Strang splitting structure-preserving high-order compact difference schemes for nonlinear convection diffusion equations

Abstract

In this paper, by using the Lagrange multiplier approach and the operator splitting method, we construct some structure-preserving high-order and efficient compact difference schemes for nonlinear convection diffusion equations. For the one-dimensional model problem, we first introduce a high-order compact Strang splitting scheme (denoted as HOC-Splitting), which is fourth-order accurate in space and second-order accurate in time. Then, by incorporating the Lagrange multiplier approach with the HOC-Splitting scheme, we construct two additional bound-preserving or/and mass-conservative HOC-Splitting schemes that do not require excessive computational cost and can automatically ensure the uniform bounds of the numerical solution. These schemes combined with an alternating direction implicit (ADI) method are generalized to the two-dimensional model problem, further enhancing the computational efficiency for large-scale modeling and simulation. Finally, ample numerical examples are presented to verify the accuracy, efficiency, and effectiveness in preserving bounds or/and mass of the proposed schemes.