Constructal design of a tubular array subjected to forced convection.

Abstract

In this work a tubular array (four tubes) subjected to a transverse forced flow is analyzed in terms of thermal performance. Taking into account that there are two main assembles usually used in heat exchanger equipment (aligned and staggered), and that there exist an uncountable number of possible assembles for an array of tubes, present work proposes to use the Constructal Theory to build an optimized assemble. The distance between tubes (p), and the region where tubes can be positioned are the geometric constraint of the problem. Four values for p were considered: p = 1.25D (tube diameter), p = 1.5D, p = 2D, p is free (no restriction). Fluid flow is considered bi-dimensional, incompressible and laminar with ReD = 10 and Pr = 0.71. Mass, momentum and energy equations were solved by the Finite Volume Method (FVM) using FLUENT software. Geometry creation and mesh generation were performed with GMSH software while VISIT software was used for the post processing. Results have shown that imposing no restriction to tube positioning do not necessarily lead to best system thermal performance. In this particular study, setting p = 2D has resulted in best thermal performance. Keywords: tubular assemble, optimization,