Evolution of a spherical pore in a viscous medium

Conclusions

Calculations based on the solution of Eq. (2) have confirmed the existence of an equilibrium pore radius, i.e., a radius to which an instantaneous radius tends with time [3]. In addition, it has been established that the equilibrium radius depends in the first place on the initial pore radius: For a relatively small pore the equilibrium radius is smaller, and for a relatively large pore larger, than the initial radius. In other words, small pores decrease, and large ones increase. There exist pores whose size does not change with time. External pressure decreases the equilibrium radius, the decrease being the greater the higher the external pressure.