Numerical Analysis of Flow-Induced Vibration and Noise Generation in a Variable Cross-Section Channel

Flow channels with a variable cross-section are important components of piping system and are widely used in various fields of engineering. Using a finite element method and modal analysis theory, flow-induced noise, mode shapes, and structure-borne noise in such systems are investigated in this study. The results demonstrate that the maximum displacement and equivalent stress are located in the part with variable cross-sectional area. The average excitation force on the flow channel wall increases with the flow velocity. The maximum excitation force occurs in the range of 0-20 Hz, and then it decreases gradually in the range of 20-1000 Hz. Additionally, as the flow velocity rises from 1 to 3 m/s, the overall sound pressure level associated with the flow-induced noise grows from 49.37 to 66.37 dB. Similarly, the overall sound pressure level associated with the structure-borne noise rises from 40.27 to 72.20 dB. When the flow velocity is increased, the increment of the structure-borne noise is higher than that of the flow-induced noise.