“…However, a restriction on time step is needed, such as - For the incompressible flow, He and his co‐authors [15–19] gave the following stability and convergence condition of implicit/explicit scheme
where and are some general positive constants depending on , which may take different values at different places. - For the perturbed dissipative evolution equations and convection‐diffusion problems, please refer to References [20–23] the condition (1.3) is needed to establish the stability and error estimates.
- For the gradient flow, the condition (1.3) is required to preserve positivity and stability of numerical schemes, we can refer to References [24, 25] and reference therein.
Among above literatures, the condition (1.3) seems to be a necessary condition of the implicit/explicit scheme. In order to bypass the restriction (1.3), Sun and his co‐authors [26, 27] developed the error splitting technique to establish the unconditional stability and convergence for nonlinear problems, and obtained a series of meaningful results.…”