Structural properties of grid operators in node implicit operator-difference schemes of two-dimensional gas dynamics on triangular grids and increasing the computational efficiency of object-oriented algorithms

The paper is devoted to the analysis of structural properties of grid analogues of invariant differential operators on unstructured triangular grids and to the improvement the object-oriented algorithms for numerical implementation of two-dimensional gas dynamics implicit grid problems for increasing the computational efficiency of these algorithms. The axial-symmetry case in a cylindrical coordinate system is considered. Some node problems are studied when the grid functions are defined and the grid equations are written in the nodes of the grid in use.