  Here, we study a level-set forced mean curvature flow with evolving spirals
and the homogeneous Neumann boundary condition, which appears in a crystal
growth model. Under some appropriate conditions on the forcing term, we prove
that the solution is globally Lipschitz. We then study the large time average
of the solution and deduce the asymptotic growth rate of the crystal. Some
large time behavior results of the solution are obtained.
