This paper represents a numerical study on the flow past a grooved circular cylinder with a diameter of D. The study aims to investigate the instabilities of the flow at laminar flow regimes when Reynolds number varies from 50 to 200. Three different geometrical grooves are examined, including square, triangular, and dimple. The grooves are located at \( \theta \) = 0°, 30°, 45°, 60° and 90°, separately relative to the front stagnation point. The effects of the groove on the flow control and imposed forces on the cylinder are studied at different Re. It is found that the presence of the groove affects the dynamic behaviour of the streamwise vortices. This behaviour leads to alteration of the pressure coefficient and a significant increment in lift coefficient, in particular for the triangular grooved cylinder. At Re = 200, the results show that the magnitude of the lift coefficient of the triangular grooved cylinder with \( \theta \) = 45° is 200% more than that of the square grooved cylinder. The results also reveal that the drag coefficient reduces up to 100% by employing a triangular groove shape at \( \theta \) = 45°. These variation in lift and drag coefficients leads to maximising the aerodynamic efficiency factor (lift-to-drag ratio) of the triangular grooved cylinder up to 200%.

本文是对流经直径为D的带槽圆柱体的流动的数值研究。该研究旨在研究当雷诺数在50到200之间变化时在层流状态下流动的不稳定性。研究了三种不同的几何凹槽，包括正方形，三角形和凹痕。凹槽位于\（\ theta \） 分别相对于前停滞点= 0°，30°，45°，60°和90°。在不同的Re下研究了沟槽对流量控制的影响和作用在气缸上的力。已经发现，凹槽的存在影响了沿流涡旋的动力学行为。这种现象导致压力系数的改变和升力系数的显着增加，特别是对于三角形槽圆柱体。在Re = 200时，结果表明\（\ theta \）  = 45°的三角形沟槽圆柱的升力系数的大小比方形沟槽圆柱的升力系数大200％。结果还表明，通过在\（\ theta \）处采用三角形凹槽形状，阻力系数最多可降低100％ = 45°。升力和阻力系数的这些变化会导致三角形开槽气缸的空气动力效率因子（升力/阻力比）最大化，最高可达200​​％。