Model Independent First Principle Method for Prediction of Heat of Condensation/Sublimation of Solid Propellant

Prediction of accurate heats of formation of solid propellant has tremendous implication in theoretically evaluating the performance of new generation solid propellants. While state-of-the-art quantum mechanical methods can accurately calculate the heat of formation in the gas phase, heat of condensation (HC) is required to convert this gas phase quantity to solid phase. To our knowledge, all existing methods for computing HC are based on fitting the experimental data for a set of model compounds using some descriptors, such as molecular groups or molecular electrostatic potentials. These methods, although useful, suffer from their inability to estimate HC for molecules containing chemical functionalities that are non-existent in the model set, thereby limiting their use for development of new propellants. In the proposed work, CFDRC plans to apply the Conductor-like Screening Model for prediction of heat of condensation. This method is truly first-principle, and combines quantum chemically computed molecular screening charge density and statistical thermodynamics to calculate heat of condensation. In Phase I, this method will be applied to compute heat of condensation for a set of compounds, and its performance will be evaluated. In Phase II, it will be extended for solid mixture, and combined with thermochemical code to compute specific and density impulses.