CFD Analysis of External Flow Vortex Shedding in Flow Over a Ribbed and Grooved Cylinder

Vortex shedding has been very less investigated and applied phenomenon in the field of fluid mechanics. Apart from tall slender column structures, subsea pipelines, and submarines, it has a lot of capability for many other applications like flowmeters, heat exchangers, etc. Vortex shedding has also been recognized as a potential generator of energy harnessing renewable resources like wind, water, etc. The energy/signals produced is highly influenced by periodic pressure fluctuations in the wake region of the bluff body. This current research work is focused on simulating two-dimensional vortex shedding of external flow over a ribbed and grooved cylinder using computational fluid dynamics (CFD). Ribbed and grooved cylindrical structures are the common structures in the engineering field. This study aims to evaluate the coefficients of drag and lift as well as vortex shedding frequency for the flow past a circular cylinder with Grooves and Ribs on the surface. The cylinder with six grooves and six ribs each at an angle of 60 degree, respectively, are compared with respect to their external flow analysis of vortex shedding. The results show that the lift and drag coefficients of grooved cylinder increased significantly as compared to regular cylinder whereas the vortex shedding frequency remained nearly the same. However, it is found that the configuration of circular cylinder with ribs showcases a significant reduction in vortex shedding frequency up to half as compared to regular cylinder, whereas the lift and drag coefficients are increased by small amounts. From the results obtained, it is suggested that for applications of structural stability in the presence of external flow cylinder with ribs are preferable whereas for energy/signals production cylinder with grooves are preferable.