Research on acoustic propagation characteristics in the four-corner tangent circular flow field in the furnace

The law of sound propagation characteristics is unclear in the flow field in the furnace, which affects the accuracy of the acoustic wave method to measure the physical field in the furnace. In order to solve this problem, the coupling simulation of the flow field and the sound field is carried out to study the influence of the flow field distribution in the furnace on the sound propagation characteristics, and the acoustic propagation experiment in the four-corner tangent circle flow field is designed. It is found that in the tangential flow field, the sound pressure level at the wake of the jet decreases at low frequencies and increases at high frequencies, and the peaks and valleys of the sound pressure level in the frequency band of 5–10 kHz are reversed. The peak value of the sound pressure level in the vortex change region near the inlet increases, and the peak and valley of the sound pressure level in the frequency band of 5–10 kHz and 13–16 kHz are reversed. Both experimental and simulation results show that with the increase of background velocity, diffusion attenuation increases and sound pressure level increases slowly. Moreover, the experimental results show that the flow field has little influence on sound pressure level in the frequency band of 4–5.5 kHz, which is suitable for the sound source frequency band for temperature field monitoring. The research results provide a principle basis for the reconstruction of the physical field in the furnace, so as to improve the accuracy of the reconstruction.