Effect of wall proximity on the flow over a heated square bluff body

Abstract

The two-dimensional numerical simulations of Newtonian fluid stream about a square bluff body have been studied in an unconfined configuration in addition in the propinquity of a plane wall. The comparison of flow and heat transfer constraints is done with the pure unconfined flow about a square obstacle. The set of physical constraints considered as Reynolds numbers (Re) = 100, 120 and Prandtl number (Pr) = 0.7 (air) at varying values of gap ratios (g). The values of drag and lift coefficients, and average Nusselt number are computed. The present study shows that on increasing the gap ratio, the drag coefficient is acquired to be the highest for the gap ratio of unity and it is observed the lowest for the unconfined case. Lift coefficient decreases and average Nusselt number increases with increasing gap ratio, but opposite effects are observed for the unconfined case. The flow becomes steady at low gap ratio, but on increasing gap ratio the flow behavior changes to periodic unsteady. The augmentation in heat transfer is found about 35% for g = 1, with respect to the corresponding value for the unconfined case.