REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

Flow over deformable circular-elliptical cylinder

Choayb Boulahbal

Military Academy, University of Defence, Belgrade chouaibboulahbal@gmail.com

Narimane Rezgui

Military Academy, University of Defence, Belgrade narimanerez.doc@gmail.com

Abstract: This work is devoted to controlling the structure of the flow around a circular cylinder, subjected to a circular-elliptic cross-section variation according to a sinusoidal predefined law. The study is carried out for the Reynolds number Re=2275, scaled amplitudes of deformation of 1% to 100% and a range of the dimensionless frequencies from 0.2 to 8. The results analysis reveals that the structure of the wake is deeply affected by parameters of control. The numerical results reveal that for amplitudes of 100% and 75% and one frequency band from 5 to 10, the drag is cancelled and becomes negative, causing a self-propulsion of the cylinder.

Keywords: wake structure, circular-cylinder, circular-elliptic deformation, flow control.