The effect of length and stiffness of an attached flexible foil on the flow field of a square cylinder is studied. The intermediate Reynolds numbers are considered in the study. For flow diagnosis, particle image velocimetry, constant temperature anemometry, and flow visualization techniques are used. The increase in the length of the foil modifies the Strouhal frequency and mean drag coefficient non-monotonically, which owes to the different wake regimes. Three different stiffness ranges are selected to see its effects on the wake characteristics of the bluff body and the dynamic response of the foil. The dynamic response of the foil depends on the wake frequency and the structural natural frequency of the foil. With an increase in the flexibility of the foil, the bending mode excitation increases, and the fluid–structure interaction becomes complex. The lock-in between the wake frequency and the natural flapping frequency adversely affects the drag coefficient of the bluff body.

研究了附着的柔性箔的长度和刚度对方筒流场的影响。研究中考虑了中间雷诺数。对于流量诊断，使用了颗粒图像测速仪，恒温风速仪和流量可视化技术。箔片长度的增加非均匀地改变了Strouhal频率和平均阻力系数，这归因于不同的唤醒方式。选择三个不同的刚度范围，以查看其对钝体的尾流特性和箔片动态响应的影响。箔片的动态响应取决于箔片的唤醒频率和结构固有频率。随着箔片柔性的增加，弯曲模式的激发增加，并且流固耦合变得复杂。唤醒频率和自然拍打频率之间的锁定不利地影响了钝体的阻力系数。