Nonlinear feedback control of bimodality in the wake of a three-dimensional bluff body

Abstract

The turbulent wake behind a square-back Ahmed body in close proximity to the ground exhibits bimodal switching. This manifests as the center of the wake randomly switching side-to-side between one of two asymmetric positions. This work is the first attempt to employ nonlinear model-based feedback control to suppress this wake bimodality. High fidelity simulations are used to develop and implement the control strategy and investigate the resulting effect on the wake and aerodynamic drag.