DefinePK

Abstract

An experimental investigation was conducted of a rotating circular cylinder immersed in a free-stream flow. The study was motivated by some apparent discrepancies between experimental and numerical studies of the fluid flow, and the general lack of experimental data, particularly in the subcritical Reynolds number regime. Of interest was the direction and origin of the lift force generated on the cylinder, which has been the subject of contradictory results in the lterature, and for which measurements have rarely been reported. The circular cylinder was tested at 3 different free stream speeds 11, 13, and 15 m /s. The dimensionless speed ratio and Reynolds number (Re) also ranged from ? = 0.6 - 1.1, and 1.50E05 - 2.14E05, respectively. Verification of the experimental was achieved through using of computational fluid dynamics (CFD) code ANSYS FLUENT15 to simulate a two-dimensional flow of a viscous incompressible fluid past a rotating cylinder subject to a circular motion. Indeed, grid independency test (GIT) as well as the effect of domain size, have been conducted and a suitable agreement was found based on comparison of the CFD and experimental fluid dynamics (EFD) results, where a good agreement with experimental data in global quantities is predicted through generating of a fine mesh enhanced with choosing of y+ value less than 1. In the next step, the attention has been focused on comparing between the simulation results of k-e, and k-?-SST viscous models, to determine the most compatible model in using CFD code with the EFD results in certain mentioned condition. Generally, simulation results of each of mentioned two equations turbulent models show similar patterns as compared to EFD. A comparison of the results showed that, the margin of error in lift force coefficient was arranged from 39 - 60 % and 10 - 14% for k-e, and k-?-SST, respectively, which surprises the shear stress transport turbulent model as more compatible viscous model. The correspondence is seen to be excellent for analyzing the characteristic of fluid flow around the rotating objects in subcritical regime of Re.