The book contains research results obtained by applying Bejan's Constructal Theory to the study and therefore the optimization of fins, focusing on T-shaped and Y-shaped ones. Heat transfer from finned surfaces is an example of combined heat transfer natural or forced convection on the external parts of the fin, and conducting along the fin. Fin's heat exchange is rather complex, because of variation of both temperature along the fin and convective heat transfer coefficient. Furthermore possible presence of more fins invested by the same fluid flow has to be considered.
Classical fin theory tried to reduce the coupled heat transfer problem to a one-dimensional problem by defining an average temperature of the fin and writing equations using this parameter. However, it was shown that this approach cannot be used because of the effects of two-dimensional heat transfer, especially in the presence of short fins. CFD codes offer the possibility to consider bi-dimensional (and more generally, three-dimensional) effects and then a more real approach to the physic phenomena of finned surface's heat exchange.
A commercial CFD code was used to analyse the case of heat exchange in presence of T-shaped fins, following an approach suggested by Bejan's Constructal Theory. The comparative results showed a significant agreement with previous research taken as a reference, and this result allows for the application of this approach to a wider range of systems. T-shaped optimized fin geometry is the starting point for further research.
Table of Contents
General Overview on Heat Transfer
Units and conversion factors
Overview of heat transfer on extended surfaces
State of the art in the T-Shaped Fins
Thermal exchange basis
Modular systems of Y-Shaped fins
Heat removal vs Pressure drops
About the Author(s)Giulio Lorenzini
, University of Parma, Italy
Giulio Lorenzini is Full Professor of Environmental Technical Physics at the University of Parma, Italy. A M.Sc. graduate in Nuclear Engineer and Ph.D. in Nuclear Engineering (titles both achieved at Alma Mater Studiorum-University of Bologna, Italy), he is author of some 150 scientific publications, most of which are scientific papers published in international peer reviewed journals and research monographies. He is currently interested in the following: optimization methods in heat transfer and fluid dynamics, Bejan's Constructal theory, bio-fluid dynamics, analytical and numerical modelling of natural phenomena.Simone Moretti
, University of Parma, Italy
Simone Moretti achieved his Ph.D. title in Agricultural Engineering in 2010 at Alma Mater Studiorum-University of Bologna, Italy. He is currently active in heat exchange research projects applied to industrial systems. His main research interests focus on fluid-dynamic and heat exchange problems faced through CFD and analytical modelling approaches, especially in relation to the use of finned surfaces and optimized heat exchanging profiles. On these topics, he published several papers in leading journals and conferences and is well trained in Bejanâ€™s Constructal theory applications.Alessandra Conti
, Alma Mater Studiorum-University of Bologna, Italy
Alessandra Conti is a Ph.D. student in Energetic and Nuclear Engineering at Alma Mater Studiorum-University of Bologna. She earned her M.Sc. degree in Nuclear Engineering in 2007 at the University "La Sapienza" of Rome. Her current research interests are the following: CFD simulation of blood flow in human arteries, CFD modelling of sprinkler dynamics, and thermal fluid-dynamic optimization.