Theoretical And Experimental Research On Acoustic Propagation Characteristics Of Elastic Fluid-filled Pipelines With Different Pipeline Parameters

Elastic fluid-filled pipeline system is widely used in many aspects by transferring mass flow and energy flow,such as transportation of petroleum,chemical and other liquids,urban water supply,water-cooling and heating systems,and even the internal composition of ships.Noise problems exist in the application of pipeline system.Previous studies on acoustic propagation in fluid-filled pipelines are relatively few.The conclusions of acoustic propagation in gas-filled pipelines are often used to deal with related problems.However,some acoustic propagation characteristics of gas-filled pipelines can not be applied to fluid-filled pipelines.Therefore,it is of great significance to study the acoustic propagation characteristics of elastic fluid-filled pipelines.In this paper,the cutoff frequency of the two models of liquid pipe wall and elastic pipe wall of elastic fluid-filled pipeline are theoretically deduced,and the sound field in two models of elastic fluid-filled pipeline is simulated by using ACTRAN software.The acoustic propagation characteristics of elastic fluid-filled pipeline are analyzed from the results of theoretical derivation and simulation result.The axial and radial propagation laws of acoustic waves in the pipeline are studied based on the cut-off frequency.At the same time,the acoustic propagation characteristics of elastic fluid-filled pipelines were experimentally studied.The acoustic propagation characteristics of five elastic filling pipes with external radius of 0.08 M and wall thickness ranging from 6.2 mm to 14.6 mm were experimentally tested.The influence of wall thickness on the acoustic propagation characteristics of elastic filled pipes was analyzed.Experimental tests were carried out on elastic liquid-filled pipes with a wall thickness of 9.6 mm and an outer radius of 0.125 M and 0.1 M.The results show that the elastic fluid-filled pipeline can transmit sound waves with a frequency higher than the cut-off frequency,and the radial sound field distribution of the pipeline conforms to the change law of the zero-order Bessel function.Changing the pipeline parameters will affect the acoustic propagation characteristics of the elastic fluid-filled pipeline.The increase in the thickness of the pipe wall will lead to a slight increase in the cut-off frequency of the pipeline.At the same time,the axial propagation characteristics of the sound waves will change.The reduction of pipe diameter will lead to a large increase in the cut-off frequency.The acoustic propagation characteristics of elastic fluid-filled pipelines can be changed by changing the pipeline parameters,and the purpose of noise reduction can be achieved.