A fundamental link between steady asymmetry and separation length in the wake of a 3D square-back body

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: [Figure not available: see fulltext.].