MOMENTUM AND HEAT TRANSFER FROM A CYLINDER IN THE UNSTEADY FLOW REGIME

Abstract

In this study, the two-dimensional fluid flow and heat transfer over a circular cylinder has been investigated numerically in the laminar unsteady flow regime. The numerical simulations are carried out for the following range of conditions: Re = 50 — 180(in steps of 10). Computational Fluid Dynamics softwares GAMBIT 2.2 and FLUENT 6.3 were used for the meshing and solving respectively. Extensive results have been presented for the fluid flow and heat transfer by way of instantaneous streamline, vorticity magnitude, velocity magnitude, pressure contours and temperature profiles. The results for drag and lift coefficients, Strouhal number, Nusselt number are found to be in an excellent agreement with the experimental/numerical data reported for a circular cylinder in the open literature. In addition, power spectrum of lift coefficient versus Strouhal number is presented. The power spectrum of lift coefficient indicates the perfect periodicity of the flow downstream of the cylinder for the range Re = 50 - 180. Finally, simple correlation for the total drag coefficient and time-averaged Nusselt number as a function of Reynolds number are developed for the range of conditions covered here.