Measurement of Temperature Field of Jet Impingement Over a Concave Surface Using Thermographic Phosphors and CFD Analysis

This study analyzed the characteristics of an impinging jet on a concave surface, using thermographic phosphor thermometry (TPT) and numerical method. The experiments were conducted under a jet Reynolds number of 6600, with variations in nozzle diameters (5 and10 mm) and nozzle-to-surface distances (H/d = 2 and 5). The study highlights the accuracy of the RNG k-ε turbulence model in predicting the Nusselt number distribution when compared to alternative models such as SST k-ω and realizable k-ε. The results reveal significant variations in heat transfer characteristics associated with changes in nozzle diameter and H/d (Nozzle to surface distance). A distinctive secondary peak in heat transfer was observed at H/d = 2, attributed to vortex-induced flow detachment and subsequent reattachment. Furthermore, increasing the nozzle diameter was found to enhance jet momentum, turbulence intensity, and overall heat transfer efficiency. This research provides valuable insights into the intricate dynamics of jet impingement on concave surfaces, with potential applications in various engineering fields.