Abstract
On the rate of evaporation of water drops, the following semi-empirical formula was derived: where -dm/dt=rate of evaporation; D=diffusion constant; r=radius of the drop; Cs=saturation vapour density at the temperature of the drop; C∞=vapour density in the air; Re=Reynolds number; K=β/1-β/2√RTw/2πM; β=condensation coefficient of water; R=the universal gas constant; M=molecular weight; Tw=temperature of the drop; σ=D/υ; υ=kinematic viscosity of air.
The formula is nearly equal to the Frössling's formula when r is large, and to the author's former formula when r is small.
