Real Gas Considerations for Determining Physical and Thermodynamic Properties of Gasses Involved in the Prediction of the Effects of Internal Explosions.

An investigation into the thermodynamic properties of gaseous magnesium, aluminum and their oxides has been conducted to determine the validity of assuming ideal-gas-law behavior in confined explosions when these metals are present. A number of vapor phase equations of state were tested and compared. The paucity of experimental and rigorous theoretical data mandated the use of an equation of state that would provide realistic results and yet be tolerant of reasonable variations in the estimation of necessary parameters. The parameters selected are the vapor phase critical constants, which have been estimated from the theory of corresponding states or from partition function calculations. Using the Dieterici equation, which proved satisfactory in terms of the two criteria given above, it was determined that deviation from ideal gas behavior was insignificant except in the case of metal oxides, which may have a determinable effect on the equilibrium conditions of the explosion products. Author