Heat Transfer Analysis of Circular and Annular Jet Impinging on a Wavy Surface

Abstract

This study numerically analyzes the surface cooling performance of circular and annular jets simultaneously impinging on a wavy target surface.The numerical study was carried out with RNG k-ε turbulance model by the ANSYS Fluent software. The jet-target surface distance was kept constant as H/D=2. The heat transfer on the target surface was calculated with the combinations of circular and annular jets at different Reynolds numbers (4000≤Re≤12000). In addition, the study was compared with the cases where only the circular jet and only the annular jet were active. As a result of the study, the velocity and temperature distributions obtained at different Reynolds numbers were presented. The findings showed that the simultaneous impingement of the circular and annular jets on the target surface provided higher heat transfer compared to only the circular and only the annular jets. For the combination of circular jet Reynolds number Re_in=12000 and annular jet Reynolds number Re_out=4000, it was observed that the heat transfer was improved by 2.49 compared to the circular jet and by 1.53 compared to the annular jet. The results show that the simultaneously impinging circular and annular jet has a important potential in cooling a wavy surface.