Ph.D. Tezi Görüntüleme

      In this study, natural and mixed convection in a vertical channel with discrete heat sources is studied experimentally and numerically. The aim of this study is to determine optimum geometry and operating conditions. For this purpose, studies are carried out on the basis of the constructal theory in order to optimize the spacing ratio, heat dissipation ratio, length ratio of the heat sources and cross section ratio of the channel in natural and mixed convection regimes under different working conditions. Either protruding heat sources at different protrusion ratios or flush mounted heat sources are considered. Natural convection studies include the modified Grashof numbers of 9.6x105 and 1.53x107 while mixed convection studies cover the Reynolds numbers between 1000 and 4000 for a constant value of the modified Grashof number at 1.53x107. Radiative heat transfer between the surfaces is considered. Velocity and temperature measurements are carried out and flow visualization studies are performed in the experimental work. Numerical computations are performed with ANSYS Fluent (v.15) software. As a result of the studies, it is observed that the use of identical heat sources reduces the global cooling performance of the system, and the decreasing thermal density from the entrance increases the cooling performance.