Explicit-implicit schemes for convection-diffusion-reaction problems

The basic models of problems in continuum mechanics are boundary value problems for the time-dependent convection-diffusion-reaction equations. For their study, various numerical methods are involved. After applying the finite difference, finite element or finite volume approximation in space, we arrive at the Cauchy problem for systems of ordinary differential equations whose main features are associated with the asymmetry of the operator and its indefinite. The explicit-implicit approximation time is conventionally used in constructing splitting schemes in terms of physical processes, when separated by convection and diffusion transfers, the reaction process. In this paper, unconditionally stable schemes for unsteady convection-diffusion-reaction equations are used, when explicit-implicit approximations are applied in splitting the operator reaction. An example of a model 2D problem in the rectangle is presented.