Dense gases (fluids)
Equation of state for dense reacting gases
Rare gases
Dense gases
Parameter calculator for given T and rho.
Shockwave Calculator.
Detonation Wave Calculator.
An example of three isotherms of water (388, 647, 1294 K). Shock adiabat of water for initial conditions T₀ = 300 K, ρ₀ = 995 kg / m³.
Short description
The software package makes it possible to calculate the equilibrium thermodynamic parameters of dense reacting gases and fluids, taking into account intermolecular interactions. The tested range of parameters is in temperature - from 100 to 10,000 K and up to pressures of 100 GPa. The basic parameters for setting the conditions are density, temperature and chemical elemental composition of the mixture under study. For these conditions, the equilibrium chemical composition, pressure, internal energy, heat capacity, adiabatic index and speed of sound are calculated. The calculations took into account the possibility of the formation of the following chemical components: Ar, Ne, He, Kr, N₂, N, O₂, O, H₂, H, H₂O, OH, NH₃, CO, CO₂, CH₄, NH₃, NO; condensed components of carbon and Al₂O₃.
Methods of molecular dynamics and statistical physics are used to construct the equation of state. In this case, matter is considered as a set of point objects (molecules) interacting with a central pair potential in the form of exp6. Additionally, molecules have internal degrees of freedom, the energy of which depends only on temperature. To determine the pressure and total energy of the system, the problem of the motion of a small ensemble of particles (NVT ensemble of 50-100 molecules) is numerically solved, while the internal energy of the system is calculated as the sum of the kinetic energies of molecules and the potential energy of interaction, the pressure is calculated by the Virial Theorem. The selection of the parameters of pair interaction potentials was carried out from the conditions of the best agreement with the experimental data: tables of thermodynamic values of the American Standards Institute, shock adiabats of liquefied gases, compression in diamond anvils, and detonation parameters of condensed explosives.
The software package allows one to determine the equilibrium thermodynamic parameters of gas mixtures at a given density and temperature, to calculate shock and detonation adiabats. To construct the shock adiabat, the nonlinear Hugoniot equation is numerically solved in terms of density and temperature, while all the necessary parameters (pressure and specific internal energy) are calculated by the method described above. The detonation parameters are determined from the Chapman-Jouguet conditions - on the shock adiabat with energy release, there is a point with the conditions D = u + c, where D is the front velocity, u is the mass velocity, and c is the equilibrium speed of sound.
Documentation
Presentation (ru, en). Album of percussion and detonation adiabats .