Open Access

ARTICLE

Turbulent Flow Produced by Twin Slot Jets Impinging a Wall

Fatiha Bentarzi¹, Amina Mataoui^{1, *}

1 Theoretical and applied laboratory of fluid mechanics, Physics Faculty, University of Science and Technology Houari Boumediene-USTHB, Algiers, Algeria.

* Corresponding Author: Amina Mataoui. Email: .

Fluid Dynamics & Materials Processing 2018, 14(2), 107-120. https://doi.org/ 10.3970/fdmp.2018.06046

Abstract

The dynamics of two fully developed turbulent jets, perpendicular to a heated flat plate and related heat transfer mechanism are analysed numerically. This problem is relevant to several thermal engineering applications. The governing equations are solved by a finite volume method with a second order RSM model combined with wall functions used for turbulent modelling. The possibility to improve heat transfer is assessed taking into account the characteristic parameters for the jet-wall interaction. In particular, a parametric study is conducted by varying the jet Reynolds number (Re) and the nozzle to plate distance (D). The distance between the two jets (H) is set to 20 times the nozzle thicknesses (w). The results show the presence of a complex scarf vortex formed around each impinging jet, and a fountain-up wash flow resulting from the interaction of the jet with the wall. Though an increase in the Reynolds number has a weak effect on the overall flow structure, it produces a systematic rise of Nusselt number. The maximum heat transfer is reached at the stagnation points (dynamics similar to those already known for a single jet). The influence of the non-dimensional parameter (D/w) on the Nusselt number, however, is significant. The maximum local heat exchange between the wall and the flow occurs when the wall is located at the end of the potential core (D=6 w). The average Nusselt number is correlated with the Reynolds number, for two ranges of impinging distances (wall located before and after the potential core end).

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