International Journal of Heat and Mass Transfer, Vol.54, No.1-3, 636-644, 2011
Laminar forced convection in a heat generating bi-disperse porous medium channel
Thermal management of heat generating electronics using the Bi-Disperse Porous Medium (BDPM) approach is investigated. The BDPM channel comprises heat generating micro-porous square blocks separated by macro-pore gaps. Laminar forced convection cooling fluid of Pr = 0.7 saturates both the micro- and macro-pores. Si-dispersion effect is induced by varying the porous block permeability Da(1) and external permeability Da(E) through variation in number of blocks N-2. For fixed Re, when 10(-5) <= Da(1) <= 10(-2), the heat transfer Nu is enhanced four times (from similar to 200 to similar to 800) while the pressure drop Delta p* reduces almost eightfold. For Da(1) < 10(-5), Nu decreases quickly to reach a minimum at the Mono-Disperse Porous Medium (MDPM) limit (Da(1) -> 0). Compared to N-2 = 1 case, Nu for BDPM configuration is high when N-2 >> , i.e., the micro-porous blocks are many and well distributed. The pumping power increase is very small for the entire range of N-2. Distributing heat generating electronics using the BDPM approach is shown to provide a viable method of thermo-hydraulic performance enhancement Z. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords:Forced convection;Mono-disperse;Bi-disperse;Porous medium;Electronics cooling;Heat generation