The evacuated tube solar thermal collector, as one of the most efficient solar thermal collectors, has been widely used in solar water heating systems for residential and industrial buildings. The performance of these collectors is determined by different physical phenomena including heat conduction, heat convection and fluid dynamics. In this study, these physical processes were theoretically analyzed and then incorporated into a finite element analysis simulator in order to conduct a numerical analysis on their performance. For this purpose, 2D and 3D finite element models were developed to simulate and visualize the temperature distribution as well as the velocity field inside the fluid domain. Parameters such as mounting angle, aspect ratio, tube arrangement, and sunlight incidence angle were changed in the models with the purpose of investigating their effects on the overall efficiency of these collectors.;Key words: Finite element analysis, evacuated tube collector, thermal performance. |