Enhancing forced convection by inserting porous substrate in the core of aparallel-plate channel

Investigates numerically the mechanism of enhancing heat transfer by using porous substrate. The numerical investigation is carried out for transient forced convection in the developing region of a parallel-plate channel part ially filled with a porous medium. A porous substrate is inserted in the ch annel core in order to reduce the boundary layer thickness and hence, enhan ce heat transfer Darcy-Brinkman-Forchheimer model is used to simulate the p hysical problem. Results of the current model show that the existence of th e porous substrate may improve the Nusselt number at the fully developed re gion by a factor of four and even higher depending an the value of Darcy nu mber. If is found that the maximum Nusselt number is achieved at an optimum thickness. Also, the study shows that partially filled channels have bette r thermal performance than the totally filled ones. However, there is an op timum thickness of porous substrate, beyond it the Nusselt number starts to decline.