T-S波与边界层尾缘相互作用的数值研究

现代喷气式飞机的主要噪声源之一是在机翼的尾缘及喷流发动机的出口处，即流体流过尾缘时产生的强烈脉动，目前这类脉动产生噪声的机理尚不清楚。用直接数值模拟的方法，研究了二维亚音速情况下，上下来流相同的流体流过无限薄平板时。平板单边的T-S波和尾缘及尾迹流相互作用产生声场的可能性。结果表明，尾迹流中的Lighthill应力张量能在远场产生声场。此时声源不是点，而是一个区域，该声场的波动特征主要依赖于定常尾迹流的速度分布产生的不稳定扰动。

Numerical Study on Interaction of T-S Wave and Trailing Edge of Boundary Layer

One of the main causes of the noises of the modern jet plane is the strong fluctuation generated by the flows passing by the trailing edge of the airfoil and the outlet of jet engine,and the mechanism of generation of noises caused by the fluctuation has not been clear at present.Whether or not the sound field would be generated by the interactions among the T-S wave introduced at the entrance of one side of the plate,the trailing edge and wake flows is studied by direct numerical simulation,while the same 2-D subsonic incoming flows pass through a piece of infinitely thin flat plate.The result shows that the Lighthill stress tensors in the wake flows could generate sound field in the far field.However,the sound source is not a point but locates in a region.The characteristics of the sound field mainly rely on the instable disturbance generated by the volicity's distribution of the steady wake flows.