Prediction of Flow Dynamics over Cavities by Detached Eddy Simulation

In this investigation, the flow simulation over different types of cavities (two- and three-dimensional) was performed. The effect of turbulence was implemented with detached-eddy simulation using the Spalart - Allmaras one-equation model. Initially, the flow behavior was investigated and compared for open and closed cavities. In the sound pressure level spectra of the closed cavity, only the broadband noise can be observed, while in the open-cavity case, it consisted of harmonic frequency peaks. Results of the two- and three-dimensional computations were compared with each other and with the available experimental data. It was observed that the results of three-dimensional simulations compared well with the experimental data, and the amplitude of the pressure fluctuations in the two-dimensional case was larger than in the three-dimensional model. Moreover, the pressure fluctuation of the two-dimensional cavity was more periodic than that of the three-dimensional case. Subsequently, a cavity with two circular openings on top, representing a landing gear housing, was investigated. Results show that the existence of these openings changes the characteristics of the flow inside the cavity, and the computed frequencies differ from the results calculated by the Rossiter semi-empirical formula. [PUBLICATION ABSTRACT]