variavel0=<b>Andre Roberto Nisgoski</b> - nisgoski@labsolar.ufsc.br Universidade Federal de Santa Catarina
<b>Marcia Barbosa Henriques Mantelli</b> - marcia@emc.ufsc.br Universidade Federal de Santa Catarina
<b>Abstract.</b> The present study presents the two-phase flow phenomenon inside the tubes of the loop thermosyphon. The principal objective is to determine the constructive parameters that means the lowest temperature gradient between the four sections from loop thermosyphon, aiming the temperature homogenization. For this, an experimental apparatus of glass and other of stainless steel were made and an analytical model were developed. This model is simple and can be used as a design tool. Kutateladze and Kaminaga correlations showed good values in estimation of the boiling and condensation. Magnitude order of the 10-2 for the equivalent thermal resistance was obtained. Oscillations in the temperature measure were detected in the loop thermosyphon due to the continuos formation and escape of the vapor bubble in the evaporator section. The experimental uncertainty from the thermal resistance was about 1.2 %.
<b>Keywords.</b> Two-Phase Loop Thermosyphon, Heat Transfer, Two-Phase Flow.