Symmetry-preserving discretizations in Lagrangian cell-centered hydrodynamics

This paper discusses constructing discretizations in Lagrangian cell-centered hydrodynamics (CCH) that preserve cylindrical symmetry on unequal-angle-zoned grids in two-dimensional Cartesian geometry. We achieve this by modifying the nodal solver (Corot and Mercier, 2018) and updating the total and internal energy equations. The method is a unique solution to the challenging problem of ensuring symmetry in vectors. A criterion is established for determining whether or not this symmetry correction should be applied. We prove that both nodal and zonal quantities maintain a symmetry distribution. Numerical illustrations using unequal-angle initial zoning are presented to demonstrate the efficiency of the scheme.