Dynamic and thermal characteristics of a turbulent and heated offset jet were numerically investigated using Ansys Fluent. The jet's heated bottom wall is mounted with a single square-section rib and characterized with constant heat flux. The flow velocity, at the nozzle exit, corresponds to a Re value of 39 000, besides the offset ratio is assumed to be fixed at 5. Nine different rib positions were tested in order to figure out which is the optimum one that enhances most the heat transfer. Detailed analysis of the development of the flow in addition to the convective heat transfer features is presented. The results showed that flow behavior changes significantly with the presence of the rib. Further, the heat transfer investigation revealed two optimum rib positions that guarantee the heat transfer amelioration.

A combined turbulent wall jet and offset jet (also known as the dual jet) with and without the presence of a parallel co-flow stream is studied. The standard k –ω turbulence model is used to predict the turbulent flow. The study focuses on the effects of the co-flow velocity (CFV) on the heat-transfer characteristics of the dual jet flow with the bottom wall maintained at a constant wall temperature. The CFV is varied up to 40% of the jet inlet velocity, and the height of the offset jet is varied from 5 to 11 times the jet width with the inlet Reynolds number taken as 15,000. The heat-transfer results reveal that the local Nusselt number ( Nu x ) along the bottom wall exhibits a peak at the immediate downstream of the nozzle exit, followed by a continuous decay in the rest of the converging region before showing a small rise for a short streamwise distance in the merging region. Further downstream, in the combined region, Nu x gradually decreases with the downstream distance. Except the merging region, no influence of co-flow is observed in the other two flow zones (converging and combined regions). In the merging region, for a given offset ratio (OR), Nu x remains nearly constant for a certain axial distance, and it decreases as the CFV increases. As a result of the increase in the CFV, the average Nusselt number decreases, indicating a reduction in overall convective heat transfer for higher values of the CFV. A regression analysis among the average Nusselt number ( ), CFV, and OR results in a correlation function in the form of within the range OR = 5–11 and CFV = 0–40%.

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