The Numerical Simulation Study On Effect Of Phase Transition In Hypervelocity Impacting

During hypervelocity impacting, the shock pressure is far higher than the material strength, and the material behavior is similar to the behavior of compressible liquid, in the region of impact. For hypervelocity impacting, the effect of compression, even the effect of phase transition may play an important part.As to discuss the effect of phase transition during hypervelocity impacting, the GRAY equation of state (EOS) was brought in the SPH program, and was applied in the simulation of hypervelocity impacting, in this paper. By comparing the results gotten from the GRAY EOS and the Tillotson EOS, some conclusions were found as follows:1. Under low velocities, the shape characteristics parameters of debris clouds given by the GRAY EOS accord with the corresponding results gotten by the Tillotson EOS, which shows that, the GRAY EOS is fit for being applied in numerical simulations of hypervelocity impacting.2. The effect of phase transition in hypervelocity impacting leads to differences between the results given by the two EOSs, which is shown by the shape, mass, velocity and momentum characteristics of debris clouds obtained from the numerical simulation with the two EOSs.3. The distribution of the material density, pressure, temperature and phase, and the region, where phase transition of melting and vaporizing happened, and where the ejected debris came, were offered in this paper.4. The protection capability of the Whipple structure is sensitive to the material phase transition and thermal softening, which is shown by the comparation of the results of the numerical simulation on the protection capability of the Whipple structure with the two EOSs.