Computational Chemistry Applications to LOW Altitude Plume Signature Modeling

The remote detection of infrared emissions from the hot plumes of boosting missiles is a core component of our missile defense system. Inherent in the detection and interpretation of these emissions is an accurate and detailed understanding of rocket plume phenomenology. We are proposing to develop and test techniques to substantially enhance the chemical mechanisms central to understanding plume radiance. Through the focused application of computational chemistry to areas of the chemical mechanism not amenable to experimental observation, we will augment existing chemical models, focusing on lower altitude flows. We will initially investigate the sensitivity of calculated continuum flow fields and signatures on certain key chemical reactions involved in plume afterburning and afterburning cessation. Based on this sensitivity test, the state specific reaction rate constants for a key reaction will be calculated using modern computational chemistry techniques. These rates will be applied to the continuum flow field models, whose output will be used to generate plume radiance maps to validate the approach. In Phase II we will apply the methods developed to many reactions of interest and integrate this detailed chemistry into plume modeling codes.