Fluid Flow and Heat Transfer Characteristics of Multiple Swirling Impinging Jets at Various Impingement Distances

Abstract

This research investigates the fluid flow and heat transfer characteristics for the effect of multiple swirling jets impinging on a heated plate. In this regard, numerical simulations were performed for the inline-type jet arrangement using ANSYS v16.2. Governing equations for turbulent swirl flows were solved by coupled algorithm whereby turbulences are described by SST k-ω model. The analysis is studied for Reynolds number Re = 11600 and swirl number 0.74 at impingement distances equal to 1, 2, 3 and 4 times nozzle diameter. The numerical results showed that impinging distance has a significant effect on both heat transfer and fluid flow characteristics. In case of low impinging distance (H=1D) swirling effect was dominant and the strong recirculation zones resulted in a higher heat transfer from the heated surface. With the increase of impingement distance, the turbulent kinetic energy reduced significantly near the heated surface. It was evident that for higher impingement distance (H=4D) the effect of swirl was greatly reduced resulting in a lower heat transfer from the heated surface