Evaporation of Water into a Sub‐Zero Air Stream

Abstract

Evaporation of water into sub‐zero air stream to simulate water surface conditions during North American winters has been experimentally carried out. The study covers an air velocity range from 10 to 160 cm/sec and air temperatures up to 20°C below that of the water surface. The results can be well represented by N_um = 12.7 + 0.00288 R_eL, where N_um and R_eL are the Nusselt number for mass transfer and the Reynolds number based on the length of the evaporating surface. This correlation gives a value about two and one‐half times higher than the result calculated from the Bowen ratio.