Droplet condensation in turbulent flows

PACS. 47.27.Eq – Turbulence simulation and modeling. PACS. 47.27.Gs – Isotropic turbulence; homogeneous turbulence. Abstract. – The problem of droplet growth by condensation in a turbulent flow of nearly saturated vapour is addressed theoretically and numerically. We show how the presence of an underlying turbulent velocity field induces a correlation between droplet trajectories and supersaturation. This leads both to the enhancement of the droplet growth rate and to a fast spreading of the droplet size distribution. Introduction. – The evolution of microdroplets in a turbulent environment is an issue of great interest for a variety of applications ranging from health care [1], to engineering, to atmo-spheric sciences [2–4]. In the latter context, microdroplet growth by condensation/evaporation is a phenomenon of paramount importance for the early stages of cloud evolution. Warm clouds are essentially a polydisperse aerosol of water droplets suspended in a moist air. Th