The present paper aims to investigate numerically small amplitude oscillation of NACA 0012 airfoil at Re = 1000. The airfoil is sinusoidally pitching around the quarter chord point with 1° pitch amplitude about a mean angle of attack. The computations are performed for mean angles of attack ranging from 0° to 60° and for pitching frequencies of 1 Hz and 4 Hz. The effect of the mean angle of attack and pitching frequency on the instantaneous forces as well as the vortex structure is investigated in comparison with the non-oscillatory conditions. It was shown that airfoil oscillations at the investigated conditions change the amplitude of oscillation of the aerodynamic loads. The instantaneous drag coefficient is always positive for pitching airfoil at 1 Hz. In the meantime, there are time intervals where instantaneous drag coefficient becomes negative for pitching motion at 4 Hz for mean angles of attack from 3° to 36°.

中文翻译：

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低雷诺数下俯仰 NACA 0012 翼型的非定常空气动力学

本论文旨在研究 NACA 0012 翼型在 Re = 1000 时的数值小振幅振荡。翼型围绕四分之一弦点以 1° 俯仰振幅围绕平均攻角进行正弦俯仰。计算是针对 0° 到 60° 的平均攻角以及 1 Hz 和 4 Hz 的俯仰频率进行的。与非振荡条件相比，研究了平均攻角和俯仰频率对瞬时力以及涡流结构的影响。结果表明，在研究条件下的翼型振荡会改变气动载荷的振荡幅度。对于 1 Hz 的俯仰翼型，瞬时阻力系数始终为正。同时，