Ph.D. Tezi Görüntüleme | |||||||||||||||||||||
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| Summary: In this study, flow and heat transfer in a slot air jet flow impinging on semi-cylindirical concave surfaces were investigated experimentally and theoretically. Using a concave surface, it is aimed at increasing surface heat transfer and at obtaining a more uniform cooling by preventing the boundary layer seperation from the surface. For six different values of the Reynolds number and eight different values of the nozzle-plate distance, hydrodynamical and thermal characteristics were investigated. In hydrodynamic study, pressure distributions on the surface were obtained for varying working conditions. It was found that the pressure coeffient at stagnation point increased for all the Reynols numbers tested as the value of H/W decreases. It was also detemined that at small nozzle-to-plate spacings, such as 2H/W<6, the value of the pressure coefficient at the stagnation point is about 1. For H/W6, because jet center line velocity decreases rapidly, it was seen that pressure coefficient values decrease significantly. It was also concluded that the mean pressure coefficient values and the stagnation point pressure coefficient values take lowest values for the flat plate.As a result, for an effective cooling of concave surfaces, the optimum Reynolds number for different radius of curvature was determined for each radius. In this regard, the present study consists of six chapters. In the first chapter, general information and literature review are presented. In second chapter, hydrodynamical and heat transfer experimental setups are described and stages of experimental and numerical studies are explained. In the third section, findings are presented in graphs and tables. The results of this study are summarized in the fourth chapter and recommendations are presented in the fifth section. The used sources are given in sixth chapter.
Key Words: Slot Impinging Jet, Concave Surface Curvature, Fluent, Pressure Coefficient | |||||||||||||||||||||