In this article, we establish the existence and uniqueness of solutions to the coupled reaction-diffusion models using Banach fixed point theorem. The Galerkin finite element method is used for the approximation of solutions, and an a priori error estimate is derived for such approximations. A scheme is proposed by combining the Crank-Nicolson and the predictor-corrector methods for the time discretization. Some numerical examples are considered to illustrate the accuracy and efficiency of the proposed scheme. It is found that the scheme is second-order convergent. In addition, nonuniform grids are used in some cases to enhance the accuracy of the scheme. KEYWORDS a priori error estimate, Brusselator, coupled reaction-diffusion models, Crank-Nicolson method, existence and uniqueness, Galerkin method, Gray-Scott, predictor-corrector method
INTRODUCTIONThe coupled reaction-diffusion models frequently arise in the field of chemistry [1, 2], biology [3,4], sociology [5], physics, geology, ecology, and so forth. These models are naturally applied in chemistry, for example, the Brusselator model. However, such models can also describe dynamical processes of nonchemical nature, for instance, the predator-prey model. In 1952, in his pioneering work on morphogenesis, Turing [6] first proposed that the reaction-diffusion systems may be used to study the replicating patterns such as stripes, spots, and dappling, seen on the skin of many animals such as zebras, lions, and cats. In [6], Turing explained that the involvement of diffusion, Numer Methods Partial Differential Eq. 2019;35:830-850. wileyonlinelibrary.com/journal/num