Core Concepts
The authors propose and analyze robust and structure-preserving time discretization and linearization schemes for solving degenerate and singular evolution systems arising in models for biofilm growth and other applications. The schemes are shown to be well-posed, preserve positivity and boundedness of the solutions, and converge unconditionally.
Abstract
The content presents a numerical analysis of a class of degenerate quasilinear parabolic systems that arise in modeling biofilm growth and other applications. The key points are:
Motivation and background:
The system consists of a degenerate parabolic equation coupled with either a parabolic or an ODE equation, exhibiting degenerate and singular diffusion.
Such systems appear in modeling biofilm growth, porous medium flow, wildfire spreading, and other applications.
Time discretization:
A semi-implicit time discretization scheme is proposed that decouples the equations, allowing for efficient sequential solution.
The time-discrete solutions are shown to be well-posed, positive, bounded, and converge to the time-continuous solutions as the time step goes to zero.
Linearization:
For the nonlinear time-discrete problems, two iterative linearization schemes are introduced: the L-scheme and the M-scheme.
The L-scheme is shown to converge unconditionally, while the M-scheme achieves a faster convergence rate in the non-degenerate case.
The convergence of the linearization schemes is proven to be independent of the spatial discretization.
Numerical results:
Finite element discretization is employed, and the performance of the proposed schemes is compared to other commonly used schemes.
The results confirm the robustness and efficiency of the proposed time discretization and linearization approaches.