Flow Separation Phenomena for Steady Flow over a Circular Cylinder at Low Reynolds Number

Abstract

Flow separation is one of the major distinguishing phenomena between the theoretical or potential flow and actual fluid flow that introduces several aerodynamic forces and other renowned phenomena. Here in this article, different flow separation phenomena such as onset of separation, angular position of the separation point, size of the separation bubble, drag due to the separation and effect of the blockage ratio on the position of the separation point for steady flow over a smooth circular cylinder are studied numerically using the finite volume method at very low Reynolds number up to 50, and the trends of change of these phenomena with increasing Reynolds number are expressed in the form of some empirical equations and compared with results of previously published literature. The separation starts at Reynolds numbers as low as 2.0 and the starting-separation angle is 146.557° from the upstream stagnation point, while with increasing Reynolds number, the point of separation travels upstream and the separation bubble length increases. The profound effect of the blockage ratio on the location of the separation point is evident in this numerical analysis. Favre-averaged Navier-Stokes equations, a k-ɛ turbulence model and the finite volume method are used for numerical analysis, in which heat transfer or generation, and buoyancy effects are not taken in account.