Effect of structural characteristics on the natural convective heat transfer performance of copper foam

The effects of porosity, pore diameter and heating direction on the heat transfer performance of copper foam under natural convection were experimentally investigated. The open cell copper foam with highly controllable porosity ranging from 65% to 85% and mean pore diameters of 330 mu m, 560 mu m, 850 mu m and 1200 mu m were manufactured using a space holder method. The natural convective heat transfer coefficient of the copper foam was measured using a purpose-designed device. The influence mechanism of porosity, pore diameter and heating direction on heat transfer was analysed and discussed. The results showed that when the porosity is less than 75%, the effect of porosity on heat transfer is not significant, but as the porosity increases further, the heat transfer performance decreases significantly. The optimal pore size was found to be 850 mu m, while the heat transfer performance of other pore sizes depends on the porosity. It was also found that the samples heated from the side generally showed better heat transfer performance than the samples heated from the bottom. The influence of porosity and pore size on natural convective heat transfer performance is mainly caused by changes in thermal conductivity and permeability. This research provides important guidance for the design of future heat sinks.

Automated summary

This study experimentally investigated the effects of porosity, pore diameter, and heating direction on the heat transfer performance of copper foam under natural convection. The open-cell copper foam with controllable porosity and different pore sizes was fabricated, and the natural convective heat transfer coefficient was measured. The results showed that porosity had a significant effect on heat transfer performance when it exceeded 75%, with an optimal pore size of 850 μm. Samples heated from the side exhibited better heat transfer performance compared to those heated from the bottom. Changes in thermal conductivity and permeability were the main factors influencing the natural convective heat transfer performance due to variations in porosity and pore size.