Freezing enhancement around a horizontal tube using copper foil disks

Freezing of water saturated in circumferentially arranged copper foils around a cooling tube is studied experimentally and numerically. The copper foils need not to be welded to the cooling tube but are merely placed around the tube so that the freezing system is easily arranged. Copper foils greatly enhance freezing compared with that of a bare tube, even with a small copper volume fraction in the freezing system. Numerical calculations by means of a continuum model predict well freezing enhancement. The effect of the copper foils is also considered numerically for the melting process in order to compare with freezing. It is seen that copper foils contribute more to the melting enhancement than to the increase of the freezing rate.