Enthalpy charts: for dissociating gas mixtures in the temperature range 600 deg to 4000 deg K

Abstract

Enthalpy charts have been constructed to facilitate dealing with the thermodynamic problems of combustion and flow of dissociating gases within the temperature range of 600 deg to 4,000 deg K. By means of a quantity called 'reaction enthalpy' (which is defined in this note), it is possible without previous knowledge of the composition of the mixture of gases to work out dissociation processes occurring at equilibrium. Also, if required, the composition of the mixture can be obtained from the charts. The charts are confined to the C,H,O-system, but their extension to include N in the system is quite simple. 28 charts with the total pressure p and the molar ratio nC/nH as parameters have been constructed in the first place for the four pressures p = 0.1, 1.0, 10.0 and 100.0 kg/sq cm, and for the seven molar ratios nC/nH = 0, 0.2, 0.4, 0.6, 0.8, 1.0 and ∞. The four charts (reduced in scale) for the molar ratio nC/nH = 0.4 are attached as examples. Full scale charts will be supplied on request. The present note describes work that had to be laid aside in 1947, and has now been resumed. The work done up to that date has been already described by Lutz.