A Three-Dimensional Stochastic Model of DSD Evolution in Warm Rain

A 3D model for the resolution of the stochastic equation describing the evolution of the raindrop spectra is presented in this work. This model uses the Quadrature Method of Moments (QMOM) for the prediction of rainfall microstructure including coalescence, breakup, accretion, evaporation and condensation mechanisms. The stochastic equation is solved for the lower order moments of the Droplet Size Distribution. It is shown that the QMOM is able to capture the temporal evolution of DSD in warm rain. Results obtained with the QMOM approach will be compared with alternative formulations in terms of computational time and physical consistency. In addition, simulation results will be compared with experimental measurements in an attempt to better understand and quantify the dynamic of coalescence and breakup mechanisms in the evolution of raindrop spectra.