370 / 2021-07-26 15:38:40

Baesd Hybrid Simulation Method Study of Pipe Resonance Cavity noise

Resonance Cavity; Aero-Acoustics; unsteady CFD; steady CFD; SNGR; Strouhal number

Taking the pipeline valve resonant cavity as the research object, this paper conducts the study of the acoustic resonance characteristics of the cavity based on the experimental test and numerical simulation methods. This paper aims to solve the resonance of the pipeline cavity based on the method of Lighthill and makes an analysis of the advantages and disadvantages of the transient CFD (Computational Fluid Dynamics) + CAA (Computational Aero-Acoustics) and the steady CFD + CAA for calculating the aerodynamic noise of the pipeline valve. According to the research results, it can be shown that below the cut-off frequency, the low-medium frequency of the aero-acoustic can be obtained through the transient method while the high frequency aero-acoustic can be obtained by the Stochastic Noise Generation and Radiation (SNGR) method based on the steady-state CFD. This paper is intended for discussing the influence of the shape, size, flow rate and other factors of the pipeline and valve on the noise frequency and sound pressure by comparing the simulation results and the experimental results after calculating different types of resonant cavity on the basis of finalizing the calculation method with the full-band frequency. influences. The results show that there will be the acoustic resonance when the Strauha number is between 0.27 ~ 0.6, and the acoustic resonance frequency bears the mark of the frequency lock with the increase of the flow velocity. As the length of the bypass pipe increases, the acoustic resonance frequency decreases.