A fractal analysis of dropwise condensation heat transfer

In this paper, a fractal model for dropwise condensation heat transfer is developed based on the fractal characteristics of drop size distributions on condensing surfaces. Expressions for the fractal dimension and area fraction of drop sizes are derived, which are shown to be a function of temperature difference between condensing surface and saturated vapor. The condensation heat transfer is found to be a function of the fractal dimension for drop sizes, maximum and minimum drop radii, the temperature difference, and physical properties of fluid. The predicted total heat flux from a condensing surface based on the present fractal model is compared with existing experimental data. Good agreement between the model predictions and experimental data is found, which verifies the validity of the present model.