Paper Title
Numerical Simulation of Natural Convection Heat Transfer in Annular Fin-Tubes

Abstract
The use of natural convection and heat exchangers with horizontal tubes under natural convection flow is a common practice used in air conditioning systems, refrigerators and many more. The purpose of this study is to investigate flow behavior and natural convection heat transfer through horizontal fin-tubes. Regarding the examination of natural convection through annular fins, there is no numerical simulation involving a comprehensive examination of phenomena and details. In this research, the results of numerical simulation of natural convection in a simple horizontal cylinder are compared with the existing equations. Afterwards, using the only existing empirical equations, the results of the simulation of horizontal fins under natural convolution are validated. The obtained results provide a clear picture of the phenomena and flows. In addition, the way the heat is transferred to the annular fin tubes is shown. ANSYS CFX software has been used to model and analyze annular fins. Air temperature contours and density, as well as temperature distribution and variations in different locations are given. Keywords - Natural Convection, Fin Tubes, Annular Fins