  The possible impact of temperature differences during crystal growth is
investigated in this study. The organic molecule considered is mandelic acid,
an important component for the pharmaceutical industry. The productivity of
generating pure mandelic acid crystals are largely determined by the growth
process. Reaction conditions, purity of the components, supersaturation,
temperature, but possibly also temperature gradients play a central role during
crystal growth. In this study a numerical model based on a hybrid solver
combining the lattice Boltzmann method with finite differences is developed to
model the crystallization dynamics of (S)-mandelic acid (S-ma) taking
quantitatively into account temperature effects. At first, the fourth-order
finite-difference method used to model energy and species conservation is
validated. Then, comparisons are carried out regarding temperature changes
within the single-crystal growth cell. In practice, the molar heat generation
at the crystal interface shows only a small effect on the temperature field in
the surrounding domain, with temperature differences below $1.5$ degree.
Finally, the study is extended to investigate the impact of forced convection
on the crystal habits while taking into account temperature differences.
