Akademik Veri Yönetim Sistemi
HEAT TRANSFER RESEARCH, cilt.48, sa.3, ss.211-220, 2017 (SCI-Expanded)
This work experimentally studied heat transfer associated with three aluminum-foam heat sinks having various porosity size of 10, 20, and 40 PPI (pore per inch). Air was used as the coolant. Aluminum-foam heat sinks have been placed in discrete form on heat sources in a rectangular channel in order to investigate the heat transfer effect on the electronic equipment performance. The lower surface of the channel was equipped with 8 x 2 aluminum-foam heat sinks placed on copper blocks subjected to a uniform heat flux. All the channel surfaces were insulated. The experimental study was made for Reynolds numbers varying from 531 to 2461, while the Grashof number ranged from 4.2 x 10(7) to 2.7 x 10(8). The results show that the row-averaged Nusselt number values increase with increasing Grashof number for all pore densities. While the first row of the foam is affected by forced convection flow, with increase in the buoyancy-induced flow and the onset of instability, the row-averaged Nusselt number increases around the middle section of the rows because of the heat transfer enhancement. Comparisons made between the foams having different pore densities show that the 10 PPI aluminum-foam heat sink displays 3% and 18% higher Nusselt number values than those of the 20 PPI and the 40 PPI, respectively, because of its high permeability and low pore density characteristics. The results obtained also represent that the aluminum-foam heat sinks show 2 to 3 times higher thermal performance than those of no aluminum-foam case in the channel.