Database and Numerical Procedures for Extending the Spectral Range of Plume Signature Codes

Over many data collection campaigns, a large number of propulsion related signature events have been observed across an extended range of the electromagnetic spectrum. The current suite of plume modeling tools contains the basic framework for flowfield and signature generation, but lacks the underlying physical mechanisms and supporting property databases to properly account for alternate waveband regions. Recent efforts by Spectral Sciences, Inc. (SSI) used innovative computational chemistry techniques and laboratory data to generate a database of chemical rates among ro-vibrational state specific levels to extend the wavelength range of signature codes. The present approach develops and tests innovative procedures to compress the number of database states and rates, making routine applications possible. Phase I demonstrated the approach with simple single-cell / single species models and with full plume flowfield and signature calculations of field data using a detailed chemical kinetic mechanism. Phases II/III will upgrade plume signature codes to include additional gas and condensed phase (particulate) signature mechanisms and radiation transport methods for creating signatures from output flowfields. A major task in Phase II will be validation against field data. Approved for Public Release | 18-MDA-9522 (23 Feb 18)