Analysis of pulsating convection from two heat sources mounted with porous blocks

The present work details the numerical simulation of forced pulsating convective flow in a parallel-plate channel with two porous-block-attached strip heat sources at the bottom wall. The analysis is based on the use of unsteady Navier–Stokes equation in the fluid region, the transient Darcy–Brinkman–Forchheimer flow model in the porous region, and the energy equation on the thermal field. Both the mixing enhanced convection caused by porous block and the oscillatory enhanced convection caused by pulsation flow are examined. This study details the effects of variations in the Darcy number, pulsating frequency and amplitude, porous blockage ratio, to illustrate important fundamental and practical results. The results show that the periodic alteration in the structure of recirculation flows, caused by both porous block and flow pulsating, has a direct impact on the flow and thermal characteristics near the heat source region. In addition, it is shown that specific choices in certain governing parameters, such as the size or permeability of porous block, and the frequency and amplitude of external pulsation can produce profound enhanced heat transfer on the cooling of heat sources. The cycle-average local surface temperature distribution of heater for pulsating-flow case with porous block is more uniform than that for pure steady-flow case. The method combining flow pulsation with finite-size fiber-porous heat sink can be considered as an augment heat transfer tool for cooling electronic devices.