Modelling of phase separation in liquids with a miscibility gap

An analytically tractable theory is developed and solutions are presented describing the simultaneous action of three processes occurring during the phase transformation of a single phase fluid into a dispersion of partially or immiscible liquids. These processes are nucleation, diffusional growth and sedimentation due to the action of gravity. A general partial differential equation describing the transformation is developed and solved. Some special cases like a constant or time dependent nucleation rate are treated explicitly. They are compared with experiments performed with immiscible aluminum-bismuth alloys. The agreement between theoretical prediction and experimental results is satisfactory.