Unified In-Space Propulsion Framework for Prediction of Plume-Induced Spacecraft Environments

Chemical contamination of spacecraft components as well as thermal and force loading from firing liquid propellant thrusters are critical concerns for in-space propulsion applications. Gas molecular contamination and liquid droplet deposition due to incomplete combustion threaten to damage surface materials, sensitive instruments and optical sensors, and poses major risks for mission success. Liquid propellant thrusters operate in space at near-vacuum conditions, and contaminants traverse a complex mixed continuum-rarefied environment upon exiting the thruster nozzle. Current CFD modeling capabilities for in-space propulsion analysis have made great strides, but fall short of providing the fidelity required to simulate the contaminant transport around the spacecraft with sufficient efficiency and accuracy. This STTR will develop and deliver an innovative computational architecture for prediction of plume flow impingement and contaminant dispersal through mixed flow environments for in-space propulsion analysis. CFDRC will supplement the massively parallel Loci framework with a unified solver for prediction of mixed continuum-rarefied flows with contaminant dispersal. This will enable better understanding of thermal and force loading and contamination of spacecraft components, and enable design of safer next-generation in-space propulsion systems. A proof-of-concept was developed and successfully demonstrated during Phase I for in-space thruster plume contamination environments. Phase II will deliver production continuum-kinetic-particle predictive capabilities with adaptive mesh/algorithm refinement for multi-component molecular gases, which will provide NASA with next-generation tools for detailed investigations of contaminant environments for spacecraft configurations.