EFFECTS OF PRANDTL NUMBER ON IMPINGING JET HEAT TRANSFER UNDER A SEMI-CONFINED TURBULENT SLOT JET

Abstract

Despite the extensive literature dealing with impinging jet heat transfer, little attention has been directed at the effect of fluid Prandtl number. Almost without exception, earlier studies, both experimental and numerical, deal with air or water as the jet fluids. The objective of this work was to carry out numerical experiments using a computational fluid dynamics simulation code to examine the effect of different thermal properties of the fluid (gas or liquid phase) on heat transfer and to correlate the effect of the fluid Prandtl number on heat transfer under a semi-confined turbulent slot jet. New results are presented for different gases viz. air, argon, nitrogen, hydrogen, helium, ammonia and ethylene and several liquids viz. water, benzene, ethanol, turpentine and isobutyl alcohol. Local, stagnation and average values of the impingement Nusselt number as well as the heat transfer coefficient were reported. Empirical correlations are derived for the stagnation and average Nusselt numbers as a function of the fluid Prandtl number on the basis of extensive numerical experiments