Relation of deposition to drop size when the rate law is nonlinear

Measurements of drop size distributions have been obtained by photography for air-water annular flow in a 4.2 cm vertical pipe. Results are presented for a constant superficial gas velocity (36 m/s) for different liquid flows. It is shown that droplet deposition rates can be interpreted by relating the deposition constant directly to the root-mean square of the velocity fluctuations of the drops. The observed decrease of the deposition constant with increasing liquid flow cannot be explained by an increase in drop size. It is suggested that droplet-droplet interactions cause a decrease in drop turbulence. Copyright (C) 1996 Elsevier Science Ltd.