Lagrangian Trajectory Modeling of Lunar Dust Particles

TL;DR

This paper presents a mathematical model and software to predict lunar dust particle trajectories influenced by rocket jet gases, using CFD/DSMC data, and compares results with Apollo landing videos.

Contribution

It introduces a novel trajectory modeling approach that integrates CFD/DSMC data for lunar dust particles, enhancing prediction accuracy.

Findings

Model accurately predicts dust trajectories under high-velocity gas flow.

Comparison with Apollo videos validates the model's effectiveness.

Assumption of short-duration particle flight simplifies calculations.

Abstract

A mathematical model and software implementation developed to predict trajectories of single lunar dust particles acted on by a high velocity gas flow is discussed. The model uses output from a computation fluid dynamics (CFD) or direct simulation Monte Carlo (DSMC) simulation of a rocket nozzle hot gas jet. The gas density, velocity vector field, and temperature predicted by the CFD/DSMC simulations, provide the data necessary to compute the forces and accelerations acting on a single particle of regolith. All calculations of trajectory assume that the duration of particle flight is much shorter than the change in gas properties, i.e., the particle trajectory calculations take into account the spatial variation of the gas jet, but not the temporal variation. This is a reasonable first-order assumption. Final results are compared to photogrammetry derived estimates of dust angles form Apollo landing videos.