Experimental study on the effect of adaptive flaps on the aerodynamics of an Ahmed body

We perform wind tunnel tests on the turbulent flow around a square-back Ahmed to analyze the use of rear flexibly hinged parallel plates as a control strategy to reduce the drag in a self-adaptive manner under changing flow conditions. Those rigid flaps are able to rotate, adopting an angle,. The observed fluid-structure interaction phenomena results in an important decrease of the drag coefficient of the original body, outperforming purely rigid flaps in aligned and yaw conditions. Additionally, hinged flaps are shown to interact with the reflectional-symmetry-breaking (RSB) modes, typically present in the wake of three-dimensional bodies.