Abstract
In order to examine the changes of the velocity of evaporation from a free water surface produced by wind, experiments on evaporation were made under various wind velocities of 0-10m per sec in a wind tunnel. To compare the results with Tra_??_ert's evaporation formals, QP/T (E-e) (1-0.0142t) was calculated from the evaporation velocity Q, where P is the atmospheric pressure, T absolute temperature of air. E-e saturation difference of air, t temperature of air in °C and 1-0.014t a correction by which Trabert's evaporation formula Q=T/CP(E-e)√W should be multiplied, where IV is the wind velocity, according to the experiment of Okazaki and others.
The results are as follows.
(i) The term √W should be substituted by √W-C, where C is a constant of 0.3_??_0.5m per sec.
(ii) At large wind velocities of 6-7m per sec or more, the quanity becomes constant, which does not depend on the wind velocity.
