Publication

Abstract : This paper investigates flow over a stationary circular cylinder (diameter, D) with locally applied roughness height, ‘k’ applied at certain circumferential locations of the cylinder in the presence of a detached wake splitter plate with varying length, L. The numerical simulations are done by using commercial software ANSYS Fluent. This numerical study is conducted at a Reynolds number value of 25,000, k/δ = 1.1 (δ is the boundary layer thickness at a given circumferential location) and L/D = 0.5, 1, 1.5, 2.0 at different roughness locations α = 0°, 9°, 31°, 65°, and 75°. The results indicate that lift coefficient, drag coefficient, and Strouhal number are significantly affected as the L/D ratio increases, whereas with the change in the roughness location, the aerodynamic/hydrodynamic characteristics are not notably affected. Longer splitter plate along with roughness application is found to cause two effects: (a) considerable reduction in drag coefficient and Strouhal number and (b) considerable increase in the lift coefficient.