The results of an experimental study concerning wall boundary effects on the lock-in behavior of the shedding vortex of a circular cylinder, which is forced to oscillate transversely in a uniform flow at moderate Reynolds number Re = 2000, are presented in this paper. A height-adjustable flow channel is designed to study the boundary effect. Two sets of experiments are organized to study the lock-in behavior by changing the blockage ratio and oscillation amplitude separately. When the blockage ratio exceeds a critical value, the boundary effects are observed and the Strouhal number of the stationary cylinder increases non-linearly. As the blockage ratio increases, both the lower and upper limits of the lock-in region move to the lower value of excitation frequency, and the extent of the lock-in region decreases first and then increases. The boundary changes the effects of oscillation amplitude on lock-in behavior. When free from the boundary effect, as the oscillation amplitude increases, a V-shaped boundary of the lock-in region is observed, and the extent of the lock-in region increases monotonically. In comparison, under the influence of the boundary, the extent of the lock-in region first increases with the increase of the oscillation amplitude, and then decreases with the increase of the oscillation amplitude. Hysteresis loops are first observed near the lower limits of the lock-in region for some ranges of blockage ratio and oscillation amplitude in a forced-vibration system, and the extent of the hysteresis loop is affected by the two parameters.

关于壁边界对圆柱体的脱落涡旋的锁定行为的实验研究的结果，圆柱体的涡旋在中等雷诺数R e = 2000下被迫以均匀流动的方式横向振荡， 本文介绍。设计了高度可调的流道，以研究边界效应。组织了两组实验，通过分别更改阻塞率和振荡幅度来研究锁定行为。当堵塞率超过临界值时，观察到边界效应并且固定缸的斯托洛哈尔数非线性地增加。随着阻塞率的增加，锁定区域的上限和下限均移至激励频率的下限值，并且锁定区域的范围先减小，然后增大。边界改变了振荡幅度对锁定行为的影响。在没有边界效应的情况下，随着振荡幅度的增加，可以观察到锁定区域的V形边界，锁定区域的范围单调增加。相比之下，在边界的影响下，锁定区域的范围首先随着振荡幅度的增加而增加，然后随着振荡幅度的增加而减小。首先在强制振动系统中，在某些区域的阻塞率和振荡幅度范围内，在锁定区域的下限附近观察到磁滞回线，并且磁滞回线的程度受这两个参数的影响。