Spacecraft propulsive landings on unprepared regolith present in extra-terrestrial environments pose a high risk for space exploration missions. Plume/regolith interaction results in (1) the liberation of dust and debris particles that may collide with the landing vehicle and (2) craters whose shape itself can influence vehicle dynamics. To investigate such gas-granular interactions for large-scale problems using standard Lagrangian approach, particles on the order of billions would need to be modelled to account for large landing areas, making the approach impractical. An effective alternative is to use an Eulerian-Eulerian approach where the granular mixture is represented using a two-fluid model and the granular material physics are considered using constituent relations. This effort aims to provide a state-of-the-art Eulerian-Eulerian approach with novel granular material models in the highly scalable computational framework Loci used by NASA engineers. At the end of Phase I, a massively parallel Loci-based version of a gas-granular flow solver featuring compressible flow, single gas species, and novel granular material models for spherical and irregular (single-component) particle mixture will be developed and demonstrated, with a TRL starting at 2 and ending at 4. Phase II effort will add higher model fidelity to the gas phase with a multi-component approach, an extension of the granular models for poly-disperse mixtures, overset-mesh with six degrees-of-freedom for lander vehicle motion, and compatibility to other Loci-based tools and modules such as CHEM.
Potential NASA commercial applications include the NASA led lunar and Mars lander development projects. Human class Mars lander plume-surface analysis is provided to propulsive Entry, Descent, Landing and Ascent (EDL&A) systems integration teams under the Evolvable Mars Campaign (EMC). Lunar lander developments include the NASA led Lunar Pallet Lander and industry lunar landers by Masten, Astrobotic, and Blue Origin which benefit from NASA technical support through the CATALYST program.
Potential non-NASA applications include a wide range of sand and dust related military and civilian applications such as rotorcraft sand/dust brownout and engine dust ingestion. In addition, multiphase flows occur in many applications in chemical, petro-chemical and fossil-energy conversion industries where accurate modeling of particle shape play a huge role in the flow behavior of real particulate systems.