关键词: 空腔流动曰气动噪声曰谱本征正交分解渊SPOD冤曰金属丝网曰流动控制 

Abstract: The internal weapon bay of an aircraft is a typical cavity structure, and the aerodynamic noise it excites adversely affects the airframe structure and the equipment inside the bay. Proposing effective flow control methods to suppress cavity aerodynamic noise is therefore of great significance for improving the overall performance of aircraft. This paper proposes a passive cavity flow control method based on wire mesh. Numerical simulations under supersonic conditions are carried out for the M219 cavity calibration model with a length-to-depth ratio of 5 by us鄄 ing the improved delayed detached eddy simulation (IDDES) method. The noise reduction effects of wire meshes with different porosities are analyzed and compared with those of a flat-plate spoiler. The flow field structures and noise mechanisms are further analyzed by using the spectral proper orthogonal decomposition (SPOD) method. The results show that the wire mesh allows part of the air to flow through while lifting the other part of the flow. This unique flow-splitting mechanism can both weaken the shear layer instability noise and suppress the trailing-edge impingement noise, thus achieving simultaneous control of the two noise sources. The trailing-edge impingement noise corresponds to the low-order Rossiter modes, whereas the shear layer instability noise corresponds to the high-order Rossiter modes. When the porosity of the wire mesh is 0.30, excellent noise reduction performance is achieved. Compared with the flat-plate spoiler, the wire mesh avoids the introduction of additional noise sources and exhibits better overall noise reduction performance. This study provides a new passive control method and theoretical support for the study of cavity flow control.

Key words: cavity flow, aerodynamic noise, spectral proper orthogonal decomposition (SPOD), wire mesh, flow contro