In this research, the fluid and thermal characteristics of a rectangular turbulent jet flow is studied numerically. The results of three-dimensional jet issued from a rectangular nozzle are presented. A numerical method employing control volume approach with collocated grid arrangement was employed. Velocity and pressure fields are coupled with SIMPLEC algorithm. The turbulent stresses are approximated using k-ε model with two different inlet conditions. The velocity and temperature fields are presented and the rates of their decay at the jet centerline are noted. The velocity vectors of the main flow and the secondary flow are illustrated. Also, effect of aspect ratio on mixing in rectangular cross-section jets is considered. The aspect ratios that were considered for this work were 1:1 to 1:4. The results showed that the jet entrains more with smaller AR. Special attention has been drawn to the influence of the Reynolds number (based on hydraulic diameter) as well as the inflow conditions on the evolution of the rectangular jet. An influence on the jet evolution is found for smaller Re, but the jet is close to a converged state for higher Reynolds numbers. The inflow conditions have considerable influence on the jet characteristics.

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A study has been made of the flow and heat transfer to a circular cylinder from an isothermal impinging air jet. Numerical solutions of the governing conservation equations have been obtained utilizing a non-orthogonal curvilinear coordinate grid. The study focused on low Reynolds numbers (based on nozzle average exit velocity and cylinder diameter) in the range of 132-1315 and H/W = 2, 4, 6 and 8 which corresponds to the ratio of distance between the nozzle and cylinder to nozzle width. The flow is stable and symmetric over the range of parameters studied. The effects of buoyancy, diffusion and cooling of the cylinder, the development of the wall jet, and the recirculating bubble all affect the flow and heat transfer. The average Nusselt number increases with increasing Reynolds. Also the distance between the nozzle and the cylinder has a strong effect on the heat transfer.

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