Theoretical Estimation of New Propellant Ingredient Heats of Condensation

A critical concern in the manufacture of rocket engines is the development of new propellants to increase performance. A fundamental measure of rocket engine performance is the specific impulse, which is the force delivered per weight of propellant consumed. Due to the potentially high cost of laboratory experiments, the development of new rocket propellants is often guided by computational methods for estimating specific impulse. These methods are based upon accurate knowledge of the heat of condensation. Quantum chemical methods are not currently capable of accurately predicting condensed phase heats of condensation. The current empirically based methods are limited to interpolating between molecules that are chemically similar. For many propellants, experimental measurements of chemically similar molecules do not exist. Thus, a computational procedure capable of extrapolating to these molecules is needed. Spectral Sciences, Inc. proposes to address this need by developing an innovative semi-empirical method of relating fundamental molecular interactions to heats of condensation. In Phase I, we propose to test our strategy on a well characterized reaction set. In Phase II, novel methods of chemical modeling techniques based on the results of Phase I will be developed into a software toolkit.