We build finite difference schemes for a class of fully nonlinear parabolic equations. The schemes are polyhedral and grid aligned. While this is a restrictive class of schemes, a wide class of equations are well approximated by equations from this class. For regular (C^'") solutions of uniformly parabolic equations, we also establish of convergence rate of O{a). A case study along with supporting numerical results is included.Mathematics subject classification: 65M06, 65M12.
Contents 'The remainder of this section recalls the setting for our nonlinear parabolic equations and the necessary regularity results. Section 2 is a case study with a simple example equation. Error estimates are obtained directly in this simpler setting, and supporting numerical results are presented.The first part of section 3 recalls general results on nonlinear elliptic schemes. The second part presents new material on error estimates in terms of the residual for perturbed equations, the methods of lines, and finally for fully discrete difference schemes. |The main results are in the section 4. Here the class of schemes is established. The schemes are shown to be elliptic, and consistent, which is enough to prove convergence. Then the error estimates of the previous section are used to obtain a convergence rate.
Nonlinear parabolic equationsOur results concern the fully nonlinear parabolic Partial Differential Equation (PDE)where fi is a domain in R", along with initial and boundary conditionsuix, t) = hix, t), for (x, t) on dU x (0, T).The fully nonlinear elliptic partial differential operator F[u] is given by
[] M(1.1)Here Du and D^u denote the gradient and Hessian of u, respectively. The function FiX, p, r, x) is defined on S" x R" x R x fî, and S" is the space of symmetric n x n matrices. The natural setting for equations of this type is viscosity solutions [7]. Definition 1.1. The differential operator (1.1) is nonhnear or degenerate elliptic if FiN,p,r,x) < F(M,p,s,x) whenever r < s and M < N. (1.2) Here M < N means that M -N is a nonnegative definite symmetric matrix. The corresponding parabolic operator (PDE) is called nonlinear or degenerate parabolic.