Integrals of Motion and Velocity of Sound in Local Equilibrium Flows of Ionized Monatomic Gases

Local equilibrium flows of ionized chemically homogeneous monatomic gases are considered. Macroscopic equations of conservation of momentum, energy, total number of ions with maximum charge, and total number of electrons (both bound and free) are used. Some integral relations are derived for these equations. An analytical formula is obtained that allows the influence of the electron energy and thermal ionization on the velocity of sound to be investigated. The temperature dependences for equilibrium concentration components and the adiabatic coefficient in ionized helium with various densities are presented as an illustration.