Pressure distribution, aerodynamic forces and wake-vortex evolution of a sectional cable model controlled with steady windward-and-leeward jets

A novel bluff-body control concept by using combined windward-and-leeward jets was introduced to modify the wake-vortex patterns and suppress the aerodynamic forces acting on a circular cylinder. Wind tunnel investigations are performed at a subcritical Reynolds number of Re = 3.33 × 104, which is a typical Re level that the wind-induced cable vibrations usually occur. The strength and effectiveness of active control in the present study are characterized with a dimensionless equivalent jet momentum coefficient Cµ. The particle image velocimetry (PIV) technique is employed to measure the wake flow patterns of the baseline and controlled cylinders to reveal the great modifications of active control to the cylinder wake. Except for PIV tests, surface pressure measurements are also conducted to obtain the pressure distribution around the cylinder surface so as to estimate the aerodynamic forces, i.e., drag and lift forces acting on the baseline and controlled cylinders. Pressure measurement results demonstrate clearly the control effectiveness and the wake flow topologies obtained by PIV system help to uncover the mechanism of windward-and-leeward jet control.