Elecrostatic vs. aerodynamic forces in a droplet cluster

A new paper by our international group: A. Fedorets, L. A. Dombrovsky, E. Bormashenko and M. Nosonovsky “On relative contribution of electrostatic and aerodynamic effects to dynamics of a levitating droplet cluster” Int. J. Heat Mass Transfer, 133 (2019) 712-717. New experimental results show decisively that the repulsion force between the microdroplets in a levitating self-assembled cluster is due to the aerodynamic effects and not the Coulomb electrostatic repulsion. The negative charge of a droplet is too small (on the order of 500 elementary charges) to cause any significant force. The polarization of water droplets in an external electric field results in an additional attraction force between the droplets and water layer.