Implicit free-Lagrange method for computing two-dimensional magnetogas-dynamic flows
This paper examines the IFLA (Implicit Free-LAgrange) method developed by the authors for computing two-dimensional nonstationary MGD flows. This is a method of the third category based on an implicit completely conservative operator-difference MGD scheme on an irregular triangular Lagrangian grid of variable structure. The grid structure must be changed because a Lagrangian grid associated with a moving medium may be distorted in the process of computation. The appearance of triangular cells that strongly deviate from a regular triangle disrupts the approximation of differential operators by their grid analogs and ultimately leads to a breakdown of the grid. Automatic grid adjustment in computing time, which involves arbitrary changes of grid structure preserving the triangularity property, makes it possible to maintain a nearly perfect grid (consisting of regular triangles). Grid-structure adjustment in the IFLA method is possible also because the difference operators are written on an arbitrary irregular triangular grid.
scientific article; zbMATH DE number 1188588