边界层转捩区声辐射的预报方法研究

对Lighthill剪切应力脉动模型和Liepmann位移厚度脉动模型进行了讨论,在此基础上,本文提出利用Krane偶极子声源模型对Liepmann单极子声源模型进行改进。数值计算结果表明:作为偶极子声源的Lighthill理论剪切应力脉动模型,预报的噪声级偏低;而作为单极子声源的Liepmann模型,预报的噪声级又偏高;本文提出的两种改进模型预报的噪声级则与Lauchle实验值的一致性较好。

Prediction method for noise radiated from boundary layer transition

For the boundary layer transition noise, the Lighthill model of fluctuating shear stress and the Liepmann model of fluctuating boundary fayer displacement thickness are discussted. On this paper, the Liepmann model of fluctuating boundary layer displacement thickness is improved by using the Krane dipole sound source model. Numerical calculation result shows, the Lighthill model is belong to dipole sound source model and predicts too low noise levels, Liepmann model belongs to monopole sound source model and predicts too high noise levels, on the other hand, the noise levels calculated by our improvement models much agree with the Lauchle measured data.