EFFECT OF AIDING AND OPPOSING BUOYANCY ON THE HEAT AND FLUID FLOW ACROSS A SQUARE CYLINDER AT RE = 100

Abstract

The effect of buoyancy on the flow structure and heat transfer characteristics of an isolated square cylinder in upward cross flow is investigated numerically for Re = 100 and a Prandtl number of 0.7. The influence of buoyancy on the recirculation length, drag and lift coefficients, Strouhal number, and time-averaged Nusselt number on the cylinder, and on each of its surfaces, is investigated. The degeneration of the Kármán vortex street, previously observed experimentally for the circular cylinder, is also found for the more bluff square cylinder at a critical Richardson number of 0.15. Heat transfer characteristics of the heated/cooled cylinder are studied as a function of Richardson number.