Düz oluklu ısı borularının ısıl performans karakterizasyonu

Heat pipes are promising heat removal devices widely used in a variety of fields ranging from thermal management of electronic components to terrestrial and aerospace applications. Their working principle, phase change of a working fluid, makes them superior to other conventional cooling methods. This thesis study focuses on flat grooved heat pipes and the effects of working fluid, filling ratio, groove density, and input heat flux on their thermal performance are investigated. During the study, two aluminum heat pipe generations and one silicon heat pipe configuration, each having a set of different groove densities, are fabricated. In each set, different methods of heating and cooling are applied. In all the experiments on aluminum heat pipes, the working fluid is isopropyl alcohol due to its wetting characteristics that makes it compatible with the aluminum surface. For the case of silicon, the heat pipes are charged with isopropyl alcohol and water. The optimum filling ratio, corresponding to the minimum temperature difference along the heat pipe and maximum effectiveness, is reported for each heat pipe. Moreover, as one of the operational limitations of heat pipes, the occurrence of dryout is visually observed and its extent is reported for each heat pipe operating at different filling ratios under different heat inputs. Furthermore, to find the heat input to the heat pipes of first generation and to simulate the phase change in one of the heat pipes of second generation, two 3-D computational models are developed and temperature distribution along the heat pipes are verified by the experimental results.