  Given the multitude of growth habits, pronounced sensitivity to ambient
conditions and wide range of scales involved, snowflake crystals are one of the
most challenging systems to model. The present work focuses on the development
and validation of a coupled flow/species/phase solver based on the lattice
Boltzmann method. It is first shown that the model is able to correctly capture
species and phase growth coupling. Furthermore, through a study of crystal
growth subject to ventilation effects, it is shown that the model correctly
captures hydrodynamics-induced asymmetrical growth. The validated solver is
then used to model snowflake growth under different ambient conditions with
respect to humidity and temperature in the plate-growth regime section of the
Nakaya diagram. The resulting crystal habits are compared to both numerical and
experimental reference data available in the literature. The overall agreement
with experimental data shows that the proposed algorithm correctly captures
both the crystal shape and the onset of primary and secondary branching
instabilities. As a final part of the study the effects of forced convection on
snowflake growth are studied. It is shown, in agreement with observations in
the literature, that under such condition the crystal exhibits non-symmetrical
growth. The non-uniform humidity around the crystal due to forced convection
can even result in the coexistence of different growth modes on different sides
of the same crystal.
