Forced convection in a bingham plastic fluid from a heated rotating cylinder

Abstract

In this work, forced convection heat transfer from a heated rotating cylinder in a stream of a Bingham plastic fluid has been investigated numerically over wide ranges of Reynolds number (0.1≤Re≤40), Prandtl number (10≤Pr≤100), Bingham number (0≤Bn≤103) and dimensionless rotational velocity (0≤α≤5). The results are presented in terms of the isotherm contours and Nusselt number (local and average). Also, the effects of the cylinder rotation and fluid yield stress are examined on the relative increase or decrease in the rate of heat transfer relative to a stationary cylinder (α=0) and in a Newtonian fluid (Bn=0). At high Bingham numbers, heat transfer increases more than 100% with respect to the value in Newtonian fluids and approximately by 70% over and above its value for a stationary cylinder. Finally, the Nusselt number results have been consolidated as a function of Re, Pr, Bn and α via a simple expression.