Numerical simulation of acoustic field characteristics of flow-induced noise by coking on the inner wall of furnace tubes
This study focuses on pipelines containing the initial coke block area,and the influence of coke parameters on the sound field distribution is mainly discussed.A two-dimensional calculation model of the pipeline is developed to investigate the part of the flow field and sound field of the pipeline containing the coke block.Based on large eddy simulation and generalized Lighthill equation by using Fluent software and Actran acoustic software.The instantaneous data of the flow field calculated by Fluent software is imported into Actran acoustic software to complete the sound field calculation,and the noise distribution characteristics obtained by calculation were studied.The results show that when there is no coke block attached to the inner wall of the pipe,the flow field pressure in the pipe is evenly distributed.There is no volume sound source distribution in the sound field,and the sound pressure level has no obvious change.When the inner wall of the pipeline is coking,there is flow noise,and its sound pressure level changes obviously with the pressure pulsation.As the Angle of attack of the coke block increases from 90° to 120°,the total sound pressure level does not change obviously.As the height of the coke block increases from 2 mm to 8 mm,the total sound pressure level increases.The maximum sound pressure level area appears behind and above the coke block when the height is 8 mm and the angle of attack is 120°.When the coke block is attached to the pipeline,the pressure pulsation amplitude is stable,and the sound pressure level in the pipeline changes gently when the fluid does not pass through the coke block.After the fluid flows through the coke,the sound pressure level behind the coke block is higher than that in front because the turbulent stress behind the coke block is greater than that in front.As the fluid progresses,the backflow area behind the coke block attaches to the pipeline wall,resulting in an initial increase and subsequent decrease in the sound pressure level from the inlet to the outlet until it reaches a steady state.The study of the distribution of the sound field in the furnace tube and the influence of the coke block state on the sound field can guide for predicting the state of the coke block inside the furnace tube.
safety engineeringflow-induced noisesound field simulationsound field distribution
NETL
NSTL
万方数据
维普
