How cloud droplets grow to raindrops in warm clouds, clouds without ice crystals, have puzzled scientist for a long time. In this project, the possible enhancement of droplet growth by turbulence is investigated. The first step in this project is to include droplet microphysics, condensation and collection processes, in a DNS code. One traditional Eulerian method and one novel Lagrangian method are implemented. Both methods are tested and the Lagrangian method is found to be superior in accuracy and computational efficiency for the problem at hand.
Li, X., A. Brandenburg, N.E.L. Haugen, and G. Svensson, 2017: Eulerian and modified Lagrangian approaches to multi-dimensional condensation and coagulation. Journal of Advances in Modeling Earth Systems. Journal of Advances in Modeling Earth Systems 9 (2), 1116-1137.
Fig. Snapshot of the spatial distribution of droplets from 3-D turbulence simulation. Darker color represents larger droplets.