Abstract View
Possible, Impossible and Expected Diameters and Flow Rates in Droplet Aerosols
MAKSIM MEZHERICHER, Howard A. Stone, Princeton University
Abstract Number: 718
Working Group: Aerosol Physics
Abstract
In our recent work we demonstrated a novel liquid atomization technique producing aerosols of submicron-diameter droplets for pure solvents, suspensions, and solutions. Our aerosol generation process is based on disintegration by gas jets of thin liquid films formed as bubbles on a liquid surface. For this system and, in general, for any other aerosol generation system, one of the arising questions is how to theoretically predict possible, impossible and expected droplet diameters and flow rates which the system will produce at different regimes. And another question is how to compare our aerosol generation method with other techniques, and in general how to compare between different aerosol production methods.
In this work we show that the diameters and flow rates of the produced droplets are governed by the interplay of process timescales including capillary breakup, liquid viscosity, and gas jet pressure.
Timescale ratios can be converted into the ratios of specific energies and into the ratios of specific energy rates provided by the gas jets and dissipated by the atomized liquid. Using those ratios, we developed a new theoretical approach to determine an upper limit of droplet diameters and flow rates in droplet aerosol generation and introduce atomization diagrams. The theoretically predicted and measured droplet diameters and droplet flow rates for various liquids (water, gasoline, diesel) were a good agreement for our aerosols of submicron-diameter droplets.
Using the developed theoretical analysis to compare between our droplet generation method with conventional pressure nozzle, we demonstrate that our approach can also serve as a theoretical framework for comparison between different aerosol and spray production techniques.