Flow topology and heat transfer analysis of slotted and axisymmetric synthetic impinging jets

Abstract

This work is focused on exploring the flow and heat transfer capabilities for slotted and axisymmetric cavity configurations for synthetic impinging jets; the jet is enclosed between two isothermal parallel plates, impinging into the top hot plate. Numerical simulations using the Arbitrary Lagrangian-Eulerian formulation of the Navier-Stokes equations are performed for Reynolds numbers of 50, 300 and 500 and a jet formation criteria of 3. The pattern of the flow from both configurations differ, which result in different impinging behaviors. The slotted jet is wider than the axisymmetric one, showing an increased turbulent mixing and a lower velocity deficit. On the other hand, the narrower jet of the axisymmetric configuration results in less mixing and more penetration, with a higher velocity deficit. This leads to a higher heat transfer peak in the axisymmetric configuration with a faster decay when moving away from the jet centerline than observed for the slotted configuration.