Constructal multi-scale tree-shaped heat exchangers
- 1 August 2004
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 96 (3), 1709-1718
- https://doi.org/10.1063/1.1766089
Abstract
This paper describes the conceptual design and performance of balanced two-stream counterflow heat exchangers, in which each stream flows as a tree network through its allotted space. The two trees in counterflow are like two palms pressed against each other. The paper develops the relationships between effectiveness and number of heat transfer units for several tree-counterflow configurations: (i) constructal dichotomous trees covering uniformly a rectangular area, (ii) trees on a disk-shaped area, and (iii) trees on a square-shaped area. In configurations (ii) and (iii) each stream flows between the center and the periphery of the area. Configurations (i) and (ii) are trees with minimal resistance to fluid flow. Configuration (iii) is designed by minimizing the length of each duct in the network. The paper reports the formula for the number of heat transfer units in each configuration. Unlike in counterflows formed by two parallel streams, in which the longitudinal temperature gradient is constant, in the counterflow formed by two trees the longitudinal temperature gradient is steeper as one approaches the periphery of the tree canopy. The application of dendritic heat exchangers to devices with maximal transport density is discussed, e.g., electronics cooling, fuel cell architectures, etc.Keywords
This publication has 12 references indexed in Scilit:
- Porous and Complex Flow Structures in Modern TechnologiesPublished by Springer Science and Business Media LLC ,2004
- Metal foams as compact high performance heat exchangersMechanics of Materials, 2003
- Fundamentals of Heat Exchanger DesignPublished by Wiley ,2003
- Optimal tree-shaped networks for fluid flow in a disc-shaped bodyInternational Journal of Heat and Mass Transfer, 2002
- Tree-shaped flow structures designed by minimizing path lengthsInternational Journal of Heat and Mass Transfer, 2002
- Tree-shaped insulated designs for the uniform distribution of hot water over an areaInternational Journal of Heat and Mass Transfer, 2001
- The tree of convective heat streams: its thermal insulation function and the predicted 3/4-power relation between body heat loss and body sizeInternational Journal of Heat and Mass Transfer, 2001
- CONTROL OF FLUID DYNAMICS WITH ENGINEERED FRACTALS - ADSORPTION PROCESS APPLICATIONSChemical Engineering Communications, 1999
- The Effectiveness of Mass Fractal CatalystsFractals, 1997
- A Counter Current Vascular Network Model of Heat Transfer in TissuesJournal of Biomechanical Engineering, 1996