Abstract The present study is a revisit to Ludwig Prandtl’s elimination of von Kármán vortex street behind a circular cylinder by using steady suction in the boundary layer. We show in particular the full-time vortex evolutions and vortex dynamics in the wake. The wind tunnel investigations are conducted at the Reynolds number (Re) of 2.0 × 10 4 . Slot suction is implemented symmetrically on both lower and upper boundary layers of the cylindrical test model to modify the flow separation process and to eliminate the downstream vortex street. The boundary layer suction is described by the dimensionless momentum parameter of suction relative to the free-stream airflow. A high-speed particle image velocimetry system is employed in the present study to visualize the flow patterns and capture the wake dynamics of the natural and modified cylinders controlled with boundary-layer suction. Graphic abstract

中文翻译：

---

Ludwig Prandtl 的设想：用边界层吸力消除 von Kármán 涡街

摘要 本研究是对路德维希·普朗特 (Ludwig Prandtl) 通过在边界层中使用稳定吸力消除圆柱体后面 von Kármán 涡街的重新审视。我们特别展示了尾流中的全时涡旋演化和涡旋动力学。风洞研究在雷诺数 (Re) 为 2.0 × 10 4 时进行。在圆柱形测试模型的下边界层和上边界层上对称实施槽吸，以修改流动分离过程并消除下游涡街。边界层吸力由吸力相对于自由气流的无量纲动量参数描述。本研究采用高速粒子图像测速系统来可视化流动模式并捕获由边界层吸力控制的自然和修改后的圆柱体的尾流动力学。图形摘要