

Abstract

The relevance. Increasing requirements for reliability and safety of gas pipelines. One of the promising methods to ensure compliance with these requirements is to equip gas pipelines with aeroacoustics monitoring systems. These systems make it possible to detect leaks and mechanical impacts on a pipe by registering aeroacoustics oscillations, propagating in the transported gas. At the same time, the issue of improving the accuracy of such systems remains relevant. It can be achieved by better consideration of a gas flow impact on aeroacoustics oscillations, taking into account the effect of convective amplification. This effect was revealed in studies of propagation of aeroacoustics oscillations in air ducts, turbines, as well as in studies of sound propagation from moving aircraft and high-speed trains. But it has not been described in relation to gas pipelines. This article presents experimental data confirming the convective amplification impact on the amplitude of aeroacoustics oscillations in the main gas pipeline, quantitative description of influence of this effect. The paper demonstrates the possibility of improving the accuracy of aeroacoustics monitoring systems, taking into account the convective amplification. The main aim. Confirm the presence of the convective amplification effect while the aeroacoustics oscillations propagating in the main gas pipeline. Object. A linear part of the main gas pipeline. Methods. Use of the aeroacoustics monitoring system for registration of aeroacoustics oscillations in the gas pipeline during the movement of a cleaning gauge and at leaks simulation; comparison of the amplitude of aeroacoustics oscillations, propagating up and down the transported gas. Results. The authors confirmed in field experiments the presence of the convective amplification effect during the cleaning gauge movement and leaks simulating. They carried out a quantitative assessment of the convective amplification influence on the aeroacoustics oscillations amplitude. The paper introduces the example of the convective amplification impact on the accuracy of the source of acoustic oscillations location in a gas pipeline. Conclusions. When propagating upstream of the gas the aeroacoustics oscillations amplitude is higher than when propagating downstream of the gas at the same distance from the source. The value in the amplitude difference is comparable to the value of the convective amplification in quantitative terms. Taking into consideration of the convective amplification effect improves the accuracy of determining the linear coordinate of the acoustic oscillations source in the gas pipeline.