A. Rashid and N. Hasan VortexShedding Suppression in Mixed Convective Flow past a Heated Square Cylinder
953 - 961
2011
5
6
International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering http://waset.org/publications/7771
http://waset.org/publications/54
World Academy of Science, Engineering and Technology
The present study investigates numerically the
phenomenon of vortexshedding and its suppression in twodimensional
mixed convective flow past a square cylinder under the
joint influence of buoyancy and freestream orientation with respect
to gravity. The numerical experiments have been conducted at a
fixed Reynolds number (Re) of 100 and Prandtl number (Pr) of 0.71,
while Richardson number (Ri) is varied from 0 to 1.6 and freestream
orientation, α, is kept in the range 0o≤ α ≤ 90o, with 0o
corresponding to an upward flow and 90o representing a crossflow
scenario, respectively. The continuity, momentum and energy
equations, subject to Boussinesq approximation, are discretized using
a finite difference method and are solved by a semiexplicit pressure
correction scheme. The critical Richardson number, leading to the
suppression of the vortexshedding (Ric), is estimated by using
StuartLandau theory at various freestream orientations and the
neutral curve is obtained in the Riα plane. The neutral curve
exhibits an interesting nonmonotonic behavior with Ric first
increasing with increasing values of α upto 45o and then decreasing
till 70o. Beyond 70o, the neutral curve again exhibits a sharp
increasing asymptotic trend with Ric approaching very large values
as α approaches 90o. The suppression of vortex shedding is not
observed at α 90o (crossflow). In the unsteady flow regime, the
Strouhal number (St) increases with the increase in Richardson
number.
International Science Index 54, 2011