Thermodynamic properties of gases behind shock waves

The research on high-energy shock wave is a field of large interest including nuclear explosion, hypersonic flows as well as laser forming plasmas. During the relevant interaction a high-temperature, high-pressure plasma is formed, which in some cases can be ascribed to the family of thermal plasmas, characterized by equilibrium between the different degrees of freedom, including chemical and internal ones. Thermal plasmas can be described by equilibrium chemical thermodynamics, in particular statistical thermodynamics is used in this field to get information about the input data (entropy, enthalpy and specific heat of single species). Thermal plasmas are usually characterized by a single temperature for all species, including the vibrationally, rotationally and electronically distributions among the excited states, while dissociation and ionization (Saha) equilibria characterize them. On the other hand thermal plasmas with different temperatures are still accepted in this kind of literature, the different temperatures characterizing the corresponding reservoirs of energy. The internal distributions are still Boltzmann at a given (different) temperature; chemical equilibrium thermodynamics again characterizes the plasma properties even though caution must be exercised in using it. Typical conditions for thermal plasmas are temperatures in the range of 5 000-50 000 K, pressure in the 10-2-103 atm. range and ionization degree larger than 10-5. © 2012 Springer-Verlag Berlin Heidelberg.