TY - EJOU
AU - Bentarzi, Fatiha
AU - Mataoui, Amina
TI - Turbulent Flow Produced by Twin Slot Jets Impinging a Wall
T2 - Fluid Dynamics \& Materials Processing
PY - 2018
VL - 14
IS - 2
SN - 1555-2578
AB - 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).
KW - Twin impinging jets
KW - heat transfer
KW - turbulence
KW - CFD
KW - fountain flow
DO - 10.3970/fdmp.2018.06046