A three-dimensional numerical simulation of impinging jet arrays on a moving plate

Abstract

The structure of the flow field and its effect on the heat transfer characteristics of a jet array system impinging on a moving heated plate are investigated numerically for Reynolds numbers between 100 and 400 and for steady state conditions. An array consisting of 24 square jets (3 rows x 8 columns) impinging on a moving heated flat surface is considered as a representative pattern. The simulations have been carried out for jet-to-jet spacing in the range 2D-5D and for nozzle exit to plate distance of 0.25D, where D is the jet width. The velocity ratios of the moving heated plat to the jet velocity (R(m) = u(p)/u(j)) used are in the range 0.25-1.0. The obtained results were compared with published data for the case of fixed heated plate (R(m) = 0.0). The results show that the streamwise profile of the Nusselt number exhibit strong periodic oscillations, spatially. The amplitude of the periodic oscillations of the Nusselt number is attenuated as one proceeds in the downstream direction. For such small nozzle-to-plate spacing used, the results show that the ratio R has no effect on the oscillations of Nusselt number. (C) 2009 Elsevier Ltd. All rights reserved.