Akdağ, ÜnalAkçay, SelmaÜn, NecatiDanışmaz, Merdin2024-07-182024-07-1820240891-6152https:/dx.doi.org/10.1080/08916152.2024.2356165https://hdl.handle.net/20.500.12451/12151Annular impinging jets create a more uniform flow on the impact surface compared to circular impinging jets, allowing the surface to cool better. Additionally, periodic flow oscillations significantly increase heat transfer by reducing the thermal resistance on the surface. Therefore, this study experimentally investigated the heat transfer characteristics of a synthetic annular jet impinging on a flat surface with constant heat flux. In the experiments, the jet-target surface distance (H/D), jet Reynolds number (Rej), oscillation amplitude (Ao), and Womersley number (Wo) were changed. In contrast, the Prandtl number (Pr) and other geometric parameters were kept constant. The effects of these parameters on heat transfer were analyzed and the results were compared with continuous circular and annular impinging jets. Local temperature values on the target surface were obtained for different parameters and heat transfer from the surface was calculated. Experimental results showed that heat transfer increased with decreasing H/D ratio for all jet types. The highest heat transfer on the surface was achieved in synthetic jet flow. Heat transfer increased as the oscillation amplitude decreased.eninfo:eu-repo/semantics/embargoedAccessAnnular JetFlat Target SurfaceHeat Transfer EnhancementSynthetic Impingement JetArticle10.1080/08916152.2024.2356165Q1N/A