Experimental investigation for wake of the circular cylinder by attaching different number of tripping wires

Abstract

An experimental study is conducted on flow past a circular cylinder fitted with some tripping wires on its surface. The work investigates the dependency of the critical wire locations on the wire size and Reynolds numbers, and examines the wake and vortex shedding characteristics in an effort to advance the understanding of the critical wire effects beyond the existing literature. The primary aim of this investigation is to assess the significance of the angular locations of the surface trip wire. The wire size is 1.5 mm (wire_ to_ cylinder diameter ratio is 0.075), where in different angular locations attached in to the cylinder (by different number of trip wires, 2, 4, 6, 8, 10) and two Reynolds numbers (Re=10000 and Re=35000). Particularly, positioning the tripping wires at 45˚ (with 4 trip wires) maximally decreased the drag coefficients by 41.6% and 70.6% (Re=10000 and Re=35000, respectively), in comparison with the coefficients produced without the tripping wires. The variations of the Strouhal number is found to be, roughly, inversely related with drag coefficient.