ISSN Online: 2379-1748
ISBN Flash Drive: 978-1-56700-431-1
ISBN Online: 978-1-56700-430-4
First Thermal and Fluids Engineering Summer Conference
THE EFFECT OF SURFACE HEATING ON THE VORTEX SHEDDING IN FLOWPAST CIRCULAR CYLINDER
Resumo
Flow past a heated/cooled circular cylinder is computationally investigated in this paper. The presence of a buoyancy force arising due to a change in density alter the vortex shedding dynamics. The governing
equations, Navier-Stokes and energy equation within the Boussinesq approximation along with continuity
equation are solved using a hybrid FEM-FVM technique. In this work we focus on the minimum Reynolds
number at which vortex shedding occur. In hydrodynamic stability literature, this value is most often termed as
the critical Reynolds number, which is approximately 47 for flow past an unheated cylinder. This demarcation
between steady and unsteady regimes of the flow changes due to surface temperature. Due to an increase in
surface temperature the frequency of vortex shedding is known to enhance. We show that the nondimensional
shedding frequency, the Strouhal number increases with heating and has a strong dependence on Prandtl
number and Richardson number of the flow, which are a measure of fluid diffusivities and buoyancy force
respectively. We also discuss the regime of complete suppression of vortex shedding due to cylinder surface
temperature.