Prediction of Flow Dynamics over Cavities by Detached Eddy Simulation

摘要

In this investigation, the flow simulation over different types of cavities (two- and three-dimensional) wasnperformed. The effect of turbulence was implemented with detached-eddy simulation using the Spalart–Allmarasnone-equation model. Initially, the flow behavior was investigated and compared for open and closed cavities. In thensound pressure level spectra of the closed cavity, only the broadband noise can be observed, while in the open-cavityncase, it consisted of harmonic frequency peaks. Results of the two- and three-dimensional computations werencompared with each other and with the available experimental data. It was observed that the results of three-ndimensional simulations comparedwellwith the experimental data, and the amplitude of the pressure fluctuations innthe two-dimensional case was larger than in the three-dimensional model.Moreover, the pressure fluctuation of thentwo-dimensional cavity was more periodic than that of the three-dimensional case. Subsequently, a cavity with twoncircular openings on top, representing a landing gear housing, was investigated. Results show that the existence ofnthese openings changes the characteristics of the flow inside the cavity, and the computed frequencies differ fromthenresults calculated by the Rossiter semi-empirical formula.