Heat transfer on a flat wall due to a rectangular turbulent jet

Abstract

We present Large Eddy Simulation (LES) results of heat transfer and flow evolution of a turbulent two-dimensional rectangular jet of air, of height H, impinging upon a flat wall. Rectangular jet is quasi-two dimensional, i.e. planar jet with infinite slot-width. Exit of jet is set at four distances, D, from wall, D = 4H, 3H, 2H, H. Distance of slot exit to wall modifies flow evolution, reported as mean and instantaneous, compared to experimental data. In mean flow Undisturbed Region of Flow, URF, and, in instantaneous flow, Negligible Disturbances Flow, NDF, and Small Disturbances Flow, SDF, are reported for the various distances D/H. In order to evaluate influence of flow parameters on heat transfer and flow evolution, two levels of turbulence are imposed on slot jet exit, i.e. 1% and 6%. The level of turbulence modifies heat transfer results, as far as convective heat transfer and Nusselt number are concerned. The shape of Nusselt number distribution along impinged wall is different according to level of turbulence. The paper presents a very good comparison with experimental Nusselt numbers, for the first time in literature.