Hypervelocity impact modeling with different equations of state

This study focuses on the simulation of hypervelocity impact problems with different equations of state (EOSs). We used a high-order multi-material Godunov method in Eulerian form and applied an “exact” multi-material Riemann solver to find more accurate individual phase advection fluxes regardless of the aggregate state. We investigated effects of melting in strong shock waves, evaporation in rarefaction waves and spallation. We found that a careful treatment of the spall formation mechanism is of greatest importance in obtaining accurate numerical results. Three types of wide-range EOSs are discussed—caloric EOS in unified analytical form for condensed and rarefied matter; thermodynamically complete stable multi-phase EOS in tabular form which does not allow for metastable states; and thermodynamically complete metastable EOS in tabular form which permits metastable gas, liquid or solid phases.