AN ANALYSIS OF THERMAL AND DIFFUSION EFFECTS ON DROPLET GROWTH RATES.
CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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The effects of thermal and diffusion limitations on growth rates and temperature history of small droplets are analyzed for a supersaturated vapor in an inert carrier gas. The growth rates are determined for the cases of constant field conditions, and changing fluid conditions due to vapor deposition on droplets. The analysis is so formulated as to describe the growth process as the droplet size increases from microscopic free-molecular to macroscopic continuum. For the constant field case, closed-form solutions are obtained for the droplet temperature and growth as functions of time by expressing approximately the saturation pressure of the condensing vapor as a linear function of the temperature within moderate temperature ranges. An analysis is also made of the droplet growth and temperature increase in a changing environment. The change is caused by the depletion of the vapor concentration as a result of condensation on the droplets. Equations involving conservations of mass and energy are solved, incorporating thermal and diffusion limitations, the droplet concentration and the fluid temperature change due to liberation of the heat of condensation. Author
- Physical Chemistry