Models of cooling and freezing of living biological tissues with a flat ruler applicator

In this work, we construct new mathematical models of cooling and freezing of living biological tissue with a flat, long ruler applicator located on its surface. The models are two-dimensional boundary-value problems (including Stefan-type problems) and have applications in cryosurgery. The method of numerical study of these problems is based on smoothing discontinuous functions and applying locally one-dimensional difference schemes to “smoothed” problems without explicitly identifying the boundaries of the influence of cold and the boundaries of the phase transition.