Investigation on low-frequency sound propagation characteristics of fluid-filled steel pipeline

Abstract

With the development of vibration reduction and noise reduction technology, the propeller noise, hydrodynamic noise and equipment base noise in submarines have been effectively suppressed. The sea pipeline system contains mechanical noise and fluid pulsation noise, which is one of the main noise sources of submarines. The fluid-filled steel pipeline is the basic component of the sea pipeline system. It is of great significance to study the low-frequency sound propagation characteristics of the fluid-filled steel pipeline system to effectively suppress the low-frequency noise of the pipeline system to the sea and achieve quiet submarines. At present, there are few studies on the sound propagation of fluid-filled steel pipeline, and most of them refer to gas-filled pipes. It is believed that there are low-frequency plane waves in the pipeline, which leads to the design of muffling devices only for liquids, the role of the pipe wall in the propagation of low-frequency sound is ignored. In this paper, according to the relationship between normal waves and medium wave velocity, a sound propagation model of fluid-filled steel pipeline is proposed, which is verified by experimental research. Through this model, the propagation path of low-frequency sound in the fluid-filled steel pipeline is clarified, which has an important guiding role in the vibration and noise reduction of the fluid-filled pipeline system.