In this study, cooling of a constant temperature cube that represents electronic components inserted inside a channel are investigated. For this purpose, primary air with constant velocity is transferred from channel input, and secondary air with impinging jet is transferred to channel upper surface which corresponds to top part of the components. The flows are in contact with the cube that has constant temperature and effects the thermal boundary layer on the cube surfaces to create a heat transfer from cube to fluid. This situation is simulated under turbulence conditions for different values of nozzle jet input velocity (Vj) and channel input velocity (Uc) using Reynolds number between 30000-90000 based on channel input velocity. For this purpose, velocity, temperature, and pressure distributions are obtained for the solution region using CFD package program. As a result, flow and thermal characteristics inside the channel are parametrically calculated based on Reynolds number, Nusselt number, and cube surface temperature.

Les rideaux d'air sont des jets plan traversants conçus pour isoler deux volumes adjacents communicants. De tels systèmes sont communément utilisés dans le but de minimiser les transferts de masse ou de chaleur entres deux zones tout en conservant une libre circulation des personnes et des engins entre ces mêmes zones.Des installations expérimentales ont été conçues pour étudier plusieurs configurations de rideaux d'air et déterminer la meilleure efficacité pour préserver l'énergie ou pour confiner les fumées dans le cas de feux en tunnels routiers. L'analyse a porté principalement sur la dynamique de l'écoulement. Deux configurations composées d'un ou deux rideaux de jet d'air simple ou double ont été comparées. Elles ont été réalisées pour faciliter les mesures vélocimétriques par images de particules (PIV).

The Instability modal behavior of coherent structures in a jet-small cylinder impinging flow field is extensively studied by hot-wire anemometry measurements. The free jet is employed with a small cylinder of 3 mm in diameter located in the potential core region at the impinging length of L/H = 1.5 for the near field impingement and L/H = 4 for the far field impingement. The jet exit velocity is operated at 10 m/sec with the Reynolds number of 1.03 × 104 based on the nozzle exit width H = 15mm. The impinging jet is locally excited at the nozzle exit with varicose mode (m =0) and sinuous mode (m = 1) disturbances at the fundamental frequency of the natural jet flow. Data indicate that the jet flow is greatly altered and significantly enhanced by strengthening the coherent structures of the flow due to resonance according to the feedback mechanism. Although the original natural jet preferably exhibits the varicose mode, the strong sinuous mode is dominant in the flow field owing to the presence of the small cylinder in the potential core region. In the near field impingement, the wake region behind the cylinder preserves the pure sinuous mode to where the jet vortices merge and then mildly fades out. Whereas in the jet shear layer, the sinuous mode exists in the initial portion and gradually transforms to the varicose mode. In the far field impingement, the alternate mode dominates in each frequency stage in pure impinging case and the modal behavior follows the selected mode with the introducing acoustic waves in the acoustic excitation cases.