Numerical simulation of structure-borne noise in a T-shaped tee considering fluid-structure interaction

In order to research the structure-borne noise characteristics of a T-shaped tee considering fluid-structure interaction (FSI), large eddy simulation and the acoustic finite element method were used to simulate the flow field and structure-borne noise related to T-shaped tees under different inlet and outlet combinations. The results show that the frequency domain sound pressure level (SPL) distribution under various inlet flow velocities is stable, the structure-borne noise of the T-shaped tee is a high-frequency noise, and the SPL curves provide a peak distribution. Meanwhile, the distribution characteristics of the structure-borne noise in the frequency domain follow similar trends under different inlet flow velocities. Additionally, the structure-borne noise does not produce the mechanical resonance of the system. When the inlet velocity increases from 1 to 3 m/s, the total sound pressure level (TSPL) increases from 83.71 to 98.18 dB, a relative increase of 17.3%. In addition, the frequency domain distributions of the SPL under various inlet and outlet combinations are basically similar. The TSPL of four inlet and outlet combinations for the structure-borne noise are III, IV, II, and I in descending order. When the inlet flow velocity is 1, 2, and 3 m/s, in the case of combination I, the TSPL of the structure-borne noise decreases by 6.28, 5.59, and 6.39 dB, in contrast to the case of combination III, respectively. This study provides the guidance for the noise control and structural optimization design of a T-shaped tee considering the FSI.