The wake dynamics behind a sinusoidally pitching custom designed symmetrical airfoil is analyzed computationally. The effect of pitching frequency and pitching amplitude is investigated independently at a constant Reynolds number. The wake patterns are found to exhibit a transition from von Karman to reverse von Karman vortex street and from symmetric reverse von Karman vortex street to asymmetric deflected wake as established. For laminar flow under investigation, the contours of time-varying velocity fluctuations are presented. The mean profiles of velocity and the fluctuations at different locations in the wake show that the thrust wakes are generated at the expense of energy of the surrounding fluid. The temporal behavior of the flow field is analyzed using the phase plot. The time series plots of force coefficients show a periodic loading on the airfoil. Proper orthogonal decomposition (POD) analysis of drag, neutral and thrust wakes displayed the evolution of coherent structures in the flow field. The evolution of these structures portray the transitions in the wake of the airfoil. The merging of coherent structures in an asymmetric deflected wake turns out to be an efficient way of identifying the location of deflection.

对正弦俯仰定制设计的对称翼型后面的尾流动力学进行了计算分析。在恒定的雷诺数下独立研究俯仰频率和俯仰幅度的影响。已发现，尾流模式表现出从von Karman到反向von Karman涡街和从对称反向von Karman涡街到非对称偏转尾流的过渡。对于正在研究的层流，提出了时变速度波动的轮廓。尾流中不同位置的速度和波动的平均曲线表明，推力尾流的产生是以周围流体能量为代价的。使用相图分析流场的时间行为。力系数的时间序列图显示了机翼上的周期性载荷。阻力，中性和推力尾流的正确正交分解（POD）分析显示了流场中相干结构的演变。这些结构的演变描绘了机翼的尾随过渡。相干结构在不对称偏转尾流中的合并被证明是识别偏转位置的有效方法。