LAUSR

Abstract The problem of combined entry convection between the walls of a duct and a hydrodynamically developing flow is revisited for the geometry of a two-dimensional slot. Accurate calculations of the local and average Nusselt numbers are reported for an extended range of inverse Graetz number ( Z H ≥ 10 − 6 ), and a wide range of Prandtl number (0.1 ≤ Pr ≤ 500), while considering both constant temperature and constant heat flux wall conditions. Accuracy in this work is achieved by applying a transformation of variables to remove the singularity along the perimeter of the duct inlet before integrating the governing equations. Results of this investigation are correlated for all inverse Graetz numbers and Prandtl numbers Pr ≥ 0.5. Correlations for the local and average Nusselt numbers, and both wall conditions, are accurate to ±2.1% when compared to the benchmark results of this work.