We consider special numerical approximations to a domain decomposition method for a boundary value problem in the case of singularly perturbed nonlinear convection-diffusion equations, with the perturbation parameter ε. As a rule, a differential problem is approximated by nonlinear grid equations (iteration-free schemes), which are then solved by suitable iterative methods. In the case of ε-uni...

In this paper, numerical solution for singularly perturbed problem with nonlocal boundary conditions is obtained. Finite difference method used to discretize on the Bakhvalov-Shishkin mesh. The some properties of exact are analyzed. error obtained first-order in discrete maximum norm. Finally, an example solved show advantages finite method.

In this article, using non-polynomial cubic spline we develop the classes of methods for the numerical solution of singularly perturbed two-point boundary-value problems. The purposed methods are secondorder and fourth-order accurate and applicable to problems both in singular and non-singular cases.Numerical results are given to illustrate the efficiency of our methods and compared with the me...

One-dimensional convection-diffusion problem with interior layers caused by the discontinuity of data is considered. Though standard Galerkin finite element method (FEM) generates oscillations in the numerical solutions, we prove its convergence in the ε-weighted norm of the first order on a class of layer-adapted meshes. We use streamline-diffusion finite element method (SDFEM) in order to sta...

Asymptotic formulas, as ε → 0, are derived for the solutions of the nonlinear differential equation εu+Q(u) = 0 with boundary conditions u(−1) = u(1) = 0 or u′(−1) = u(1) = 0. The nonlinear term Q(u) behaves like a cubic; it vanishes at s−, 0, s+ and nowhere else in [s−, s+], where s− < 0 < s+. Furthermore, Q (s±) < 0, Q (0) > 0 and the integral of Q on the interval [s−, s+] is zero. Solutions ...

We considered finite difference methods of higher order for semilinear singularly perturbed boundary value problems, consisted of constructing difference schemes on nonuniform meshes. Construction of schemes is presented and convergence uniform in perturbation parameter for one method is shown on Bakhvalov’s type of mesh. Numerical experiments demonstrated influence of different meshes on devel...

The error generated by the classical upwind finite difference method on a uniform mesh, when applied to a class of singularly perturbed model ordinary differential equations with a singularly perturbed Neumann boundary condition, tends to infinity as the singular perturbation parameter tends to zero. Note that the exact solution is uniformly bounded with respect to the perturbation parameter. F...

The error generated by the classical upwind finite difference method on a uniform mesh, when applied to a class of singularly perturbed model ordinary differential equations with a singularly perturbed Neumann boundary condition, tends to infinity as the singular perturbation parameter tends to zero. Note that the exact solution is uniformly bounded with respect to the perturbation parameter. F...