Numerical Study of the Effect of Turbulent Wake of Cylinder on Vortex Shedding from Flat Plate in Tandem Arrangement

ABSTRACT: Disturbed regions of flow will always appear in presence of any fluid flow over a stationary or moving body. These regions structures depend on both flow characteristics as well as the body. Body shape, surface roughness, orientation, size, flow velocity and viscosity are all influential parameters in the extent of disturb region. The flow structure behind multiple arrangements on bluff bodies are still an interesting subject and vastly under research because of the interaction between wakes. The development of different computational fluid dynamics (CFD) codes and commercial software are all as a result of this need for better understanding on the flow behavior. Vortex shedding from different bluff geometries is one of the most attractive and significantly important areas in fluid mechanics. Recent years with global warming issues caused by aerodynamic drag forces, rising fuel prices and safety measures, the vortex shedding has become more important. Energy conservation examples include but not limited to automobiles and skyscrapers (convection heat loss). Furthermore, it is important in structural design to limit the oscillation amplitude of the structure as well as preventing resonance phenomena. Simulation the flow structure and characteristic behind a circular cylinder and a normal flat plate in tandem arrangement with the same diameter and width at six gap ratios was performed. The impact of the circular cylinder turbulent wake on shedding frequency and Strouhal number of the plate were the main aim of this study. Commercial computational fluid dynamics software, ANSYS/CFX 15.0® was used. Shear stress transport turbulent model were used as simulation technique. The geometry modeling was done with respect to the test section of the EMU Mechanical Engineering Aerodynamics laboratory for data comparison in future studies and justification of the results. The shedding frequency and Strouhal number for each case were calculated and compared with respect to geometry and gap ratio. Keywords: Vortex Shedding, Bluff Bodies, Strouhal Number, Shedding Frequency. …………………………………………………………………………………………………………………………