Heat transfer distribution for a free/porous system with forced convection and heat generation : a numerical study

This paper reports on a numerical study for steady flow and heat transfer distribution for a configuration relevant to Liquid Composite Molding, where a gap between a porous substrate and the solid boundary of a mold cavity yields an edge flow. The flow within the porous domain is modeled by the Brinkman-Forchheimer formulation, and the edge flow itself is described by the Navier-Stokes equations. The cure of the fluid (resin) is simulated as a volumetric heat generation. The predictions are obtained using a well-tested control-volume finite element method, however, a novel methodology had to be devised to define the interface between the free and porous system. The most relevant finding is the critical role of the gap upon the quality of the part. The presence of the gap can reduce substantially the average flow through the porous substrate, therefore yielding high temperature levels in this region. These temperatures may be sufficiently high to cause serious defects to the part being molded.