Abstract

Suction applied at the base of a square-back Ahmed body is shown to create a global effect on the wake, reducing the recirculating bubble length and increasing the base drag. Weak suction causes a small shortening of the bubble and intensifies the steady reflectional symmetry breaking (RSB) mode present in the horizontal direction. Stronger suction significantly suppresses the RSB mode, indicating that the steady asymmetric instability does not bear a highly curved bubble. The stabilized wake experiences very low frequency oscillations in the horizontal direction together with a well synchronized shedding mode in the vertical direction.

Graphic abstract

中文翻译：

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3D方形背板主体之后，稳态不对称与分离长度之间的基本联系

摘要

图中显示了在方形后卫艾哈迈德（Ahmed）车身底部施加的吸力会对尾流产生整体影响，从而减少了再循环气泡的长度并增加了底部阻力。弱吸力会引起气泡的少量缩短，并会增强水平方向上出现的稳定反射对称破坏（RSB）模式。较强的吸力可显着抑制RSB模式，表明稳定的不对称不稳定性不会带有高度弯曲的气泡。稳定的尾流在水平方向上经历非常低的频率振荡，在垂直方向上经历了很好同步的脱落模式。

图形摘要