Flow and heat transfer in graded porous media and its application in aeroengine cooling

Abstract

In recent decades, many studies on flow and heat transfer in porous media have been conducted by researchers to take advantage of its high specific surface area and good heat transfer performance. What is more, the graded porous media have also drawn great attention since the graded arrangement enhances local heat transfer coefficient, so as to improve the overall heat transfer performance and temperature uniformity. The new forms of structure provide a new design of cooling system for some high-power heat sources, such as electronic components, compact heat exchangers, and hot components in aeroengine. In this chapter, the problems of channels filled with vertically graded porous media and axially graded porous media have been introduced, respectively. The flow and heat transfer characteristics of graded porous media have been studied based on porous media theory, considering the parameters of porosity, permeability, pore diameter, etc. The profiles of velocity and temperature vary with different porosity arrangements present. The maximum heat transfer coefficient was obtained for the case of high porosity at the center and low porosity near the wall. Furthermore, the possibility of application in the aeroengine cooling has been discussed.