Control of the flow around a finite square cylinder with a flexible plate attached at the free end

A flexible plate vertically clamped at the free-end leading edge was used to modulate aerodynamic forces on a wall-mounted finite square cylinder. The side width (d) of cylinder 40 mm and aspect ratio (H/d) 5. made low-density polyethylene, with d thickness 0.04 mm. length ranged from d/8 d. All measurements were carried out in low-speed wind tunnel free-stream velocity (U?) ranging 4 20 m/s, corresponding Reynolds number 10 960 54 800. It found that behaves distinctly depending its has significant effects When U? is smaller than critical Ucr, which closely related plate, statically deforms, having negligible influence exceeds flaps periodically, resulting reduction forces. maximum mean drag, fluctuating lateral force reaches approximately 5%, 25%, 60%, respectively. insensitive both flapping frequency. Flow visualization particle image velocimetry results point induces large-scale vortices shear flow, suppress formation spanwise vortex shedding make upper part near wake symmetrical. configuration pressure fluctuation free end also addressed.