Low-Altitude Plume Chemistry Signature Modeling

A common thread in developing low altitude plume optical and radar signature models is the identification of the relevant chemical reaction mechanisms and rate constants to incorporate in plume flowfield calculations. This generalization applies to all missile systems (theater, tactical and strategic) and to all plume flowfield codes. While the reaction mechanism for many systems can be reasonably prescribed, knowledge of all the pertinent rate constants is problematic. The purpose of the proposed Phase II plan is to : (1) identify those reactions whose rates most significantly affect plume optical and/or radar signatures and RF attenuation, and (2) utilize state-of the-art computational chemistry methodology to determine Arrhenius expressions for these rate constants. A number of reaction groups that must be accounted for in the prediction of solid and liquid propellant plume flowfield properties will be considered in the Phase II plan. The propellants include: aluminized, composite solid propellants containing ammonium perchlorate, and hydrocarbon-fueled and amine-fueled liquid propellants. The reaction groups to be studied include:H2/CO combustion, hydrocarbon (CH4, C2H2, soot) combustion, ignition/extinction (HO2, H2O2) reactions, chlorine (HCl, Cl) reactions and electron/ion (Na+, K+, O2-, OH-, Cl-) reactions.