FORCED-CONVECTION FREEZING HEAT-TRANSFER CHARACTERISTICS IN A RETURN BEND WITH A RECTANGULAR CROSS-SECTION

Experiments have been performed to investigate the freezing heat trans fer characteristics in a return bend with a rectangular cross section. The experiments were carried out for two kinds of duct heights of 30 and 50 mm under the fixed size of 300 mm in duct width and 159 mm in c urvature radius of convex wall. Both the convex and concave walls of a return bend were kept less than the freezing temperature of water. It was found that the freezing characteristics on the convex wall are ma rkedly different from those on the concave wall of a return bend, and that the cooling temperature ratio is one of the most important parame ters on the forced-convection freezing heat transfer in a return bend.