Effect of Channel Confinement on Mixed Convective Flow Past an Equilateral Triangular Cylinder

Abstract

The present work investigates the mixed convective flow and heat transfer characteristics past a triangular cylinder placed symmetrically in a vertical channel. At a representative Reynolds number, Re = 100, simulations are carried out for the blockage ratios β=1/3,1/4, and 1/6. Effect of aiding and opposing buoyancy is brought about by varying the Richardson number in the range -1.0≤Ri≤1.0. At a blockage ratio of 1/3, suppression of vortex shedding is found at Ri = 1, whereas von Kármán vortex street is seen both at β=1/4 and 1/6, respectively. This is the first time that such behavior of blockage ratio past a triangular cylinder in the present flow configuration is reported. Drag coefficient increases progressively with increasing Ri and a slightly higher value is noticed at β=1/3. For all β, heat transfer increases with increasing Ri. Flattening of Nuavg –Ri curve beyond Ri>0.75 is observed at β=1/3.