This study experimentally investigates the effects of a circular impinging jet on heat transfer and flow dynamics. Using an aluminum nozzle with a diameter of d=13.8 mm, experiments were conducted within the Reynolds number range of 5000−25000. The nozzle-to-plate distance (h/d) was varied between h/d=2−10 to evaluate the jet's performance. Local Nusselt numbers (Nu), stagnation point Nusselt number (Nu0), and average Nusselt numbers (Nuavg) were analyzed in detail. The results demonstrated that both the nozzle-to-plate distance and Reynolds (Re) number significantly influence heat transfer performance. Increased Reynolds numbers and optimal h/d distances led to enhanced heat transfer at the stagnation point. These findings highlight the potential of impinging jets for energy-efficient cooling applications. The optimal nozzle-to-plate distance for maximum heat transfer was found to be h/d = 6, with a 30.5% increase in Nusselt number at Re = 25000. Additionally, turbulence intensity played a crucial role in heat transfer performance, particularly in the wall jet region, where it enhanced mixing and improved thermal efficiency.
Çelik et al. (Mon,) studied this question.