Effect of weak sound on separated flow over an airfoil
Effect of weak sound on separated flow over an airfoil
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DOI：
10.1016/j.fluiddyn.2003.08.002
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发表时间：
2003-10
影响因子：
1.5
通讯作者：
K. Ishii;S. Suzuki;S. Adachi
中科院分区：
文献类型：
--
作者：
K. Ishii;S. Suzuki;S. Adachi
本文研究了弱声激励对翼型分离流的影响。对NACA 0 0 12翼型在攻角α= 12，来流马赫数M= 0.1，弦雷诺数Re= 5× 10 4和1× 10 5的条件下进行了二维数值模拟。外部声压的振幅设定为无穷远处静压的0.05%。结果表明，适当频率的声波使时均升力系数增大。该有效频率范围取决于雷诺数;其平均值与Zaman等人对不同翼型的实验结果一致。在有效频率范围内，翼型层流边界层中的最大涡量变大。另一方面，升力系数振荡的振幅具有相同的依赖于声激励频率的两个雷诺数。
This paper is concerned with the effect of weak acoustic excitation on a separated flow over an airfoil. Two-dimensional numerical simulations are performed for an NACA0012 airfoil at an angle of attack α= 12 in the flow with the main stream Mach number M= 0.1 and chord Reynolds numbers, Re= 5× 10 4 and 1× 10 5. The amplitude of the external sound pressure is set at 0.05% of the static pressure at infinity. It is shown that the acoustic waves with appropriate frequencies make time-averaged lift coefficients higher. This effective frequency range depends on the Reynolds number; its mean value agrees with the experimental results of Zaman et al. for different airfoils. In the effective frequency range, the maximum vorticity in the laminar boundary layer of the airfoil becomes larger. On the other hand, the amplitudes of lift coefficient oscillation have the same dependence on the acoustic excitation frequency for both Reynolds numbers.