COMPARISON OF THE NONHOMOGENIZED DYNAMIC METHOD OF CELLS AND A HYDRODYNAMIC CALCULATION FOR WAVE-PROPAGATION

The performance of the nonhomogenized dynamic method of cells (NHDMOC) theory is compared to a standard finite-difference Lagrangian hydrody namic calculation. The NHDMOC is based on a truncated Legendre expansi on for the particle displacement field. In the present work, the expan sion is kept to third-order. The NHDMOC and hydrodynamic theories diff er in that the former uses a finite-difference solution to update the time dependence of the equations, whereas the latter uses finite-diffe rence solutions for both the temporal and spatial variables. Both theo ries are used to model longitudinal shock-wave propagation in steel, a rising from high-velocity planar impact. To achieve the same high-qual ity resolution of the stress and particle velocity profiles, the NHDMO C consistently requires coarser spatial and temporal grids. The NHDMOC is also less dependent on artificial viscosity to control unphysical, high frequency, oscillations in the numerical solutions of the theory . (C) 1999 Elsevier Science B.V. All rights reserved.