Some improvements of the nonequidistant Engquist-Osher scheme

摘要

Two nonequidistant finite-difference schemes for quasilinear singular perturbation problems are given, and their properties are discussed and compared. One of them corresponds to the equidistant Lorenz modification of the Engquist-Osher scheme. The other one switches in dependence on the cell Reynolds number. Both schemes show quadratic L1 accuracy, but the second one gives better pointwise results.