Experimental study of convective heat transfer of a nanofluid through a pipe filled with metal foam.

The interaction of nanofluids with extended surfaces in the form of porous structures and its effect on the thermal performance of the heat exchanger is not well documented. In this study, the forced convective heat transfer due to flow of Al 2 O 3 /Water nanofluid through a circular tube filled with a metal foam is investigated experimentally. An isothermal boundary condition is created and the pressure drop and the heat transfer rate are measured over a range of flow rates. The results are compared with values for water flowing through a similar tube without the metal foam insert. The experimental data indicate a significant improvement in the heat transfer rate at the cost of a pressure drop increase. Our experimental data also show a direct relationship between the Nusselt number and the volume fraction of Al 2 O 3 . [ABSTRACT FROM AUTHOR]