Compact Heat Transfer Flow Structures

Abstract

In this chapter we discuss a series of developments that point in the direction of applying porous media concepts to the description, simulation, and optimization of compact systems with complex flow structures. Compact and miniaturized heat exchangers are primary examples of this trend. Other examples are chemical reactors, fiber filters, brush seals, and the modeling of microsegregation during the solidification of alloys. The new aspect highlighted by these developments is that flow structures are optimized so that flow systems exhibit maximum global performance subject to global constraints. Optimization of flow structure means that in the beginning the flow geometry is free to change. The system is free to morph. Global performance is achieved through the generation of flow architecture (Bejan, 2000). The flow structure becomes a porous medium with purpose, that is, a designed porous medium.