Yang, DangguoLi, JianqiangLiu, JunZhang, YiLi, Yaohua2018-06-062018-06-062013-03Open Journal of Fluid Dynamics , 2013, 3, 23-31http://dx.doi.org/10.4236/ojfd.2013.31003http://hdl.handle.net/123456789/1488Analysis of coupling aerodynamics and acoustics are performed to investigate the self-sustained oscillation and aerodynamic noise in two-dimensional flow past a cavity with length to depth ratio of 2 at subsonic speeds. The large eddy simulation (LES) equations and integral formulation of Ffowcs-Williams and Hawings (FW-H) are solved for the cavity with same conditions as experiments. The obtained density-field agrees well with Krishnamurty’s experimental schlieren photograph, which simulates flow-field distributions and the direction of sound wave radiation. The simulated self-sustained oscillation modes inside the cavity agree with Rossiter’s and Heller’s predicated results, which indicate frequency characteristics are obtained. Moreover, the results indicate that the feedback mechanism that new shedding-vortexes induced by propagation of sound wave created by the impingement of the shedding-vortexes in the shear-layer and rear cavity face leads to self-sustained oscillation and high noise inside the cavity. The peak acoustic pressure occurs in the first oscillation mode and the most of sound energy focuses on the low-frequency region.enSound Pressure Frequency SpectrumSound Pressure LevelAerodynamic NoiseSound GenerationPhysical MechanismCavityAnalysis on Physical Mechanism of Sound Generation inside Cavities Based on Acoustic Analogy MethodArticle