Thermochemical Model Conversion and Usage in Energetic Materials Applications.

The software described in this document is and adaptation of the coded model of propellant combustion developed at Naval Weapon Center NWC China Lake. The program is known as the Propellant Evaluation Program. PEP. The PEP simulation is a Fortran implementation of an equilibrium model for solid fuel combustion under the processes of constant pressure, adiabatic combustion and isentropic, adiabatic expansion. This code was converted for usage on a Prime 9955 minicomputer system from an original copy of version 11978 from NWC. The CRL adaptation does not presently include all of the original IO capabilities, but rather is structured toward the most simple and direct approach to input setup and execution. At present all IO is terminal oriented with individual files available for lineprinter or hardcopy. The conversion has been made from Univac 1108 Fortran IV to F77. Notable steps in the conversion are described in Appendix 1. The thermochemical model is useful in calculations of a variety of high-temperature thermodynamic properties and performance levels for solid fuel propellants. It has been employed in various flare development programs as well in its original application of solid fuel motor characterization. The program will handle a maximum of twelve chemical elements in the initial conditions and track up to two hundred combustion products in the end state.