THERMAL ANALISYS AND GEOMETRIC OPTIMIZATION OF A TUBULAR ARRAY USING CONSTRUCTAL DESIGN

Vagner Andrade Pedrotti¹; Jeferson Avila Souza¹; Elizaldo Domingues dos Santos¹; Liércio André Isoldi¹

¹ Universidade Federal do Rio Grande

doi:10.20906/CPS/COB-2015-2214

Resumo

This paper discussed a study with the objective of maximize energy efficiency in a tubular array containing four tubes, subjected to a transverse flow. Taking into account that a large variety of tubular arrangements can exist, in present work it was developed a tubular array assemble which does not uses any kind of preformed arrangement (aligned or staggered) for positioning the tubes. Using the principle of constraints and objectives of Constructal Design and a objective function dependent on the speed and temperature fields, it was calculated, in a deterministic way, the location where the cylinders should be positioned. Proposed tubular array thermal performance was than compared with standard configurations suggested in the literature. The distance between tubes (p) is also considered one of the metrics constraints of the study. It was studied four variations: p is free (no restriction), p= 1.25D, p= 1.5D, p= 2.D, where D is the diameter of the cylinders. Fluid flow is set as laminar, permanent, two- dimensional, incompressible, with forced convection and Prandtl number equal to 0.71. It was evaluated three values for the Reynolds number: ReD= 10, ReD= 50 and ReD=100. Mass, momentum and energy equations were solved by the Finite Volumes 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 show that the Constructal matrix (optimized) assembles was more efficient, creating geometric formations that allows greater heat exchange between the fluid and the tubes.

Palavras-chave: Constructal Design; Tubular array; Geometric optimization