Aeroacoustic Investigation of a Cavity with and without Doors by Delayed Detached Eddy Simulation

In the present study, an effort was made to numerically investigate rectangular cavity aeroacoustics with and without doors. The simulation was performed on an open cavity with an aspect ratio of 5:1:1 at Mach 0.85 using the delayed detached eddy simulation (DDES) approach based on the Spalart-Allmaras model. Two cavity configurations, a clean cavity and a cavity with doors, were modeled. The results obtained from the clean cavity were compared with the experimental sound pressure levels (SPL) and the root mean square for the pressures applied. Furthermore, comparisons of frequencies were made using a modified semi-empirical Rossiter formula. The simulation using DDES precisely predicted the pressure fluctuation and the results matched the experiment quite well. The SPLs at the rear of the cavity were much higher than those in the front due to the instability of the shear layer impinging on the rear wall. Comparisons of DDES for the clean cavity and the doors-on cavity revealed that the SPLs inside the cavity as well as the magnitude of tones are amplified by the side doors. The main focus of this investigation was to obtain a better understanding of the open cavity acoustic resonance phenomenon and investigate the effects of cavity doors on the SPL.