A New Internal Energy Calculation for the HELP Code and its Implications to Conical Shaped Charge Simulations.

摘要

When the HELP code is applied to conical shaped charge warhead problems, the computed internal energy predicts a thermal state completely different than that indicated by experiments. The cause of this phenomenon is the numerical interchange of the kinetic energy to internal energy which is generated by terms of the order of the truncation error in the kinetic energy calculation. A correction is given and qualitative thermal agreement is achieved, for the first time, between a HELP code simulation and experimental evidence for a conical shaped charge. Furthermore, the ad hoc usage of a predetermined upper bound on the specific internal energy in the equation of state routine for shaped charge calculations is no longer required. The effects of the modification on the pressures, velocities, specific total energies and densities are discussed.