Crystallization nuclei in liquid in a sound field

Abstract

This paper is concerned with the theoretical investigation of crystallization nuclei undergoing radially symmetric oscillations in supercooled liquids and supersaturated solutions exposed to a sound field. Periodic crystallization and melting processes occurring in the course of these oscillations are shown to result in higher amplitudes. This enhances the nonlinear interaction of sound with an oscillating nucleus which results in the phenomenon of rectified heat transfer, i.e. a slow (as against the sound cycle) process of heat pumping into a nucleus. Another peculiar feature of the nonlinear interaction between the sound and the nuclei is evidenced by the fact that the location of nucleation sites in a standing sound wave depends on the dimensions of nuclei and the sound frequency—a situation differing substantially from the case of solid particles without phase transformations. It is shown that phase transformations may markedly increase the absorption and dispersion of the speed of sound propagating in crystallizing liquids as compared with liquids containing solid particles without phase transformations. It is also shown that an increase in the amplitude of the oscillations of crystallization nuclei enhances their interaction with each other.