Continuity Equation

Let PSD of a precipitate phase be the PSD of a precipitate phase, number of particles per unit volume the number of particles per unit volume, mean radius the mean radius and particle volume fraction the particle volume fraction, is expressed as

[Eq. 1]          Equation for the number of particles per unit volume (continuty theory)

[Eq. 2]          Equation for the mean radius (continuty theory)

[Eq. 3]          Equation for the particle volume fraction (continuty theory)

The time evolution of PSD of a precipitate phase follows the continuity as in Langer and Schwartz [1980Lan].

[Eq. 4]          Equation for continuity as in Langer and Schwartz (continuity theory)

Where growth rate of a particle of size r is the growth rate of a particle of size particle r, and distributed nucleation rate is the distributed nucleation rate, which is defined by

[Eq. 5]          Equation for the nucleation rate (continuity theory)

where nucleation rate is the nucleation rate.

Reference

[1980Lan] J. S. Langer, A. J. Schwartz, Kinetics of nucleation in near-critical fluids. Phys. Rev. A. 21, 948–958 (1980).