NUMERICAL-SOLUTION FOR SPHERICAL LASER-DRIVEN SHOCK-WAVES

The history of the flow behind a laser-driven shock is investigated in the context of variable energy blast waves. Thereby the total laser e nergy absorbed by the blast is assumed to vary proportionally to some power of time. Due to the high temperatures and pressures occurring in the initial phase of the flow a real gas model has been employed. It accounts for vibration, dissociation; electronic excitation; ionizatio n and intermolecular forces. Radiative and conductive heat transfer ar e considered as well. The numerical computations were carried out usin g the method of characteristics. A self-similar strong shock solution serves as initial condition. It turns out that the exponent which dete rmines the time-dependent addition of energy at the shock front is lim ited for physical reasons. The computed far-field solutions expand the temporal scope of the self-similar solution domain, which has been th e main subject of the classical literature, into the non-self-similar domain at late time. The differences between the solutions obtained fo r real gas and perfect gas are less significant than in the case of th e classical point explosion.