Effect of Upstream Cylinder on the Wake Structure and Evolution of Flow over a Finned Circular Cylinder

Abstract

This paper reports the results of Computational Fluid Dynamics (CFD) simulations to investigate the effect of an upstream cylinder on the wake structure and evolution of flow over a finned circular cylinder evenly attached with rectangular ribs around its circumference and identifying the near-wall vortex structure are formed. Also examined the effect of the number of ribs (n=3, 5) in a low Reynolds number range of 60–180. The main concern in the aerospace domain is the vortex induced vibrations. It is necessary to find ways to reduce the fluid forces and stabilise the flow wake either actively or passively. Therefore, be it in the field of aerodynamics and in offshore wind turbines. The near-wall vortices and their evolution are sensitive to Re as well as n. The evolution of flow around the cylinder with 3 ribs (n = 3) QS are formed in the corners over which the boundary layers stride. The subordinate vortices disappear at Re=60, possibly attributed to the relatively great viscous force at such lower Re. The evolutions of flow over the finned cylinder with 5 ribs at three representative Re cases are compared. The number of Sub created in accompany with a main vortex grows with the increase in Re. and then generates the main vortices behind the associated ribs