Numerical investigation of the effects of installing four trip wires with different diameters on the mean and fluctuation velocities and characteristics of the wake around the circular cylinder

The vortex shedding is one of the main reasons for vibration in cylindrical bodies. Accordingly, by controlling the vortex shedding, the vortex-induced vibration (VIV) can be controlled in these objects. Correcting the shape of objects through installing trip wires, installing screw plates, and creating holes on the object can reduce these vibrations. For this purpose, in the present study, the effects of installing four trip wires with different diameters on the vortex pattern, mean and fluctuation velocities, characteristics of the wake such as defect velocity and half width are numerically investigated in variable stations ( X / D = 1.06, 1.54, 2.02, 5, 7, 10) at different inlet velocities 2.85, 10 and 20 m/s. The diameter of the circular cylinder was 20 mm, and the diameter of the installed trip wires was 0.25, 0.5, 0.75, 1, and 1.5 mm. The disturbance trip wires were installed at positions θ = ± 40 and ± 140. The results showed that the vortex pattern is sensitive to the installation of trip wires. By decreasing the diameter of the trip wires, the length of the shear layer decreases. In the area near the model (rotating area), the half width increases for a smooth cylinder. The velocity defect parameter is decreased by increasing the Reynolds number and decreasing the diameter of the trip wires.