Heat transfer coefficient of porous copper with homogeneous and hybrid structures in active cooling

Heat transfer coefficients of porous copper samples with single- and double-layer structures, fabricated by the lost carbonate sintering process, were measured under forced convection conditions using water as the coolant. Compared with the empty channel, introducing a porous copper sample enhanced the heat transfer coefficient 5–8 times. The porous copper samples with double layers of porosities of 60% and 80% often had lower heat transfer coefficients than their single layer counterparts with the same overall porosities because the coolant flowed predominantly through the high-porosity layer. For the same double-layer structure, the order of the double layer had a large effect on the heat transfer coefficient. Placing the high-porosity layer next to the heat source was more efficient than the other way around. The predictions of a segment model developed for the heat transfer coefficient of multilayer structures agreed well with the experimental results.