The resulting systems of transient non-linear partial differential equations (PDEs) in
the space–time domain together with the set of initial and boundary conditions were numerically solved
by utilising the finite element method (FEM) coupled to the Arbitrary Lagrange–Eulerian (ALE) procedure
to account for the shrinkage phenomenon using a commercial package (COMSOL Multi-physics™, Comsol
AB, Stockholm, Sweden).